Dissertation (Ph.D.)--University of South Florida, 2009. / Includes vita. Includes bibliographical references. Also available online.

Dissertation (Ph.D.)--University of South Florida, 2009. / Title from PDF of title page. Document formatted into pages; contains 103 pages. Includes vita. Includes bibliographical references.

Danos teciduais de qualquer natureza desencadeiam uma série de eventos que irão promover a regeneração ou a cicatrização do tecido lesado. Este reparo é um processo complexo que envolve a interação de diversos tipos celulares que são ativados por uma vasta gama de mediadores químicos, componentes da matriz extracelular, microorganismos e alterações físico químicas no microambiente da lesão e das áreas adjacentes. A participação do fator de crescimento endotelial vascular (VEGF) e de seus dois principais receptores (VEGFR-1 e -2) é de grande importância nos processos de cicatrização levando-se em conta a neovascularização. Após uma análise circunstanciada da literatura sobre os efeitos da radioterapia na neovascularização e a relação com a expressão do VEGF e VEGFR-1 e -2 na cicatrização observou-se que ainda há uma série de questões a serem investigadas. O objetivo desse projeto de pesquisa é estudar a expressão imuno-histoquímica do VEGF e VEGFR-1 e -2 e a densidade vascular sanguínea (DVS) após incisão e reparação cutânea em animais sob influência da radioterapia e em um período de aproximadamente seis meses. Neste estudo foram utilizados 60 ratos da linhagem Wistar distribuídos aleatoriamente em seis grupos (controle 3 e 6 meses, radioterapia pré-cirúrgica 3 e 6 meses, radioterapia pós-cirúrgica 3 e 6 meses). Após a eutanásia dos animais de acordo com os princípios bioéticos, foram retirados os espécimes alvo que foram avaliados macro e microscopicamente. O estudo imuno-histoquímico dos VEGFs foram realizados usando os anticorpos específicos supracitados nas diluições especificadas pelo fabricante, enquanto o estudo do DVS foi realizado com o anticorpo Von Willebrand Factor (VWF) que foi utilizado para marcar especificamente as células endoteliais. Nos períodos de tempo estudados, evidenciou-se a expressão significativa destes fatores de crescimento no tecido, na maioria dos casos. Os casos primeiramente irradiados apresentaram celularidade bizarra, com células gigantes e multinucleadas, estruturas do estroma hialinizadas e necrose imunomarcadas de moderada a forte para receptores de VEGF no endotélio e vasos sanguíneos. Essas características são consistentes com a literatura, uma vez que a forte relação do VEGFR-2 e a sua persistência na neovascularização e formação de tecido de granulação foram evidenciados. Os resultados mostraram que a expressão de VEGF é constantemente expressa em diferentes tempos da cicatrização de feridas e formação de cicatriz / Tissue damages of any nature unchain a series of events that will promote regeneration or healing of the injured tissue. This repair is a complex process that involves the interaction of various cells types. These cells are activated by a vast gamma of chemical mediators of the extracellular matrix, microorganisms and chemical and physical alterations in the injury microenvironment and adjacent areas. The participation of vascular endothelial growth factors (VEGF) and their two main receptors (VEGFR-1 and -2) has great importance in the healing process considering neovascularization. After a detailed analysis of the literature about radiotherapy effect in neovascularization and its relation with the expression of VEGF and VEGFR-1 and -2 in the healing, it was observed that there are many questions to be investigated. The objective of this study was to evaluate the immunohistochemical expression of VEGF and VEGFR-1 and -2 and sanguineous vessel density (DVS) after incision and cutaneous repairing in animals under influence of the radiotherapy at three and six months. This study used 60 Wistar rats randomly distributed in six groups: control, preoperative radiotherapy and postoperative radiotherapy, of 3 and 6 month each. The specimens evaluated macro/microscopically were removed after animal\'s sacrifice, in accordance to clinical ethics principles. The immunohistochemistry study of VEGFs were conducted using above-mentioned specific antibodies in manufacturer specified dilutions, while the study of the DVS was performed with the Von Willebrand Factor antibody (VWF) which was used to mark endothelial cells specifically. In both periods studied, surgical wound and radiation damages are similar in most cases. The primarily irradiated cases presented bizarre cellularity, multinucleated giant cells, stromal hyalinization structures, moderate to strong necrosis, overexpression of VEGF receptors in the endothelium and blood vessels in consequence of radiotherapy. These findings are in accordance to the literature, since the strong relationship between VEGFR-2 receptor and its persistence in neovascularization and granulation tissue formation were seen. Our results have shown that VEGF expression is constantly expressed in different times of wound healing and scar formation

