Introdução: O carcinoma de células escamosas (CEC) do canal anal é uma neoplasia pouco frequente, correspondendo a 1-5% dos tumores intestinais. Entretanto, o risco de CEC do canal anal vem crescendo. O tratamento padrão do CEC de canal anal nos estádios II-III consiste em 5-fluorouracil infusional associado a mitomicina-C e radioterapia, desde 1974. Estudos clínicos com o objetivo de identificar novos esquemas terapêuticos mais convenientes para câncer do canal anal devem continuar. Métodos: Pacientes com CEC de canal anal T2-4N0M0 ou T (qualquer) N1-3M0, com bom performance clínico, função renal e hematológica normais foram tratados com capecitabina 825 mg/m2 12/12 horas durante a radioterapia associada a dose única de mitomicina-C 15 mg/m2 no Dia 1. O objetivo primário do estudo foi determinar a taxa de controle local em 6 meses da associação de capecitabina, mitomicina-C e radioterapia em pacientes com câncer do canal anal. Os objetivos secundários foram determinar a taxa de toxicidade aguda graus 3-4, conforme os critérios da CTCaev4.0, taxa de resposta completa 6 semanas após término da quimio-radioterapia, sobrevida global e livre de progressão e taxa de colostomia em 1 ano. O tamanho da amostra foi calculado usando a ferramenta \"estágio único de Fleming\". Considerando 85% de eventos esperados (taxa de controle local em 6 meses), 1 desvio padrão e 5% de erro alfa, o tamanho ideal da amostra foi de 51 pacientes. Resultados: De novembro/2010 a fevereiro/2014, 51 pacientes foram incluídos, sendo avaliados 43 pacientes. Dezessete pacientes (39,5%) tinham estádio II, 11 (25,6%) estádio IIIA e 15 (34,9%) estádio IIIB. O seguimento mediano foi de 23,1 meses. Entre os pacientes que foram avaliados em 6 meses, 3 (7%) apresentaram resposta clínica parcial, 37 (86%) tiveram resposta clínica completa e 3 (7%) apresentaram progressão de doença. O controle loco-regional em 6 meses foi de 86%. Em relação às toxicidades graus 3-4, observaram-se diarreia grau 3, em 4,6% dos pacientes, radiodermite grau 3, em 23,2%, vômitos grau 3, em 2,3%, plaquetopenia graus 3-4, em 6,9%, leucopenia grau 3, em 6,9%, e linfopenia grau 3, em 11,6%. Um paciente HIV positivo (2,3%) apresentou choque séptico grau 4, pneumonia grau 4, meningoencefalite herpética grau 4 e síndrome de ativação macrofágica grau 4. A taxa de colostomia foi de 18,6%. Conclusão: Capecitabina e mitomicina-C são um tratamento bem tolerado em pacientes com carcinoma de canal anal, com controle loco-regional em 6 meses em 86% dos pacientes. Palavras-chave: carcinoma de células escamosas, câncer anal, capecitabina, radioterapia, mitomicina-c / Background: Squamous cell carcinoma (SCC) of the anal canal is an uncommon malignancy accounting for 1-5% of intestinal tumors; however, its incidence has been increasing. Treatment for stage II and III anal canal SCC is infusional 5-fluorouracil associated with mitomycin and radiotherapy, since 1974. More convenient treatments for patients are needed. Methods: Patients with SCC of anal cancer T2-4N0M0 or T (any) N1-3M0, with good performance status, normal blood, and renal function were treated with capecitabine 825 mg/m2 bid during radiotherapy associated with a single dose of mitomycin 15 mg/m2 on day 1. Primary objective was local control rate at 6 months determined by clinical examination and radiological assessment. Sample size was calculated using Fleming single stage design. Results: From november/2010 to february/2014 51 patients were initially included, however 43 patients were assessed. Seventeen patients (39.5%) were stage II, 11 patients (25.6%) stage IIIA, and 15 patients (34.9%) stage IIIB. Four patients (9.3%) were HIV-positive, while 39 (90.7%) were HIV-negative. Median follow-up was 23.1 months. Among patients who finished the treatment and were reevaluated at 6 months 3 patients (7%) presented partial response, 37 patients (86%) had complete response, and 3 patients developed progression of the disease (7%). Regarding grade 3-4 toxicities, 10 patients (23.2%) had grade 3 radiodermitis, 3 patients (6.9%) had grade 3-4 thrombocytopenia, 5 (11.6%) had grade 3 lymphopenia, 1 patient (2.3%) had grade 3 vomiting, 2 patients (4.6%) had grade 3 diarrhea and 3 patients (6.9%) had grade 3 leukopenia. One HIV+ patient had septic shock, pneumonia, herpetic encephalitis and macrophage activation syndrome. Colostomy rate was 18.6%. Conclusions: Capecitabine and mitomycin with radiotherapy seem to be a safe treatment for SCC of the anal cancer, with a complete response rate in 6 months of 86%

