ABSTRACT
Electrochemical treatment is an alternative modality for tumor treatment based on the application of a low intensity direct electric current to the tumor tissue through two or more platinum electrodes placed within the tumor zone or in the surrounding areas. This treatment is noted for its great effectiveness, minimal invasiveness and local effect. Several studies have been conducted worldwide to evaluate the antitumoral effect of this therapy. In all these studies a variety of biochemical and physiological responses of tumors to the applied treatment have been obtained. By this reason, researchers have suggested various mechanisms to explain how direct electric current destroys tumor cells. Although, it is generally accepted this treatment induces electrolysis, electroosmosis and electroporation in tumoral tissues. However, action mechanism of this alternative modality on the tumor tissue is not well understood. Although the principle of Electrochemical treatment is simple, a standardized method is not yet available. The mechanism by which Electrochemical treatment affects tumor growth and survival may represent more complex process. The present work analyzes the latest and most important research done on the electrochemical treatment of tumors. We conclude with our point of view about the destruction mechanism features of this alternative therapy. Also, we suggest some mechanisms and strategies from the thermodynamic point of view for this therapy. In the area of Electrochemical treatment of cancer this tool has been exploited very little and much work remains to be done. Electrochemical treatment constitutes a good therapeutic option for patients that have failed the conventional oncology methods.
ABSTRACT
Introdução: Com dois experimentos consecutivos, avaliaram-se: (1) o impacto de um campo elétrico na eficiência de quimioterápicos e na resposta proliferativa de linfócitos contra o tumor (ensaio MTT) no modelo murino; e (2) o efeito da eletricidade isolada ou associada à quimioterapia no tratamento de tumores de cabeça e pescoço espontâneos de cães e gatos. Métodos: (1) Cinco milhões de células do tumor ascítico de Ehrlich foram injetadas no dorso de 35 camundongos machos Balb/c. Após sete dias, os camundongos foram divididos em sete grupos, recebendo diferentes combinações de cisplatina ou bleomicina associada ou não a eletricidade. A progressão do tumor foi medida diariamente em cada camundongo e as diferenças entre os grupos foi avaliada por ANOVA. O impacto imunológico do tratamento foi avaliado pela co-cultura de células do tumor de Ehrlich com linfócitos provenientes de camundongos tratados e não tratados, sendo a co-cultura com células alogênicas utilizada como controle. A seguir, foi realizado um estudo seqüencial e não-comparativo (2) onde cães e gatos que apresentavam tumores espontâneos de cabeça e pescoço foram biopsiados, estadiados e tratados com eletricidade isolada ou associada à quimioterapia em um hospital veterinário. Resultados: (1) A área média do tumor (+/- desvio-padrão) dos camundongos que receberam cisplatina ou bleomicina associada à eletricidade foi significativamente menor se comparada aos controles (p<0.05). O ensaio MTT demonstrou que os linfócitos de camundongos tratados com eletricidade promovem a eliminação das células do tumor de Ehrlich na co-cultura. No estudo (2), 28 animais (14 cães e 14 gatos) foram tratados com eletricidade isolada (15 casos) ou combinada à quimioterapia. A carga elétrica média/volume do tumor foi 38,50 C/cm3. Por análise univariada, fatores que influenciaram na sobrevida foram o estádio T (p=0.04) e a carga/volume do tumor (p<0.01). Conclusões: (1) Eletricidade potencializa tanto o efeito de cisplati....
Introduction: With two consecutive experiments, we evaluated (1) the impact of electricity on chemotherapy response and on the lymphocyte proliferative response against the tumor (MTT assay) in a murine tumor model and (2) the effect of electricity alone and combined with chemotherapy in the treatment of spontaneous head and neck tumors of cats and dogs. Methods: (1) Five million cells of Ehrlich Ascitic Tumor were injected into the dorsal region of 35 male Balb/c mice. Seven days later, mice were divided into 7 groups, receiving different treatments combining Cisplatin or Bleomycin with electricity. Tumor progression in each mouse was measured daily and differences among the groups were assessed by ANOVA test. The immune impact of treatment was evaluated by the co-culture of lymphoid cells of treated and untreated mice with Ehrlich Tumor cells using co-culture with allogenic cells was used as a control. Following these results, we done a (2) sequential and non comparative study, in which dogs and cats presenting with a malignant neoplasm were clinically evaluated, staged and treated by electrolysis or electrochemotherapy in a veterinary hospital. Results: (1) The mean tumor area (+/- standard deviation) of mice receiving Cisplatin or Bleomycin with electricity were found significantly smaller if compared to that of controls (p<0.05). The co-culture results suggest that lymphocytes from mice treated by electricity promote elimination of Ehrlich Tumor cells in culture. In the study (2) 28 animals (14 dogs and 14 cats) were treated by electricity alone (15 cases) or combined to chemotherapy. The mean electrical charge/tumor volume was 38,50 C/cm3. By univariated analysis, factors impacting on survival were T stage (p=0.04) and charge/tumor volume (p<0.01). Conclusions: (1) Electricity enhanced the effect of both Cisplatin and Bleomycin and probably also stimulated an immune response against the tumor...
ABSTRACT
A intenção deste trabalho é a de sugerir um modelo numérico para a detecção de tumores em regiões do corpo humano. Assim, empregando a técnica dos dois eletrodos (TDE) na região em teste (RET), indica-se o Método dos Elementos Finitos (MEF), associado com um método probabilístico, para predizer o espalhamento dos potenciais elétrico medidos (calculados). Muitos eventos aleatórios afetam os potenciais e, devido a isto, o resultado do método numérico empregado (diagnóstico) caracteriza a probabilidade de detecção do tumor no ser humano.
