Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Petros Karakitsos is active.

Publication


Featured researches published by Petros Karakitsos.


Head & Neck Oncology | 2011

Oral squamous cell cancer: early detection and the role of alcohol and smoking

Anna Zygogianni; George Kyrgias; Petros Karakitsos; Amanta Psyrri; John Kouvaris; Nikolaos Kelekis; Vassilis Kouloulias

ObjectiveOral squamous cell carcinoma has a remarkable incidence worldwide and a fairly onerous prognosis, encouraging further research on factors that might modify disease outcome.Data sourcesA web-based search for all types of articles published was initiated using Medline/Pub Med, with the key words such as oral cancer, alcohol consumption, genetic polymorphisms, tobacco smoking and prevention. The search was restricted to articles published in English, with no publication date restriction (last update 2010).Review MethodsIn this review article, we approach the factors for a cytologic diagnosis during OSCC development and the markers used in modern diagnostic technologies as well. We also reviewed available studies of the combined effects of alcohol drinking and genetic polymorphisms on alcohol-related cancer risk.ResultsThe interaction of smoking and alcohol significantly increases the risk for aero-digestive cancers. The interaction between smoking and alcohol consumption seems to be responsible for a significant amount of disease.ConclusionPublished scientific data show promising pathways for the future development of more effective prognosis. There is a clear need for new prognostic indicators, which could be used in diagnostics and, therefore a better selection of the most effective treatment can be achieved.


Molecular Carcinogenesis | 2009

COMMON POLYMORPHISMS IN THE VASCULAR ENDOTHELIAL GROWTH FACTOR GENE AND COLORECTAL CANCER DEVELOPMENT, PROGNOSIS, AND SURVIVAL

Konstantinos Dassoulas; Maria Gazouli; Spyros Rizos; George Theodoropoulos; Zoi Christoni; Nikolaos Nikiteas; Petros Karakitsos

Angiogenesis plays an important role in growth, progression, and metastasis of tumors. The most important regulator of angiogenesis is vascular endothelial growth factor (VEGF). VEGF expression has been associated with advance stage and poor survival of several cancers. In the present study we evaluated the association of functional polymorphisms in the VEGF gene with colorectal cancer development, prognosis, and survival. Three hundred twelve consecutive patients with surgically treated colorectal adenocarcinoma were enrolled in the present study. The genomic DNA was extracted from paraffin‐embedded tissue and five VEGF (−2578C>A, −1154G>A, −634G>C, −460T>C, and +936C>T) gene polymorphisms were determined using a polymerase chain reaction‐restriction fragment length polymorphism assay. VEGF −2578C>A, −1154G>A, −634G>C, −460T>C, and +936C>T genotype and allele frequencies were similar among patients and controls. There was a trend showing carriers of the −2578A and +936T alleles more frequent among patients with CRC, but these differences did not reach statistical significance. Furthermore, no correlation was found between all these variants and tumor characteristics like size, histological grading, positive regional lymph node metastases or tumor stage. However, the −2578AA, −634CC, and +936TT genotypes found to be related with a significantly lower overall survival in our study. In conclusion, VEGF gene polymorphisms were found to be an independent prognostic marker for Greek CRC patients.


Clinical Microbiology and Infection | 2013

Evaluation of viral co-infections in hospitalized and non-hospitalized children with respiratory infections using microarrays

