Biomedical subjects

Petros Karakitsos

Publications and source records attributed to Petros Karakitsos.

12 recordsLinked to original sources

PubMed2006

Vascular endothelial growth factor polymorphisms in gastric cancer development, prognosis, and survival.

BACKGROUND: Angiogenesis plays an important role in growth, progression, and metastasis of tumors. Vascular endothelial growth factor (VEGF) overexpression has been associated with advanced stage and poor survival in several cancers. METHODS: The association of functional single nucleotide polymorphisms (SNPs) of VEGF gene with gastric cancer development, prognosis, and survival in a case-control study of 100 gastric cancer Greek patients was evaluated. The genotyping was performed by PCR-RFLP analysis. RESULTS: Our results revealed a marginally significant association of the 634CC genotype (P = 0.042) with increased risk for gastric cancer development. None of the rest of the examined polymorphisms or haplotypes conferred any gastric cancer susceptibility. A strong association between the -2578AA (P = 0.025), -634CC (P = 0.013), +936CT (P = 0.028), +936TT (P = 0.0001) genotypes and a larger tumor size was observed, while the 2578AA and -634CC genotypes were strongly correlated to poor differentiation (P = 0.01) and advanced stage of disease (P = 0.039), respectively. In addition, our results indicated that metastatic disease frequency was more accentuated among the +936TT carriers (P = 0.0035). Interestingly, carrying the -634CC genotype was associated with decreased overall survival rates (46.67%). CONCLUSIONS: The present study suggests that VEGF polymorphisms may contribute to gastric tumor characteristics; these observations, however, requiring further confirmation in a larger multi-ethnic study.

Aged↗

PubMed2006

Relation between common polymorphisms in genes related to inflammatory response and colorectal cancer.

AIM: To investigate the association between common single nucleotide polymorphisms (SNPs) in inflammatory response-related genes such as interleukin (IL)-6, IL-8, tumor necrosis factor alpha (TNFalpha), peroxisome proliferators-activated receptor gamma (PPARgamma), intercellular adhesion molecule-1 (ICAM-1) and the risk of colorectal cancer (CRC) in a group of Greek patients. METHODS: The study group consisted of 222 CRC patients and 200 healthy controls. Genotyping was performed using allele-specific PCR of PRC-RFLP and the results were confirmed by sequencing. We studied the association of SNPs in the IL-6 (-174G>C), IL-8 (-251T>A), TNFalpha (-308G>A), ICAM-1 (R241G and K469E), and PPARgamma (Pro12Ala) genes and the risk of CRC. RESULTS: The IL-6 -174G, R241 and K469 alleles of ICAM-1 were associated with increased risk of CRC (OR = 1.77, 95% CI: 1.34-2.34; OR = 1.83, 95% CI: 1.23-2.72; and OR = 1.35, 95% CI: 1.03-1.77 respectively). The IL-8 and TNFalpha polymorphisms had no effect. Whereas the PPARgamma Pro12 genotype was associated with increased risk of disease (OR = 1.78, 95% CI: 1.25-2.49). CONCLUSION: The association between common SNPs in immunologic response-related genes and CRC is reported in the present study. Apart from shedding light on the mechanisms of malignancy initiation and progression, SNPs may improve appropriate screening for sub-populations at risk.

Aged↗

PubMed2006

Discriminating benign from malignant thyroid lesions using artificial intelligence and statistical selection of morphometric features.

The objective of this study was to perform a comparative investigation of the capability of various classifiers in discriminating benign from malignant thyroid lesions. Using May Grunvald-Giemsa-stained smears taken by fine needle aspiration (FNA) and a custom image analysis system, 25 nuclear features describing the size, shape and texture of the nuclei were measured in each case. A statistical pre-processing of features revealed that only 4 of the 25 features are important when discriminating benign from malignant thyroid lesions, which were transformed and fed to four classifiers for subsequent analysis. The cases were divided into one set used for the training of classifiers, a second set used as the test set, and the remaining cases with no clear classification formed an ambiguous test set. Classification was performed at the nuclear and patient level. The technique described in this study produced encouraging results and promises to be a helpful tool in the daily cytological laboratory routine.

Anthropometry↗

PubMed2006

The potential of feature selection by statistical techniques and the use of statistical classifiers in the discrimination of benign from malignant gastric lesions.

