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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Rizika a limity laparoskopie v léčbě gynekologických zhoubných nádorů / Risks and limits of laparoscopy in the treatment of gynecological cancers

Charvát, Martin January 2016 (has links)
The thesis evaluates the results of experimental protocol involving the fertility sparing treatment procedure in early stage cervical carcinoma (LAP I protocol). Sentinel lymph node detection and experimental extirpation of afferent channels using laparoscopy and its technical aspects were analysed in prospective group of 85 women. The oncologic results and early/late morbidity show that established surgical procedures can be considered safe with minimal morbidity, provided that the indication criteria are met. The second part analyses the results of 148 women with no further pregnancy plans suffering from cervical tumors less than 2 cm in size with invasion less than half of the stroma (LAP II protocol). The oncological results in our defined group are very good and comparable to 'standard' procedure of modified radical hysterectomy type B or C with lower morbidity. In the separate section the thesis analyses the possibilities of laparoscopy in endometrial cancer treatment including the potentials of use of sentinel lymph node detection and technical aspects of laparoscopy in obese women. Currently the biggest controversy is the use of laparoscopy in malignant ovarian tumors. Our oncogynaecological study group at FN Motol prefers the laparotomic approach and we chose to include the set of advanced...
182

Avaliação imunoistoquímica da expressão das metaloproteinases de matriz 2 e 9 e CD31 em carcinomas espinocelulares de soalho bucal / Evaluation of matrix metalloproteinases 2 and 9 and CD31 immune staining in squamous cell carcinomas of the floor of the mouth

Flávio Monteiro Amado 04 December 2007 (has links)
Avaliar a expressão das MMPs 2 e 9 e CD31 por meio de imunoistoquímica em carcinomas espoinocelulares de soalho bucal, e correlacionar os resultados com variáveis demográficas, estadiamento tumoral TNM, parâmetros microscópicos, como invasão perineural, embolização, grau de diferenciação tumoral, e sobrevida. Material e métodos: dados de prontuários de 41 pacientes foram coletados e o diagnóstico histopatológico foi revisado com lâminas recém preparadas. Seções de 5 m foram montadas em lâminas silanizadas e submetidas à imunomarcação pelo sistema streptoavidina-biotina utilizando os anticorpos anti MMP2, MMP 9 e CD31 humanos. A presença de imunomarcação das MMPs foi quantificada utilizando um retículo com 100 pontos em 20 campos de cada lâmina obtidos com objetiva de 40x. Os vasos foram identificados pela imunomarcação com anti-CD31 contando-se aqueles que apresentavam lumem e e tamanho menor do que 50m em cinco campos (objetiva de 20x) na área de maior vascularização das lesões. Para verificar a associação entre as variáveis numéricas e os marcadores, o teste não paramétrico U de Mann-Whitney foi utilizado e, em tabelas de contingência, o teste de freqüências do qui-quadrado foi aplicado. O teste exato de Fisher foi adotado quando pelo menos uma freqüência esperada foi menor do que 5 em tabelas 2X2. O Método de Kaplan-Meier foi utilizado para estimar as probabilidades de sobrevida global e o teste de logrank para comparar as curvas de sobrevida. O nível de significância de 5% foi adotado para todos os testes estatísticos. Resultados: houve correlação estatisticamente significante entre marcação para MMP 2 e metástase em linfonodo. Os fatores relacionados negativamente com a sobrevida foram estadiamento N, tipo histológico, invasão neural e marcação de MMP 9. Conclusão: a intensidade de imunomarcação de MMP 2 e MMP9 pode ser indicativa de metástase em linfonodo e menor probabilidade de sobrevida, respectivamente. / Compare the expression of MMPs 2 and 9 and CD31 by the use of immune histochemistry, in squamous cell carcinomas of the floor of the mouth, and obtain the relationship between those markers and demographic aspects, TNM stage, nerve invasion, blood vessel intravasation, degree of tumor differentiation and survival rates. Material and methods: data from 41 patients were reviewed. Tissue sections with 5 m were mounted in silanized glasses, and submmited to immune staining by the streptoavidin-biotin method, using the anti MMP2, MMP 9 and CD31 human antibodies. The presence of staining was quantified in a 100 points grade in 20 fields of each lesion, with a 40X magnification. Blood vessels smaller than 50m that were identified with the CD31 were counted in 5 fields of the hot spot area of the tumor. To verify the association between immune staining and numerical variables, the non parametric Mann-Whitney U test was used, and the chi-square test was verified. The exact Fisher test was adopted when at least one of the expected frequencies in 2X2 tables was less than 5. The Kaplan-Meier method was used to estimate the probabilities of global survival, and the log-rank test was used to compare the survival curves. Results: there was statistically significant association between MMP 2 immune staining and regional metastasis. The variables associated with poor survival rates were N stage, histological grade, nerve invasion and immune staining for MMP 9. Conclusion: the grade of immune staining can be an indicative of node metastasis and poor survival rate, respectively.
183

