<p>Lymph nodes are organs of efficiency. Once activated, they essentially function to optimize and accelerate the production of the adaptive immune response, which has the potential to determine survival of the host during an initial infection and protect against repeated infections, should specific and appropriate immunological memory be sufficiently induced. We now have an understanding of the fundamental structure of lymph nodes and many of the interactions that occur within them throughout this process. Yet, lymph nodes are dynamic and malleable organs and much remains to be investigated with regards to their responses to various types of challenges. In this work, we examined multiple inflammatory scenarios and sought to understand the complex ways that lymph nodes can be externally targeted to impact immunity. First, we outline a novel mechanism of cellular communication, where cytokine messages from the periphery are delivered to draining lymph nodes during inflammation. These signals are sent as particles, released by mast cells, and demonstrate the ability of the infected tissue to communicate to lymph nodes and shape their responses. Based on these interactions, we also explored the ability to therapeutically or prophylactically modulate lymph node function, using bioengineered particles based on mast cell granules, containing encapsulated cytokines. When we used these particles as a vaccine adjuvant, we were able to polarize adaptive immune responses, such as to promote a Th1 phenotype, or enhance a specific attribute of the immune response, such as the production of high avidity antibodies. We then explore three examples of lymph node-targeting pathogens: Salmonella typhimurium, Yersinia pestis and Dengue virus. Each of these pathogens has a well-characterized lifecycle including colonization of draining lymph node tissue. In the case of S. typhimurim, we report that the virulence this pathogen depends on a specific shut down of the chemotactic signals in the lymph node that are required to maintain appropriate cellular localization within it. Our results demonstrate that these architecture changes allow S. typhimurim to target the adaptive immune process in lymph nodes and contribute to its spread in vivo and lethality to the host. With Y. pestis, similar targeting of cellular trafficking pathways occurs through the modulation of chemokine expression. Y. pestis appears to use the host's cellular trafficking pathways to spread to lymph nodes in two distinct waves, first exploiting dendritic cell movement to lymph nodes and then enhancing monocyte chemoattractants to replicate within monocytes in draining lymph nodes. These processes also promote bacterial spread in vivo and we further demonstrate that blocking monocyte chemotaxis can prolong the host's survival. In the third example of pathogen challenge, we report for the first time that mast cells can contribute functionally to immunosurveillance for viral pathogen, here, promoting cellular trafficking of innate immune cells, including NK cells, and limiting the spread of virus to draining lymph nodes. For each of these three examples of lymph node targeting by microbial pathogens, we provide data that modulation of cellular trafficking to and within lymph nodes can drastically influence the nature of the adaptive immune response and, therefore, the appropriateness of that response for meeting a unique infectious challenge. Cumulatively this work highlights that a balance exists between host and pathogen-driven modulation of lymph nodes, a key aspect of which is movement of cells within and into this organ. Cytokine and chemokine pathways are an area of vulnerability for the host when faced with host-adapted pathogens, yet the lymph node's underlying plasticity and the observation that slight modulations can be beneficial or detrimental to immunity also suggests the targeting of these pathways with therapeutic intentions and during vaccine design.</p> / Dissertation

