Biomedical subjects

N Kavantzas

Publications and source records attributed to N Kavantzas.

At least 19 recordsLinked to original sources

PubMed2006

Diabetes may increase risk for oral cancer through the insulin receptor substrate-1 and focal adhesion kinase pathway.

In light of recent epidemiological studies that associate diabetes mellitus with increased risk for oral cancer, we investigated in diabetic (type I) and normal rats with induced oral squamous cell carcinoma whether the molecular basis for that putative association involves insulin receptor substrate-1 (IRS-1) and focal adhesion kinase (FAK). Fourteen diabetic and 12 normal rats developed cancer after 4-nitroquinoline-N-oxide treatment, while six diabetic and six normal animals were used as controls. Oral sections were studied using monoclonal antibodies against IRS-1 and FAK proteins. Expression of IRS-1 was significantly higher in diabetic than normal rats, but it decreased in diabetic animals with tumor, especially in more advanced stages. FAK expression was significantly higher in rats with cancer in comparison to the ones without it, regardless the diabetes status. These data suggest that the IRS-1/FAK pathway is altered by diabetes resulting in reduced cell adhesion and possibly increasing risk for oral cancer.

Animals↗

PubMed2006

Heregulin, cysteine rich-61 and matrix metalloproteinase 9 expression in human carotid atherosclerotic plaques: relationship with clinical data.

OBJECTIVES: Heregulins (HRGs) are known to induce expression of angiogenic factors such as cysteine rich-61 (CYR61) and collectively to promote neoangiogenesis. Along with extracellular matrix remodelling, mediated by matrix metalloproteinases (MMPs), these factors are important in atherogenesis. The aim of the present study was to investigate HRG, CYR61 and MMP-9 expression and their relationship with clinical and histopathological findings in carotid occlusive disease. MATERIALS AND METHODS: Specimens of human carotid atherosclerotic plaque (n=90) were obtained by endarterectomy. Expression of HRG, CYR61 and MMP-9 was assessed by immunohistochemical and Western blot analysis. Associations between protein expression and degree of carotid stenosis, presence of symptoms, presence of an infarct in CT scan and carotid plaque histopathology were investigated. RESULTS: An increase in HRG, CYR61 and MMP-9 expression was found, particularly in neovascularized regions of the plaques. High HRG expression was associated with the degree of carotid stenosis (p=0.028) and plaque histopathology (p=0.002). More than half of specimens from plaques with >90% stenosis had intense expression of CYR61 (p=0.047). Increased expression of MMP-9 was associated with degree of stenosis and presence of cerebral infarct on CT scan (p=0.05). CONCLUSION: HRG, CYR61 and MMP-9 are highly expressed in human atherosclerotic carotid plaques. The association with the degree of stenosis and/or plaque histopathology implies an involvement in lesion progression.

Blotting, Western↗

PubMed2006

Effect of green tea on angiogenesis and severity of atherosclerosis in cholesterol-fed rabbit.

BACKGROUND AND AIMS: Since the development of the atherosclerotic plaque requires the growth of new microvessels in the plaque itself (vasa vasorum), we postulated that green tea may exert an anti-atherogenic effect. METHODS AND RESULTS: Thirteen male New Zealand white rabbits were studied for 17 weeks. All rabbits were fed an hypecholesterolemic diet. After 2 weeks of adaptation rabbits were randomly assigned into two groups. Animals in Group A were fed the hypercholesterolemic diet and received plain tap water ad libitum. Animals in Group B were fed with the same diet and furthermore received 2.5% (g/g) green tea for 17 weeks. CONCLUSION: According to our results the atherosclerotic lesions were more severe in Group B than in Group A specimens. Also, the number of VEGF positively stained foam cells and smooth muscle cells of Group B were significantly greater than in Group A. About 30% less plaque was found in Group A than in the control group (Group B). So, our study showed that the consumption of green tea leads to a reduction of atherosclerosis as well as a significant decrease of VEGF expression in the atherosclerotic plaque of rabbit aorta. The hypothesis that probably green tea may produce its anti-atherogenetic effect through an anti-angiogenetic mechanism needs more investigation.