<p>The electronic structures of the nucleobases, 5-fluorouracil compounds, DNA, metallic DNA, and samples of boron nitride are investigated. Soft X-ray absorption (XAS) and emission (XES) spectroscopy using synchrotron radiation are used to probe the unoccupied and occupied partial densities of electronic states, respectively. Hartree-Fock and density functional theory calculations have been included to compare with experimental results.</p> <p>A systematic approach to understanding the complicated electronic structure of DNA and metallic DNA systems is to initially examine smaller components. Detailed experiment and theory for both absorption and emission spectroscopy was. performed for the nucleobases and 5-fluorouracil compounds. Main transitions in the XAS and XES spectra are identified. X-ray spectroscopy has proven to be extremely sensitive to changes in the environment of various DNA samples. The local chemical environment plays an important role in determining the electronic structure of DNA. In agreement with previous results indicating metallic DNA is more efficient at the transfer of electrons than DNA, XES measurements reveal that there are a higher number of charge carriers in the metallic system. Both liquid and powder samples of (Ni)·M-DNA are found to have a high spin Ni(II) configuration. The drying process significantly alters the electronic structure of the metallic DNA sample. A comparison of high quality single crystals and thin films of boron nitride found that differences between the electronic structures of the nanocrystalline films and the single crystal samples exist, and the surface roughness of the substrate plays an important role in determining the structure of the resulting deposited film.</p>

<p>The electronic structures of the nucleobases, 5-fluorouracil compounds, DNA, metallic DNA, and samples of boron nitride are investigated. Soft X-ray absorption (XAS) and emission (XES) spectroscopy using synchrotron radiation are used to probe the unoccupied and occupied partial densities of electronic states, respectively. Hartree-Fock and density functional theory calculations have been included to compare with experimental results.</p> <p>A systematic approach to understanding the complicated electronic structure of DNA and metallic DNA systems is to initially examine smaller components. Detailed experiment and theory for both absorption and emission spectroscopy was. performed for the nucleobases and 5-fluorouracil compounds. Main transitions in the XAS and XES spectra are identified. X-ray spectroscopy has proven to be extremely sensitive to changes in the environment of various DNA samples. The local chemical environment plays an important role in determining the electronic structure of DNA. In agreement with previous results indicating metallic DNA is more efficient at the transfer of electrons than DNA, XES measurements reveal that there are a higher number of charge carriers in the metallic system. Both liquid and powder samples of (Ni)·M-DNA are found to have a high spin Ni(II) configuration. The drying process significantly alters the electronic structure of the metallic DNA sample. A comparison of high quality single crystals and thin films of boron nitride found that differences between the electronic structures of the nanocrystalline films and the single crystal samples exist, and the surface roughness of the substrate plays an important role in determining the structure of the resulting deposited film.</p>

Hematopoiesis is an intricately regulated homeostatic process that maintains all of the differentiated blood cell lineages. N-ethyl-N-nitrosurea (ENU) is a powerful mutagen that induces point mutations randomly in the genome. ENU was used in a dominant forward genetic screen to identify novel mutations in regulators of hematopoiesis and to create new mouse models of hematopoietic disease. The objectives of this thesis were to characterize two mutants that originated from the dominant screen (7192 and 7238) and to develop a pharmacologically sensitized screen that would detect a unique set of mutations undetectable in the dominant screen. The 7192 mutant from the ENU dominant screen presented with elevated microcytic red blood cells (RBC) and increased polychromasia. The causative mutation was identified as a nonsense mutation in Ank1 (Q895X) that coded for a truncated ANK1 protein. Ank17192 is a novel mouse model of hereditary spherocytosis (HS), a human disease that results from increased RBC fragility. We have demonstrated that Ank17192/+ mice model a mild HS and Ank17192/7192 mice model severe HS. The 7238 mutant from the dominant ENU screen was macrothrombocytic and carried a missense mutation in Myh9 (Q1443L). The Myh97238/7238 mice are viable and have a more severe phenotype of macrothrombocytopenia. Myh97238 is the first mouse model for Myh9 related disorders that accurately models the genetic origins and the systemic manifestations of the disorder. A pharmacologically sensitized screen using chemotherapeutic drugs was designed to induce stress hematopoiesis to detect mutations that alter cell cycle of hematopoietic progenitors or stress hematopoiesis. Analysis of both peripheral blood and progenitor recovery kinetics, determined that 5-fluorouracil (5FU) and phenylhydrazine were good candidates for a pharmacologically sensitized screen. 5FU was successfully incorporated into an ENU dominant screen, and 13 platelet recovery outliers were detected. From these outliers, three mutant lines were successfully established.

