Panagiota Ravazoula

Distal embolism during percutaneous revascularization of infra-aortic arterial occlusive disease: an underestimated phenomenon.

Purpose: To investigate distal embolism during endovascular procedures of the infra-aortic arteries by utilizing a commercial filter basket and unveil any correlation between the baseline clinical and procedural variables and the histopathological findings of the collected particles. Methods: In a prospective study, 48 patients (37 men; mean age 70.8±7.8 years, range 50–83) underwent endoluminal therapy of infra-aortic lesions (stenosis >75% or occlusion; mean lesion length 52.2±38.0 mm) with standard endovascular procedures. A nitinol filter basket (n=50) was employed for distal protection. The collected particles were histopathologically analyzed. The harvested specimens were quantified after digital image post processing. Results: Procedural success of filter-protected revascularization was 93.8%. Three failures included 1 vasospasm, 1 distal embolus, and 1 side-branch occlusion. The total area of retrieved particles per basket was 2.76±6.49 mm2 (range 0.0–40.3). Particles with a major axis >1 and >3 mm were detected in 29 (58.0%) and 6 (12.0%), respectively, of the examined filters. Collected particles consisted primarily of platelets and fibrin conglomerates, trapped erythrocytes, inflammatory cells, and extracellular matrix. Increased lesion length, increased reference vessel diameter, acute thromboses, and total occlusions were positively correlated with higher amounts of captured particles (p<0.05). Multivariate analysis incriminated declotting procedures as the only independent predictor of increased embolic burden (p<0.05). Conclusion: The embolism phenomenon during infra-aortic interventions is frequent and underestimated. The liberated particles consisted primarily of atheromatous plaque elements and thrombus. The reported data might support the application of a protective filter basket in selected subsets of lesions with a riskier embolic profile and whenever declotting procedures are performed.

Automated diagnosis of brain tumours astrocytomas using probabilistic neural network clustering and support vector machines

A computer-aided diagnosis system was developed for assisting brain astrocytomas malignancy grading. Microscopy images from 140 astrocytic biopsies were digitized and cell nuclei were automatically segmented using a Probabilistic Neural Network pixel-based clustering algorithm. A decision tree classification scheme was constructed to discriminate low, intermediate and high-grade tumours by analyzing nuclear features extracted from segmented nuclei with a Support Vector Machine classifier. Nuclei were segmented with an average accuracy of 86.5%. Low, intermediate, and high-grade tumours were identified with 95%, 88.3%, and 91% accuracies respectively. The proposed algorithm could be used as a second opinion tool for the histopathologists.

Potential Role of Bcl-2 and Bax mRNA and Protein Expression in Chronic Hepatitis Type B and C: A Clinicopathologic Study

Bcl-2 oncoprotein regulates programmed cell death by providing a survival advantage to rapidly proliferating cells, and bax protein promotes apoptosis by enchanting cell susceptibility to apoptotic stimuli. In this study, we assessed the expression of bcl-2 and bax in liver biopsies from patients with chronic hepatitis (CH) Type B (HBV) and C (HCV). The study comprised 65 liver biopsies from 65 patients with HBV (n = 37) and HCV (n = 28) and 10 normal liver biopsies as controls. The HAI score ranged from 3/18–13/18, and the fibrosis Stage, from 1–6 (7 HBV/10 HCV). Pathologic examination included the following: (1) immunohistochemical stains in paraffin sections for bcl-2 and bax protein expression, (2) Western blot analysis (bcl-2 and bax protein levels evaluation), (3) ISH (detection of bcl-2 and bax mRNA), and (4) ISH (TUNEL-ABI [apoptotic body index]). In CH cases, both bcl-2 and bax protein and mRNA were detected in portal and intralobular lymphocytes and in cholangiolar epithelial cells in interface areas and fibrous bands. Bax protein and mRNA was expressed within hepatocytes and epithelial cells of interlobular ducts in portal tracts. Bcl-2 mRNA was present in periportal hepatocytes only in cases with Stage 5–6 fibrosis. Western blot analysis showed a decreased bcl-2 and an increased bax expression toward advanced fibrotic stages. In CH cases, ABI was reverse correlated with the percentage of bcl-2 expression and was correlated directly with the percentage of bax expression (P < .001). The results of this study suggest that in cases of chronic HBV or HCV infection, bax may be involved in the hepatocyte cycle regulation during infection, whereas its expression in intraportal bile duct epithelium implies that this protein enhances susceptibility of these particular cells to apoptosis. The increased bax expression and ABI in fibrosis Stages 1–5, imply that they are responsible for hepatocytes depletion through apoptosis, during progress of liver fibrosis and fibrous tissue accumulation, until cirrhosis is established. Bcl-2 mRNA expression in periportal hepatocytes only in Stages 5 and 6 suggests that this oncogene is involved in the late stages of progressive liver fibrosis and failure and furthermore that periportal hepatocytes are resistant to apoptosis. Bcl-2 expression, in cholangioles of interface area, suggests that this oncoprotein may be involved in growth regulation of these epithelial cells. Further research is warranted to specify the exact role of apoptosis and apoptotic genes involved in liver fibrosis process in cases of chronic HBV and HCV infection. This may lead to new strategies in the management of human liver disease to prevent the progression to chronic liver failure.

