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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.
121

Estudo retrospectivo de dermatopatias em gatos através de diagnóstico histopatológico realizados no setor de Patologia Veterinária da UFRGS, Porto Alegre (1990 - 2012)

Scherer, Heloisa Azevedo January 2015 (has links)
Dentre as especialidades veterinárias, a dermatologia, juntamente com oncologia foram as que se destacaram a partir de 1980. Cerca de 30% dos atendimentos clínicos de carnívoros domésticos são associados com alterações dermatológicas. A maior parte dos dados disponíveis inclui estudos de outros países o que pode não refletir a realidade brasileira. O objetivo deste estudo foi apresentar a prevalência das principais dermatologias neoplásicas e não neoplásicas registradas em gatos, através de diagnósticos histopatológicos de biópsias da pele, realizados no setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (SPV-UFRGS). Um estudo retrospectivo incluiu os resultados de biópsias de pele em gatos registrados entre 1990 e 2012, nos arquivos de diagnósticos histopatológicos do SPV-UFRGS, Porto Alegre, RS, Brasil. De um total de 443 biópsias cutâneas em gatos, 308 casos foram lesões de origem neoplásica que ocorreram em maior prevalência (69%) e afetaram, mais frequentemente, gatos idosos, independente do sexo. Nessa categoria, destacaram-se carcinoma epidermoide 32,14% (99/308), fibrossarcoma 18,83% (58/308), tricoblastoma 12,66% (39/308) e mastocitoma 7,47% (23/308). Entre as lesões de causas não neoplásicas, foram analisadas as de causas micóticas 22,22% (30/135), das quais, a esporotricose apresentou maior ocorrência, com maior prevalência em machos. As lesões de causas alérgicas ocuparam a segunda posição 18,52% (25/135) em prevalência, na categoria não neoplásica. As três dermatopatias mais frequentes foram neoplásicas, micóticas e alérgicas. As neoplasias afetaram mais frequentemente gatos idosos, independentemente do sexo. O carcinoma epidermoide é a dermatopatia neoplásica de maior ocorrência, em gatos sem raça definida, sem predisposição sexual. A esporotricose é a dermatomicose mais frequente e afetou principalmente gatos machos. A escassez de dados registrados nas fichas de solicitação de biópsia reduziu conclusões adicionais. Partindo-se do princípio de que a dermatite solar pode evoluir para o carcinoma epidermoide, e considerando-se o expressivo número de diagnósticos desta alteração entre todas as amostras cutâneas 22,35% (99/443), pode-se reforçar a importância deste estudo ao dermatologista de um país tropical, dando subsídios para a indicação da prevenção à exposição solar, visando prevenir a ocorrência da doença, aumentando o bem-estar dos gatos. / Both dermatology and oncology are areas that showed high development since the 1980s. It is estimated that approximately 30% of the clinical services for domestic carnivores have been associated with dermatological alterations. Most of the available data include studies developed outside the country and may not reflect the local situation. This study aimed to presents the prevalence of the main dermatological alterations affecting domestic cats and that were diagnosed by histopathological analysis in the Setor de Patologia Veterinária of Universidade Federal do Rio Grande do Sul (SPV-UFRGS).A retrospective study included the findings observed in feline skin biopsies recorded between 1990 and 2012 in the histopathological files from the SPV-UFRGS. In a total of 443 biopsies, 308 cases showed neoplastic origin which corresponded to most lesions (69%) and affected mostly aged cats, regardless of sex. This category included epidermoid carcinoma 32,14% (99/308), fibrosarcoma 18,83% (58/308), trichoblastoma 12,66% (39/308) and mastocytoma 7,47% (23/308). Epidermoid carcinoma was the top neoplastic dermatopathy and affected mostly undefined breed cats without sexual predisposition. Among the non-neoplastic cases, the mycoses 22,22% (30/135) and the allergic lesions 18,52% (25/135) were the most prevalent. Sporotrichosis was the predominant mycotic alteration and affected especially male cats. Therefore, the three most prevalent categories of dermatopathies affecting cats were neoplasia, mycosis and allergy. Thelack of data recorded in the clinical sheets for biopsy request minimized additional conclusions. Results showed here are highlighted upon consideration that solar dermatitis may evolve to epidermoid carcinoma, which has occurred in a high prevalence in this tropical country, where the prevention to the exposition of these animals to the solar radiation assumes a great role for animal care.
122

Identificação de variantes germinativas no gene E-caderina / CDH1 e de fatores ambientais de risco em pacientes jovens portadores de câncer gástrico / Identification o -E cadherin /CDH1 germline variants and environmental risk factors in early onset gastric cancer patients