The objective of this study was the investigation of the potential value of morphometry, feature selection and statistical classifiers techniques, such as neural networks, for the classification of benign from malignant gastric nuclei and cases. One hundred and twenty gastric smears, routinely processed and stained by Papanicolaou technique, were analyzed by a customized image analysis system. Data from half of the cases were selected to form the training set, while the remaining data formed the test set. A feature selection technique was applied in order to identify the most important nuclear features, which were used in a second stage by statistical classifiers to classify a nucleus as benign or malignant. Using the classifier results for the nuclear classification, a method to classify each individual patient was developed. The performance of the proposed method was validated through the test set. The technique described in this report produces significant results at the nuclear and patient level and promises to be a powerful assistance tool for everyday cytological laboratory routine.

Anthropometry↗

PubMed2005

Study on the morphology and reproducibility of the diagnosis of endometrial lesions utilizing liquid-based cytology.

BACKGROUND: The objective of the current study was to determine the diagnostic cytomorphologic criteria for liquid-based cytology and to evaluate the reproducibility and usefulness of the cytologic diagnosis in endometrial lesions. METHODS: A total of 162 direct endometrial samplings taken from postmenopausal women were evaluated by 2 skilled cytopathologists in endometrial cytology. The cytologic diagnosis was made according to the 1994 classification scheme of the World Health Organization. After establishment of the criteria, three additional cytopathologists without any experience in liquid-based endometrial cytology examined the same cases to determine interobserver variability. The intraobserver variability also was evaluated by all the observers. RESULTS: The cytomorphologic criteria were established in the following four diagnostic categories: atrophic endometrium, hyperplasia without atypia, hyperplasia with atypia, and adenocarcinoma. The overall interobserver agreement was nearly perfect with a kappa value of 0.89 during the checking round and ranged from moderate to substantial with kappa values of 0.48-0.80, respectively, in the other diagnostic rounds (P < 0.0001); hyperplasia with atypia was found to be the most difficult category to identify correctly. Furthermore, the intraobserver agreement ranged from substantial to perfect with kappa values of 0.61-1.00 in all diagnostic rounds (P < 0.0001). CONCLUSIONS: Liquid-based cytology allows for standardized and reproducible endometrial preparations, which in turn allows the application of common diagnostic criteria among cytopathologists. Furthermore, liquid-based cytology in combination with endometrial sampling could be a useful tool for the outpatient diagnosis of endometrial lesions, which could reduce unnecessary curettage.

Adenocarcinoma↗

PubMed2005

The role of liquid-based cytology in the investigation of breast lesions using fine-needle aspiration: a cytohistopathological evaluation.

INTRODUCTION: Liquid-based cytology processing of breast fine-needle aspiration (FNA) specimens has been used in our institution since 1999. The aim of this study was to investigate the role of liquid-based cytology (Thin-Prep(R)) in the evaluation of breast FNA specimens. PATIENTS AND METHODS: This study was carried out on 352 cases corresponding to equal number of women (134 malignant and 218 benign) examined from September 1999 to June 2003. A direct to vial study was planned. Aspirated material was directly immersed to cytolytR vial (Cytyc Corporation, Boxborough, MA). The specimens were transported to the laboratory non-refrigerated within 24 hr. Thin-Prep slides were made using the Thin-Prep 2000 processor. The remaining material was embedded in paraffin. RESULTS: Altogether, 352 cases were examined and unsatisfactory smears were observed in 14 (3.9 %) out of all cases. The histologic examination verified that 128 out of 131 total malignant cases and 203 out of 207 total benign cases were correctly diagnosed with the cytological technique. False positives were found in four cases and false negative in three cases. Liquid-based technique presented a sensitivity of 97.7%, a specificity of 98%, a positive predictive value (PPV) of 96.9%, a PNV of 98.5%, and an over all accuracy (OA) of 97.9%. CONCLUSIONS: The processing of FNA breast specimens using liquid-based cytology offers an accurate diagnostic tool. Liquid-based cytology could reduce the uncertainty based in the cytological evaluation of FNA, because it offers the possibility to embed material in paraffin and take tissue sections with histological appearance identical to those observed in routine histological sections. Moreover it offers the potential advantage of retraining extra material for the purpose of ploidy analysis and immunohistochemical study in order to offer information concerning the expression of prognostic markers such as p53, MIB-1, steroid hormone receptors, and EGFR.

Biopsy, Fine-Needle↗

PubMed2005

Potential of radial basis function neural networks in discriminating benign from malignant lesions of the lower urinary tract.

OBJECTIVE: To investigate the potential value of morphometry and neural network tools for discriminating benign from malignant nuclei and lesions of the lower urinary tract. STUDY DESIGN: The study group consisted of 33 cases of lithiasis, 41 cases of inflammation, 66 cases of benign hyperplasia of the prostate, 4 cases of carcinoma in situ, 48 cases of grade 1 transitional cell carcinoma of the bladder (TCCB) and 123 cases of grade 2 and 3 TCCB. Images of routinely processed voided urine smears stained by the Giemsa technique were analyzed by a custom image analysis system. Analysis of the images gave a data set of features from 31,158 nuclei. A radial basis function (RBF)-type neural network was employed to discriminate benign from malignant nuclei, based on the extracted morphometric and textural features. Subsequently a second RBF classifier was employed to discriminate benign from malignant cases. The nuclei from 156 randomly selected cases (50% of total cases) was used as a training set, and the nuclei from the remaining 159 cases made up the test set. Similarly, in an attempt to discriminate at the patient level, the same 156 cases were used to train an RBF classifier; the remaining 159 cases were used for the test set. The cases used for training and testing the 2 classifiers (nuclear and patient level) were the same for the 2 kinds of classifiers. RESULTS: Application of the RBF classifier permitted the correct classification of 93.64% of benign nuclei and 85.61% of malignant, giving an overall accuracy of 84.45%. At the patient level the RBF classifier permitted an overall accuracy of 94.97%. These results were on the test sets. CONCLUSION: The role of nuclear morphologic features in the cytologic diagnosis of lower urinary tract alterations was confirmed by the results of this study. The observed overlap in feature space indicates that the nuclear characteristics do not form strictly separate clusters; that fact explains the difficulty morphologists have with reproducible identification of nuclei from the lower urinary tract. Application of RBF offers good classification at the nuclear and patient level and promises to become a powerful tool for everyday practice in the cytologic laboratory.

Algorithms↗

PubMed2005

DNA ploidy and immunomarking of bladder urothelial tumors before and after intravesical bacillus Calmette-Guérin treatment.

OBJECTIVE: To investigate DNA ploidy and immunoexpression of Ki-67 and p53 as predictivefactors in cases of superficial urothelial cell carcinoma (UCC) treated with bacillus Calmette-Guérin (BCG). STUDY DESIGN: Samples were obtained from 66 patients with UCC (pTa grade 3 or high grade and pT1 independent of grade or with concomitant carcinoma in situ) before and after intravesical BCG treatment. DNA ploidy analysis (ploidy balance, degree of hyperploidy and aneuploidy, proliferation index) was done by static cytometry. Ki-67 and p53 were analyzed immunohistochemically in paraffin-embedded tissue, and their quantification was carried out using an image analysis system. RESULTS: During a mean follow-up of 63.8 months, 31 of the 66 patients developed recurrent tumors (46.9%). DNA ploidy analysis showed that ploidy balance as well as degree of hyperploidy and aneuploidy were not statistically different between recurrent and nonrecurrent tumors. Only proliferation index was statistically significant between recurrent and nonrecurrent tumors. No statistically significant difference was observed in the percentage of Ki-67- and p53-positive cells between primary tumors that recurred and those that did not. CONCLUSION: These findings suggest that only proliferation index has predictive value for recurrence and progression in UCC treated with BCG.

Adult↗

PubMed2004

Application of discriminant analysis and quantitative cytologic examination to gastric lesions.

OBJECTIVE: To investigate of the potential value of morphometry and discriminant analysis for the classification of benign and malignant gastric cells and lesions. STUDY DESIGN: The data set consisted of 13,300 cells from 120 cases composed of 30 cases of cancer, 26 cases of gastritis and 64 cases of ulcer according to the final histologic diagnosis. The cytologic diagnosis was divided into 5 categories (gastritis, ulcer, inflammatory dysplasia, cancer and true dysplasia). Classification was attempted at 2 levels: the cell level to classify individual cells and the case level to classify individual cases. For the cellular classification the measured cells from 50% of available cases were selected as a training set to construct a model. The cells from the remaining cases were used as a test set to validate the model. Similarly for case classification, the same 50% of cases that were used for cell classification were used as a training set and the remaining cases as a test set. Images of routinely processed gastric smears stained by the Papanicolaou technique were analyzed by a customized image analysis system. RESULTS: Application of discriminant analysis on the test set gave correct classification of 98.4% of benign cells and 67.1% of malignant cells. On case classification, 100% accuracy was achieved for benign and malignant cases, both for the training and test sets. CONCLUSION: The application of discriminant analysis described in this paper could produce significant classification results at the cellular and individual case level.

Cell Size↗

PubMed2002

Potential of the learning vector quantizer in the cell classification of endometrial lesions in postmenopausal women.