Angiogenesis Inhibitors↗

PubMed2006

Study of phospho-beta-catenin subcellular distribution in invasive breast carcinomas in relation to their phenotype and the clinical outcome.

Beta-catenin has a crucial role in cell-cell adhesion as well as a signaling role as a member of the Wnt pathway. The aim of this study was to examine the clinicopathological and prognostic value of phosphorylated beta-catenin, as well as its relation to the tumors' phenotype, in breast cancer. Immunohistochemistry was applied on 141 paraffin-embedded breast tissue specimens for the detection of phospho-beta-catenin, ER, PR, c-erbB-2, p53, Ki-67, bcl-2, uPAR and TIMP-1. For each case, a phospho-beta-catenin index was determined by image analysis. Phospho-beta-catenin staining was detected in the cytoplasm and the nucleus of the malignant cells. Cytoplasmic phospho-beta-catenin was statistically higher in carcinomas of smaller tumor size (P = 0.030), lower stage (P = 0.026), decreased Ki-67 and high c-erbB-2 immunoreactivity (P = 0.052 and P = 0.037, respectively). Nuclear phospho-beta-catenin showed a parallel correlation with ER and ERbeta (P = 0.022 and P = 0.043, respectively), bcl-2 (P = 0.042), uPAR in cancer cells (P = 0.041) and TIMP-1, although the correlation was borderline (P = 0.066). Cytoplasmic phospho-beta-catenin was found to be independently correlated with prolonged disease-free and overall survival (P = 0.046 and P = 0.002, respectively), whereas nuclear localization was correlated with a shortened overall survival (P = 0.046). In conclusion, phospho-beta-catenin may have a different involvement in invasive breast carcinomas, according to its subcellular distribution. Nuclear localization seems to be related to an aggressive tumor phenotype, negatively affecting patients' overall survival, whereas cytoplasmic localization is associated with a favorable tumor phenotype and a longer disease-free and overall survival.

Adult↗

PubMed2005

Angiogenesis in Hodgkin's lymphoma: a morphometric approach in 286 patients with prognostic implications.

The significance of angiogenesis in Hodgkin's lymphoma (HL) is not well defined. The aim of this study was to evaluate various morphometric characteristics of microvessels in lymph node sections of 286 patients with HL at diagnosis and investigate their relationship with clinicopathologic parameters and prognosis. Microvessel density (MVD), total vascular area (TVA) and several size- and shape-related microvascular parameters were quantitated--after anti-CD34 immunohistochemical staining--in the region of most intense vascularization, using image analysis. An increase in microvessel caliber parameters (area, perimeter, major and minor axis length) and a decrease in MVD were noted with increasing stage. An inverse relationship was recorded between MVD and the number of involved sites (NIS) and LDH. In univariate analysis, overall disease-specific survival was adversely affected by MVD and TVA, whereas inferior failure-free survival (FFS) was associated with the presence of more flattened vessel sections. Multivariate analysis disclosed that the extent of angiogenesis (MVD/TVA), age and the NIS independently affected overall survival. Accordingly, FFS was independently linked to the shape of microvessels and albumin levels or the NIS. In conclusion, our data support the view that angiogenesis in HL provides independent prognostic information, requiring the concomitant evaluation of quantitative and qualitative aspects of microvascular network.

Adolescent↗

PubMed2005

Hepatic expression of the proliferative marker Ki-67 and p53 protein in HBV or HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma.