Perfil temporal da inflamação pulmonar induzida pela isquemia/reperfusão intestinal em ratos. Estudo do papel do sistema linfático. / Time profile of lung inflammation induced by intestinal ischemia/reperfusion in rats. Role of the lymphatic system.

Luana Beatriz Vitoretti 17 May 2010 (has links)
A isquemia/reperfusão intestinal (I/R-i) se associa ao desenvolvimento de inflamação pulmonar aguda, que pode ser modulada por mediadores inflamatórios presentes na linfa. Avaliamos os efeitos da I/R-i sob a inflamação pulmonar e a participação do sistema linfático. Wistar machos foram submetidos a 45 min de isquemia intestinal e 24, 72 ou 120 h de reperfusão. Outro grupo teve o ducto linfático bloqueado antes da isquemia. Os resultados revelaram maior inflamação pulmonar nos animais reperfundidos por 120 h em relação aos outros períodos de reperfusão estudados. Os animais apresentaram aumento de MPO e permeabilidade. Aumento de VEGF e de IL-1<font face=\"Symbol\">&#946 e diminuição de IL-10 no explante pulmonar. Diminuição de vWf e aumento de integrina <font face=\"Symbol\">&#9461, PECAM-1 e colágeno I e IV no endotélio pulmonar. Os dados indicam que mecanismos temporais modulam a resposta inflamatória decorrente da I/R-i. Mediadores na linfa e na circulação participam do desencadeamento/manutenção da inflamação pulmonar alterando a integridade do endotélio e ativando o pulmão que libera mediadores adicionais. / Intestinal ischemia/reperfusion (i-I/R) is associated with the development of acute lung inflammation, which can be modulated by inflammatory mediators present in the lymph. We evaluated the effects of i-I/R in lung inflammation and the involvement of the lymphatic system. Wistar rats were subjected to 45 min of intestinal ischemia and 24, 72 or 120 h of reperfusion. Another group had the lymphatic duct blocked before ischemia. The results revealed greater lung inflammation in animals reperfused for 120 h in comparison to other periods studied. These animals showed increased MPO and permeability. Increased VEGF and IL-1<font face=\"Symbol\">&#946 and decreased IL-10 in lung explants. Decreased vWf and increased <font face=\"Symbol\">&#9461 integrin, PECAM-1 and collagen I and IV in the pulmonary endothelium. These data indicate that temporal mechanisms modulate the inflammatory response due to i-I/R. Mediators in the lymph and circulation participate in the initiation / maintenance of lung inflammation by altering the integrity of the endothelium and activating the lung which release additional mediators.
184

Valor adicional da sequência de difusão na acurácia diagnóstica da ressonância magnética no estadiamento linfonodal de pacientes com neoplasia de próstata / Incremental value of diffusion-weighted imaging in diagnostic accuracy on lymph node staging of prostate cancer by Magnetic Resonance Imaging

