Atividade antitumoral e imunológica de abrina e pulchelina em tumor mamário murino

O termo “câncer” corresponde ao conjunto de cerca de 100 doenças que têm em comum o crescimento desordenado de células que invadem os tecidos e órgãos, podendo metastatisar para outras regiões do corpo. Os tumores de mama e colo do útero são os mais frequentes no sexo feminino. Neste estudo, avaliou-se o efeito tóxico de injeções intratumorais de abrina e pulchelina com ou sem β-D-galactose sobre o desenvolvimento do tumor mamário murino, verificando sua influência sobre o sistema imune. Proteínas inativadoras de ribossomos (RIPs) abrina, obtida de sementes de Abrus precatorius, e pulchelina, de sementes maduras de Abrus pulchellus subsp. tenuiflorus, foram utilizadas e como droga controle foi usada a Doxorrubicina. As RIPs foram administradas em camundongos fêmeas Balb/c. A partir dos tumores retirados dos animais em estudo, verificou-se o percentual de inibição do crescimento tumoral, medindo-se o tamanho e os pesos dos tumore. A partir de culturas de macrófagos obtidos dos animais de estudo, avaliou-se a produção de NO, TNF-α e IL-12 pelas RIPs na presença ou ausência de β-D-galactose. A IL-10 foi quantificada a partir de linfócitos esplênicos. A viabilidade celular foi verificada quando as células foram sujeitas às ações das RIPs. Com base nos resultados obtidos, observou-se que as RIPs não apresentaram potencial antitumoral, pois não houve redução do tamanho do tumor em relação ao controle, exceto pela abrina (p<0,05). Contudo, verificou-se que houve um possível efeito inibitório da toxicidade de abrina e pulchelina pela galactose sobre as células tumorais. As substâncias testadas (abrina, pulchelina e doxorrubicina) nas concentrações utilizadas nos testes de citotoxicidade ...

Busca de parceiros físicos das proteínas ADAM23 e MX1, utilizando o sistema de duplo híbrido em Saccharomyces cerevisae

A metilação de ilhas CpG em regiões regulatórias de vários genes tem sido descrita como um processo importante no silenciamento de genes supressores de tumor e diretamente envolvida no processo de carcinogênese de uma série de tumores. O estudo desses genes afetados pela metilação em tumores visa identificar possíveis marcadores moleculares para o diagnóstico, prognóstico e tratamento de tumores, além de possibilitar a descoberta de fatores importantes no processo biológico do câncer. Os genes MX1 e ADAM23 foram identificados como diferencialmente metilados em linhagens celulares provenientes de carcinoma de cabeça e pescoço. Neste sentido, ao estudar o perfil diferencial de metilação de genes em carcinomas de células escamosas de cabeça e pescoço, o gene MX1 foi identificado como diferencialmente expresso. Dessa forma, para elucidar a função destes genes no controle da carcinogênese, o presente estudo buscou identificar ligantes celulares das proteínas MX1 e ADAM23 por meio de rastreamentos de duplo-híbrido, usando bibliotecas de cDNA de cérebro fetal humano. Os rastreamentos com a proteína ADAM23 não geraram resultados positivos por isso não são aqui discutidos. Foi realizado rastreamento com a proteína MX1, que resultou em aproximadamente 1,0x106 transformantes, dos quais 74 foram confirmados pelo ensaio de duplo-híbrido e codificam para 9 ligantes já conhecidos e 21novos ligantes prováveis de MX1. Entre esses novos ligantes prováveis estão proteínas que já haviam sido descritas como ligantes de MX1, incluindo a própria proteína MX1, o que valida os resultados obtidos com este rastreamento. Além disso, grande parte dos ligantes identificados são fatores envolvidos no processo de SUMOilação de proteínas, na formação de corpúsculos nucleares denominados PML-NB e uma série de proteínas relacionadas ao controle da transcrição e apoptose... (Resumo completo, clicar acesso eletrônico abaixo)