To evaluate hepatic expression of the nuclear proliferative marker Ki-67 and the p53 oncoprotein in hepatitis B virus (HBV)/HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma (HCC). We studied needle liver biopsies from 107 patients with cirrhosis and no HCC (52 HBV, 55 HCV) who had been assessed for protocol studies, and 57 cirrhotic patients with HCC (40 HBV, 17 HCV). We evaluated small and large cell dysplastic changes along with the expression of Ki-67 and p53 by immunohistochemistry. The labelling index (LI) was defined as the proportion (%) of positive-stained nuclei of the 500 measured. Large and small cell dysplastic changes were observed in 12 and 9% of specimens respectively. Only small cell changes were associated with Ki-67 expression. Ki-67 LI was 5.50 +/- 5.7 in cirrhosis (13.90 +/- 3.84 in those with small cell dysplastic changes vs 4.64 +/- 4.98 in those without, P < 0.01), 10.2 +/- 5.95 in cirrhosis with HCC (P < 0.05) and 18.56 +/- 10 in HCC (P < 0.01). Neither the presence of small cell dysplastic changes nor the expression of Ki-67 was related to severity or aetiology of cirrhosis. Expression of p53 was observed in 30% of the non-tumorous and in 53% of the neoplastic tissue obtained from patients with HCC, with no differences between HCV and HBV. Ki-67 and p53 expression was associated with the tumour grade (P < 0.001). Our observations clearly demonstrate the association between the proliferation activity and the morphological changes in the cirrhotic liver from the non-dysplastic to dysplastic lesion to HCC. They also support the hypothesis that p53 alterations are a rather late event in carcinogenesis and related to HCC grade. And finally, they suggest that the final steps of hepatocarcinogenesis are common and independent of the aetiology of the chronic viral infection.

Adult↗

PubMed2004

The frequency and distribution of mast cells in pleomorphic adenomas of salivary glands.

AIM: To investigate whether the frequency and distribution of mast cells (MCs) in pleomorphic adenomas (PAs) of major and minor salivary glands justifies the suggestion that there exists an association between MCs and mucoid stromal changes in PAs. METHODS: The material consisted of 22 cases of pleomorphic adenoma (eight arising in major and 14 in minor salivary glands) and a control group represented by five cases of monomorphic adenoma (MA). Representative 3-microm thick, paraffin-embedded sections were stained with H&E and Azur A. Computer-aided image analysis was performed in order to evaluate the relative surface area occupied by epithelial and connective tissue components, as well as the absolute number of MCs. RESULTS: According to our findings, PAs from minor salivary glands contain significantly greater numbers of mast cells compared with tumours from major glands. Additionally, the distribution of MCs within the stromal connective tissue appeared not to be random. CONCLUSION: It is possible that differences in the pattern of connective tissue might influence the actual concentration of MCs and that these differences are responsible for the observed variations between major and minor gland PAs.

Adenoma, Pleomorphic↗

PubMed2004

Hypoxia-inducible factor 1alpha/vascular endothelial growth factor axis in astrocytomas. Associations with microvessel morphometry, proliferation and prognosis.

Hypoxia-inducible factor (HIF)-1alpha is a transcription factor that promotes ischaemia-driven angiogenesis. The aim of this study was to determine the relation of HIF-1alpha to vascular endothelial growth factor (VEGF; an important angiogenic molecule in brain tumours), p53 expression, angiogenesis, proliferative potential and clinical outcome in a large series of diffuse astrocytomas. Expression of HIF-1alpha, VEGF, Ki-67 (a proliferation-associated marker) and p53 was determined immunohistochemically in 83 adult patients with supratentorial diffuse astrocytomas. Microvessels, highlighted by means of anti-CD34 immunohistochemistry, were enumerated with computer-assisted image analysis. Although HIF-1alpha and VEGF were expressed in the majority of cases, their levels increased significantly with increasing grade and proliferative potential. HIF-1alpha positively correlated with microvessel counts and VEGF with total vascular area and the presence of rounder vessel sections. There was a positive correlation of VEGF with p53 expression in astrocytomas and anaplastic astrocytomas. In univariate analysis, both VEGF and HIF-1alpha were associated with shortened survival in the entire cohort, but lost significance when grades II/III and grade IV were analysed separately. Multivariate analysis revealed that the combination of HIF-1alpha with grade was a significant prognostic indicator. HIF-1alpha expression may be used to refine the prognostic information provided by grade in patients with diffuse astrocytomas. Its adverse prognostic effect is most likely mediated by hypoxia, the driving force for HIF-1alpha accumulation.