Versican but not decorin accumulation is related to malignancy in mammographically detected high density and malignant-appearing microcalcifications in non-palpable breast carcinomas

BackgroundMammographic density (MD) and malignant-appearing microcalcifications (MAMCs) represent the earliest mammographic findings of non-palpable breast carcinomas. Matrix proteoglycans versican and decorin are frequently over-expressed in various malignancies and are differently involved in the progression of cancer. In the present study, we have evaluated the expression of versican and decorin in non-palpable breast carcinomas and their association with high risk mammographic findings and tumor characteristics.MethodsThree hundred and ten patients with non-palpable suspicious breast lesions, detected during screening mammography, were studied. Histological examination was carried out and the expression of decorin, versican, estrogen receptor α (ERα), progesterone receptor (PR) and c-erbB2 (HER-2/neu) was assessed by immunohistochemistry.ResultsHistological examination showed 83 out of 310 (26.8%) carcinomas of various subtypes. Immunohistochemistry was carried out in 62/83 carcinomas. Decorin was accumulated in breast tissues with MD and MAMCs independently of the presence of malignancy. In contrast, versican was significantly increased only in carcinomas with MAMCs (median ± SE: 42.0 ± 9.1) and MD (22.5 ± 10.1) as compared to normal breast tissue with MAMCs (14.0 ± 5.8), MD (11.0 ± 4.4) and normal breast tissue without mammographic findings (10.0 ± 2.0). Elevated levels of versican were correlated with higher tumor grade and invasiveness in carcinomas with MD and MAMCs, whereas increased amounts of decorin were associated with in situ carcinomas in MAMCs. Stromal deposition of both proteoglycans was related to higher expression of ERα and PR in tumor cells only in MAMCs.ConclusionsThe specific accumulation of versican in breast tissue with high MD and MAMCs only in the presence of malignant transformation and its association with the aggressiveness of the tumor suggests its possible use as molecular marker in non-palpable breast carcinomas.

The potential role of TGFbeta1, TGFbeta2 and TGFbeta3 protein expression in colorectal carcinomas. Correlation with classic histopathologic factors and patient survival.