S. Kouni; Petros Karakitsos; A. Chranioti; M. Theodoridou; G. Chrousos; Athanasios Michos

Abstract The impact of viral co-infections and recently discovered viruses on the epidemiology of respiratory infections in children is still unclear. To simultaneously detect viruses that are involved in the aetiology of respiratory infections, we used a DNA/RNA microarray assay that identifies 17 different viruses or viral subtypes. Rhinopharyngeal washes were taken from 611 children (aged 1 month to 14 years) who presented in the emergency department with respiratory infections from June 2010 to June 2011 and were treated as outpatients (299, 48.9%) or hospitalized (312, 51.1%). Lower respiratory tract infection was diagnosed more often in hospitalized children (68% versus 36%, p 0.001). Of 397 children in which microarrays detected viral infection (70.1%), a single virus was found in 228 (57.4%) and two or more viruses in 169 (42.5%). The most prevalent viruses among children with positive samples were respiratory syncytial virus (RSV) in 225 (56.6%), parainfluenza virus (PIV) in 118 (29.7%), rhinovirus (RV) in 73 (18.4%), followed by influenza in 56 (14.1%), adenoviruses in 31 (7.8%), bocavirus in 25 (6.3%), human metapneumovirus in 15 (3.7%) and enteroviruses in 12 (3%). Most common viral co-infections were RSVA–RSVB in 46 children (27.2%), RSV–Influenza in 20 (11.8%), RSV–RV in 18 (10.6%) and PIV–RV in 13 (7.7%). Multiple logistic regression analysis revealed that viral co-infections were associated with increased probability for hospitalization (OR 1.52, 95% CI 1.01–2.29, p 0.04), and previous pneumococcal vaccination was associated with decreased probability for hospitalization (OR 0.52, 95% CI 0.33–0.81, p 0.004). We conclude that viral co-infections are involved in a significant proportion of children with an acute respiratory infection and may increase the severity of clinical presentation and the risk for hospitalization.


Journal of Clinical Ultrasound | 1998

Adenomyoma and leiomyoma: Differential diagnosis with transvaginal sonography

D. Botsis; Dimitrios Kassanos; George E. Antoniou; Emanouil Pyrgiotis; Petros Karakitsos; Dimitrios Kalogirou

The purpose of this study was to evaluate the capability of transvaginal sonography to differentiate adenomyomas from leiomyomas.


Gastric Cancer | 2007

Vascular endothelial growth factor and endoglin (CD-105) in gastric cancer

Nikolaos Nikiteas; Nikolaos Tzanakis; George Theodoropoulos; Vassilios Atsaves; Zoi Christoni; Petros Karakitsos; Andreas C. Lazaris; Antonis Papachristodoulou; Christos Klonaris; Maria Gazouli

BackgroundVascular endothelial growth factor (VEGF) overexpression has been associated with advanced stage and poor survival in several cancers. Additionally, CD-105 (endoglin) was proposed as a marker of neovascularization in solid malignancies. The aim of the present study was to (1) evaluate the VEGF and CD-105 expression in gastric carcinoma, (2) determine the role of VEGF gene sequence variations in VEGF expression in gastric carcinoma, and (3) correlate the results of VEGF and CD-105 expression with other standard prognostic parameters, such as size, grade, stage of the disease, metastases, and patient survival.MethodsVEGF and CD-105 expression were evaluated in 100 unrelated gastric cancer patients using immunohistochemistry. For the genotyping, DNA was isolated from the blood of the gastric cancer patients and from 100 healthy individuals. The genotyping was performed by polymerase chain–restriction fragment length polymorphism analysis.ResultsVEGF protein was strongly expressed in the cytoplasm of 36% of the gastric carcinoma samples tested. In all cases, high VEGF expression was accompanied with high endoglin expression. Our results revealed no statistical significant association of any VEGF gene polymorphism with the VEGF and endoglin expression. The correlation of VEGF/CD-105 expression with the clinicopathological parameters of gastric cancer showed that the high expression of VEGF/CD015 was correlated only with lymph node metastasis (P = 0.028). The Kaplan-Meier survival curves have shown a clear association of overall survival after diagnosis of gastric cancer with high VEGF, as well as high CD-105 expression.ConclusionOur results support that VEGF and CD-105 are closely relevant to lymph node metastasis and act as two valuable indicators of prognosis.


Cytopathology | 2007

The role of liquid‐based cytology in the investigation of thyroid lesions

Magdalini Stamataki; D. Anninos; E. Brountzos; John Georgoulakis; J. Panayiotides; Z. Christoni; George Peros; Petros Karakitsos

Objective:  This study investigates the role of liquid‐based cytology by ThinPrep® technique in the detection of thyroid lesions.


