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Biomedical subjects

J Smolle

Publications and source records attributed to J Smolle.

At least 91 records · Page 5Linked to original sources
PubMed1996

Optimization of linear image combination for segmentation in red-green-blue images.

OBJECTIVE: To present an iterative algorithm that selects the optimal pair of grey level image components of red-green-blue (RGB) and hue-luminance-saturation (HLS) color image models and the optimal weighting factor for automated segmentation of the structure of interest in color images. STUDY DESIGN: The method was based on a stepwise technique, searching for the image combination that yielded the maximum two-sample t value for the grey levels of the object of interest and of the background. As a result, a transformed grey level image providing a two-peak grey level histogram suitable for automated thresholding was provided. RESULTS: The segmentation of collagen bundles in hematoxylin and eosin-stained slides of cutaneous melanomas is presented as an example. Though each of the RGB and HLS grey level images showed extensive overlap of objects and background, the combined image facilitated clear-cut discrimination. CONCLUSION: The proposed algorithm permits the discrimination of specified objects in color images that are not characterized by grey level in any of the underlying grey level image components.

Diagnostic Imaging↗
PubMed1996

Immunoglobulin A (IgA) deposits in lesional skin of a patient with blepharochalasis.

We describe a 21-year-old male patient with blepharochalasis, a form of localized acquired cutis laxa. He had a 13-year history of recurrent swelling attacks of the eyelids of unknown origin leading to periocular localized cutis laxa. Histology of lesional skin confirmed almost complete loss of elastic fibres in the reticular and papillary dermis. Immunofluorescence and immunoelectron microscopy studies showed abundant immunoglobulin A (IgA) deposits around the remaining elastic fibres. Control skin of the forearm was negative. These findings support the hypothesis that immunopathogenetic mechanisms may contribute to the elastolytic process of blepharochalasis.

Adult↗
PubMed1995

Pathology of tumor-stroma interaction in melanoma metastatic to the skin.

Tumor invasion and metastasis formation largely depend on tumor-stroma interaction. In the present study morphological correlates of tumor-stroma interaction were examined in 344 melanoma lesions metastatic to the skin. In particular, the presence of simple infiltration into the surrounding dermis or subcutis without evident stromal reaction, the incorporation of pre-existent dermal collagen or subcutaneous fat cells into the tumor bulk, and the formation of a peritumoral capsule or intratumoral fibrous septa were evaluated. Our results showed that simple infiltration into the surrounding tissue as well as the incorporation of pre-existent stroma tissue without destruction is associated with poor outcome, whereas capsule and fibrous septa are favorable prognostic signs, particularly in subcutaneous lesions. Remarkably, simple infiltration is a prognostic indicator independent of the location of the metastasis (locoregional or distant), as shown by multivariate analysis. These data indicate that morphological aspects of tumor-stroma interaction in metastatic skin lesions of melanoma may reflect biological behavior of the tumor cells, may facilitate a pathological subclassification of metastatic melanoma in addition to clinical data, and are directly related to the patient's outcome.

Adult↗
PubMed1995

Biological significance of tumor thickness. Theoretical considerations based on computer simulation.

Maximum vertical tumor thickness is a highly significant prognostic criterion in cutaneous melanoma. To date, little is known about the problem, why thick lesions are more capable of metastatic spread than thin ones. To evaluate theoretical possibilities of the biological impact of thick lesions, computer simulation of tumor growth was performed. In a set of 35,000 simulated tumors, the thickness of the resulting tumor was measured and the functional simulation settings contributing to tumor thickness were identified by statistical methods. It turned out that in this theoretical model of tumor growth, besides time, which is the most important factor, other factors contribute to tumor thickness. These are tumor cell motility, particularly when stimulated by stromal elements, a decreased rate of tumor cell loss, and pronounced proliferation associated with high numbers of cell cycle generations in the tumor cells. These findings are in agreement with experimental data indicating that metastatic capacity may depend on increased motility, stroma-induced motility stimulation, evasion from the host immune system, and genetic instability manifesting during cell cycling. Thus the observations may help to clarify the relationship of vertical tumor thickness and poor clinical outcome in cutaneous melanomas.

Cell Cycle↗
PubMed1995

Quantitative assessment of fat cells in subcutaneous metastatic melanoma. Correlation with outcome.