Aline de Araújo Naves 01 June 2017 (has links)
INTRODUÇÃO: O adenocarcinoma de próstata (CaP) é a segunda neoplasia maligna de órgãos sólidos mais frequente em homens no mundo. As metástases linfonodais alteram o estadiamento e o prognóstico dos pacientes. O objetivo deste trabalho é avaliar a acurácia diagnóstica da Ressonância Magnética de próstata (RMP) na detecção de metástases linfonodais pélvicas e avaliar a acurácia dos critérios morfológicos, da imagem ponderada em difusão (DWI) e coeficiente de difusão aparente (ADC). MATERIAIS E MÉTODOS: No período de 1 de janeiro de 2015 a dezembro de 2016 foram avaliados, por dois observadores, 60 exames de RMP de pacientes que realizaram prostatectomia radical e linfadenectomia pélvica. Em momentos diferentes foi realizada análise morfológica (sequência ponderadas T2) e da DWI, com a medida do ADC e comparado o desempenho de ambas. RESULTADOS: Na análise por paciente da sequência T2 e DWI, a RMP apresentou uma sensibilidade variando de 45,5% a 63,6% e especificidade de 87,0% a 97,6%, sem diferença estatisticamente significativa. Já na análise por lesão os valores da sensibilidade variaram de 15,4% a 53,8% e a especificidade de 86,3% a 90,6%. Apenas para o observador 1 (menos experiente) a DWI aumentou a detecção de linfonodos. Não foi verificada diferença estatisticamente significativa entre as dimensões dos linfonodos positivos e negativos ou do ADC. CONCLUSÃO: A DWI não aumentou a acurácia diagnóstica da RMP no estadiamento linfonodal de pacientes com CaP. O critérios isolados de tamanho e o valor do ADC não apresentaram boa acurácia devido a sobreposição entre os valores dos linfonodos normais e patológico. / INTRODUCTION: Prostate cancer (PC) is the second most common malignancy in men worldwide. Lymph node metastases change the staging and prognosis of these patients. The objective of this study was to evaluate the adittional value of Diffusionweighted magnetic resonance imaging (DWI-MRI) using mean apparent diffusion coefficient (ADC) to lymph node staging of patients with PC. MATERIALS AND METHODS: Between January 2015 and December 2016, two observers evaluated 60 consecutive MRI exams of patients who underwent radical prostatectomy and pelvic lymphadenectomy. At different times, morphological analysis (T2 sequences) and DWI were performed with the ADC measurement and compared the performance of both. RESULTS: In per patient analysis of T2 and DWI images, MRI showed a sensitivity ranging from 45.5% to 63.6% and specificity from 87.0% to 97.6%, with no statistically significant difference. In per lesion analysis, sensitivity ranged from 15.4% to 53.8% and specificity from 86.3% to 90.6%. Only for observer 1 (less experienced) DWI increased lymph node detection. There was no statistically significant difference between dimensions of the positive and negative lymph nodes as well as ADC measurement. CONCLUSION: DWI did not increase the diagnostic accuracy of MRI in the lymph node staging of patients in PC. Mean ADC and lymph node size, alone or in combination, did not showed good accuracy due to the overlap between normal and pathological lymph node findings.
185

Validade do mapeamento do linfonodo sentinela na detecção de metástase linfática cervical do carcinoma papilífero da glândula tireoide / Impact of sentinel lymph node mapping to detect papillary thyroid carcinoma lymph node metastasis