Accurate detection of the spread of cancer is critical for planning the best treatment strategy for a patient. Currently, an invasive sentinel lymph node biopsy is commonly used to detect metastases after a primary tumor is detected. This procedure results in patient morbidity, requires weeks of waiting, and is prone to sampling error. This dissertation presents new developments in an emerging biomedical imaging modality – photoacoustic imaging – and their application to improving the detection of metastases in the lymphatic system in a metastatic mouse model of squamous cell carcinoma of the oral cavity. Label-free spectroscopic photoacoustic imaging is demonstrated to detect hypoxia that results from the development of sub-millimeter cancer foci in the lymph node. In order to improve the sensitivity to micrometastases, molecularly-activated plasmonic nanosensers which are targeted to the epidermal growth factor receptor are introduced. The nanosensors are demonstrated to detect metastases consisting of only a few tens of cells. Improvements to spectroscopic photoacoustic imaging are then demonstrated by selecting imaging wavelengths based on the spectral properties of the optical absorbers. Finally, a new contrast agent – silica-coated gold nanoplates – are used to map the sentinel lymph node with high contrast. The final result is a set of tools that can be used to noninvasively detect micrometastases and improve molecular photoacoustic imaging. / text

The development of hybridoma technology nearly forty years ago set the foundation for the use of antibodies in the life sciences. Subsequent advances in recombinant DNA technology have allowed us to adapt antibody genes to various screening systems, greatly increasing the throughput and specialized applications for which these complex biomolecules can be adapted. While selection systems are a powerful tool for discovery and evolution, they can be slow and prone to unintended biases. We see computational approaches as an efficient process for rapid discovery and engineering of antibodies. This is particularly relevant for biodefense and emerging infectious disease applications, for which time is a valuable commodity. In the first chapter of this work, we examine computational protocols for ‘supercharging’ proteins. This process resurfaces the target protein, adding charged moieties to impart specialized functions such as thermoresistance and cell penetration. Current algorithms for resurfacing proteins are static, treating each mutation as an event within a vacuum. The net result is that while several variants can be created, each must be tested experimentally to ensure the resultant protein is functional. In many cases, the designed proteins were severely impaired or incapable of folding. We hypothesize that a more dynamic approach, keeping an eye on energetics and the consequences of mutations will yield a more efficient and robust method for supercharging, successfully adding charges to proteins while minimizing deleterious effects. We continue on this theme applying the successful algorithm to supercharging antibodies for increased function. Utilizing the MS2 model biosensor system, we rationally engineer charges onto the surface of an antibody fragment, increasing thermoresistance, minimizing destabilizing effects, and in some cases actually increasing affinity. Finally, we apply next-generation sequencing approaches to the rapid discovery of antibodies directed against the Zaire Ebolavirus species. We utilize a local immunization strategy to generate a polarized antibody repertoire that is then sequenced to provide a database of antigen-specific variants. This repertoire is probed in silico and individual antibodies selected for analysis, bypassing time- and resource-consuming selection experiments. / text

Aims: To describe use of post-operative radiation for endometrial cancer in Ontario. To identify system-related and patient-related factors affecting access to this treatment. Materials and Methods: We performed a retrospective population-based cohort study of patients with surgically resected endometrial cancer in the Canadian province of Ontario between 1992-2003. Patients with evidence of incurable cancer at diagnosis or previous cancer diagnosis were excluded. We used multiple logistic regression to assess patient and system factors affecting radiation use. We controlled for disease-related and treatment-related factors: histology, surgical staging, type of hysterectomy and peritoneal biopsy. We applied a mixed model to account for clustering of data by operating hospital. Results: 9,411 women comprised the study cohort. The median age was 63 years. 