The metastatic behavior of tumor cells largely depends on tumor-stroma interactions. In the present study, a particular morphological feature of tumor-stroma interaction was evaluated; hematoxylin-eosin-stained slides of 81 lesions of melanoma metastatic to the skin involving the subcutis were examined by automated image analysis for the presence of preexistent fat cells in the tumor. The area occupied by fat cells, expressed in micrometers squared per slide, was of prognostic significance; lesions with a fat cell area of < 41,000 microns 2 showed a 2-year survival rate of 42%, versus 10% in lesions with a fat cell area of > 41,000 microns 2 (log-rank test, z = 3.24; p < or = 0.01). The adverse effect of fat cell area on prognosis still was seen when age, sex, and site of metastatic spread were concomitantly taken into account in a Cox proportional-hazard model. These data indicate that melanoma deposits involving the subcutis with preservation of preexistent subcutaneous fat cells have high metastatic potential and a high risk for rapid internal dissemination.

Adipose Tissue↗
PubMed1995

Correlation of melanoma cell motility and invasion in vitro.

Cell motility and the ability to grow invasively are crucial properties within the metastatic cascade. The relation of cell motility in vitro and metastatic behaviour of tumour cells in animal experiments indicates that they are directly correlated. We undertook this study to see whether a quantitative correlation could be found in complex in vitro systems. Using the assay of directional migration and a newly developed image analysis system to measure cell motility of K1735-M2 mouse melanoma cells and the embryonic chick heart assay of Mareel to follow invasion, we examined the influence of eight compounds on cell motility seven compounds on invasion. For stationary motility we calculated the change of density, area of change, area of ruffling sites (representing only changes at the leading edge and tail of the cell), number of ruffling sites, area of changing intracellular particles and number of intracellular particles. Velocity of single tumour cells and directional migration were also measured. In the invasion assay the parameters STRCSTR and INVASLOG, expressing different forms of stromal (i.e. embryonic chick heart) disintegration and degradation, were calculated. Directional migration and all parameters of stationary motility except number of ruffling sites, changing intracellular particles and number of changing intracellular particles correlated significantly (p < 0.05) with STRCSTR and INVASLOG. For velocity, area of change and area of ruffling we found the most significant correlation with parameters of invasion indicating that both stationary and translocative motility contribute to invasion. Our systems also showed that the compounds tested exerted differential effects on various aspects of motility.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Computer simulations of histologic patterns in melanoma using a cellular automaton provide correlations with prognosis.

Computer simulations have been used frequently in the life sciences to investigate the mechanisms of morphologic pattern formation. The cellular automaton program SMN5 is designed to simulate tumor growth and to estimate biologic properties by comparing real tumor patterns with computer-simulated reference patterns. This method was applied to 195 cases of primary melanoma of the skin. S-100-stained sections were evaluated by image analysis and compared statistically to a reference set of 4000 simulated patterns. Estimates of tumor cell proliferation, motility, cell loss, cohesion, stroma destruction, and intercellular signals (autocrine and paracrine factors affecting growth, motility, and cell loss) were calculated. Twelve of 18 estimated parameters correlated significantly with tumor progression, as indicated by vertical tumor thickness (linear regression analysis: p < or = 0.05), and 13 of 18 parameters carried prognostic significance (log rank test: p < or = 0.05). Poor prognosis was associated particularly with a pronounced increase in the estimates of proliferation, tumor cell motility, and stromal degradation. Poor prognosis was also associated with a decrease in the estimates of cell loss, tumor cell cohesion, and paracrine growth factor dependence. In multivariate analysis using Cox's proportional hazard model, stromal degradation and motility showed prognostic information in addition to conventional prognostic parameters. The study shows that analytical comparison of real tumors with computer-simulated patterns of a cellular automaton facilitates a functional interpretation of tumor morphology, which carries prognostic significance in cutaneous melanoma.

Computer Simulation↗
PubMed1995

Ultraviolet irradiation induces acute changes in melanocytic nevi.