José Higino Steck 23 June 2016 (has links)
INTRODUÇÃO: O mapeamento do linfonodo sentinela (MLNS) é largamente utilizado em pacientes com melanoma cutâneo, câncer de mama e outras neoplasias malignas sólidas com a finalidade de estadiá-las e indicar esvaziamento linfático apenas na presença de metástase. Nos últimos anos aumentou o interesse pelo uso do MLNS em pacientes com carcinoma papilífero de tireoide (CPT) sem metástases linfáticas detectáveis clinicamente (estádio cN0), devido à alta frequência de metástases ocultas nesses pacientes. O MLNS pode evitar o esvaziamento linfático do compartimento central (ECC) em portadores de CPT sem metástase. Mesmo que não se planeje o ECC eletivo, o MLNS pode também ser usado para estadiar adequadamente o pescoço e indicar tratamento posterior com radioiodoterapia em casos com metástase. Esse estudo tem como objetivo verificar: 1) a efetividade da técnica do MLNS nos pacientes com CPT; 2) a acurácia do MLNS em diagnosticar as metástases linfáticas; 3) se o MLNS pode modificar o estadiamento dos pacientes com CPT cN0. MÉTODOS: Trata-se de estudo de acurácia, prospectivo longitudinal de 38 casos consecutivos de CPT clinicamente N0, atendidos em um único centro, no período de 2010 a 2015. Todos foram submetidos à tireoidectomia total, MLNS com radiofármaco e ECC eletivo. Os resultados relativos ao MLNS foram comparados com o exame anatomopatológico do conteúdo do ECC. RESULTADOS: O tempo médio de seguimento dos doentes foi de 36 ± 13 meses. Os LNS foram localizados com maior frequência nos níveis VI e III. O LNS foi detectado em 95% da casuística e os valores de avaliação de testes diagnósticos foram: 1 falso negativo, 95% de sensibilidade, 100% de especificidade, 94% de valor preditivo negativo e 97% de acurácia. O MLNS foi capaz de reestadiar 49% dos pacientes inicialmente N0 para pN positivo. Quanto ao grupo de estadiamento AJCC (que leva em conta a idade), 3% dos pacientes foram reestadiados para estádio III e 18% para estádio IV. CONCLUSÕES: 1) a técnica de MLNS utilizada nos pacientes com CPT foi efetiva em 95% dos procedimentos realizados; 2) a acurácia do MLNS em diagnosticar as metástases linfáticas cervicais foi de 97%; 3) o MLNS re-estadiou os portadores de CPT, classificados clinicamente como N0, para pN positivo em 49% da casuística, e para estádio III e IVa em 21% / INTRODUCTON: Sentinel lymph node mapping (SLNM) is widely perfomed in melanoma, breast cancer and other solid tumors, to adequately stage these diseases. More recently, the interest in SLNM for clinically N0 Papillary Thyroid Cancer (PTC) has increased due to the high rate of occult metastases in these patients, to avoid unnecessary central neck dissection (CND), and its complications. Even if routine elective CND is not planned, SLNM can be used to adequately stage the neck, and to indicate further treatment with radioiodine in cases with neck metastases, for instance. This study aims to evaluate 1) SLNM effectiveness in PTC patients, 2) SLNM accuracy to diagnosis lymph node metastases and 3) if SLNM can upstage cN0 PTC patients. METHODS: This is a prospective longitudinal, diagnostic test accuracy study with 38 consecutive cN0 PTC patients, treated in a single center between 2010 and 2015. Surgical treatment in all cases included total thyroidectomy and elective CND after SLNM. Results of SLNM were compared to CND pathological findings, in order to verify if sentinel lymph node (SLN) predicted the occurrence of PTC occult lymph node metastasis. RESULTS: The mean patients\' follow-up was 36 ± 13 months. 133 SLN were found in the neck, on levels VI and III. The SLN was identified in 95% of the patients with 1 false negative, 95% sensitivity, 94% negative predictive value and 97% accuracy. The SLNM upstaging from cN0 to pN+ was 49%, with 3% stage III and 18% stage IVa. CONCLUSION: 1) SLNM was effective in 95% of procedures, 2) SLNM accuracy was 97%, 3) SLNM upstaging from cN0 to pN+ was 49%, and to stage III and IVa was 21%
186

Tratamento com VEGFC para revascularização linfática em membros pélvicos de camundongos / VEGFC treatment for lymphatic revascularization of mice hindlimb