OBJECTIVE: To investigate the potential of artificial neural networks for cell identification in endometrial lesions from postmenopausal women. STUDY DESIGN: The study was performed on cytologic material obtained by the Gynoscann endometrial cell samplerfrom 12 cases of atrophic endometrium, 48 cases of hyperplasia without cytologic atypia (18 cases of simple hyperplasia and 30 cases of complex hyperplasia), 12 cases of hyperplasia with cytologic atypia (complex atypical hyperplasia) and 48 cases of adenocarcinoma (30 cases of well-differentiated, 12 cases of moderately differentiated and 6 cases of poorly differentiated carcinoma). From each case approximately 100 cells were examined using a custom image analysis system. A learning vector quantizer (LVQ) identified the collected data. RESULTS: Investigation of cells from Endometrial Alterations with LVQ proved that according to the nuclear characteristics, as expressed by morphometric and textural measures, the endometrial cells from postmenopausal women may be identified as belonging to one of thefollowing three groups: atrophy, hyperplasia without cytologic atypia (simple and complex hyperplasia) and malignant neoplastic lesions (atypical complex and adenocarcinoma). CONCLUSION: The role of nuclear morphologic features in the cytologic diagnosis of endometrial alterations was confirmed. The overlap in thefeature space observed indicates that cell characteristics do not form strictly separate clusters. Thatfact explains the difficulty that morphologists have with the reproducible identification of cells from endometrial lesions in postmenopausal women. Application of LVQ offers a good classification at the cell level and promises to be a powerful toolfor classification on the individual patient level andfor the clarification of the natural history of endometrial pathology.

Adenocarcinoma↗

PubMedDate not supplied

Increasing diagnostic accuracy with a cell block preparation from thin-layer endometrial cytology: a feasibility study.

OBJECTIVE: To investigate (1) the feasibility of preparing cell blocks by inverted filter sedimentation (IFS-CB) from endometrial samplings processed by the ThinPrep (TP) technique (Cytyc Corp., Boxborough, Massachusetts, U.S.A.), and (2) the possibility of increasing the diagnostic accuracy of TP endometrial cytology by examining the tissue architecture as an adjunctive method of detecting endometrial lesions. STUDY DESIGN: Three hundred one endometrial samplings were obtained, using the Endogyn endometrial device (Biogyn S. n.c., Italy), from perimenopausal and postmenopausal women. The endometrial samplings were collected in a vial with liquid fixative for the TP processing. One TP slide was prepared from each case. If adequate material remained in the vial after the TP slide preparation, it was processed for IFS-CB preparation. RESULTS: IFS-CB preparation was processed in 263 cases (87%) with adequate material. Diagnoses on IFS-CB preparations obtained by endometrial sampling matched those of the hysterectomy specimens. The addition of IFS-CB histology to the cytologic diagnosis by TP increased the diagnostic accuracy of endometrial cytology to 96.3% and 100% for benign/atrophic endometrium and adenocarcinoma, respectively (p = 0.39 and 0.46). In hyperplasia without atypia and hyperplasia with atypia, the diagnostic accuracy increased significantly, to 96% and 95.3%, respectively (p = 0.037 and < 0.001). CONCLUSION: This study illustrates the merit of linking TP cytology with direct endometrial sampling, including small tissue fragments and material adequate for IFS-CB preparation. TP cytology provides an accurate cytologic diagnosis and the possibility of IFS-CB preparation, which could be a valuable diagnostic adjunct to TP cytology.

Adenocarcinoma↗

PubMedDate not supplied

Primary effusion lymphoma. A case report.

BACKGROUND: Primary effusion lymphoma (PEL) is a rare type of lymphoma that presents as an effusion, seldom with evidence of a solid neoplasm elsewhere; thus, cytology is the basic diagnostic method. It usually occurs in HIV-positive males with a history of Kaposi's sarcoma (KS), and DNA sequences of human herpesvirus 8 (HHV-8) are detected by molecular analysis. The distinct morphologic, immunophenotypic, molecular and clinical characteristics render this neoplasm a new pathologic entity. CASE: A 57-year-old, HIV-positive man presented to the hospital with ascites and absence of neoplasm on radiologic investigation. Cytologic evaluation of the ascitic fluid revealed the presence of highly atypical, pleomorphic lymphoid cells. Immunocytochemistry of the lymphoma cells was positive for CD45 (leukocyte common antigen), CD30 and epithelial membrane antigen antigens and negative for panB, panT and cytokeratin antigens. DNA sequences of HHV-8 were identified by polymerase chain reaction (PCR), and DNA ploidy analysis showed aneuploidy. The patient died 5 months after the diagnosis. CONCLUSION: Conventional and ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) cytology, in combination with immunocytochemistry and PCR for HHV-8 DNA sequences, can lead to an accurate diagnosis of PEL. DNA ploidy analysis confirms the aggressive nature of this neoplasm.

Ascitic Fluid↗