Adolescent↗

PubMed2003

Prognostic predictors of gastrointestinal stromal tumors: a multi-institutional analysis of 102 patients with definition of a prognostic index.

AIMS: The aim of this study is to identify prognostic factors influencing survival in patients with gastrointestinal stromal tumors (GISTs) and to identify a mathematical model that can predict lifetime expectation. METHODS: One hundred and two patients with GISTs, were followed retrospectively for a median period of 32 months (from 1 to 82 months). Complete follow-up data were available in 72 cases. All tumors were surgically resected and examined by conventional light microscopy, immunohistochemistry and image analysis. The tumors' location, size, histologic characteristics, immunophenotype, proliferative activity index (assessed by proliferating cell nuclear antigen (PCNA) and Ki-67 immunoreactivity) and the apoptotic markers bcl-2 and bax, were considered as potential prognostic factors and were correlated with patient survival. RESULTS: Tumor size >8 cm (p<0.03), presence of necrosis (p<0.02), number of mitoses >5/10 HPF (p<0.01), metastasis (p<0.001), and PCNA index >10% (p<0.004) were significant predictors of poor survival. Bcl-2 protein (p<0.0007) was a favorable prognostic indicator. If all tumors were treated as of uncertain malignant potential, the following mathematic model named GISTs Prognostic Index (GPI), could be formed by the linear regression technique: GPI exp=(49.6 months-Status of metastasis x 22.9185-Size in cm x 0.6801+bcl-2 expression% x 0.2569) (r(2)=0.67) (Prob>F=0.0001). CONCLUSIONS: Tumors' size, necrosis, mitoses, metastasis and PCNA index are independent poor prognosticators, while bcl-2 protein is associated with favorable prognosis. An interesting equation for survival in patient with GISTs has been reported.

Adult↗

PubMed2003

Vascular endothelial cadherin expression in human carotid atherosclerotic plaque and its relationship with plaque morphology and clinical data.

OBJECTIVES: To determine the relationship between Vascular Endothelial (VE)-cadherin expression in carotid plaques, carotid plaque morphology and clinical findings of carotid disease. MATERIALS AND METHODS: Fifty-three formalin-fixed, paraffin embedded specimens of human carotid atherosclerotic plaque obtained by endarterectomy and 20 normal postmortem arteries (control group) were studied. Thirty patients were symptomatic and 23 asymptomatic. The expression of VE-cadherin was examined by an avidin-biotin immunoperoxidase technique using specific monoclonal antibodies against this molecule. We used a scale for the estimation of the expression of the VE-cadherin, in which negative expression was indicated by 0, weak expression by 1, and strong expression by 2. In serial sections we also determined the cellular phenotype of atherosclerotic plaques: i.e. the endothelial cells (F8), macrophage (CD68) and smooth muscle cells. Possible relations between variables in statistical analysis were examined by the chi-square test or Fisher's exact test. RESULTS: Expression of VE-cadherin was observed in small newly established vessels, particularly in areas with intense inflammatory infiltrations by macrophages and leucocytes. A strong expression of VE-cadherin was evident particularly in symptomatic instead in asymptomatic patients (43% vs. 13%, p=0.057), in high degree stenosis group (81% vs. 0%, p=0.005), and in patients with ischaemic infarct in brain scan (71% vs. 23%, p=0.021). On the other hand, there was no relation between molecule expression and plaque ultrasonic characteristics (echogenic or echolucent, p=0.499). Finally, there was a significant statistical correlation in the expression of VE-cadherin and the histological type of the plaque, namely fibrotic and complicated plaques. Strong VE-cadherin expression was observed in 64% of complicated plaques instead of 6.5% in fibrotic plaques (p=0.001). CONCLUSION: An intense expression of VE-cadherin in carotid plaques is linked with plaque instability, high degree of stenosis and clinical events. This molecule seems to be a marker of progression of the atherosclerotic plaque.

Aged↗

PubMed2003

Clinicopathologic correlations of bone marrow angiogenesis in chronic myeloid leukemia: a morphometric study.

Various morphometric characteristics of microvessels, highlighted by means of anti-CD34 immunohistochemical staining, were evaluated in the bone marrow of 52 patients with chronic myeloid leukemia (CML) in chronic phase, in relation to several clinicopathologic parameters. Twenty control bone marrows and 15 cases of CML in blastic phase were also studied. Microvessel density (MVD), total vascular area (TVA) and several size- and shape-related parameters were quantitated in the region of most intense vascularization using image analysis. Overall, the group of chronic phase CML had higher MVD and size-related parameters and more branching microvessels than controls. Blastic phase was characterized by increased numbers of microvessels with a rounder shape and smaller caliber than chronic phase. A positive correlation emerged between marrow fibrosis and MVD as well as between white blood cell counts and rounder vessel sections. No relationship existed between microvascular parameters and Hasford or Sokal prognostic scores. In univariate analysis, overall and progression-free survival were adversely affected by MVD, size-related parameters, increased platelet count, age and spleen size. Multivariate analysis indicated that microvessel area was related to progression-free survival, whereas both MVD and area were significant prognosticators of overall survival, even when Hasford or Sokal scores are introduced into the model. Our data suggest that changes in angiogenic parameters may participate in the conversion of normal marrow to CML and ultimately to blastic transformation. More importantly, MVD and microvessel caliber are significant predictors of patient survival and progression.

Adolescent↗

PubMed2003

Mitosin, a novel marker of cell proliferation and early recurrence in intracranial meningiomas.

The expression of mitosin, a novel proliferation-associated molecule was evaluated immunohistochemically in a consecutive series of 47 patients with primary intracranial benign and atypical meningiomas. Mitosin expression was correlated with proliferation markers Ki-67 (MIB-1), proliferating cell nuclear antigen (PCNA), topoisomerase IIalpha (TopoIIalpha) and mitotic index, as well as with standard clinicopathological parameters and patient outcome. Seven tumors recurred (14.8%) following gross total resection, within a follow-up period ranging from 21 to 108 months (median 60 months). The higher proliferation indices were obtained with mitosin and PCNA and the lower ones with TopoIIalpha. Mitosin labeling index (LI) ranged from 0.1 to 57% (median 3%), with a significant overlapping of values between grades. A significant positive correlation was shown between mitosin LI on the one hand and Ki-67 LI (p < 0.001), or the mitotic index (p = 0.027) on the other. The incidence of recurrence was higher in cases with a mitosin LI higher than 3% (p = 0.048). Univariate analysis disclosed mitosin LI (p = 0.033) along with the mitotic index (p = 0.024) and tumor size (p = 0.028) as significant predictors of shortened recurrence-free survival. In multivariate analysis, the labeling indices of mitosin (p = 0.035) and Ki-67 (p = 0.032), along with tumor size, were shown to provide independent prognostic information, beyond that obtained by standard clinical and pathological parameters. However, as indicated by factor analysis, the prognostic information yielded by mitosin was superior to that provided by the remaining proliferation markers (p = 0.041). We conclude that mitosin immunohistochemical expression, although failing to discriminate between benign and atypical meningiomas, may be of use as a novel cell proliferation marker and as a predictor of tumor recurrence.

Antigens, Neoplasm↗

PubMed2003

Immunohistochemical detection of cell cycle regulators, Fhit protein and apoptotic cells in parathyroid lesions.