Juliana Shimara Pires Ferrão 29 July 2013 (has links)
A revascularização linfática é um desafio e o estabelecimento de novas estratégias terapêuticas podem melhorar a qualidade de vida de pessoas que sofrem de distúrbios linfáticos. O objetivo deste estudo foi verificar a capacidade de tratamento com VEGFC exógeno na melhoria da vascularização linfática de uma maneira dependente do tempo em membros pélvicos (MP) de camundongos após a remoção do linfonodo inguinal. O linfonodo inguinal esquerdo foi removido cirurgicamente para mimetizar patologias com diminuição da vascularização linfática. Densidade vascular linfática (Vv) e de comprimento (Lv) foram avaliadas por imunohistoquímica, seguidas de estereologia, após a cirurgia com ou sem o tratamento com VEGFC exógeno. O grupo controle não foi manipulado, mas recebeu soro fisiológico em vez de tratamento com VEGFC exógeno. As expressões do VEGFC e FLT4 local foram avaliadas por qPCR. Houve efeito do tempo sobre Vv e Lv no Grupo Cirurgia e diferença significativa entre os grupos Controle e Cirurgia nas três regiões estudadas (região proximal, média e distal) do MP esquerdo (MPE). A Lv mostrou diferença significativa entre os grupos Controle e Cirurgia somente na região média do MPE. A Vv e a Lv para o Grupo Tratamento foram maiores do que os outros grupos em todas as regiões do MPE. A expressão gênica do VEGFC e do FLT4 apresentou efeito do tempo em todas as regiões do MPE para os grupos Cirurgia e Tratamento. Ambas as expressões gênicas do VEGFC e do FLT4 apresentaram diferença significativa entre os grupos Controle e Cirurgia, entre os grupos Cirurgia e Tratamento e entre os grupos Controle e Tratamento. Os resultados mostraram que os camundongos são bons modelos experimentais para o uso de VEGFC exógeno como terapia de revascularização linfática, e o tratamento com VEGFC exógeno aumenta vascularização linfática já após 3 dias de dano linfático. / Lymphatic revascularization is a challenge and the establishment of new therapeutic strategies may improve quality of life from those suffering from lymphatic disorders. The objective of this study was to verify the VEGFC treatment capacity in improving lymphatic vascularization in a time-dependent manner in mouse hind limb (HL) after removal of inguinal lymphnode. The left inguinal lymphnode was surgically removed to mimetize pathologies with decreased lymphatic vascularization. Lymphatic vascular density (Vv) and length (Lv) were evaluated by immunohistochemistry followed by stereology after surgery and/or VEGFC treatment. Control group was not manipulated but received saline instead of VEGFC treatment. VEGFC and FLT4 local expression were assessed by qPCR. There was effect of time over Vv and Lv in the SG and significant difference between CG and SG in the three studied regions (proximal, medium and distal region) of the left HL (LHL). The Lv showed significant difference between CG and SG only in the medium region. The Vv and the Lv for TG were higher than the other groups in all regions of LHL. VEGFC and FLT4 gene expression presented time effect in all regions of the LHL for SG and TG. Both VEGFC and FLT4 gene expression presented significant difference between CG and SG, between SG and TG, and between CG and TG. The results show that mice are good experimental models for VEGFC use as therapy for lymphatic revascularization, and VEGFC treatment increased the lymphatic vasculature already after 3 days of lymphatic damage.
187

Understanding Ten-Eleven Translocation-2 in Hematological and Nervous Systems

Pan, Feng 03 December 2014 (has links)
I proposed the study of two distinct aspects of Ten-Eleven Translocation 2 (TET2) protein for understanding specific functions in different body systems. In Part I, I characterized the molecular mechanisms of Tet2 in the hematological system. As the second member of Ten-Eleven Translocation protein family, TET2 is frequently mutated in leukemic patients. Previous studies have shown that the TET2 mutations frequently occur in 20% myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN), 10% T-cell lymphoma leukemia and 2% B-cell lymphoma leukemia. Genetic mouse models also display distinct phenotypes of various types of hematological malignancies. I performed 5-hydroxymethylcytosine (5hmC) chromatin immunoprecipitation sequencing (ChIP-Seq) and RNA sequencing (RNA-Seq) of hematopoietic stem/progenitor cells to determine whether the deletion of Tet2 can affect the abundance of 5hmC at myeloid, T-cell and B-cell specific gene transcription start sites, which ultimately result in various hematological malignancies. Subsequent Exome sequencing (Exome-Seq) showed that disease-specific genes are mutated in different types of tumors, which suggests that TET2 may protect the genome from being mutated. The direct interaction between TET2 and Mutator S Homolog 6 (MSH6) protein suggests TET2 is involved in DNA mismatch repair. Finally, in vivo mismatch repair studies show that the loss of Tet2 causes a mutator phenotype. Taken together, my data indicate that TET2 binds to MSH6 to protect genome integrity. In Part II, I intended to better understand the role of Tet2 in the nervous system. 5-hydroxymethylcytosine regulates epigenetic modification during neurodevelopment and aging. Thus, Tet2 may play a critical role in regulating adult neurogenesis. To examine the physiological significance of Tet2 in the nervous system, I first showed that the deletion of Tet2 reduces the 5hmC levels in neural stem cells. Mice lacking Tet2 show abnormal hippocampal neurogenesis along with 5hmC alternations at different gene promoters and corresponding gene expression downregulation. Through the luciferase reporter assay, two neural factors Neurogenic differentiation 1 (NeuroD1) and Glial fibrillary acidic protein (Gfap) were down-regulated in Tet2 knockout cells. My results suggest that Tet2 regulates neural stem/progenitor cell proliferation and differentiation in adult brain.
188

Filariose bancroftiana na Amazônia Ocidental brasileira: implicações para transmissão e controle. / Survey of bancroftian filariasis infection in humans and culex mosquitoes in the Western Brazilian region: implications for transmission and control.

