Diagnóstico diferencial no melanoma primário e metastático por espectroscopia FT-Raman

PURPOSE: To qualify the FT-Raman spectral data of primary and metastatic cutaneous melanoma in order to obtain a differential diagnosis. METHODS: Ten normal human skin samples without any clinical or histopathological alterations, ten cutaneous melanoma fragments, and nine lymph node metastasis samples were used; 105, 140 and 126 spectra were obtained respectively. Each sample was divided into 2 or 3 fragments of approximately 2 mm³ and positioned in the Raman spectrometer sample holder in order to obtain the spectra; a monochrome laser light Nd:YAG at 1064 nm was used to excite the inelastic effect. RESULTS: To differentiate the three histopathological groups according to their characteristics extracted from the spectra, data discriminative analysis was undertaken. Phenylalanine, DNA, and Amide-I spectral variables stood out in the differentiation of the three groups. The percentages of correctly classified groups based on Phenylalanine, DNA, and Amide-I spectral features was 93.1%. CONCLUSION: FT-Raman spectroscopy is capable of differentiating melanoma from its metastasis, as well as from normal skin.OBJETIVO: Qualificar os dados espectrais FT-Raman do melanoma cutâneo primário e metastático e assim realizar o diagnóstico diferencial. MÉTODOS: Foram utilizadas amostras de 10 fragmentos de pele sem alterações clínicas ou histopatológicas, 10 de melanomas cutâneos e 9 de metástases linfonodais; 105, 140 and 126 espectros foram obtidos respectivamente. Cada amostra foi dividida em 2 ou 3 frações de 2 mm³ e posicionada no porta amostras do espectrômetro Raman para obtenção dos espectros, por meio da excitação do espalhamento inelástico pelo laser de Nd:YAG em 1064 nm incididos na amostra. RESULTADOS: Para diferenciar os três grupos formados de acordo com as características fornecidas pelos espectros, realizamos a análise discriminante dos dados. As variáveis espectrais Fenilalanina, DNA e Amida-I se destacaram na capacidade de diferenciação dos três grupos histológicos. A porcentagem de classificação correta utilizando estes critérios foi de 93,1%; o que mostra a eficiência da análise realizada. CONCLUSÃO: A espectroscopia FT-Raman é capaz de diferenciar o melanoma de sua metástase, assim como da pele normal.UNIFESPUniversidade Federal de São Paulo (UNIFESP) Department of SurgeryPathology DepartmentPathology Department Federal University of ABC Head of Center for Human and Natural Sciences (CCNH)UNIVAP Institute of Research and Development Head of Biomedical Vibrational Spectroscopy LaboratoryUniversidade Federal de São Paulo (UNIFESP) Department of Surgery Head of Division of Plastic SurgeryUNIFESP, Department of SurgeryUNIFESP, Department of Surgery Head of Division of Plastic SurgerySciEL

O efeito do ácido ascórbico tópico na cicatrização cutânea

Introdução: A ferida cirúrgica apresenta altos níveis de radicais livres em resposta ao dano cutâneo, o que gera a hipótese de um possível benefício do uso de antioxidantes no reparo destas feridas, tal como a aplicação tópica do ácido ascórbico. No entanto, pesquisas recentes obtiveram conclusões discrepantes para este tipo de tratamento. O objetivo é avaliar o efeito do ácido ascórbico tópico na cicatrização cutânea por meio de uma revisão de escopo. Métodos: A revisão de escopo foi realizada na base de dados Medline, Lilacs e Cochrane, com os descritores: ácido ascórbico, creme para a pele e cicatrização de feridas. Foram definidos como critérios de inclusão: ensaios clínicos randomizados, observacionais e revisões sistemáticas, em humanos, com data de publicação de até 5 anos, nas línguas inglesa, portuguesa ou espanhola. Foram excluídas: revisões narrativas, dissertações, teses, editoriais, estudos in vitro e em animais. Por fim, foi realizada a classificação dos estudos através da metodologia GRADE. Resultados: Foram encontrados 83 estudos e, após triagem, seis artigos foram selecionados. Destacou-se o uso do ácido ascórbico na concentração de 5 a 20% e de seus derivados (0,075% a 9,55%). Apresentaram a qualidade GRADE moderada os desfechos: aumento da firmeza cutânea e redução da vermelhidão, e alta qualidade: melhora na hidratação, elasticidade, colorometria das manchas e melhora do fechamento das feridas. Conclusão: O ácido ascórbico promove melhor elasticidade cutânea, diminuição do eritema e melhor fechamento das feridas. Apesar destes fortes indícios, ensaios clínicos randomizados com menor risco de viés de aferição e com maior casuística ainda se fazem necessários