OBJECTIVE: The pathological distinction between parathyroid neoplasms and hyperplasias remains difficult. Changes in cell cycle control may lead to clonal proliferation and precede tumorigenesis. The parathyroid adenoma 1 oncogene, subsequently identified as the gene encoding cyclin D1, has been shown to be important to parathyroid tumour development. In addition to cell proliferation, the mechanisms of parathyroid cell turnover include apoptosis. The tumour-suppressor activity of the fragile histidine triad gene (FHIT) is linked to its proapoptotic function and cell cycle control. We attempted to evaluate the cellular proliferative kinetics and apoptotic function of the parathyroid glands in patients with non-familial hyperparathyroidism (HPT). DESIGN: TIssue specimens were taken from 40 patients with primary HPT (17 adenomas, two carcinomas and 21 primary hyperplasias) and from 30 patients with secondary HPT. Normal glands served as controls. METHODS: In a standard immunohistochemical procedure, monoclonal antibodies to Ki-67 antigen and single-stranded DNA were applied to detect cycling and apoptotic cells respectively; polyclonal antibodies to cyclin D1 and Fhit protein were used. Immunostaining was estimated by image analysis and statistical analysis was subsequently performed. RESULTS: Significantly higher proliferative and apoptotic indexes were detected in the diseased glands in comparison with normal controls. In neoplastic and secondarily hyperplastic glands, apoptotic indexes were higher than in primarily hyperplastic glands; the difference between neoplastic and primarily hyperplastic glands was statistically significant (P=0.034). Cyclin D1 was overexpressed in a considerable proportion of tumours (68.4%). A reduction of Fhit protein immunoreactivity was selectively noticed in carcinomas. CONCLUSIONS: In primary hyperplasia, the remarkable proliferation of parathyroid glands may be due to the reduction of the apoptotic process. FHIT gene abnormalities are worthy of investigation in parathyroid carcinogenesis.

Acid Anhydride Hydrolases↗

PubMed2002

Prognostic implications of microvessel morphometry in diffuse astrocytic neoplasms.

Astrocytic brain tumours, particularly malignant astrocytomas, are recognized to be highly vascular neoplasms with potent angiogenic activity. Recent research has shown that quantification of microvessel density (MVD), as a measure of the degree of angiogenesis, constitutes a strong prognostic indicator in patients with astrocytomas. However, the significance of other morphometric aspects of microvessel network has not been tested so far. In this report, histological sections from 70 astrocytomas (grades II to IV), immunostained for CD34, were evaluated by image analysis for the quantification of MVD, total vascular area (TVA), and microvascular branching, as well as several morphometric parameters related to vessel size or shape. Minor axis length increased with grade (P = 0.045) but MVD and TVA presented a peak in grade III (P = 0.033 and P < 0.001, respectively). Size and shape related parameters affected survival in univariate analysis of grade IV and grades II/III, respectively. In multivariate analysis, only branching counts, along with age and grade, were the independent predictors of survival. Although MVD, TVA and branching counts were adversely related to disease-free survival in grades II and III (univariate analysis), only TVA remained statistically significant in multivariate analysis. It is concluded that TVA and branching counts are prognostically more informative than MVD for patients with diffuse astrocytic tumours.

Adolescent↗

PubMed2002

Immunodetection and clinico-pathological correlates of two tumour growth regulators in laryngeal carcinoma.

Activation of telomerase, present in the vast majority of all human cancers, is associated with elongation of chromosomal telomeres and consequent cell immortalization. Telomere length homeostasis is a dynamic process governed by the negative feedback mechanism of the telomeric repeat binding factor 1 (TRF1) which inhibits the action of telomerase in telomerase-positive cells. In an attempt to investigate markers of tumour growth as possible prognostic indicators in laryngeal cancer, we studied the expression of TRF1 and of the proliferation marker Ki67 on 96 invasive squamous carcinomas of the larynx. A standard three step immunoperoxidase staining method was applied on paraffin sections incubated with appropriate polyclonal antibodies. The percentages of Ki67- and TRF1-immunopositive cancerous cells were calculated by image analysis. Univariate and multivariate statistical analysis of the staining results were performed in order to detect any association of the examined immunomarkers with the tumours' classical clinicopathological variables including nuclear morphometric features as well as with patients' disease-free survival. Ki67 immunostaining was positively linked with advanced patients' age, nodal involvement as well as presence of early recurrence. No relation was found between proliferative fraction and TRF1 immunoexpression. TRF1 was expressed in 55.2% of all cases and was positively linked only to tumour size. Multivariate statistical analysis revealed the presence of lymph nodal metastasis and Ki67 immunopositivity index > or = 20% as significant predictors of relapse. Increased Ki67 immunostaining appears to be a promising marker of tumour aggressiveness in laryngeal cancer. After one point at the tumour's natural history, the maintenance of tumour growth does not seem to depend on cell proliferation but on TRF1 immunoexpression. Whether the latter can be used for the identification of immortalized cells in every-day practice is worth investigating.