Há um número crescente de pessoas e animais com obesidade e sobrepeso, com consequente aumento no número de pacientes resistentes à insulina e portadores de Diabetes mellitus (DM). O fator de crescimento vascular endotelial (VEGF) tem sido caracterizado como uma molécula importante em inúmeros mecanismos fisiopatológicos. Em diabéticos, pesquisas indicam uma redução deste fator em alguns tecidos estudados, sendo esta menor expressão envolvida com o desenvolvimento de hipóxia tecidual e não cicatrização de feridas. Neste contexto, este trabalho teve como objetivos caracterizar um modelo diabético induzido por dieta, avaliar a vascularização, expressão gênica e proteica do VEGFA e seus receptores FLT1 e KDR em pâncreas de camundongos diabéticos e não diabéticos, antes e após a terapia gênica com VEGF. O estudo consistiu de 2 fases para as quais foram utilizados cinquenta camundongos, na primeira fase foram utilizados 28 animais distribuídos em 6 grupos experimentais: submetidos à dieta controle (CT) e dieta hipercalórica (DH) por 3, 4 e 6 meses. Na segunda fase, 4 grupos experimentais foram avaliados aos 4 meses: CT e DH sem vetor terapêutico (CTPLL e DHPLL) e CT e DH com vetor terapêutico (CTVEGF e DHVEGF). A análise gênica pelo PCR em tempo real e proteica pela imuno-histoquímica evidenciou queda na expressão de VEGF, FLT1 e KDR no grupo DH, sendo que a variável estereológica de densidade de volume vascular (Vv) indicou queda significativa (p<0,05) da vascularização pancreática no grupo DH em relação ao CT aos 3, 4 e 6 meses do estudo. O DM foi caracterizado com queda significativa (p<0,05) na insulinemia após 4 meses com DH. Após a injeção pancreática no grupo DHVEGF do lentivírus contendo a sequência que condifica o VEGF, foram observados aumento na expressão gênica de VEGF , FLT1 e KDR (p<0,05), com aumento de Vv vascular pancreático e aumento na insulinemia. Os resultados obtidos sugerem que é possível obter um modelo animal diabético induzido por dieta, que o VEGF e seus receptores participam da evolução e estabelecimento do quadro diabético, levando a uma redução da vascularização pancreática, e que o aumento na expressão do transgene no pâncreas de camundongos diabéticos possa contribuir para a revascularização pancreática e função das células B. / There is an increasing number of people and pets showing overweight and obesity, with a consequent growth of the number of insulin-resistant and diabetic patients. The vascular endothelial growth factor (VEGF) has been characterized as an important molecule in many physiopathological states. Recent studies indicate a reduction in VEGF content in some tissues of diabetic patients causing tissue hypoxia and impairing cicatrization. In this context, this study aimed to characterize a diet-induced diabetic animal model and to evaluate vascularization, gene and protein expression of VEGFA and its receptors KDR and FLT1, in pancreas of diabetic and non-diabetic mice before and after gene therapy with VEGF. The study was divided in two phases and fifty male mice were used. In the first phase 28 animals were distributed into 6 groups: control diet (CT) and high calorie diet (DH) for 3, 4 and 6 months. In the second phase, four experimental groups were evaluated at 4 months: CT and DH without therapeutic vector (CTPLL and DHPLL) and CT and DH with therapeutic vector (CTVEGF and DHVEGF). The genetic analysis using real time PCR and protein by immunohistochemistry showed decrease in expression of VEGF, FLT1 and KDR in the DH group, and the stereological estimate of vascular volume density (Vv) indicated a significant decrease (p <0,05 ) of vascularization in pancreatic DH group relative to the CT at 3, 4 and 6 months of the study. Diabetic mice were characterized with a significant decrease (p <0,05) in insulin after 4 months with DH. After injection of lentivirus containing the VEGF sequence in DHVEGF´s pancreas, increase in VEGF, FLT1 and KDR gene expression (p <0.05) was observed, accompanied by the increase of vascular Vv and insulinemia. The results suggest that it is possible to obtain a diabetic animal model induced by diet, that VEGF and its receptors participate in the development and establishment of the diabetic state, leading to a reduction of pancreas vascularization, and that the increase of transgene expression in the pancreas of diabetic mice may contribute to the revascularization and function of pancreatic B cells.

Objetivo: Avaliar os efeitos da panfotocoagulação a laser (PRP) comparando com a PRP associada com injeção de 0,5 mg de ranibizumabe intravítreo (IVR) em pacientes com retinopatia diabética proliferativa (RDP) com características de alto risco. Métodos: Estudo prospectivo incluindo pacientes portadores de RDP de alto risco sem tratamento prévio, distribuídos aleatoriamente em dois grupos: grupo PRP e grupo PRPplus. Avaliações oftalmológicas padronizadas, incluindo melhor acuidade visual corrigida (MAVC), de acordo com o Early Treatment Diabetic Retinopathy Study (ETDRS), medidas da área de vazamento de fluoresceína na angiofluoresceinografia (FLA), medida da espessura do subcampo macular (ESM) na Tomografia de Coerência Óptica (OCT) foram realizadas na visita inicial e nas semanas 16 (±2), 32 (±2) e 48 (±2), além de eletrorretinograma (ERG) de campo total, realizado na visita inicial e na semana 48 (±2). Resultados: Vinte e nove de 40 pacientes (n=29) completaram as 48 semanas do estudo. Na visita inicial, a média ± erro-padrão da média (EPM) de FLA (mm2) foi de 9,0 ± 1,3 e 11,7 ± 1,3 (p=0,1502); MAVC (logMAR), 0,31 ± 0,05 e 0,27 ± 0,06 (p=0,6645) e ESM (µm), 216,3 ± 10,7 e 249,4 ± 36,1 (p=0,3925), nos grupos PRP e PRPplus, respectivamente. Foi notada significativa (p<0,05) redução na FLA em todas as visitas do estudo em ambos os grupos; porém significativamente maior no grupo PRPplus, em relação ao grupo PRP, no final da visita 48 (PRP = 2.9 ± 1.3 mm2; PRPplus = 5.8 ± 1.3 mm2; p = 0.0291). Observou-se piora na MAVC em todas as visitas após o tratamento no grupo PRP (p<0,05), enquanto que no grupo PRPplus não foram encontradas mudanças na MAVC. Aumento significativo na ESM foi observado em todas as avaliações do estudo no grupo PRP e significativa diminuição na ESM foi detectada na semana 16 do grupo PRPplus, e não foi encontrada diferença significativa, em relação à visita inicial, nas semanas 32 e 48. Quanto ao ERG, foi notada significativa diminuição na amplitude da onda-b dos bastonetes para 46 ± 5% (p<0,05) do valor da visita inicial no grupo PRP e para 64 ± 6% no grupo PRPplus. Essa regressão foi significativamente maior no grupo PRP do que no grupo PRPplus (p=0,024). Resultados similares foram observados para resposta máxima combinada (MC) da amplitude da onda-b, com redução na semana 48, comparada com a visita inicial, de 45 ± 4% no grupo PRP e 62 ± 5% no grupo PRPplus. A diminuição deste parâmetro foi significativamente maior no grupo PRP do que no grupo PRPplus (p=0,0094). A MC da amplitude da onda-a, os potenciais oscilatórios (PO) e a resposta ao flicker de 30 Hz mostraram redução estatisticamente significativa na análise intragrupos, mas sem diferenças na análise entre os grupos. Conclusão: Após a PRP foi associado IVR com maior redução na FLA na semana 48, comparado com PRP isoladamente, em olhos com RDP de alto risco, sendo que o uso adicional de IVR à PRP parece proteger contra discreta perda de acuidade visual e espessamento macular observado em olhos tratados com PRP isoladamente. Na análise do ERG, resultados sugerem que o tratamento de RDP de alto risco com PRP associado com IVR é efetivo para o controle da RDP e permite menor uso do laser, que, consequentemente, leva à perda funcional menor da