The effect of topical ascorbic acid on cutaneous healing

Introduction: The surgical wound has high levels of free radicals in response to skin damage, which raises the hypothesis of a possible benefit from using antioxidants in repairing these wounds, such as the topical application of ascorbic acid. However, recent research has found conflicting conclusions about this type of treatment. The objective is to evaluate the effect of topical ascorbic acid on skin healing through a scope review. Methods: The scope review was carried out in the Medline, Lilacs and Cochrane databases, with the descriptors: ascorbic acid, skin cream, and wound healing. Inclusion criteria were defined as randomized clinical trials, observational and systematic reviews, in humans, with a publication date of up to 5 years, in English, Portuguese or Spanish. The following were excluded: narrative reviews, dissertations, theses, editorials, in vitro and animal studies. Finally, the studies were classified using the GRADE methodology. Results: 83 studies were found, and six articles were selected after screening. The use of ascorbic acid in the concentration of 5 to 20% and its derivatives (0.075% to 9.55%) stood out. The outcomes presented a moderate GRADE quality: increased skin firmness and reduced redness, and high quality: improved hydration, elasticity, colorimetry of the stains and improved wound closure. Conclusion: Ascorbic acid promotes better skin elasticity, reduced erythema and better wound closure. Despite these strong indications, randomized clinical trials with a lower risk of measurement bias and greater casuistry are still necessary

DNA Extraction Systematics for Spectroscopic Studies

Study of genetic material allows the comprehension the origin of the many biochemical changes that follow diseases, like cancer, promoting the development of early preventive inquiry and more efficient individual treatments. Raman spectroscopy can be an important tool in DNA study, since it allows probe molecular vibrations of genetic material in a fast way. The present work established a systematic way for extract DNA in suitable concentrations and structural integrity allowing studies by Raman spectroscopy or other spectroscopic technique, including bio-analytical sensors for probing genetic alterations

Spectral Region Optimization for Raman-Based Optical Biopsy of Inflammatory Lesions

Objective: The biochemical alterations between inflammatory fibrous hyperplasia (IFH) and normal tissues of buccal mucosa were probed by using the FT-Raman spectroscopy technique. The aim was to find the minimal set of Raman bands that would furnish the best discrimination. Background: Raman-based optical biopsy is a widely recognized potential technique for noninvasive real-time diagnosis. However, few studies had been devoted to the discrimination of very common subtle or early pathologic states as inflammatory processes that are always present on, for example, cancer lesion borders. Methods: Seventy spectra of IFH from 14 patients were compared with 30 spectra of normal tissues from six patients. The statistical analysis was performed with principal components analysis and soft independent modeling class analogy cross-validated, leave-one-out methods. Results: Bands close to 574, 1,100, 1,250 to 1,350, and 1,500 cm(-1) (mainly amino acids and collagen bands) showed the main intragroup variations that are due to the acanthosis process in the IFH epithelium. The 1,200 (C-C aromatic/DNA), 1,350 (CH(2) bending/collagen 1), and 1,730 cm(-1) (collagen III) regions presented the main intergroup variations. This finding was interpreted as originating in an extracellular matrix-degeneration process occurring in the inflammatory tissues. The statistical analysis results indicated that the best discrimination capability (sensitivity of 95% and specificity of 100%) was found by using the 530-580 cm(-1) spectral region. Conclusions: The existence of this narrow spectral window enabling normal and inflammatory diagnosis also had useful implications for an in vivo dispersive Raman setup for clinical applications.FAPESPCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNP