ABSTRACT
BACKGROUND/AIMS: Skin cancer diagnosis depends, to a great extent, on visual inspection and histopathological examination of excised tissues. The aim of this study is to evaluate the ability of electrical impedance scanning to differentiate between benign and malignant skin lesions. METHODS: A preclinical study was conducted on 40 nude mice injected subcutaneously with a human melanoma strain. Impedance measurements were recorded every week to correlate electrical changes with tumor growth and histological findings. A clinical study was also performed on 178 human suspicious skin lesions before excision. The impedance measurements were correlated to the histopathological results. RESULTS: Normalized conductivity and capacitance, recorded on growing skin tumors in nude mice, were shown to change relative to lesion size. Necrosis, present in most of the larger lesions, was associated with a decrease in the electrical conductivity. Similar electrical parameters were used to classify human melanoma lesions with 92% sensitivity and 67% specificity. In addition, four out of five BCC lesions were correctly diagnosed. Moreover, dysplastic lesions were diagnosed with 91% sensitivity and 59% specificity. For comparison, physicians diagnosed melanoma lesions with 75% sensitivity and 87% specificity and dysplastic lesions with 46% sensitivity and 80% specificity. CONCLUSIONS: The animal study showed that electrical impedance measurements reflect morphological changes related to the growth of a cancerous skin lesion. These findings are in agreement with a preliminary clinical study. Electrical Impedance Scanning can therefore be considered as an objective and non-invasive tool for differentiation between benign and malignant skin lesions.
Subject(s)
Electrodiagnosis , Melanoma/diagnosis , Skin Neoplasms/diagnosis , Animals , Diagnosis, Differential , Electric Capacitance , Electric Impedance , Galvanic Skin Response , Humans , Melanoma/pathology , Mice , Mice, Nude , Necrosis , ROC Curve , Sensitivity and Specificity , Skin Diseases/diagnosis , Skin Neoplasms/pathologyABSTRACT
There have been several reports implying a benefit for heparin therapy in patients with refractory ulcerative colitis. Although this effect has been attributed to the anti-inflammatory properties of heparin, other mechanisms have not been excluded. Heparin is a potent modulator of receptor binding of growth factors such as fibroblast growth factor (FGF), vascular endothelial growth factor, and heparin-binding epidermal growth factor (HB-EGF), that play a role in wound repair. We examined the effect of heparin on the functional levels of FGF and HB-EGF in a model of experimental colitis. Fifty-six Wistar rats were divided into four groups: group 1 was the control group, group 2 received s.c. heparin 50 units/kg/d, group 3 underwent induction of 3% iodoacetamide colitis, and group 4 underwent induction of colitis and heparin treatment. Rats were killed and evaluated for severity of colitis by macroscopic and microscopic colitis scores, area of inflammation, and myeloperoxidase levels. FGF and HB-EGF levels were functionally assessed in colonic tissue in each group. Heparin therapy resulted in significant improvement in macroscopic and microscopic features of colitis (p < 0.05), accompanied by a partial reduction in myeloperoxidase levels. FGF receptor binding activity was identical in groups 1 and 2 but increased more than 3-fold after colitis induction in group 3 (p < 0.05). Treatment with heparin caused a significant decrease in FGF concentration. Levels of HB-EGF binding activity were similar in groups 1 and 2 and decreased in group 3 (p < 0.01). Heparin caused a significant increase in HB-EGF content in group 4 (p < 0.05). Levels of growth factors are altered differently in experimental colitis. Colonic FGF binding activity increases with colitis, whereas HB-EGF binding decreases with colitis. These trends were reversed by heparin, concomitant with a clinical and pathologic improvement in colitis. We suggest that one mechanism of heparin-mediated improvement in colitis may involve tissue healing associated with changes in functional levels of colonic growth factors.
Subject(s)
Colitis/drug therapy , Epidermal Growth Factor/metabolism , Fibroblast Growth Factors/metabolism , Heparin/therapeutic use , Animals , Colitis/chemically induced , Colitis/metabolism , Drug Evaluation, Preclinical , Heparin/pharmacology , Heparin-binding EGF-like Growth Factor , Intercellular Signaling Peptides and Proteins , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Iodoacetamide/toxicity , Male , Peroxidase/analysis , Protein Binding/drug effects , Rats , Rats, WistarABSTRACT
Fez-se um estudo em uma amostra de 169 crianças de 0 a 3 anos de idade de diferentes níveis sócio-econômicos com o objetivo de demonstrar as relaçöes entre os vários fatores de risco e déficit no desenvolvimento neuro-psicomotor. Foram feitas várias associaçöes entre os fatores de risco e déficit no desenvolvimento neuro-psicomotor e se encontrou significância na associaçäo com antecedentes mórbidos