26.2% received adjuvant radiation. The proportion of patients receiving radiation varied between cancer centre catchment areas from 18.0% to 34.3% (median 26.3%). In multivariate analysis, older patients were more likely to receive radiation up to the age of 80 (p<.0001). Patients who lived further from regional cancer centres were less likely to receive radiation (p=.0210). Patients who had their surgery during longer prevailing wait times at regional cancer centres were less likely to receive radiation (p=.0441). There was a 2.7-fold variation in the odds of radiation use between cancer centre catchments (p<.0001). Management at a comprehensive gynecologic oncology centre was associated with use of radiation for patients who had surgical staging of lymph nodes. Year of diagnosis and neighborhood income quintile did not significantly affect the use of radiation. Conclusions: There is wide variation in use of radiation for endometrial cancer in Ontario. There is evidence that system factors unrelated to patient’s needs affect use of adjuvant radiation for endometrial cancer in Ontario. Age is a key patient-related factor affecting radiation use. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2009-08-07 22:02:37.308

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Objetivos: Avaliar a eficácia da injeção intraoperatória para identificação do linfonodo sentinela (LS) em câncer de mama com o uso do Dextran 500-99m-Tecnécio (Tc) e azul patente. Analisar se as doses do radiofármaco, o IMC (índice de massa corporal) e o volume da mama influenciam no tempo para migração ao LS. Metodologia: Estudo prospectivo, realizado entre abril de 2008 e junho de 2009, que incluiu 74 biópsias de LS em pacientes com câncer de mama em estádios T1N0 e T2N0. Injetou-se, após indução anestésica, de 0,5 a 1,5 mCi de Dextran 500-99m-Tc filtrado 0,22 μm na região subareolar num volume de 5 ml e 2 ml de azul patente. Resultados: Identificou-se o LS em 100% dos casos. Um LS (1,35%) estava marcado apenas com o azul patente. A taxa de identificação com o “probe” foi de 98% (73/74 casos). A dose média de radiofármaco aplicada foi 0,97 mCi + 0,22. O tempo médio para marcação do LS foi de 10,7 minutos (+ 5,7min). Identificamos em média 1,66 LS com o radioisótopo. A dose aplicada não apresentou relação com o tempo para captação (p=0,73). Quanto maior o volume da mama e IMC, maior o tempo para captação na região axilar (Pearson Correlation r=0,393 p<0,01; r=0,469 p<0,01 - respectivamente). Conclusão: A injeção intraoperatória do radiofármaco é eficaz para identificação do LS em câncer de mama. O tempo para marcação do LS é maior em pacientes com IMC elevado e mamas volumosas. Doses maiores de radiofármaco não diminuem o tempo de migração. / Objectives: To determine the identification of sentinel lymph node (SLN) in breast cancer after intraoperative injection of Dextran 500‐99mTechnetium (Tc) and blue dye. To analyze if the doses of the radioisotope, body mass index (BMI) and breast volume influence the migration time of the SLN. Methodology: Prospective study between april 2008 and june 2009, which included 74 biopsies of SLN in patients with breast cancer in stages T1N0 and T2N0. Intraoperative injection after induction of general anesthesia, 0.5 to 1.5 mCi of dextran 500‐99m‐Tc filtered 0.22 μm in the subareolar region in a volume of 5 ml and 2 ml of blue dye. Results: We identified the SLN in 100% of cases. In one case (1.35%) the SLN was marked only with the blue dye. The SLN identification rate with the probe was 98% (73/74 cases). The mean dose of radioisotope injected was 0.97 + 0.22 mCi. The average time to mark the SLN was 10.7 minutes (+ 5.7 min). We identified an average 1.66 SLN with the radioisotope. The dose had no effect on the time to capture (p = 0.73). The larger breast volume and BMI, the greater the capture time in the axillary region (Pearson Correlation r=0.393 p <0.01, r=0.469 p <0.01 - respectively). Conclusion: Intraoperative injection of the radioisotope is effective for the identification the SLN in breast cancer. Time to mark the SLN is higher in patients with high BMI and large breasts. Higher doses of radioisotope do not decrease the migration time.