Ultraviolet (UV) light represents one of the factors that might play a role in the initiation and promotion of malignant transformation of human melanocytes. To determine the short-term effects of UV irradiation on melanocytic nevi in vivo, we investigated one half of symmetric melanocytic nevi after a single UV exposure with double the patient's minimal erythema dose. This half was compared with the nonirradiated, shielded half of the same nevus. The different parts were examined histologically for differences and immunohistochemically for the presence of HMB-45 antigen and proliferating cell nuclear antigen. The features were assessed quantitatively by image analysis. One week after the single UV irradiation, we observed a significant increase of suprabasally located melanocytes and a markedly enhanced expression of HMB-45, whereas proliferative activity of the cells was unchanged. In nevi that were excised 2 or 3 weeks after irradiation, no significant differences were observed between the irradiated and the nonirradiated part. The results indicate that a single UV irradiation may induce transient melanocytic activation with morphologic and histologic changes. Although these data do not formally assess resemblance to melanoma, these changes may be similar to those of melanoma in situ.

Adolescent↗
PubMed1995

Multinucleate cell angiohistiocytoma: treatment with argon laser.

Multinucleate cell angiohistiocytoma mainly affects middle-aged women, and usually presents as grouped reddish-brown papules. Histopathological features include the presence of multinucleate cells in the reticular dermis, and numerous dilated dermal vessels. The lesions are benign, and may persist for years. Treatment is needed for cosmetic reasons. We report the successful use of the argon laser to treat two patients who had multinucleate cell angiohistiocytoma.

Adult↗
PubMed1995

Confocal laser scanning microscopy: a new optical microscopic technique for applications in pathology and dermatology.

Confocal laser scanning microscopy (CLSM) is a new optical microscopic technique, which offers significant advantages over conventional microscopy. CLSM is microscopy of optical sections. Light, which is emitted from regions other than the focal plane, is cut off by introducing a diaphragm in the beam path. The result is an optical "slice", which shows more details because the blurring from out of focus haze disappears. It has been repeatedly used in experimental, but also in diagnostic dermatopathology. The "in vivo" confocal microscopy, applied directly to the intact skin provides details of living cells in the superficial layers comparable to that of fixed and stained tissue. While the extent of its future applications is hard to predict, its potential for applications in dermatology appears enormous, particularly for studies of fixed or living tissues, where it is desirable to obtain clear images many micrometers below the surface of the tissue under examination.

Animals↗
PubMed1995

Approach to diagnostic image analysis of melanocytic tumors.

Numerous attempts have been made to apply image analysis in dermatopathology. The technics used comprise measurement of nuclear size, shape, chromatin content, and texture, evaluation of immunohistological slides, assessment of proliferation, pattern analysis, and tumor volume estimation. For commonly accepted routine use, however, image analysis research has to be extended to large numbers of cases, using straightforward and reproducible measuring procedures, and to the development of ready-to-use equipment for specific tasks. In this way, image analysis in dermatopathology might supply useful diagnostic tools in addition to conventional microscopy, and may increase our understanding of morphology as a whole.

Diagnosis, Differential↗
PubMed1995

Diagnostic reliability of dermoscopic criteria for detecting malignant melanoma.

BACKGROUND: Recently a new standardized terminology in dermoscopy has been provided by a Consensus Meeting held by the Committee on Analytical Morphology of the Arbeitsgemeinschaft Dermatologische Forschung in Hamburg in order to be applied to further studies in this field. OBJECTIVE: In this study on 159 pigmented skin tumors including 65 melanomas, the validity of various dermoscopic criteria proposed by the Consensus Meeting for detecting melanoma was evaluated. METHODS: In each lesion, a detailed clinical and dermoscopic examination, photographic documentation of the clinical and dermoscopic appearance, surgical excision and histopathologic evaluation were performed. Statistical analyses including chi 2 statistics, logistic regression analysis and CART (classification and regression tree) analysis were applied. RESULTS: The diagnosis of melanoma using dermoscopy could be obtained easily, if combinations of the following criteria were observed: whitish veil, pigment network alterations (e.g. irregular pigment network, narrow pigment network, broad pigment network), irregular extensions, black dots and gray-blue areas. Interestingly, however, clinical and dermoscopic examination to detect melanomas yielded the same results, namely a sensitivity of 94%. The combined use of both methods led to an increase in the diagnostic sensitivity of 95%, whereas the combination of clinical and dermoscopic examination with logistic regression analysis of dermoscopic criteria enabled us to detect all 65 melanomas in our data set, thus providing a sensitivity of 100%. Furthermore, an algorithm for the classification of melanoma based on the evaluation of dermoscopic criteria has been constructed by CART analysis showing that the presence of a whitish veil in combination with a pigment network inevitably indicates melanoma. CONCLUSION: The validity of the various dermoscopic criteria set forth by the Consensus Meeting could be demonstrated as some criteria (e.g. whitish veil, irregular pigment network, irregular extensions) were observed with a significant higher frequency in melanomas.