retina do que o tratamento com PRP isoladamente. / Objective: To evaluate the effects of panretinal photocoagulation (PRP) compared with PRP plus intravitreal injection of 0.5 mg of ranibizumab (IVR) in patients with high-risk proliferative diabetic retinopathy (PDR). Methods: Prospective study included patients with high-risk PDR and no prior laser treatment randomly assigned to receive PRP (PRP group) or PRP plus IVR (PRPplus group). Standardized ophthalmic evaluations including best-corrected visual acuity (BCVA) measured according to the methods used in the Early Treatment Diabetic Retinopathy Study (ETDRS), fluorescein angiography to measure area of fluorescein leakage (FLA) and optical coherence tomography (OCT) for the assessment of central subfield macular thickness (CSMT), were performed at baseline and at weeks 16 (±2), 32 (±2) and 48 (±2). Eletroretinographic (ERG) was measured according to ISCEV standards at baseline and at week 48 (±2). Results: Twenty-nine of 40 patients (n = 29 eyes) completed the 48-week study follow-up period. At baseline, mean ± SE FLA (mm2) was 9.0 ± 1.3 and 11.7 ± 1.3 (p = 0.1502); BCVA (logMAR) was 0.31 ± 0.05 and 0.27 ± 0.06 (p = 0.6645); and CSMT (µm) was 216.3 ± 10.7 and 249.4 ± 36.1 (p = 0.3925), in the PRP and PRPplus groups, respectively. There was a significant (p < 0.05) FLA reduction at all study visits in both groups, with the reduction observed in the PRPplus group significantly larger than that in the PRP group at week 48 (PRP = 2.9 ± 1.3 mm2; PRPplus = 5.8 ± 1.3 mm2; p = 0.0291). Best-corrected visual acuity worsening was observed at 16, 32 and 48 weeks after treatment in the PRP group (p < 0.05), while no significant BCVA changes were observed in the PRPplus group. A significant CSMT increase was observed in the PRP group at all study visits, while a significant decrease in CSMT was observed in the PRPplus group at week 16, and no significant difference in CSMT from base- line was observed at weeks 32 and 48. ROD b-wave amplitude was significantly reduced to 46 ± 5 % (p<0.05) of baseline in the PRP group and 64±6% (p<0.05) in the PRPplus group. This reduction was significantly larger in the PRP group than in the PRPplus group (p=0.024). Similar results were observed for the dark-adapted Combined Response (CR) b-wave amplitude, with a reduction at 48 weeks compared to baseline of 45 ± 4 % in the PRP group and 62 ± 5 % in the PRPplus group; the reduction in CR b-wave amplitude was significantly larger in the PRP group than in the PRPplus group (p=0.0094). CR a-wave, oscillatory potentials, cone single flash, and 30 Hz flicker responses showed statistically significant within-group reductions, but no differences in between-group analyses. Conclusions: Intravitreal ranibizumab after PRP was associated with a larger reduction in FLA at week 48 compared with PRP alone in eyes with high-risk PDR, and the adjunctive use of IVR appears to protect against the modest visual acuity loss and macular swelling observed in eyes treated with PRP alone. In ERG analyses, the results suggest that treating high-risk PDR with PRP plus IVR is effective for PDR control, and permits the use of less extensive PRP which, in turn, induces less retinal functional loss, than treatment with PRP alone.