Objetivos: Avaliar a eficácia da injeção intraoperatória para identificação do linfonodo sentinela (LS) em câncer de mama com o uso do Dextran 500-99m-Tecnécio (Tc) e azul patente. Analisar se as doses do radiofármaco, o IMC (índice de massa corporal) e o volume da mama influenciam no tempo para migração ao LS. Metodologia: Estudo prospectivo, realizado entre abril de 2008 e junho de 2009, que incluiu 74 biópsias de LS em pacientes com câncer de mama em estádios T1N0 e T2N0. Injetou-se, após indução anestésica, de 0,5 a 1,5 mCi de Dextran 500-99m-Tc filtrado 0,22 μm na região subareolar num volume de 5 ml e 2 ml de azul patente. Resultados: Identificou-se o LS em 100% dos casos. Um LS (1,35%) estava marcado apenas com o azul patente. A taxa de identificação com o “probe” foi de 98% (73/74 casos). A dose média de radiofármaco aplicada foi 0,97 mCi + 0,22. O tempo médio para marcação do LS foi de 10,7 minutos (+ 5,7min). Identificamos em média 1,66 LS com o radioisótopo. A dose aplicada não apresentou relação com o tempo para captação (p=0,73). Quanto maior o volume da mama e IMC, maior o tempo para captação na região axilar (Pearson Correlation r=0,393 p<0,01; r=0,469 p<0,01 - respectivamente). Conclusão: A injeção intraoperatória do radiofármaco é eficaz para identificação do LS em câncer de mama. O tempo para marcação do LS é maior em pacientes com IMC elevado e mamas volumosas. Doses maiores de radiofármaco não diminuem o tempo de migração. / Objectives: To determine the identification of sentinel lymph node (SLN) in breast cancer after intraoperative injection of Dextran 500‐99mTechnetium (Tc) and blue dye. To analyze if the doses of the radioisotope, body mass index (BMI) and breast volume influence the migration time of the SLN. Methodology: Prospective study between april 2008 and june 2009, which included 74 biopsies of SLN in patients with breast cancer in stages T1N0 and T2N0. Intraoperative injection after induction of general anesthesia, 0.5 to 1.5 mCi of dextran 500‐99m‐Tc filtered 0.22 μm in the subareolar region in a volume of 5 ml and 2 ml of blue dye. Results: We identified the SLN in 100% of cases. In one case (1.35%) the SLN was marked only with the blue dye. The SLN identification rate with the probe was 98% (73/74 cases). The mean dose of radioisotope injected was 0.97 + 0.22 mCi. The average time to mark the SLN was 10.7 minutes (+ 5.7 min). We identified an average 1.66 SLN with the radioisotope. The dose had no effect on the time to capture (p = 0.73). The larger breast volume and BMI, the greater the capture time in the axillary region (Pearson Correlation r=0.393 p <0.01, r=0.469 p <0.01 - respectively). Conclusion: Intraoperative injection of the radioisotope is effective for the identification the SLN in breast cancer. Time to mark the SLN is higher in patients with high BMI and large breasts. Higher doses of radioisotope do not decrease the migration time.

Orientador: Maria Jaqueline Mamprim / Resumo: A literatura veterinária possui escasso conteúdo a respeito do uso da ultrassonografia e elastossonografia para caracterização de lesões em linfonodos de cães. O objetivo do primeiro estudo foi comparar as características ultrassonográficas e elastossonográficas entre 50 linfonodos neoplásicos (LN) e 69 linfonodos não neoplásicos (LNN), em cães, com base no diagnóstico microscópico. A hipótese desse estudo é que seja possível distinguir lesões neoplásicas e não neoplásicas com tais técnicas de imagem. Variáveis quantitativas foram comparadas entre os grupos com teste t de student não pareado e, as variáveis categóricas, com teste U de Mann-Whitney. Linfonodos neoplásicos apresentaram dimensões significativamente maiores, relação entre eixo curto e eixo longo (RECEL) superior, maior frequência na perda da arquitetura interna, distribuição vascular predominante mista, índices de resistividade (IR) e de pulsatilidade (IP) superiores e maior rigidez à distribuição do escore elastográfico, em comparação com LNN. O objetivo do segundo estudo foi descrever as características ultrassonográficas e elastossonográficas de 25 linfonodos caninos parasitados por Leishmania spp. A hipótese desse estudo é que seja possível padronizar linfonodos contendo formas amastigotas de Leishmania spp por meio da ultrassonografia e elastografia. Houve