Purpose:This study investigates the expression of tumor growth factors TGFβ1, TGFβ2 and TGFβ3 in tissue material from patients with colorectal carcinoma and evaluates their correlation with known prognostic markers and patient survival.Patients and Methods:The study included 124 patients with colorectal carcinoma. According to the TNM classification of malignant tumors, 26 tumors were identified as being stage I, 30 stage II, 48 stage III, and 20 stage IV, whereas 106 tumors were low-grade and 18 high-grade malignancies. On paraffin sections, the streptavidin-biotin technique using antibodies against TGFβ1, TGFβ2 and TGFβ3 was applied. Morphological and immunohistochemical results were correlated with clinicopathologic parameters.Results:TGFβ1 protein was expressed in 88 out of 124 (71%) carcinomas, whereas TGFβ2 and TGFβ3 proteins were detected in all tumors examined. Normal colonic mucosal epithelial cells expressed TGFβ2 (significantly less as compared to neoplastic cells; p < 0.01) and TGFβ3 (p > 0.05 compared to neoplastic cells), but not TGFβ1. Statistical analysis revealed a higher expression of TGFβ1 in low-grade carcinomas (p = 0.009) and a higher presence of TGFβ2 in advanced tumors (p = 0.008). TGFβ1 expression was related with increased disease-free and overall survival (p < 0.05 each). The presence of TGFβ2 was correlated with worse prognosis (p < 0.05). Cox analysis revealed that besides tumor grade and stage, TGFβ1 expression constituted an independent prognostic factor.Conclusion:This study shows that in adenocarcinomas of the colon, there is a differential expression of TGFβ1, TGFβ2 and TGF3. TGFβ1 may be implicated in the pathogenesis of these tumors, since it is expressed only in neoplastic but not in normal cells. TGFβ1 is related with an increased disease-free and overall survival and constitutes an independent prognostic factor. In advanced stages, TGFβ2 seems to be involved in tumor progression and is related with worse prognosis.Ziel:Diese Studie untersuchte die Expression der Tumorwachstumsfaktoren TGFβ1, TGFβ2 and TGFβ3 in Gewebeproben von Patienten mit kolorektalen Karzinomen und prüfte ihre Korrelation mit bekannten prognostischen Markern und mit dem Überleben der Patienten.Patienten und Methodik:Die Studie umfasste 124 Patienten mit kolorektalen Karzinomen. Nach der TNM-Klassifikation wurden 26 Tumoren als Stadium I, 30 als Stadium II, 48 als Stadium III und 20 als Stadium IV eingeordnet, während 106 Tumoren Low-Grade- und 18 High-Grade-Malignome waren. Paraffinschnittpräparate wurden nach der Streptavidin-Biotin-Methode mit Antikörpern gegen TGFβ1, TGFβ2 und TGFβ3 behandelt. Die morphologischen und immunhistochemischen Befunde wurden mit klinisch-pathologischen Parametern korreliert.Ergebnisse:TGFβ1 wurde in 88 von 124 (71%) Karzinomen exprimiert, während TGFβ2 und TGFβ3 in allen untersuchten Tumoren gefunden wurden. Normale Epithelzellen der Dickdarmschleimhaut exprimierten TGFβ2 (signifikant weniger verglichen mit neoplastischen Zellen; p < 0,01) und TGFβ3 (p > 0,05 verglichen mit neoplastischen Zellen), aber kein TGFβ1. Die statistische Analyse ergab stärkere TGFβ1-Expression in Low-Grade-Karzinomen (p = 0,009) und eine verstärkte Präsenz von TGF2 in fortgeschrittenen Tumoren (p = 0,008). Die TGFβ1-Expression korrelierte mit verlängertem krankheitsfreien und Gesamtüberleben (jeweils p < 0,05). Das Vorliegen von TGFβ2 korrelierte mit schlechterer Prognose (p < 0,05). Die Cox-Analyse ergab, dass neben Tumorgrad und -stadium die TGFβ1-Expression einen unabhängigen prognostischen Faktor darstellte.Schlussfolgerung:Diese Studie zeigt für Adenokarzinome des Kolons und Rektums Unterschiede in der Expression von TGFβ1, TGFβ2 und TGFβ3. TGFβ1 könnte in der Pathogenese dieser Tumoren eine Rolle spielen, da es nur in neoplastischen, nicht aber in normalen Zellen exprimiert wird. TGFβ1 geht mit verlängertem krankheitsfreien und Gesamtüberleben einher und ist ein unabhängiger prognostischer Faktor. In fortgeschrittenen Stadien scheint TGFβ2 für die Tumorprogression relevant zu sein und ist mit einer schlechteren Prognose verbunden.

The Potential Role of TGFβ1, TGFβ2 and TGFβ3 Protein Expression in Colorectal Carcinomas