Adolescent↗

PubMed2002

Diagnostic approach of effusion cytology using computerized image analysis.

The objective of this study is to investigate whether image cytometry is a sensitive and specific method for the differential diagnosis of equivocal cells in routine cytology of effusion smears. One hundred four effusion smears were studied from routine cytologic material. Cytologically 56 (53.8%) of the smears were classified as malignant, 26 (24%) as suspicious and 22 (21.1%) as benign. Two morphometric variables (nuclear major axis length and nuclear area) of the nuclei were measured by an image analysis system. Higher values for the area were found for malignant rather than benign and suspicious cells (p < 0.0005 and p < 0.005 respectively). The same result was extracted for the nuclear major axis length values (p < 0.0005 and p < 0.0005 respectively). Values of nuclear major axis length and nuclear area didn't differ significantly between benign and suspicious cells (p = 0.071 and p = 0.066 respectively). The results show that the range of the values for suspicious cells is closer to the range of the benign cells. Cytomorphometry of the effusion smear cells may provide important information for the differentiation of atypical mesothelial cells from malignant adenocarcinoma cells.

Adenocarcinoma↗

PubMed2002

Computerized nuclear morphometry and quantitation of angiogenesis in thyroid neoplasms.

The aim of this study was to investigate the nuclear and angiogenetic profile in different types of thyroid neoplasms and to make any possible statistical comparison between the different nuclear morphometric and angiogenetic parameters, in order to search for new diagnostic and prognostic criteria. Sixty two cases of thyroid neoplasms were classified as follows: 31 papillary carcinomas, 10 follicular neoplasms (5 adenomas and 5 carcinomas), 5 undifferentiated carcinomas, 6 Huerthle-cell carcinomas and 10 medullary carcinomas. Using an image analysis system, six nuclear morphometric and eight angiogenetic variables were measured for each case. Concerning nuclear morphometric variables, statistical differences were found mainly between undifferentiated and overall subtypes of differentiated carcinomas, as well as between follicular adenomas and carcinomas. Concerning angiogenesis variables, statistical differences were found only in the vessel's minor axis length between undifferentiated and overall subtypes of differentiated carcinomas, between MVD of follicular adenomas and carcinomas respectively, as well as between MVD of medullary carcinoma and follicular cell carcinomas generally. In conclusion nuclear morphometry and quantitation of angiogenesis could offer two additional parameters in the distinction between follicular adenomas and carcinomas. However, they cannot serve as absolute diagnostic criteria since they are only based on statistical differences. From a prognostic point of view, nuclear morphometry may have some relevance as far as follicular-cell neoplasms are concerned since the more aggressive anaplastic carcinomas have a distinct morphometric profile. Moreover, our study revealed differences in the angiogenetic profile between medullary and follicular cell carcinomas.

Adenocarcinoma, Follicular↗

PubMed2001

Texture analysis of fluorescence microscopic images of colonic tissue sections.

The aim of this study was to assess the potential of texture analysis for the characterization of fluorescence images from colonic tissue sections stained with a novel and selective fluoroprobe, Rhodamine B-phenylboronic acid. Fluorescence microscopy images of colonic healthy mucosa (n = 35) and adenocarcinomas (n = 35) were digitally captured and subjected to image texture analysis. Textural features derived from the grey level co-occurrence matrix were calculated. A modified version of the multiple discriminant analysis criterion was used to choose an appropriate subset of features. A minimum Mahalanobis distance, linear discriminant classifier and a simple evaluation 'score' method were used to classify image feature data into the two categories. A subset of four textural features was selected and used for the description and classification of each image field. They were found appropriate to correctly classify 95% of the images into the two classes, using two different classifiers. These features contained information about local homogeneity and grey level linear dependencies of the image. This study demonstrated that texture analysis techniques could provide valuable diagnostic decision support in a complex domain such as colorectal tissue.

Adenocarcinoma↗