Radioterapia com elétrons

Radiotherapy is a field of medical physics, which has been going through a scientific and technological advancement, it is extreme important the professionals that work in this area continuous their study to improve the quality of service provided. For it, they should know the physical principles related as well their employment in radiotherapy. The electrons have been using in therapy of superficial tumors, because they show rapid decrease of dose in depth, they don’t expose the deeper tissues to radiation. The electron therapy has replaced the surface therapy with x-ray and mold brachytherapy, and nowadays, it represents 10 to 15% of radiotherapy treatments. This study brings the definition of physical parameters used in the dosimetry of electron beam, describes the tests for quality control of linear accelerator with a electrons beam, as well the activities realized in the Radiotherapy Division, of Hospital de Clinicas, in the Universidade Estadual of Campinas, in the Clinac 2100C machine

Estudo da toxicidade de diferentes doses do Diuron (3-(3,4 -dichlorophenyl)-1,1-dimethylurea) no epitélio da bexiga de ratos wistas machos por microscopia eletrônica de varredura

Diuron (3-(3,4-Dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide widely used on agricultural crops such as soy, cotton and sugar cane. In a previous long-term study this herbicide exerted carcinogenic activity on the urinary bladder and renal pelvis mucosa of Wistar rats and breast of mice. Also, it was shown to be carcinogenic to the mice skin in a initiation-promotion assay. In 1997, the northamerican EPA evaluated Diuron as a “known/likely” carcinogen for humans (USEPA, 2004). In a previous study developed at this laboratory, male Wistar rats treated with Diuron 2500 ppm during 20 weeks presented increased indices of cell proliferation and incidences of simple urothelial hyperplasia (HS) in the urinary bladder. Under scanning electron microscopy (SEM) severe urothelial necrosis and hyperplasia were observed. However, in that study the urinary bladders of animals exposed to lower doses of Diuron were not examined under SEM. Therefore, the possible dose-response influence of Diuron on the urothelium under SEM is not known. The present study aimed to analyze under SEM the urinary bladder of male Wistar rats exposed to 125 ppm, 500 ppm and 2500 ppm doses of Diuron through diet during 20 weeks and to compare to the previous histological findings in the same material. Under SEM, 125 ppm and 2500 ppm groups presented significantly (p<0,05) increased incidences of simple hyperplasia, i.e., 7/10 and 8/10 respectively, compared to control group and the 500 ppm group The sensitivity of SEM was higher since it detected a 45% incidence of hyperplasiaswhile the histological analysis found only 27%. Considering SEM as the gold-standard, histology showed a 44% sensitivity, 86.4% specificity, a positive predictive value of 72,7% and negative predictive value of 65,5% and accuracy of 67,5%. Scanning Electron Microscopy...(Complete abstract click electronic access below)

Tumor venéreo transmissível canino com enfoque nos diversos tratamentos

The canine Transmissible Venereal Tumor (TVT) is a neoplasm of round cells that primarily affects the external genitalia of both male and female dogs with high casuistry. Its transmission occurs by the tumor cells’ implementation in the mucous membranes during the coitus or in other body parts through licking, scratching or direct contact with the tumor. The clinical manifestations vary according to the location. Despite being a malignant neoplasm, TVT’s metastatic potential is low. The diagnosis is based on macroscopic characteristics, clinical signs, cytology and/or histopathology exam, among which cytology is considered the best method. There are several treatment protocols for the TVT, among which, surgical excision, radiotherapy, immunotherapy and chemotherapy. Chemotherapy with vincristine sulfate is the elected treatment. However, more and more new alternatives have been developed, as the usage of natural products, homeopathy and ivermectina. They can be used as a unique treatment to neoplasm or combined to the chemotherapy in order to decrease the dose and the application number of the chemotherapic and its side effects

Importância do exame laboratorial no diagnóstico de linfoma em cães e gatos

Lymphoma is a cancer originating in solid hematopoietic tissue and is one of the most common tumors in dogs and cats. Usually the diagnosis is made late, when the disease is at an advanced stage, reducing the success of treatment, affecting the prognosis. Therefore, early diagnosis is the best tool to combat this increasingly common disease in veterinary medicine. Due to the diversity of presentations and forms of the disease, clinical signs are nonspecific and varied making the use of laboratory testing essential to lymphoma diagnosis in order of establishing the most appropriate treatment as quickly as possible, giving the patient a longer survival rate