British Journal of Obstetrics and Gynaecology | 2010

Proportion of excision and cervical healing after large loop excision of the transformation zone for cervical intraepithelial neoplasia

C Founta; M Arbyn; G Valasoulis; Maria Kyrgiou; A Tsili; Pierre L. Martin-Hirsch; N Dalkalitsis; Petros Karakitsos; D Kassanos; Walter Prendiville; A. Loufopoulos; E Paraskevaidis

Please cite this paper as: Founta C, Arbyn M, Valasoulis G, Kyrgiou M, Tsili A, Martin‐Hirsch P, Dalkalitsis N, Karakitsos P, Kassanos D, Prendiville W, Loufopoulos A, Paraskevaidis E. Proportion of excision and cervical healing after large loop excision of the transformation zone for cervical intraepithelial neoplasia. BJOG 2010;117:1468–1474.


Regulatory Peptides | 2012

Arterial stiffness and novel biomarkers in patients with abdominal aortic aneurysms

Nikolaos P.E. Kadoglou; Ioannis Papadakis; Konstantinos G. Moulakakis; Ignatios Ikonomidis; Maria Alepaki; Petros Moustardas; Stylianos Lampropoulos; Petros Karakitsos; John Lekakis; Christos D. Liapis

OBJECTIVES Pulse wave velocity (PWV) constitutes a valid index of arterial stiffness osteoprotegerin (OPG) and osteopontin (OPN) which are well-established vascular calcification inhibitors, highly correlated with inflammation, and cardiovascular events incidence. We investigated the association of PWV with the aforementioned novel biomarkers in patients with abdominal aortic aneurysm (AAA). METHODS We enrolled 108 men with AAA (AAA group) candidates for endovascular repair. We excluded patients with Marfan syndrome or other collagen-related disorders. Forty-one age-matched men, with stable coronary artery disease (CAD), but without AAA, served as controls (CO group). PWV, clinical parameters and serum levels of osteoprotegerin (OPG), osteopontin (OPN), interleukin-6 (IL-6) and IL-10 were determined. RESULTS With the exception of higher smoking rate and the lower statins usage in the AAA group, there were non-significant differences in the rest of demographic and clinical parameters (p>0.05). We found significantly higher levels of PWV in AAA than CO group (12.99±3.75 m/s vs 10.03±1.57 m/s, p<0.001). In parallel, serum OPG, OPN, IL-6 levels were considerably increased, while IL-10 levels were downregulated (p<0.001) in AAA group. PWV positively correlated with mean blood pressure, OPG concentrations and AAA diameter in univariate and multivariate analysis (R(2)=0.498, p=0.008). Finally, age and OPG remained independent determinants of AAA presence in the whole study cohort. CONCLUSIONS Arterial stiffness, circulating vascular calcification inhibitors and inflammatory mediators seem to be significantly upregulated in patients with AAA. An independent association of PWV with mean blood pressure, OPG and AAA diameter is of clinical importance which requires further investigation.


Human Pathology | 2011

Systematic analysis of proteins from different signaling pathways in the tumor center and the invasive front of colorectal cancer

Eva Karamitopoulou; Inti Zlobec; Ioannis Panayiotides; Efstratios Patsouris; George Peros; George Rallis; Christos Lapas; Petros Karakitsos; Luigi Terracciano; Alessandro Lugli

In colorectal cancer, the functional impact of proteins from different signaling pathways varies between tumor center and tumor front. Our objective was to identify differential protein expression profiles between the tumor center and the tumor front of colorectal cancer. Twenty proteins from different signaling pathways (epidermal growth factor receptor [EGFR], phosphorylated extracellular signal regulated kinase [pERK], receptor for hyalouronic acid mediated motility [RHAMM], Raf-1 kinase inhibitor protein [RKIP], β-catenin, E-cadherin, phosphorylated AK transforming [pAKT], p16, p21, Ki-67, B-cell Lymphoma-2 [BCL2], vascular endothelial growth factor, apoptosis protease activating factor 1 [APAF-1], mucin1 [MUC1], ephrin B2 receptor [EphB2], matrix metalloproteinase 7 [MMP7], phosphorylated mothers against decapentaplegic 2 [pSMAD2], caudal type homeobox transcription factor 2 [CDX2], Laminin5γ2, and mammalian sterile 20-like kinase 1 [MST1]) involved in colorectal cancer progression were studied immunohistochemically on 220 well-characterized patients using a multiple-punch tissue microarray including 437 and 430 samples from the tumor center and the invasive front, respectively. Mean expression between the tumor center and the tumor front varied statistically significantly for pSMAD2, pERK, Raf-1 kinase inhibitor protein, E-cadherin, pAKT, BCL2, vascular endothelial growth factor, EphB2, matrix metalloproteinase 7, CDX2, Laminin5γ2, MST1, and APAF-1. Overexpression of pAKT, BCL2, vascular endothelial growth factor, APAF-1, pERK, EphB2, Raf-1 kinase inhibitor protein, CDX2, E-cadherin, MST1 (P < .001 each), and pSMAD2 (P = .002) was more frequently observed in the tumor center, whereas matrix metalloproteinase 7 and Laminin5γ2 (P < .001 each) overexpression was associated with the invasive front. In multivariate analysis, vascular endothelial growth factor (P < .001), Raf-1 kinase inhibitor protein (P = .009), and Laminin5γ2 (P < .001) were the most relevant proteins with the multimarker phenotypes positive/positive/negative and negative/negative/positive being most discriminating between the tumor center and the tumor front. Moreover, the combination negative/negative/positive vascular endothelial growth factor/Raf-1 kinase inhibitor protein/Laminin5γ2 at the tumor front was associated with vascular/lymphatic invasion (P = .014), distant metastasis (P = .019), higher tumor grade (P < .001), and poorer survival (P = .05). Our findings show that, in colorectal cancer progression, vascular endothelial growth factor overexpression seems to play a role in the tumor center, whereas Laminin5γ2-positivity combined with Raf-1 kinase inhibitor protein loss is associated with tumor invasion at the front.


Gynecologic Oncology | 2011

Human papillomavirus DNA and mRNA positivity of the anal canal in women with lower genital tract HPV lesions: Predictors and clinical implications

Olga Valari; George Koliopoulos; Petros Karakitsos; George Valasoulis; Christina Founta; Dimitrios Godevenos; Lefkothea Dova; Minas Paschopoulos; Aristotelis Loufopoulos; Evangelos Paraskevaidis

OBJECTIVE Women with HPV related pathology of the lower genital tract are at higher risk for AIN and anal cancer than the general population. A strategy to identify anal disease in these women has not been formulated. The aim of this study is to examine the feasibility of HPV related biomarker testing on anal smears, to identify the risk factors for anal HPV positivity and to provide information of the clinical implications of anal HPV infection in this population. METHODS In women referred for colposcopy because of HPV related pathology of the lower genital tract (cervical cancer, CIN, VIN, warts) a detailed questionnaire, an anal smear and a cervical smear were taken. On each sample morphological cytology, flow cytometric evaluation of E6&7 mRNA, and HPV DNA detection and typing were performed. Women with a positive anal result were referred for high resolution anoscopy. RESULTS So far 235 women have been included (mean age 34.3). HPV DNA, high-risk HPV DNA, high-risk mRNA was detected in 45%, 31% and 8% of the anal smears and in 56%, 39% and 25% of the cervical smears respectively. Absolute or partial concordance of the types between the cervix and the anus was seen in 74%. Positivity for mRNA was significantly lower in the anus than the cervix (8% vs 25%). Logistic regression analysis revealed risk factors for the presence of anal HPV DNA (>3 lifetime sexual partners and presence of cervical HPV DNA), hr HPV DNA (presence of cervical hr HPV DNA), and hr mRNA (presence of cervical hr mRNA). Twelve months after LLETZ 53% of women were cervical HPV negative, but 25% of those were still HPV positive in the anus. CONCLUSIONS HPV infection of the anus is common in this group and is interlinked with the cervical infection. Anal HPV E6&7 mRNA expression is less common than in the cervix. Possible clinical implications of anal infection could be the development of AIN and recurrence of CIN after treatment due to cervical reinfection from the anal reservoir. The use of HPV biomarkers is feasible in anal smears, although especially DNA testing as triage method for referral to anoscopy is probably inappropriate due to high positivity rate.

Collaboration


Dive into the Petros Karakitsos's collaboration.

Top Co-Authors

Avatar

Aris Spathis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ioannis Panayiotides

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Christine Kottaridi

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Niki Margari

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Christos Meristoudis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Maria Alepaki

National and Kapodistrian University of Athens

View shared research outputs
Researchain Logo
Decentralizing Knowledge