Hematopoiesis is an intricately regulated homeostatic process that maintains all of the differentiated blood cell lineages. N-ethyl-N-nitrosurea (ENU) is a powerful mutagen that induces point mutations randomly in the genome. ENU was used in a dominant forward genetic screen to identify novel mutations in regulators of hematopoiesis and to create new mouse models of hematopoietic disease. The objectives of this thesis were to characterize two mutants that originated from the dominant screen (7192 and 7238) and to develop a pharmacologically sensitized screen that would detect a unique set of mutations undetectable in the dominant screen. The 7192 mutant from the ENU dominant screen presented with elevated microcytic red blood cells (RBC) and increased polychromasia. The causative mutation was identified as a nonsense mutation in Ank1 (Q895X) that coded for a truncated ANK1 protein. Ank17192 is a novel mouse model of hereditary spherocytosis (HS), a human disease that results from increased RBC fragility. We have demonstrated that Ank17192/+ mice model a mild HS and Ank17192/7192 mice model severe HS. The 7238 mutant from the dominant ENU screen was macrothrombocytic and carried a missense mutation in Myh9 (Q1443L). The Myh97238/7238 mice are viable and have a more severe phenotype of macrothrombocytopenia. Myh97238 is the first mouse model for Myh9 related disorders that accurately models the genetic origins and the systemic manifestations of the disorder. A pharmacologically sensitized screen using chemotherapeutic drugs was designed to induce stress hematopoiesis to detect mutations that alter cell cycle of hematopoietic progenitors or stress hematopoiesis. Analysis of both peripheral blood and progenitor recovery kinetics, determined that 5-fluorouracil (5FU) and phenylhydrazine were good candidates for a pharmacologically sensitized screen. 5FU was successfully incorporated into an ENU dominant screen, and 13 platelet recovery outliers were detected. From these outliers, three mutant lines were successfully established.

Resumo: A mucosite é uma das complicações orais mais incidentes relacionadas à quimioterapia, que provoca ulcerações, dor, dificuldade de alimentação e pode levar à interrupção do tratamento antineoplásico. O objetivo deste estudo foi testar o efeito do LED (Ligth Emitting Diode) no tratamento da mucosite induzida por quimioterapia em hamsters. Os animais do grupo experimental (G1) e do grupo controle (G2) receberam injeção de 5-fluoruracila nos dias 0 e 2 do experimento e tiveram as mucosas direita e esquerda arranhadas nos dias 3 e 4. O G1 recebeu tratamento com LED (630 nm, 160 mW, 12 J/cm2) durante 37,5 segundos nos dias 3, 4, 6, 8, 10, 12 e 14. A mucosa jugal foi evertida e fotografada a cada dois dias a partir do dia 4 até o dia 14. As fotografias foram classificadas por meio de uma escala de acordo com o grau de severidade da mucosite (0 a 5). O G2 não recebeu tratamento. O grupo controle negativo (G3) não foi submetido à indução de mucosite. Nos dias 5, 9, 13 e 14, as mucosas de 8 animais (G1 e G2) foram removidas para avaliação histopatológica. A análise estatística demonstrou haver diferenças significantes entre o grupo tratado com LED e o grupo não tratado (p<0,05) quando se comparou a severidade da mucosite, apesar de a avaliação histopatológica ter demonstrado degeneração muscular em aproximadamente 18% da amostra (G1). A aplicação do LED nos parâmetros utilizados neste estudo foi efetiva na redução da severidade da mucosite oral e na cicatrização das lesões, embora não tenha prevenido completamente o surgimento das mesmas. / Abstract: Mucositis is the most common oral complication of cancer chemotherapy that causes pain and impairs patient's ability to eat, swallow and may determine interruption of the treatment. The aim of this study was to evaluate the effect of LED (Ligth Emitting Diode) therapy on chemotherapy-induced mucositis in hamsters. The animals of both experimental (G1) and positive control group (G2) received intraperitoneal injections of 5-fluorouracil on days 0 and 2. All animals had right and left oral mucosa irritated by superficial scratching on days 3 and 4. The G1 received LED irradiation (630 nm, 160 mW, 12 J/cm2) during 37,5 seconds at days 3, 4, 6, 8, 10, 12 and 14. The cheek pouches were everted and photographed from day 4 until 14 at 2-day intervals. Photographs were randomly scored according to the severity of induced mucositis (0 to 5). The G2 received no treatment. The negative control group (G3) received no mucositis induction. The cheek pouches of 8 animals (G1 and G2) were dissected for histopathological examination on days 5, 9, 13 and 15. The statistical analysis showed significant differences between treated and non-treated groups (p<0,05), although histopathological findings have demonstrated muscular degeneration in 18% of the sample (G1), approximately. These results pointed out that LED therapy protocol established for this study was effective to reduce the severity of oral mucositis and accelerated the healing process, although it has not completely prevented the appearance of oral lesions. / Orientador: Fabio Cesar Braga de Abreu e Lima / Coorientador: Carlos Alberto de Souza Costa / Banca: Elisa Maria Aparecida Giro / Banca: Rosane de Fátima Zanirato Lizarelli / Mestre