Rodrigo Santa Cruz Guindalini 26 August 2016 (has links)
Introdução: Câncer gástrico é uma doença multifatorial influenciada por fatores externos e hereditários. Embora a síndrome do câncer gástrico difuso hereditário causada por mutações germinativas no gene CDHl seja uma condição rara, sua influência sobre a incidência de câncer gástrico no Brasil, que é considerado um país de alta incidência desta neoplasia, é desconhecida. Objetivos: Avaliar a frequência de variantes germinativas em CDHl e os hábitos de dieta/estilo de vida em pacientes diagnosticados câncer gástrico com idade precoce «55 anos) no Brasil. Metodologia: De outubro de 2013 a agosto 2015, foram recrutados 88 pacientes consecutivos e não aparentados diagnosticados com câncer gástrico em idade precoce em um hospital público brasileiro. Todos os éxons e regiões intrônicas flanqueadoras do CDHl foram sequenciados. Os hábitos de dieta/estilo de vida dos pacientes com câncer gástrico em idade precoce foram comparados com informações sobre os hábitos da população armazenados em bancos de dados populacionais brasileiros. Resultados: Dos 88 pacientes, 51,1% eram do sexo feminino e a média de idade no momento do diagnóstico do câncer era de 39 anos (variação, 20-55); 23% relataram história familiar de câncer gástrico em parentes de primeiro ou de segundo. A maioria dos tumores era do tipo difuso (74%), pouco diferenciado (74%) e localizava-se no terço médio ou distal do estômago (67%). No total, 24 variantes germinativas foram detectadas: 3 (12.5%) benignas, 17 (70.8%) provavelmente benignas e 4 (16.7%) variantes de significado clínico incerto (VSI). Todas as VSI são mutações missense e nunca foram relatadas previamente na literatura: c.313T> A, c.387G> T, c.1676G> A e c.1806C> A. Os pacientes com câncer gástrico diagnosticados em idade precoce apresentaram maior consumo de carne vermelha (OR: 2.591, IC 95%: 1.371-4.894) e carne processada (OR: 3.093, IC 95%: 1.591- 6.009) em comparação com os hábitos alimentares da população brasileira. Conclusão: De acordo com o nosso conhecimento, esta é a maior série investigando a contribuição de mutações germinativas de CDHl em pacientes diagnosticados com câncer gástrico em idade precoce na América Latina. Para um país considerado de alta incidência, a frequência encontrada de variantes germinativas em CDHl foi maior do que o esperado; 4 novas mutações missense foram identificadas e mais estudos são necessários para confirmar a patogenicidade dessas variantes. Fatores de risco modificáveis, como o consumo de carne vermelha e/ou de carne processada podem ter contribuído para o desenvolvimento de câncer gástrico em idade precoce na população estudada / Introduction: Gastric cancer is a multifactorial disease influenced by inherited and noninherited factors. Although hereditary diffuse gastric cancer syndrome caused by germline mutation in CDHl is arare condition its contribution to gastric cancer burden in Brazil, which is considered a high-incidence country for this neoplasia, is unknown. Objectives: To evaluate the frequency of CDHl germline variants and the dietjlifestyle habits in early-onset gastric cancer (EOGC, < 55 years old) patients in Brazil. Methodology: From October 2013 to August 2015, a total of 88 unrelated and consecutive patients attending a Brazilian public hospital with EOGC were enrolled. Ali CDHl exons and intronic boundaries were sequenced. The dietjlifestyle habits of EOGC patients have been compared to Brazilian population data bases. Results: Of 88 patients, 51.1% were female and the mean age at gastric cancer diagnosis was 39 years (range 20-55); 23% reported family history of gastric cancer in first- or second-degree rei atives. The majority of the tumors were diffuse (74%), poorly differentiated (74%), and located in the middle and distal-third of the stomach (67%). In total, 24 germline variants were detected: 3 (12.5%) benign, 17 (70.8%) likely benign, and 4 (16.7%) variants of unknown significance (VUS). Ali VUS were missense novel mutations: c.313T > A, c.387G > T, c.1676G > A, and c. 1806C > A. EOGC patients had ahigher red (OR: 2.591, 95% CI: 1.371-4.894) and processed (OR: 3.093, 95% CI: 1.591-6.009) meat intake compared to eating habits of the Brazilian population. Conclusion: To our knowledge, this is the largest series investigating the contribution of CDHl germline mutations in EOGC cancer in Latin America. For a high-incidence country, the incidence of CDHl germline variants was higher than expected; 4 novel CDHl missense mutations were identified and further studies are warranted to confirm their pathogenicity. Modifiable risk factors, such as the consumption of red and/or processed meat may have contributed to early- onset gastric cancer development in our studied population
123