Rodolfo Luis Korte 12 August 2013 (has links)
Introdução: Este trabalho tem por objetivo identificar focos de filariose linfática na amazônia ocidental brasileira e constatar a infecção natural pela W. bancrofti do mosquito vetor, o C. quinquefasciatus. O estudo abrangeu as cidades de Porto Velho (RO), Guajará Mirim (RO) e Humaitá (AM). Método: foi utilizada a técnica da gota espessa de sangue, colhida após 22h00, corada com Giemsa para avaliação humana, e a Reação em Cadeia da Polimerase (PCR) para pesquisa de DNA de W. bancrofti em mosquitos vetores. Foram analisadas e avaliadas amostras do sangue de moradores dos bairros mais antigos dessas cidades e escolares noturnas e captura de mosquitos. Resultados: O inquérito hemoscópico em moradores resultou em 935 indivíduos (54,4%) examinados de um total de 1.720 cadastrados. As pesquisas entre escolares noturnos envolveram 2.709 indivíduos (75,2%) de um total de 3.601. Todos negativos para a presença de microfilaremia. Foram coletadas 7.849 fêmeas de C. quinquefasciatus, todas apresentaram resultados negativos para DNA de W. bancrofti. / Introduction: This work is aimed to identify possible lymphatic filariasis foci in the Western Brazilian Amazonian. Porto Velho and Guajara-Mirim (Rondonia State) and Humaita (Amazonas State) were the study target area. Methods: Blood thick film method with samples collected from 10 PM to 1 AM were stained using Giemsa to evaluate human infection and PCR for W. bancrofti DNA in mosquitoes vectors. Samples from the neighborhoods of these areas and from students attending public nighttime classes in the cities referred to above were analyzed and evaluated, as well as mosquitoes captured in the houses. Results: 935 individuals (54.4%) out of a total of 1,720 individuals engaged. Sample with night students involving 2,709 individuals (75.2%) out of the total of 3,601 previously selected. No individual examined was positive for the presence of microfilariae in the blood stream. 7,849 female C.quinquefasciatus specimens were captured and after evaluated by using PCRmethod, all of them were found negative for W. bancrofti DNA.
189

Valor adicional da sequência de difusão na acurácia diagnóstica da ressonância magnética no estadiamento linfonodal de pacientes com neoplasia de próstata / Incremental value of diffusion-weighted imaging in diagnostic accuracy on lymph node staging of prostate cancer by Magnetic Resonance Imaging

Naves, Aline de Araújo 01 June 2017 (has links)
INTRODUÇÃO: O adenocarcinoma de próstata (CaP) é a segunda neoplasia maligna de órgãos sólidos mais frequente em homens no mundo. As metástases linfonodais alteram o estadiamento e o prognóstico dos pacientes. O objetivo deste trabalho é avaliar a acurácia diagnóstica da Ressonância Magnética de próstata (RMP) na detecção de metástases linfonodais pélvicas e avaliar a acurácia dos critérios morfológicos, da imagem ponderada em difusão (DWI) e coeficiente de difusão aparente (ADC). MATERIAIS E MÉTODOS: No período de 1 de janeiro de 2015 a dezembro de 2016 foram avaliados, por dois observadores, 60 exames de RMP de pacientes que realizaram prostatectomia radical e linfadenectomia pélvica. Em momentos diferentes foi realizada análise morfológica (sequência ponderadas T2) e da DWI, com a medida do ADC e comparado o desempenho de ambas. RESULTADOS: Na análise por paciente da sequência T2 e DWI, a RMP apresentou uma sensibilidade variando de 45,5% a 63,6% e especificidade de 87,0% a 97,6%, sem diferença estatisticamente significativa. Já na análise por lesão os valores da sensibilidade variaram de 15,4% a 53,8% e a especificidade de 86,3% a 90,6%. Apenas para o observador 1 (menos experiente) a DWI aumentou a detecção de linfonodos. Não foi verificada diferença estatisticamente significativa entre as dimensões dos linfonodos positivos e negativos ou do ADC. CONCLUSÃO: A DWI não aumentou a acurácia diagnóstica da RMP no estadiamento linfonodal de pacientes com CaP. O critérios isolados de tamanho e o valor do ADC não apresentaram boa acurácia devido a sobreposição entre os valores dos linfonodos normais e patológico. / INTRODUCTION: Prostate cancer (PC) is the second most common malignancy in men worldwide. Lymph node metastases change the staging and prognosis of these patients. The objective of this study was to evaluate the adittional value of Diffusionweighted magnetic resonance imaging (DWI-MRI) using mean apparent diffusion coefficient (ADC) to lymph node staging of patients with PC. MATERIALS AND METHODS: Between January 2015 and December 2016, two observers evaluated 60 consecutive MRI exams of patients who underwent radical prostatectomy and pelvic lymphadenectomy. At different times, morphological analysis (T2 sequences) and DWI were performed with the ADC measurement and compared the performance of both. RESULTS: In per patient analysis of T2 and DWI images, MRI showed a sensitivity ranging from 45.5% to 63.6% and specificity from 87.0% to 97.6%, with no statistically significant difference. In per lesion analysis, sensitivity ranged from 15.4% to 53.8% and specificity from 86.3% to 90.6%. Only for observer 1 (less experienced) DWI increased lymph node detection. There was no statistically significant difference between dimensions of the positive and negative lymph nodes as well as ADC measurement. CONCLUSION: DWI did not increase the diagnostic accuracy of MRI in the lymph node staging of patients in PC. Mean ADC and lymph node size, alone or in combination, did not showed good accuracy due to the overlap between normal and pathological lymph node findings.
190