Algorithms↗
PubMed1995

[Skin symptoms in extracutaneous lymphomas, leukemias and plasmacytomas].

In neoplastic diseases of the haemopoietic and the lymphatic system, the skin may be infiltrated specifically by neoplastic cells or may display 'nonspecific' cutaneous reactions, frequently associated with a systemic malignancy. Acute febrile neutrophilic dermatosis associated with myeloproliferative disorders and scleromyxedema, lichen myxedematosus, diffuse plane xanthomas and necrobiotic xanthogranuloma associated with paraproteinemia may serve as examples. These conditions as well as several other, often atypical cutaneous manifestations should rise suspicion as to the potential presence of some underlying systemic neoplastic disorder.

Humans↗
PubMed1994

[Wissler's allergic subsepsis].

A 20-year-old female patient with the typical signs of Wissler's subsepsis allergica (Wissler-Fanconi syndrome) is described. This rare disease is characterized by four typical symptoms: polymorphous exanthemas, recurrent high fever, leucocytosis and arthralgia. In the early stages it is difficult to differentiate from septicaemia. This syndrome has sometimes been considered equivalent to or an initial stage of Still's disease (juvenile rheumatoid arthritis) progressing to degenerative arthritis in many patients, whereas other authors have classified it as a separate entity with good prognosis. The present case demonstrates that Wissler's subsepsis allergica should be considered when ever transient polymorphous exanthema is accompanied by high recurrent fever, leucocytosis and arthralgia.

Adult↗
PubMed1994

[Late metastasis of malignant cutaneous melanoma].

Late recurrence of malignant melanoma, defined as the occurrence of metastases after a disease-free interval of 10 or more years, is a rare but well-known clinical phenomenon. We report on three female patients who developed in transit metastases 26, 15 and 10 years after excision of the primary tumour. All three patients are disease-free 8 and 9 years after resection of the metastases. Reports in the literature also indicate a favourable prognosis for patients with local recurrence or in transit or regional lymph node metastases. The prognosis for patients with late distant metastases, however, is generally poor. For the first group, an early therapeutic intervention is indicated. This and the occurrence of second and multiple primary melanomas make lifelong aftercare desirable. On the other hand, long-term aftercare of the constantly increasing number of melanoma patients will soon exceed the capacity of existing facilities. A high-risk group for late recurrence that would profit by long-term aftercare cannot be defined at the moment.

Adult↗
PubMed1994

[Retinoids in chemoprevention of tumors of the skin and mucous membranes. Theoretical principles and practical applications].

Chemoprevention, the use of drugs to prevent invasive neoplasia, has gained increasing significance in recent years. Especially for the skin, chemoprevention will become of importance, because large areas of the skin are exposed to environmental carcinogenic factors. Furthermore, many skin diseases predispose to the development of multiple skin tumors. One group of chemopreventive agents are the retinoids, which are effective modulators of cell proliferation and differentiation in normal as well as in transformed tissues. Though the mechanism of action of retinoids is not yet fully understood at the molecular level, chemoprevention studies have demonstrated the ability of retinoids to prevent the development of skin cancer, particularly in patients with xeroderma pigmentosum, multiple basal cell carcinoma and oral leukoplakia. A better understanding of the carcinogenic process should improve our ability to develop effective chemoprevention strategies.

Animals↗
PubMed1994

[Pacemaker erythema with telangiectasis ].

Pacemaker erythema is a rare, irreversible side effect of cardiac pacemakers, clinically characterized by epifocal teleangiectatic erythema. Histology reveals teleangiectatic vessels in the superficial dermis and a slight perivascular infiltrate. We report on three patients presenting with pacemaker erythema following either pacemaker or defibrillator implantation. The pathogenesis of this histopathologically uncharacteristic lesion is unknown. In contrast to peri- or postoperative pacemaker infections, physical irritation can be considered a possible triggering mechanism. Allergic reactions to the implanted material have been ruled out by negative patch test results.

Aged↗