To check the applicability of machine learning algorithms for the computer-aided diagnosis of confocal laser scanning microscopy (CLSM) views of skin lesions.Features, based on spectral properties of the wavelet transform, are very suitable for the automatic analysis because architectural structures at different scales play an important role in diagnosis of CLSM views. The images are discriminated by several machine learning algorithms, based on Bayes-, tree-, rule-, function (numeric)-, and lazy-classifiers.The function and lazy classifiers delivered best classification results. However, these algorithms deliver no information about the inference mechanism leading to the classification. The tree classifiers provided better results than the rule classifiers. To obtain more insight into the inference process, and to compare it with the diagnostic guidelines of the dermopathologists, we combined the advantages of tree, numerical, and rule classifiers and choose the classification and regression trees (CART) algorithm, which automatically generates accurate inferring rules. The classification results were relocated to the images by use of the inferring rules as diagnostic aid.The discriminated elements of the skin lesions images show tissue with features in good accordance with typical diagnostic CLSM features.
Intercellular communication and the active movement of malignant cells into and through host tissue barriers play a critical role during the complex process of tumor invasion. Motile activity, cytoskeletal actin and vinculin organization as well as gap junctional communication of in vivo benign and malignant melanocytes were compared and related to in vitro invasiveness. Normal melanocytes, Melan-a, showed significantly less motile activity, a higher organization of the actin cytoskeleton and more vinculin-containing cell-substratum adhesion plaques than highly metastatic melanoma cells, K1735-M2. There was no pronounced difference in gap junctional communication under comparable culture conditions. However, cultivation of Melan-a cells in a conventional melanocyte growth medium containing the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) enhanced intercellular communication. Melanocytes were less invasive than melanoma cells both in the embryonic chick heart model and in the Matrigel invasion assay. The least invasive activity was determined for melanocytes cultivated in TPA-deficient medium indicating that the medium supplement TPA stimulates invasion. The comparison of certain in vitro properties of both melanocytic cell lines revealed a positive correlation of motility with in vitro invasion, whereas an inverse correlation was found for the degree of actin filament organization as well as for the number of vinculin plaques. Gap junctional communication was not directly related to in vitro invasiveness.
Alternative methods are commonly used in patients with dermatologic diseases, with homeopathy being one of the most common. Homeopathy was developed by Samuel Hahnemann (1755-1843) and is based on the law of similars and the law of infinitesimals. It is a regulatory therapy where high dilutions of particular compounds are thought to induce a counterreaction in the organism. In dermatology, homeopathy is often used in atopic dermatitis, other forms of eczema, psoriasis, and many other conditions. To date, however, there is no convincing evidence for a therapeutic effect. There are only a few controlled trials, most of them with negative results. The few studies with positive results have not been reproduced. Acceptance by the patient seems largely based on counseling and emotional care rather than on objective responses to the homeopathic drugs.
It has been shown that the co-occurrence of melanoma and pre-existing naevus is not a random event and that acquired naevi may be precursors of melanoma. A critical area of chromosomal loss at 9p21 has been implicated in the genesis of malignant melanoma, representing a site of frequent somatic chromosomal deletions in melanoma. Allelic deletions within this chromosomal region most often include the tumour suppressor gene p16. The objective of this study was to search for allelic deletions on chromosome 9p21 in naevus cell clusters. A microdissection-based approach was used to analyse 30 archived primary cutaneous melanomas and associated naevi for loss of heterozygosity (LOH) at 9p21 using the polymorphic DNA markers D9S171 and IFNA. LOH was detected in 10 out of 27 informative naevi (37%) at D9S171 and in eight out of 19 (42%) at IFNA in the dissected naevus cell clusters, and in nine out of 27 (33%) at D9S171 and seven out of 19 (36%) at IFNA in the associated melanomas. In eight out of 46 (17%) cases, LOH was detected simultaneously in the naevus and the associated melanoma using both markers. Our results suggest a causal relationship for the development of melanoma within a pre-existent associated naevus. These data support the hypothesis that lesions within 9p21 play an important role in early melanoma development, since these genetic alterations are found in histologically benign melanoma-associated naevi.
Invasion of a tissue by distinct cell types is common to various biological processes including embryonic development and tumour growth. Active movement is usually considered to be a prerequisite for invasiveness. Using a computer simulation program based on a stochastic cellular automata model, we provide evidence that invasive patterns may evolve in the absence of active cellular motility. Cells characterized by low proliferation, a high rate of cell loss, pronounced tumour-stroma adhesion and an expansive instead of a destructive behaviour invade the surrounding matrix, despite a complete lack of active movement. The resulting morphological patterns are similar to those obtained with motile cells. Thus invasion does not necessarily indicate the presence of motility.