Resumo: A cavidade oral é alvo freqüente dos efeitos tóxicos dos agentes antineoplásicos por apresentar tecidos com rápida divisão celular, comparável à dos tumores malignos. Uma das complicações orais mais freqüentes da quimioterapia é a mucosite, uma alteração de caráter inflamatório para a qual ainda não existe tratamento definido. Essa complicação oral provoca desconforto e dor severa, dificulta a alimentação e pode determinar a interrupção do tratamento antineoplásico. Considerando-se a relevância clínica da mucosite, é importante encontrar meios para tratá-la. O presente estudo teve como objetivo avaliar o efeito do laser terapêutico na redução da incidência e da severidade da mucosite induzida em hamsters. O quimioterápico 5-FU foi aplicado em 60 animais nos dias 0 e 2 do experimento, nas doses de 90 e 60 mL/Kg de peso, respectivamente. Para simular o efeito de uma irritação crônica, as mucosas jugais dos animais foram escarificadas nos dias 3 e 4. Aplicou-se o laser terapêutico (InGaAlP, 683 nm, 12 J/cm2) em 5 pontos da mucosa jugal direita e esquerda de 30 animais (Grupo I), durante 7 dias. Os animais do Grupo II não receberam tratamento. O Grupo III (controle negativo) foi composto por 5 animais que não receberam o protocolo de indução de mucosite. Nos dias 0, 4, 8, 12 e 15 do experimento, as mucosas de 6 animais dos Grupos I e II foram removidas para avaliação histopatológica. A partir de fotografias tiradas diariamente, a mucosite foi classificada clinicamente. O teste de Mann-Whitney demonstrou haver diferenças estatisticamente significantes (p<0,05) entre o grupo tratado com laser e o grupo não tratado quando se comparou, clinica e histopatologicamente, a intensidade da mucosite induzida. Concluiu-se que a aplicação do laser de baixa intensidade, nos parâmetros determinados para este estudo, promoveu a redução... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: Toxic and dose-limiting effects of antineoplastic agents in oral cavity are frequently observed during cancer therapy. The available therapies are not able to destroy tumor cells without causing damage to the rapid dividing cells in normal tissues like the epithelial cells in the oral mucosa. Mucositis is the most debilitating side effect, for which there is no established treatment. This oral complication restricts intake of food and liquids, causes discomfort, severe pain and may determine interruption of the cancer therapy, interfering on the disease control. Considering the clinical significance of mucositis, it is important to find ways to treat this condition. The present study was conducted to evaluate the laser therapy effects on prevention or reduction of chemotherapy-induced mucositis in hamsters. Mucositis was induced in 60 animals with intraperitoneal injections of 5-fluorouracil (5-FU) on days 0 and 2, associated with cheek pouches scarification on days 3 and 4. Thirty animals (Group I) received laser irradiation at five points in each cheek pouch, for seven consecutives days. Laser parameters were set to 685 nm, 12 J/cm2 and 30 mW. Other 30 animals (Group II) received no treatment. In Group III, 5 animals represented the baseline control. The cheek pouches of 6 animals from Groups I and II were dissected for histophatological examination on days 0, 4, 8, 12, and 15. Daily photographs were taken and mucositis was clinically scored. The nonparametric test of Mann-Whitney showed statistical difference between treated and nontreated group (p<0.05). It was concluded that the low intensity laser therapy protocol established for this study reduced the severity of oral mucositis and accelerated the healing process, although it has not prevented the appearance of oral manifestations. / Orientador: Fabio César Braga de Abreu e Lima / Coorientador: Carlos Alberto de Souza Costa / Banca: Elaine Maria Sgavioli Massucato / Banca: Luciane Almeida Lopes / Mestre

No description available.