To this day heart failure with preserved ejection fraction (HFpEF) remains a poorly understood malady. Half of all heart failure (HF) cases are HFpEF, and the prevalence of HF is on the rise. Unlike HF with reduced ejection fraction, HFpEF has no treatment options and is often times difficult to diagnose because victims of HFpEF often have pre-existing conditions. Vascular endothelial growth factor (VEGF) has been implicated in maintaining myocardial health and is thought to play a role in HFpEF. We sought to test the hypothesis that VEGF-A plays a role in HFpEF in a hypertensive murine model of HFpEF. Using Western blot analysis we found that there was an up regulation of VEGF-A in the homogenized left ventricle (LV) of our HFpEF mice. Unexpectedly, there was a down regulation of VEGF-A in the homogenized tissue from the aorta in those mice. To study the circulating levels of VEGF in our HFpEF mice we used an ELISA. We found that our HFpEF mice had similar levels of circulating VEGF as our control. This suggests that VEGF has paracrine/autocrine role in our HFpEF model rather than endocrine, like our human data suggested. To identify the cells responsible for the expression profile we saw in the homogenized tissue data we looked at the response of adult rat ventricular myocytes (ARVM) and vascular smooth muscle cells (VSMC) to aldosterone stimulation at short (1hr) and long (24hr) time points at both physiological (50nm) and pathological (1μm) concentrations. To do this analysis we recruited the help of Western blot, ELISA and RT-PCR techniques to construct a consistent VEGF expression profile. The Western blot ARVM data showed statistically significant (P<0.05) increase in VEGF-A to pathological doses of aldosterone, especially at the longer time point. When we tested the VSMC using Western blot analysis, we found that the trend of our n=1 sample suggested a strong response to the physiological dose of aldosterone in the short term. Using the more sensitive ELISA technique to measure the VEGF content of our VCMS we increasing our sample size to n=4 and found no statistically significant (p=NS) response to aldosterone stimulation from the VSMC. However, looking at the trends in the data it is clear that VSMC increases VEGF in response to long-term physiological doses of aldosterone. This is contrary to what we found using Western blot analysis, so we queried the VEGF mRNA from the VSMC to settle the score. Unfortunately, this too proved fruitless. The RT-PCR data was not significant and the trend was that of the ARVM expression profile. We initially turned to VSMC because we hypothesized that they could contribute to the paracrine/autocrine activity similar to what we saw in the LV from the ARVM. It is unclear if VSMC play a role in HFpEF progression, but their lack of consistent response to aldosterone could potential explain the down regulation of VEGF-A we observed in the aorta of our HFpEF mice. We initially sough to test the hypothesis that VEGF-A plays a role in our HFpEF mouse model, what we found was that ARVM contribute to localized VEGF-A increased production in the LV while in the aorta there is a down regulation of VEGF-A in our HFpEF model, we are unable to make any conclusion about VSMC response to aldosterone because of insufficient sample size. Thus in conclusion, it appears that VEGF-A does play a role in our HFpEF model specifically in a paracrine/autocrine manner in the LV where the ARVM contributes to the increased production of the cytokine.

Introdução: A Organização Mundial da Saúde estimou para o ano de 2008 aproximadamente 1.38 milhões de casos novos de câncer de mama no mundo e 458 mil mortes. A maioria dos casos (56%) e das mortes (64%), ocorrendo em países economicamente desenvolvidos. Apesar dos avanços e do diagnostico precoce, um número significativo de mulheres com tumores da mama operáveis apresentando evolução desfavorável vêm à sucumbir devido ao surgimento de doença metastática. Uma melhor compreensão da heterogeneidade do tumor e das características microambientais subjacentes, bem como dos mecanismos e as consequências das suas interações é essencial para melhorar o direcionamento das terapias existentes e desenvolver novos agentes terapêuticos para o câncer. Objetivos: Descrever as características clínicas, anatomopatológicas e imuno-histoquímicas de um grupo de pacientes com câncer de mama operável, e estudar o impacto destas características no