aumento nas dimensões dos linfonodos, com RECEL próximo da normalidade. Observou-se alta prevalência de contornos irregulares, bordas nítidas e ausência d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Applicability of ultrasonography and sonoelastography for characterization of lymph node lesions has not been established. The aim of the first study was to compare sonographic and sonoelastographic features between 50 neoplastic and 69 non-neoplastic lymph nodes of dogs, categorized according to microscopy. We hypothesize that sonography and sonoelastography allow the differentiation between neoplastic and non-neoplastic lymph node lesions. Quantitative variables were compared using Student’s unpaired t test and categoric variables were assessed using non-parametric Mann-Whitney U test. Neoplastic nodes had larger size, and short-to-long axis, predominantly mixed vascular flow distribution (hilar and peripheral) on Color Doppler and on Power Doppler, higher resistivity and pulsatility indices, and higher stiffness (score predominantly 4) on elastographic chromatic scale in comparison with non-neoplastic lymph nodes. The aim of the second study was to describe sonographic and elastosonographic features of 25 canine lymph nodes parasitized with Leishmania spp. We hypothesize that sonography and sonoelastography allow standardization of lymph nodes with Leishmania spp. There was enlargement of the lymph nodes associated with maintenance of the shape. Most of the nodes had irregular contour, well-defined borders and absent hilar tissue definition. A minority of the nodes had heterogeneous uniformity due to focal hypoechoic areas or peripheric hypoechoic areas. Vascular flow dist... (Complete abstract click electronic access below) / Doutor

INTRODUÇÃO: O câncer gástrico precoce que invade a submucosa pode apresentar acometimento linfonodal em torno de 20% dos casos. O tratamento cirúrgico clássico com gastrectomia e linfadenectomia D2 é um procedimento não isento de mortalidade e morbidade. Determinar quais pacientes têm maior risco de acometimento linfonodal permitiria tratamentos com menores complicações. Recentemente diversos autores relatam maior expressão imuno-histoquímica de p53 e p21ras em tumores avançados e com pior prognóstico. Tem sido relatada também perda da expressão de p21waf1, p27kip1 e p16ink4a nos tumores avançados e algumas publicações relatam também relação entre a expressão dos marcadores e acometimento linfonodal. MÉTODOS: Foram estudados retrospectivamente 81 pacientes submetidos à gastrectomia com linfadenectomia D2 no período de 1971 a 2004 no Serviço de Cirurgia do Estômago e Intestino Delgado do Departamento de Gastroenterologia do HC-FM/USP. Os blocos de parafina contendo fragmentos dos tumores foram recuperados e novo exame histopatológico confirmou o diagnóstico. Selecionaram-se áreas representativas de mucosa normal, mucosa metaplásica e tumor para confecção de novos blocos de tissue microarrays. Foi avaliada a expressão imuno-histoquímica de p21ras, p53, p21waf1/cip1, p27kip1 e p16ink4a nos tecidos. Foram investigadas as correlações entre a expressão dos marcadores e as características clínico-patológicas dos pacientes. A análise da associação entre os dados clínicos e a positividade dos marcadores foi realizada pelo teste Qui-quadrado. RESULTADOS: Na mucosa normal, metaplásica e tumoral p53 apresentou positividade em 53%, 87,3% e 87,1% dos casos respectivamente. Nos mesmos tecidos p21ras apresentou positividade de 85,3%, 86% e 96,8%. Para p16ink4a a positividade foi de 46,3%, 91,1% e 86%. Para p27kip1 a positividade foi de 60%, 94,7% e 95,3%. Para p21waf1/cip1 a positividade foi 32,4%, 72,7% e 71,4%. Todos os tumores tiveram alguma positividade para p53. Os tumores com acometimento linfonodal apresentaram hiper-expressão(+4) de p53 em 47% dos casos contra 17% nos pacientes que não tinham acometimento. Nenhum tumor com positividade para p53 baixa(0 e +1) teve linfonodos acometidos. Nenhum tumor com p21ras negativo apresentou linfonodos acometidos. Nos pacientes com acometimento linfonodal p21ras teve positividade intensa(+2 e +3) em 88% dos casos contra 50% dos casos sem acometimento linfonodal. Houve positividade intensa(+2,+3 e +4) de p21waf1/cip1 em 71% dos tumores com acometimento linfonodal contra 28% nos pacientes