Angiogênese, células-tronco neoplásicas CD34+ e sinvastatina em modelo de carcinogênese mamária induzida quimicamente / Angiogenesis, CD34+ cancer stem-cells and simvastatin in a chemically induced mammary carcinogenesis model

Alves Junior, Marcos José, 1985- 20 August 2018 (has links)
Orientador: André Almeida Schenka / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-20T12:37:53Z (GMT). No. of bitstreams: 1 AlvesJunior_MarcosJose_M.pdf: 2901424 bytes, checksum: 6694f752f4f5762fee8876846cf1f26c (MD5) Previous issue date: 2012 / Resumo: O câncer de mama é a neoplasia maligna mais frequente e a primeira causa de óbito por neoplasia em mulheres. A despeito de toda a pesquisa e todos os progressos realizados até o momento, a morbimortalidade ainda é alta em pacientes em estádio avançado. Recentemente, foi descrito um novo modelo de carcinogênese no qual as células-tronco (CT) seriam responsáveis pela origem, heterogeneidade morfológica e autorrenovação das neoplasias malignas. Apoiando essa teoria, observam-se, na maioria das neoplasias sólidas, células com características biológicas e fenotípicas de CT, as quais são designadas células-tronco neoplásicas (CTN). Estando associadas à resistência terapêutica e recidivas tumorais a longo prazo, as CTNs constituem um importante alvo de estudos fisiopatológicos e farmacológicos. Além das CTNs, outro importante alvo terapêutico em câncer de mama é representado pela angiogênese tumoral. Contudo, raros são os estudos focados nas interrelações dessas duas estratégias. As estatinas constituem um grupo de fármacos utilizados no tratamento de primeira linha das dislipidemias e na prevenção de suas consequências cardiovasculares. Além dos efeitos antidislipidêmicos, são descritas propriedades antineoplásicas, cujas bases parecem estar associadas a ações antiapoptóticas e antiangiogênicas, ainda não totalmente esclarecidas. Resultados preliminares in vitro de Gauthaman et al. e in vivo do grupo de pesquisa em que o presente trabalho se insere apontam um efeito inibitório de estatinas (principalmente as lipofílicas) sobre CTN mamárias humanas e murinas. Assim sendo, buscou-se neste trabalho elucidar o efeito da sinvastatina sobre angiogênese tumoral, CTNs CD34+, além de investigar possíveis interrelações fisiopatológicas desses importantes elementos tumorais. Para tanto, utilizou-se um modelo consagrado de carcinogênese mamária (baseado na indução com 7,12-dimetilbenz(a)antraceno [DMBA]) em ratas Sprague-Dawley, sendo a primeira vez em que o fenômeno de angiogênese é descrito neste modelo. Após a aplicação do protocolo experimental e a eutanásia dos animais controles e experimentais, suas linhas mamárias (contendo ou não tumores) foram avaliadas morfologicamente e do ponto de vista de imunoexpressão de CD34. Nos animais tratados com sinvastatina (na dose de 40mg/kg), houve uma maior representação tecidual relativa do subtipo histológico "carcinoma ductal" quando comparado ao tecido tumoral virgem de tratamento, fato que sugere um efeito da sinvastatina sobre a plasticidade morfológica das neoplasias induzidas pelo DMBA. Também se observou redução significativa da densidade microvascular do tecido tumoral tratado em relação ao não tratado. Contudo, não foi observado efeito significante da sinvastatina sobre as CTNs CD34+, neste modelo, o que contraria resultados in vitro relatados na literatura, bem como resultados in vivo deste grupo de pesquisa. Em conclusão, neste modelo, o tratamento crônico (14 dias) com sinvastatina (na dose de 40mg/kg, ao dia - dose comparada à utilizada na terapêutica antidislipidêmica em seres humanos), apresenta efeito antiangiogênico e modulador da heterogeneidade morfológica em tumores mamários induzidos pelo DMBA / Abstract: Breast cancer is the most common malignancy and the leading cause of death from cancer among females worldwide. Despite all the research and all the progress achieved so far, the morbidity and mortality due to this cancer remains high in patients at advanced stages. Recently, it was described a new model of carcinogenesis in which stem cells (SC) could be responsible for the origin, morphological heterogeneity and self-renewal of cancer. In support of this theory, it has been observed, in most solid tumors, the presence of cells showing phenotypic and biological characteristics of stem cells, which have thus been designated cancer stem cells (CSC). Being associated with therapeutic resistance and tumor recurrence in the long run, CSCs constitute an important target in pharmacological and pathophysiological studies. In addition to CSCs, promising therapeutical targets also include tumor angiogenesis. Nevertheless, very few studies have focused on the interrelations of these two strategies. Statins are first-line anti-dyslipidemic drugs which have been shown to possess anti-neoplastic properties - possibly related to anti-apoptotic and/or anti-angiogenic effects (although these putative mechanisms have not yet been entirely investigated). Based on preliminary results of Gauthaman et al. (in vitro data) and of our group (in vivo data), indicating that statins (specially the lipophilic ones) may have a specific inhibitory effect over mammary CSCs, we sought to elucidate the in vivo effect of simvastatin on tumor angiogenesis and CD34+ CSC, simultaneously; this was achieved using a well-recognized carcinogenesis model, where a single dose of 7,12-Dimethylbenz(a)anthracene (DMBA) is used to induce of mammary tumors in Sprage-Dawley female rats. Of notice, this is the first time angiogenesis is quantitatively and morphologically assessed in this model. Our results show that simvastatin significantly increases the relative participation of invasive ductal carcinoma as a subcomponent of the induced mixed tumors, suggesting that this drug may modulate the morphologic plasticity of DMBA-induced mammary neoplasms. It was also observed a significant reduction in the microvessel density (MVD) of treated tumor tissue, when compared to that of untreated specimens. No significant difference was seen in terms of CD34+CSC number, when comparing treated and untreated tissues, which is in clear contrast to in vitro results reported in the literature and to our own in vivo results (using other CSC markers). In conclusion, in the present protocol, simvastatin, at the dose of 40mg/kg daily for 14 days (which is comparable to the anti-dyslipidemic doses used in humans), has anti-angiogenic and morphologic effects on DMBA-induced mammary tumors, but no significant action on CD34+ CSCs / Mestrado / Farmacologia / Mestre em Farmacologia
124