Purpose:This study investigates the expression of tumor growth factors TGFβ1, TGFβ2 and TGFβ3 in tissue material from patients with colorectal carcinoma and evaluates their correlation with known prognostic markers and patient survival.Patients and Methods:The study included 124 patients with colorectal carcinoma. According to the TNM classification of malignant tumors, 26 tumors were identified as being stage I, 30 stage II, 48 stage III, and 20 stage IV, whereas 106 tumors were low-grade and 18 high-grade malignancies. On paraffin sections, the streptavidin-biotin technique using antibodies against TGFβ1, TGFβ2 and TGFβ3 was applied. Morphological and immunohistochemical results were correlated with clinicopathologic parameters.Results:TGFβ1 protein was expressed in 88 out of 124 (71%) carcinomas, whereas TGFβ2 and TGFβ3 proteins were detected in all tumors examined. Normal colonic mucosal epithelial cells expressed TGFβ2 (significantly less as compared to neoplastic cells; p < 0.01) and TGFβ3 (p > 0.05 compared to neoplastic cells), but not TGFβ1. Statistical analysis revealed a higher expression of TGFβ1 in low-grade carcinomas (p = 0.009) and a higher presence of TGFβ2 in advanced tumors (p = 0.008). TGFβ1 expression was related with increased disease-free and overall survival (p < 0.05 each). The presence of TGFβ2 was correlated with worse prognosis (p < 0.05). Cox analysis revealed that besides tumor grade and stage, TGFβ1 expression constituted an independent prognostic factor.Conclusion:This study shows that in adenocarcinomas of the colon, there is a differential expression of TGFβ1, TGFβ2 and TGF3. TGFβ1 may be implicated in the pathogenesis of these tumors, since it is expressed only in neoplastic but not in normal cells. TGFβ1 is related with an increased disease-free and overall survival and constitutes an independent prognostic factor. In advanced stages, TGFβ2 seems to be involved in tumor progression and is related with worse prognosis.Ziel:Diese Studie untersuchte die Expression der Tumorwachstumsfaktoren TGFβ1, TGFβ2 and TGFβ3 in Gewebeproben von Patienten mit kolorektalen Karzinomen und prüfte ihre Korrelation mit bekannten prognostischen Markern und mit dem Überleben der Patienten.Patienten und Methodik:Die Studie umfasste 124 Patienten mit kolorektalen Karzinomen. Nach der TNM-Klassifikation wurden 26 Tumoren als Stadium I, 30 als Stadium II, 48 als Stadium III und 20 als Stadium IV eingeordnet, während 106 Tumoren Low-Grade- und 18 High-Grade-Malignome waren. Paraffinschnittpräparate wurden nach der Streptavidin-Biotin-Methode mit Antikörpern gegen TGFβ1, TGFβ2 und TGFβ3 behandelt. Die morphologischen und immunhistochemischen Befunde wurden mit klinisch-pathologischen Parametern korreliert.Ergebnisse:TGFβ1 wurde in 88 von 124 (71%) Karzinomen exprimiert, während TGFβ2 und TGFβ3 in allen untersuchten Tumoren gefunden wurden. Normale Epithelzellen der Dickdarmschleimhaut exprimierten TGFβ2 (signifikant weniger verglichen mit neoplastischen Zellen; p < 0,01) und TGFβ3 (p > 0,05 verglichen mit neoplastischen Zellen), aber kein TGFβ1. Die statistische Analyse ergab stärkere TGFβ1-Expression in Low-Grade-Karzinomen (p = 0,009) und eine verstärkte Präsenz von TGF2 in fortgeschrittenen Tumoren (p = 0,008). Die TGFβ1-Expression korrelierte mit verlängertem krankheitsfreien und Gesamtüberleben (jeweils p < 0,05). Das Vorliegen von TGFβ2 korrelierte mit schlechterer Prognose (p < 0,05). Die Cox-Analyse ergab, dass neben Tumorgrad und -stadium die TGFβ1-Expression einen unabhängigen prognostischen Faktor darstellte.Schlussfolgerung:Diese Studie zeigt für Adenokarzinome des Kolons und Rektums Unterschiede in der Expression von TGFβ1, TGFβ2 und TGFβ3. TGFβ1 könnte in der Pathogenese dieser Tumoren eine Rolle spielen, da es nur in neoplastischen, nicht aber in normalen Zellen exprimiert wird. TGFβ1 geht mit verlängertem krankheitsfreien und Gesamtüberleben einher und ist ein unabhängiger prognostischer Faktor. In fortgeschrittenen Stadien scheint TGFβ2 für die Tumorprogression relevant zu sein und ist mit einer schlechteren Prognose verbunden.

Non-palpable breast carcinomas: Correlation of mammographically detected malignant-appearing microcalcifications and molecular prognostic factors