Avaliação do efeito citotóxico da nitensidina A em células de glioblastoma multiforme e células não tumorais

Astrocitomas difusos são o tipo de tumor cerebral primario mais comum em adultos. O glioblastoma multiforme (GBM) é o astrocitoma mais frequente e letal. Pacientes diagnosticados com GBM geralmente morrem em aproximadamente 14 meses apesar do tratamento normalmente adotado. O tratamento consiste em remoção cirúrgica do tumor, radioterapia e quimioterapia com o agente alquilante temozolomida (TMZ). Entretanto, devido a elevada resistência desse tumor à radioterapia e quimioterapia, na maioria dos casos ocorre recidiva do tumor algumas semanas após a cirurgia. Baseado nesse prognóstico pobre e na elevada resistência das células de GBM à quimioterapia, a busca por novos fármacos a fim de aumentar as chances de sobrevivência e a qualidade de vida dos pacientes, é de extrema importância. Nitensidina A é um alcaloide guanidínico isolado da planta típica do cerrado brasileiro Pterogyne nitens, que demonstrou notável efeito citotóxico em células de câncer cervical. A fim de analisar o potencial da nitensidina A como antineoplásico foram realizados ensaios de citotoxicidade desta substância e da TMZ. Os resultados mostraram que a nitensidina A apresenta efeito citotóxico em concentração muito inferior à TMZ. Os resultados também demonstram que dentre as células analisadas, a RO é a célula não tumoral mais resistente a ambas as substâncias e, dentre as células tumorais, a célula mais sensível e a mais resistente são, respectivamente, U87MG e U343MG. Estes resultados indicam que a nitensidina A tem um potencial terapêutico promissor para este tipo tumoral. Experimentos adicionais estão em andamento para investigar esta hipótese

Avaliação preliminar dos efeitos de Brassica campestris sobre a obesidade induzida por dieta hipercalórica

Obesity along with overweight has been considered one of the most serious public health problems in the world, especially because they are the main risk factors for many chronic diseases such as coronary heart disease, type II diabetes mellitus, hypertension and some types of tumors, which are associated with high mortality rates. The use of functional foods and appropriate diets to promote health has grown as a mechanism for prevention, control and treatment of chronic diseases such as obesity. Several ethnopharmacological studies indicate plants species for the treatment of disorders associated with obesity with a major attraction of this regimen is perceived as safer and more effective for health than the traditional treatment with appetite suppressants. Whereas both food intake and the oral treatment with different compounds can cause changes in gene expression and that a proper diet has been valuable as a mechanism for maintaining the body's vital functions, the objective of this project was to evaluate the effects of standardized extract of Brassica campestris L. in the decrease in weight and food intake control. In vivo trials of this product were conducted and studies of its effects on energy metabolism in non-obese mice and with obesity induced by hypercaloric diet. After induction of obesity by 8 weeks, animals were treated for 21 days with the extract orally. After 21 days the animals were killed and the effects of this product were evaluated on the daily feed intake and on body weight. According to the results obtained, the extract of Brassica campestris was not effective in reducing body weight of obese animals, and did not reduce food intake

Dosimetria Física e Controle de Qualidade em Radioterapia

Radiotherapy is a multidisciplinary speciality which uses complex equipment and radiation sources for delivery of treatment, using high-energy ionizing radiation to treat cancer at several stages of complexity. Since radiation therapy is a technique which involves a precalculated radiation dose, it shall be established quality assurance programs that provide an efficient and safety treatment. The International Commission on Radiation Units and Measurements (ICRU) report No. 50 has recommended dose uniformity between 5% of the prescribed dose throughout the region of interest. This is one of the most primordial points that justify the importance of a suitable attendance of the equipments quality and performance. For quality control, the medical physicist will be involved with establishing and running a Quality Control Program (QCP). He must adapt or develop the procedures of equipment acceptance and commissioning, besides verifying the use of principles and accepted protocols of national and international reports to assure the correct quality, quantity, and placement of radiation during the performance of a radiological procedure, establishing adequate protocols to ensure accurate patient dosimetry. This present work consists of a description of the activities carried through the Sectors of Radiation Therapy of the Hospital of Clinics of the Campinas State University (Unicamp), particularly in the implementation of the Quality Control Program