estadiamento da doença, sobrevivência livre de recorrência e sobrevivência global. Além disto, analisar as potenciais correlações existentes entre estas características. Métodos: Estudo de coorte retrospectiva de base hospitalar envolvendo 86 mulheres com câncer primário de mama, submetidas a tratamento entre julho de 1999 e dezembro de 2004, no Serviço de Mastologia do Hospital de Clinicas de Porto Alegre. Dados clinicopatológicos e imuno-histoquimicos (RE, RP, HER2, Ki67 e p53) foram coletados dos registros hospitalares. Expressão do VEGF, MMP-2, MMP-9, TIMP-1 e TIMP-2 foram analisadas através de imuno-histoquimica. Variáveis contínuas foram analisadas pelo coeficiente de correlação de Spearman, ou pelo teste não paramétrico U de Mann-Whitney e H de Kruskal-Wallis, quando comparadas com variáveis categóricas. Variáveis categóricas foram analisadas pelo teste 2 de Pearson. Estimativas da probabilidade de sobrevivência foram obtidas pelo estimador não paramétrico de Kaplan-Meier e pelo semiparamétrico modelo de regressão de Cox. Comparação entre as curvas de sobrevivência foi realizada pelo teste estatístico de log-rank. O IC foi calculado em 95% e valores p< 0,05 foram considerados estatisticamente significativos. Resultados: A sobrevivência livre de recorrência em 5 e 10 anos foi de 82,2% e 68%, e a global foi de 90,2% e 82,9%, respectivamente. Número de linfonodos positivos (p= 0,00; p= 0,03), diâmetro tumoral (p= 0,01; p= 0,01) e estádio (p= 0,00; p= 0,02) são fatores de risco isolado para recorrência e óbito, respectivamente. Superexpressão de HER2 é um fator de risco isolado para recorrência (p= 0,04). Existe uma correlação positiva significativa entre: VEGF e MMP-9 (rs: 0,246; p= 0,023); TIMP-2 e MMP-2 (rs: 0,358; p= 0,001). Também foram encontradas associações significativas entre as variáveis: a) VEGF e receptor de progesterona positivo (p= 0,045); b) TIMP-2 e idade ≥ 50 anos (p= 0,002), e diâmetro ≤ 2,0 cm (p= 0,016); c) TIMP-1 e menarca ≤ 12 anos (p= 0,038); d) Maior diâmetro e alto grau histológico (2: 19,3; p= 0,004), invasão vascular (2: 12,6; p= 0,006), status do linfonodo axilar (2: 8,6; p= 0,035), número de linfonodos metastáticos (2: 7,2; p= 0,028), e recidiva a distancia (2: 4,0; p= 0,046); e) Invasão vascular e status do linfonodo axilar, e número de linfonodos metastáticos, ambos com 2: 24,7; p= 0,000. Conclusões: O número de linfonodos positivos, diâmetro tumoral, e estádio foram identificados como fatores de risco isolado para a ocorrência de recidiva e óbito. A superexpressão de HER2 é fator de risco isolado para a ocorrência de recidiva da doença. Novas pesquisas devem ser realizadas, com padronização de procedimento e um maior número de casos para melhor caracterização da doença. / Background: The World Health Organization estimated approximately 1.38 million new breast cancer cases and 458,000 deaths worldwide for 2008. Most of these (56% of new cases and 64% of deaths) occur in economically developed countries. In Brazil, approximately 52,000 new cases are predicted for 2013. Better understand the heterogeneity of the tumor and microenvironmental characteristics around you, as well as the mechanisms and consequences of their interactions is essential to improve the targeting of existing therapies and develop new therapeutic agents for cancer. Objectives: The aim of this study was to describe the clinical, anatomopathological and immunohistochemical characteristics of a group of patients with operable breast cancer, and investigate the impact of these characteristics on disease staging, disease-free survival and overall survival. In addition, the potential correlations between these characteristics were analyzed. Methods: This is a hospital-based retrospective cohort study of 86 women with primary breast cancer, subjected to surgical and adjuvant treatment between July 1999 and December 2004. Clinicopathological and immunohistochemical (ER, PR, HER2, Ki67 e p53) data were collected from hospital records. The expression of VEGF, MMP-2, MMP-9, TIMP-1 and TIMP-2 was analyzed using the immunohistochemical technique. Continuous variables were assessed with Spearman’s rank correlation coefficient, or the non-parametric Mann-Whitney U or Kruskal-Wallis H tests. Pearson’s 2 test was employed to asses categorical variables. The possibility of survival was estimated using the non-parametric Kaplan-Meier estimator and the semiparametric Cox regression model. Survival