Screening mammography has greatly increased the number of non‐palpable breast carcinomas diagnosed in asymptomatic women. Malignant‐appearing microcalcifications represent one of the earliest mammographic findings of non‐palpable breast carcinomas. Many studies have attempted to correlate radiological and histological features of malignant‐appearing microcalcifications. In the present study, we evaluated the association between mammographically detected malignant‐appearing microcalcifications and the expression profile of selected biological markers in non‐palpable breast carcinomas. Two hundred and eighty patients with non‐palpable suspicious breast lesions that were detected during screening mammography were studied. All patients underwent mammographically‐guided needle localization‐excision breast biopsy. Histological examination showed 74 (26.4%) carcinomas of various subtypes. Immunohistochemistry was carried out in 58/74 carcinomas by using a panel of monoclonal and polyclonal antibodies against estrogen receptor (ER), progesterone receptor (PR), HER‐2/neu, Bcl‐2, Bax, Fas and DNA fragmentation factor (DFF). Malignant‐appearing microcalcifications was the major mammographic finding in 45/58 (77%) patients. Nuclear ER positivity (65.5%) and PR positivity (46.5%) of non‐palpable breast carcinomas were statistically correlated with malignant‐appearing microcalcifications (p < 0.01 and p < 0.05, respectively). Statistically significant associations were also found between malignant‐appearing microcalcifications and HER‐2/neu positivity (p < 0.01), Bax positivity (p < 0.01), Fas positivity (p < 0.05) and DFF positivity (p < 0.01), whereas no statistical correlation was found with Bcl‐2 positivity (p > 0.05). Malignant‐appearing microcalcifications detected during screening mammography represent a diagnostic, prognostic and therapeutic challenge. The mammographic/biological associations and their potential implications in the management of women with non‐palpable breast carcinomas are thoroughly discussed.

Computer-based grading of haematoxylin-eosin stained tissue sections of urinary bladder carcinomas

PURPOSE A computer-based image analysis system was developed for assessing the malignancy of urinary bladder carcinomas in a more objective manner. Tumours characterized in accordance with the WHO grading system were classified into low-risk (grades I and II) and high-risk (grades III and IV). MATERIALS AND METHODS Images from 92 haematoxylin-eosin stained sections of urinary bladder carcinomas were digitized and analysed. An adequate number of nuclei were segmented from each image for morphologic and textural analysis. Image segmentation was performed by an efficient algorithm, which used pattern recognition methods to automatically characterize image pixels as nucleus or background. Image classification into low-risk or high-risk tumours was performed by means of the quadratic non-linear Bayesian classifier, which was designed employing 36 textural and morphological features of the nucleus. RESULTS Automatic segmentation of nuclei on all images was about 90% on average. Overall system accuracy in correctly classifying tumours into low-risk or high-risk was 88%, employing the leave-one-out method and the best combination of three textural and one morphological feature. Classification accuracy for low-risk tumours was 88.8% and for high-risk tumours 86.2%. CONCLUSION The proposed image analysis system may be of value to the objective assessment of the malignancy of urine bladder carcinomas, since it relies on nuclear parameters that are employed in visual grading and their prognostic value has been proved.

Urinary Bladder Tumor Grade Diagnosis Using On-line Trained Neural Networks

This paper extends the line of research that considers the application of Artificial Neural Networks (ANNs) as an automated system, for the assignment of tumors grade. One hundred twenty nine cases were classified according to the WHO grading system by experienced pathologists in three classes: Grade I, Grade II and Grade III. 36 morphological and textural, cell nuclei features represented each case. These features were used as an input to the ANN classifier, which was trained using a novel stochastic training algorithm, namely, the Adaptive Stochastic On-Line method. The resulting automated classification system achieved classification accuracy of 90%, 94.9% and 97.3% for tumors of Grade I, II and III respectively.

A computer-based diagnostic and prognostic system for assessing urinary bladder tumour grade and predicting cancer recurrence

Purpose : A computer-based system was designed, incorporating subjective criteria employed by pathologists in their usual microscopic observation of tissue samples and measurements of nuclear characteristics, with the purpose of automatically assessing urinary bladder tumour grade and predicting cancer recurrence. Material and Methods : Ninety-two cases with urine bladder carcinoma were diagnosed and followed-up. Forty-seven patients had cancer recurrence. Each case was represented by eight histological (subjective) features, evaluated by pathologists, and thirty-six automatically extracted nuclear features. Grading and prognosis were performed by neural-network based classifiers employing both histological and nuclear features. Results : Employing a combination of histological and nuclear features, highest classification accuracy was 82%, 80.5%, and 93.1% for tumours of grade I, II and III respectively. The prognostic-system, gave a significant prognostic assessment of 72.8% with a confidence of 74.5% that cancer might recur and of 71.1% that might not, employing two histological features and two textural nuclear features. Conclusions : The system for grading and predicting tumour recurrence may serve as a second opinion tool and features employed for designing the system may be of value to pathologists using descriptive grading systems.