sem acometimento. Não observamos perda de expressão de p21waf1, p27kip1 e p16ink4a nos tumores com acometimento linfonodal. Na mucosa normal p16ink4a foi hiper-expresso (+4) em 20% dos casos com infiltração perineural contra 0% nos casos sem acometimento. O mesmo marcador foi hiperexpresso em 50% dos casos com infiltração vascular contra 0% dos casos sem infiltração. Os tumores com padrão de infiltração Sm2 tiveram pouca positividade(0 e +1) de p27kip1 na mucosa normal em 89% dos casos contra 55% dos casos Sm1. CONCLUSÕES: Maior expressão de p53, p21ras e p21waf1/cip1 no tumor teve relação estatística significante com acometimento linfonodal. Ocorre aumento da expressão imuno-histoquímica de todos os marcadores da mucosa normal para o tumor. A maior hiper-expressão de p16ink4a na mucosa normal de pacientes tem relação com infiltração perineural e vascular nos tumores. A expressão dos marcadores é diferente nas raças estudadas. As pacientes do sexo feminino apresentam maior positividade de p21waf1 na mucosa normal. Pacientes com história familiar de câncer gástrico apresentam maior positividade de p16ink4a na mucosa normal, menor positividade de p21waf1/cip1 e p21ras na mucosa metaplásica. Maior positividade na mucosa normal de p21waf1/cip1 relaciona-se a sexo feminino e infiltração tipo Sm1 / INTRODUCTION: Early gastric cancer that invades the submucosa might have a lymphonodal involvement in about 20% of the cases. Gastrectomy and D2 linfadenectomy is a procedure that has presented mortality and morbidity. Determining which patients would have a greater risk of lymphonodal involvement would allow treatments with fewer complications. Recently, several authors reported a greater immunohistochemical expression of p53 and p21ras in advanced tumors with worst prognosis. It has also been reported the expression loss of p21wafl, p27kip1, and p16ink4a in advanced tumors, and, some studies also observed the relationship between the markers expression and lymphonodal involvement. METHODS: Eightyone patients who had undergone gastrectomy with D2 linfadenectomy from 1971 to 2004 were retrospectively studied. A new histopathological exam confirmed the diagnosis. Representative areas of both normal and metaplastic mucosa and of the tumor were selected for obtaining new blocks of tissue microarrays. The immunohistochemical expression of p21ras, p53, p21waf1/cip1, p27kip1 and p16ink4a in the tissues was evaluated. RESULTS: In normal, metaplastic and tumoral mucosa, p53 showed positivity in 53%, 87.3%, and 87.1% of the cases, respectively. In the same tissues, p21ras showed positivity in 85.3%, 86%, and 96.8%, respectively. The positivity of p16ink4a was 46.3%, 91.1%, and 86%, respectively. p27kip1 showed a positivity of 60%, 94.7%, and 95.3%, respectively. p21wafl/cip1 presented a positivity of 32.4%, 72.7%, and 71.4%, respectively. All tumors showed positivity for p53. Tumors with lymphonodal involvement presented hyperexpression (+4) of p53 in 47% of the cases versus 17% in patients who had not showed any involvement. No tumor with low positivity (0 and +1) of p53 showed lymphonodal involvement. No tumor with negative p21ras showed lymphonodal involvement. In patients with lymphonodal involvement, p21ras presented strong positivity (+2 and +3) in 88% of the cases versus 50% of the cases without lymphonodal involvement. There was a strong positivity (+2,+3, and +4) of p21wafl/cip1 in 71% of the tumors with lymphonodal involvement versus 28% in patients without involvement. It was not observed an expression loss of p21waf1, p27kip1 e p16ink4a in tumors with lymphonodal involvement. In normal mucosa, p16ink4a showed a hyper-expression (+4) in 20% of the cases with perineural invasion versus 0% of the cases without invasion. This same marker showed a hyper-expression in 50% of the cases with vascular invasion versus 0% of the cases without invasion. Tumors with Sm2 invasion pattern showed low positivity (0 and +1) of p27kip1 in normal mucosa in 89% of the cases versus 55% of the cases of Sm1 tumors. CONCLUSIONS: Higher expression of p53, p21ras, and p21wafl/cip1 in tumor showed a significant statistical relationship with lymphonodal involvement. A higher hyper-expression of p16ink4a in patients normal mucosa was related to perineural and vascular invasion of tumors