curves were compared using the statistical log-rank test. CI was calculated at 95% and p values <0.05 were considered statistically significant. Results: Disease-free survival at 5 and 10 years was 82.2% and 68%, and overall survival 90.2% and 82.9%, respectively. Number of positive lymph nodes (p= 0.00; p= 0.03), tumor diameter (p= 0.01; p= 0.01) and stage (p= 0.00; p= 0.02) were isolated risk factors for relapse and death, respectively. HER2 overexpression was an isolated risk factor for relapse (p= 0.04). There was a significant positive correlation between: VEGF and MMP-9 (rs: 0.246; p= 0.023) and TIMP-2 and MMP-2 (rs: 0.358; p= 0.001). Significant associations were also recorded between the following variables: a) VEGF and progesterone receptor-positive status (p= 0.045); TIMP-2 and age ≥ 50 years (p= 0.002) and diameter ≤ 2.0 cm (p= 0.016); c) TIMP-1 and menarche ≤ 12 years (p= 0.038); d) greater diameter and high histologic grade (2: 19.3; p= 0.004), vascular invasion (2: 12.6; p= 0.006), axillary lymph node status (2: 8.6; p= 0.035), number of metastatic lymph nodes (2: 7.2; p= 0.028) and distant relapse (2: 4.0; p= 0.046); e) vascular invasion and axillary lymph node status and number of metastatic lymph nodes, both with 2: 24.7 and p= 0.000. Conclusion: Number of positive lymph nodes, tumor diameter, and stage were identified as isolated risk factors for relapse and death. HER2 overexpression is an isolated risk factor for the occurrence of relapse. Further studies are needed, with standardization of the procedure and a larger number of cases, for better characterization of the disease.

Vascular Endothelial Growth Factor (VEGF) is a highly conserved ligand that is involved in the regulation of angiogenesis and vasculogenesis, however, alternative roles of the ligand have been emerging. Organisms such as jellyfish and Drosophila contain VEGF homologs, yet they do not possess endothelial cells or a vascular system indicating that VEGF might have other primitive roles. In this current study we investigated how VEGF affects the post-natal development of the intestinal epithelial by either overexpressing VEGF or by reducing the bioavailability of VEGF with the overexpression of soluble VEGF receptor (sFLT-1) within the gastrointestinal tract. After three weeks of VEGF overexpression, mutant mice displayed an increase in villus height and proliferation in the transit-amplifying zone with the decrease of crypts per measured length and Lgr5 expression. On the other hand, sFLT-1 overexpressing mice had an increase in crypt depth with a decrease in villus height, proliferation in the transit-amplifying zone, crypts per measured length and reduced expression of Dll1 and Bmp4. Overall the availability of VEGF has the ability to alter the proliferation of progenitor cells in the crypt by either a direct or indirect signals. These studies reveal that by some means VEGF is altering the developing post-natal intestinal epithelium and proliferation. Largely, elucidating the interaction between VEGF and intestinal stem cells in intestinal development and differentiation may help to advance intestinal stem cell therapies in intestinal dysfunction or disease

In der vorliegenden Arbeit wurde das Expressionsverhalten fünf zellulärer Marker beim metastasierenden Plattenepithelkarzinom des Kopf- und Halsbereiches untersucht. Bei den getesteten Markern handelte es sich um einen MAGE-A, zwei verschiedenen VEGF, einen EGFR und einen C-Src-Tyrosinkinase Antikörper. Im Einzelnen sollte hinterfragt werden, ob ein Zusammenhang zwischen der Antikörperexpression und verschiedenen, klinischen und histopathologischen Parametern (pT-Stadium, pN-Stadium, histologisches Grading, Tumorverhornung, Patientenalter, Geschlecht des Patienten) besteht. Weiterhin war von Interesse, ob Parallelen zwischen dem Expressionsverhalten der verschiedenen Antikörper untereinander zu erkennen sind. Die Ergebnisse wurden anschließend mit Erkenntnissen aus anderen Studien und Literaturangaben verglichen. / This study aimed to evaluate the expression profiles of cellular marker in metastatic head and neck cancer in the primary tumor and in the metastases. The expression profiles of MAGE-A, VEGF-A, VEGF-C, EGFR and c-Src in 50 squamous cell carcinoma were characterised by immunhistochemical stainig.

Dissertation (Ph.D.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 154 pages. Includes vita. Includes bibliographical references.