Effects of Malformed or Absent Valves to Lymphatic Fluid Transport and Lymphedema in Vivo in Mice

Pujari, Akshay S. 27 October 2017 (has links)
Lymph is primarily composed of fluid and proteins from the blood circulatory system that drain into the space surrounding cells, interstitial space. From the interstitial space, the fluid enters and circulates in the lymphatic system until it is delivered into the venous system. In contrast to the blood circulatory system, the lymphatic system lacks a central pumping organ dictating the predominant driving pressure and velocity of lymph. Transport of lymph via capillaries, pre-collecting and collecting lymphatic vessels relies on the synergy between pressure gradients, local tissue motion, valves and lymphatic vessel contractility. The direction of lymph transport is regulated by bicuspid valves distributed throughout pre-collecting and collecting lymphatic vessels. Effective transport of lymph into the venous system is of prime importance. Disruption of lymph transport, because of impaired lymphatic function, reduced numbers of vessels or valvular insufficiencies can have severe health consequences, including lymphedema for which current clinical therapies are not curative. The lymphatic valves are usually bicuspid, however, congenital malformations in the valve such as single leaflet valve formation and arrested lymphatic valve development are observed and can cause lymphedema. Here we employ 4-week-old mice to study the effects of valves and malformed valves on lymph transport shedding light into some of the potentially underlying consequences of lymphedema. Polyethylene glycol (PEG) coated latex particles were injected into the inguinal lymph node of anesthetized mice. Particle displacement measurements through efferent lymphatic vessels yielded velocity, wall shear stress, vorticity and strain of the efferent lymph flow field carrying lymph from subdermal inguinal lymph nodes. Lymphatic vessel endothelial Prox1 green fluorescent protein (GFP) marker enabled the detection of lymphatic vessel walls and valves. Flow field, flow velocity, flow rate, velocity profiles, wall shear stress, vorticity and strain values were compared in regions downstream of normal and malformed valves in two wild type mice. A Clec2-deficient mouse, which experiences lymphatic development defects and is used as a lymphedema model, was employed to further elucidate the lymphatic valves on transport. The absence of centralized pumping yields highly variable lymphatic flow cycles varying from one to fifteen seconds. The presence of lymphatic valves introduces boundary conditions that yield spatial and temporal flow gradients increasing the degree of complexity of lymph transport. The valves dictate the trajectory of the particles and promote the formation of recirculation zones. Even in the presence of valves, lymph flow commonly reverses. Congenital defects like a single leaflet valve lowers the lymph flow efficiency and promotes higher wall shear stress regions. Furthermore, the absence of functional valves in the Clec2-deficient mouse not displaying lymphedema yielded lymph flow lacking the pulsatility that characterizes normal lymphatic flow.

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