29 research outputs found
Segmentation of the melanoma lesion and its border
Segmentation of the border of the human pigmented lesions has a direct impact on the diagnosis of malignant melanoma. In this work, we examine performance of (i) morphological segmentation of a pigmented lesion by region growing with the adaptive threshold and density-based DBSCAN clustering algorithm, and (ii) morphological segmentation of the pigmented lesion border by region growing of the lesion and the background skin. Research tasks (i) and (ii) are evaluated by a human expert and tested on two data sets, A and B, of different origins, resolution, and image quality. The preprocessing step consists of removing the black frame around the lesion and reducing noise and artifacts. The halo is removed by cutting out the dark circular region and filling it with an average skin color. Noise is reduced by a family of Gaussian filters 3×3−7×7 to improve the contrast and smooth out possible distortions. Some other filters are also tested. Artifacts like dark thick hair or ruler/ink markers are removed from the images by using the DullRazor closing images for all RGB colors for a hair brightness threshold below a value of 25 or, alternatively, by the BTH transform. For the segmentation, JFIF luminance representation is used. In the analysis (i), out of each dermoscopy image, a lesion segmentation mask is produced. For the region growing we get a sensitivity of 0.92/0.85, a precision of 0.98/0.91, and a border error of 0.08/0.15 for data sets A/B, respectively. For the density-based DBSCAN algorithm, we get a sensitivity of 0.91/0.89, a precision of 0.95/0.93, and a border error of 0.09/0.12 for data sets A/B, respectively. In the analysis (ii), out of each dermoscopy image, a series of lesion, background, and border segmentation images are derived. We get a sensitivity of about 0.89, a specificity of 0.94 and an accuracy of 0.91 for data set A, and a sensitivity of about 0.85, specificity of 0.91 and an accuracy of 0.89 for data set B. Our analyses show that the improved methods of region growing and density-based clustering performed after proper
preprocessing may be good tools for the computer-aided melanoma diagnosis
Resolution invariant wavelet features of melanoma studied by SVM classifiers
This article refers to the Computer Aided Diagnosis of the melanoma skin cancer. We derive wavelet-based features of melanoma from the dermoscopic images of pigmental skin lesions and apply binary C-SVM classifiers to discriminate malignant melanoma from dysplastic nevus. The aim of this research is to select the most efficient model of the SVM classifier for various image resolutions and to search for the best resolution-invariant wavelet bases. We show AUC as a function of the wavelet number and SVM kernels optimized by the Bayesian search for two independent data sets. Our results are compatible with the previous experiments to discriminate melanoma in dermoscopy images with ensembling and feed-forward neural networks
UVB sensitivity in chronic viral hepatitis : pilot study
About 3% of the Polish population suffer from chronic viral hepatitis (CVH). CVH can be present without
any symptoms. Some patients manifest only extrahepatic involvement during the course of hepatitis. CVH can
present with symptoms of photosensitive diseases such as LE, DM, and PCT. The aim of the study was to assess UVB sensitivity in CVH patients in comparison with lupus erythematosus
(LE) patients and healthy volunteers (HV). The study group consisted of 90 patients: 30 with CVH, 30 with LE and 30 HV. We performed
phototesting in NB and BB UVB radiation and determined MED and the >1 MED erythema duration. A significant difference (p=0.01) was found between mean MED BB and NB UVB in subjects with LE and
HV. Mean persistence time of >1 MED erythema was significantly different between LE patients and HV ()
and between CVH and HV (). There were no significant differences in phototesting values between patients
with CVH type B and CVH type C, between patients with normal or higher aminotransferase activity and between
patients treated or untreated.: Our study revealed increased photosensitivity in CVH patients, especially in persistence of >1 MED
erythema. This value was similar as in LE patients. There were no correlations between virus type, liver enzymes
activity, treatment and phototesting results. Photosensitivity could be one of the extrahepatic manifestations of
CVH
Cyclin D1 and D3 expression in melanocytic skin lesions
Cyclins, cyclin-dependent kinases, as well as proteins cooperating with them are responsible for cell cycle regulation which is crucial for normal development, injury repair, and tumorigenesis. D-type cyclins regulate G1 cell cycle progression by enhancing the activities of cyclin-dependent kinases, and their expression is frequently altered in tumors. Disturbances in cyclin expression were also reported in melanocytic skin lesions. The objective of the study was to evaluate the expression of cyclins D1 and D3 in common, dysplastic, and malignant melanocytic skin lesions. Forty-eight melanocytic skin lesions including common nevi (10), dysplastic nevi (24), and melanomas (14) were diagnosed by dermoscopy and excised. Expression of cyclin D1 and D3 was detected by immunohistochemistry and quantified as percentage of immunostained cell nuclei in each sample. In normal skin, expression of cyclins D1 and D3 was not detected. The mean percentage of cyclin D1-positive nuclei was 7.75% for melanoma samples, 5% for dysplastic nevi samples, and 0.34% for common nevi samples. For cyclin D3, the respective values were 17.8, 6.4, and 1.8%. Statistically significant differences in cyclin D1 expression were observed between melanomas and common nevi as well as between dysplastic and common nevi (p = 0.0001), but not between melanomas and dysplastic nevi. Cyclin D3 expression revealed significant differences between all investigated lesion types (p = 0.0000). The mean cyclin D1 and D3 scores of melanomas with Breslow thickness <1 mm and >1 mm were not significantly different. G1/S abnormalities are crucial for the progression of malignant melanoma, and enhanced cyclin D1 and D3 expression leading to increased melanocyte proliferation is observed in both melanoma and dysplastic nevi. In histopathologically ambiguous cases, lower cyclin D3 expression in dysplastic nevi can be a diagnostic marker for that lesion type
European Constitution and National Constitution
Preface
"The history of the question of alliance, integration, and unification of European states along different lines reaches far back. We only have to mention I. Kant and J. C. Bluntschli, who saw the future of Europe in establishing a union of its states based on the rule of law. It was on the grounds of freedom and republican democracy that J. Lorimer of Edinburgh envisaged the possibility of uniting European states. Much like him, Polish thinkers too, including A. Mickiewicz, B. Limanowski, and K. Kelles-Krauz, believed that Europe would unite as soon as its constituent states were driven by shared ideals of freedom and republican democracy."(...