Les cellules cancéreuses produisent une grande quantité de ribosomes afin de synthétiser les protéines nécessaires à leur prolifération rapide. Les mécanismes qui conduisent à cette augmentation de la production de ribosome ne sont que partiellement compris, mais ils semblent intimement liés à l'acquisition du phénotype tumoral. De plus, une nouvelle théorie propose que les ribosomes ne sont pas des effecteurs neutres de la traduction, mais qu'ils jouent un rôle direct dans la régulation de l'expression génique. Cette théorie se base sur l'observation que la composition des ribosomes est hétérogène en fonction des types cellulaires et des conditions environnementales. Dans ce contexte, j'ai étudié les liens entre les altérations des signaux qui contrôlent la biogenèse des ribosomes, tant au niveau quantitatif que qualitatif, et le développement du phénotype tumoral. Ce manuscrit rapporte trois études effectuées au cours de mon travail de thèse. Ces études ont permis d'identifier : i) un nouveau régulateur de la quantité de ribosomes, la LN-Nétrine-1 et ii) des modifications de la composition et de la fonction des ribosomes induites par des altérations génétiques (perte d'activité de p53) et par l'utilisation d'une molécule chimiothérapeutique, le 5- Fluorouracile. Ces perturbations de la quantité et de la fonction des ribosomes modifient le contrôle de la traduction des cellules et la croissance, la prolifération et la survie cellulaire. Il ressort de ces résultats que les ribosomes sont des éléments qui participent au contrôle de l'expression génique et qui jouent un rôle dans la pathologie cancéreuse et la réponse au traitement chimiothérapeutique / Cancer cells produce large amounts of ribosomes to synthesize the proteins required for their rapid proliferation. The mechanisms leading to this increase in ribosome production are only partly understood, but they are related to the acquisition of the tumor phenotype. In addition, a new theory proposes that ribosomes are not neutral effectors of translation, but have a direct role in the regulation of gene expression. This theory is based on the observation that ribosome composition is heterogeneous in different cell types and according to environmental conditions. In this context, I have analyzed the relationships between changes in signals that control ribosome biogenesis, both quantitatively and qualitatively, and the development of the tumor phenotype. This manuscript reports three studies made during this PhD program. These studies identified: i) a novel regulator of the amount of ribosomes, the LN-Netrin-1 and ii) changes in the ribosome composition and function induced by genetic alterations (loss of activity of p53) and by the use of a chemotherapeutic molecule, the 5-Fluorouracil. These perturbations of the amount and the function of ribosomes modify the translation control and cell growth, cell proliferation and cell survival. From these results it can be conclude that ribosomes are elements involved in the regulation of gene expression and play a role in cancer pathology and response to chemotherapy

(thesis): Palmar-plantar erythrodysesthesia (PPE) frequently accompanies the therapy with a continuous 5-FU infusion or peroral capecitabine (5-FU prodrug). In the most severe cases this adverse effect leads to discontinuation of a needful therapy. Local 10 % uridine ointment is used to prevent and treat the said adverse event. Nevertheless, this method is not generally accepted as an effective one because it has never been proved in a randomized controlled clinical trial. Most probably, a direct effect of a cytostatic compound on the skin of hands and foots causes PPE. The toxicity of 5-FU is mediated primarily by its incorporation into RNA and by thymidylate synthase (TS) inhibition and subsequent DNA synthesis disruption. The importance of particular 5-FU toxicity mechanisms varies in different cell types. For choosing the best PPE local antidote it is necessary to find out which molecular mechanism applies in keratinocytes. We have chosen pyrimidine nucleosides as the most suitable compounds for the local PPE therapy because the uridine ointment is already being used in several oncology centers in the Central Europe. In order to find out the 5-FU toxicity mechanism, we further tested the effect of calciumfolinate (CF) which strengthens the TS inhibition by 5-FU. We studied also uracil and...