Activation of multiple hemopoietic growth factor genes in Abelson virus transformed myeloid cells

Abraham, Samuel D. M. January 1988 (has links)
The stringent requirement for hemopoietic growth factors (HGF) in the induction of hemopoiesis in vitro has raised questions as to their possible role(s) in leukemogenesis. Several recent clinical studies have shown aberrant cell growth factor gene activation in patient derived leukemic cells. Assessment of growth factor activity is often based on in vitro bioactivity assays of conditioned media or body fluids. The specificity of this type of endpoint is, however, open to question due to the overlap in biological activities of many HGFs. In assessing the role of growth factor gene expression in a murine myeloid leukemia model I have used a sensitive RNA detection procedure coupled with a vector-probe system that enables the synthesis of uniformly labelled radioactive DNA probes to detect unambiguously the expression of particular growth factor genes. The Abelson murine leukemia virus (A-MuLV) derived myeloid transformants used in this study had previously been shown to produce a multi-lineage colony stimulating activity (CSA). While these A-MuLV transformants were shown to produce GM-CSF, it seemed likely that the multi-lineage CSA was due to another factor. In addition to confirming the expression of GM-CSF mRNA, I was able to show that the cells of all four A-MuLV transformed lines tested also expressed interleukin-3 mRNA. This finding was strongly corroborated by bio-activity data obtained using the CM from the A-MuLV myeloid transformants. Additional preliminary analysis by bioactivity assays have also shown the possible presence of interleukin-6 (IL-6) and a recently described pre-B cell factor suggesting perhaps a common mechanism underlying the activation of these various growth factor genes. / Medicine, Faculty of / Medical Genetics, Department of / Graduate
125

Peptídeo C16, derivado da laminina, regula invasão, dinâmica de formação e atividade de invadopódios em linhagens celulares de carcinoma epidermóide e fibrossarcoma. / Laminin-derived peptide C16 regulates invasion and invadopodia activity/dynamics in squamous cell carcinoma and fibrosarcoma cell lines.

Adriane Sousa de Siqueira 02 June 2014 (has links)
A laminina contém peptídeos que podem ser liberados por proteólise. Nosso laboratório estuda os efeitos de peptídeos da laminina em biologia tumoral. Neste trabalho, verificamos se C16 (cadeia g1) estimularia invasão e atividade de invadopódios em células de carcinoma epidermóide (CAL27) e fibrossarcoma (HT1080). C16 promoveu aumento na taxa de invasão e atividade de invadopódios em ambas às linhagens celulares, comparado ao peptídeo controle C16SX. Microscopia em time-lapse demonstrou que C16 induz aumento na atividade de invadopódios em função do tempo. C16 estimula fosforilação de Src e ERK 1/2, e inibição da via ERK reduz invasão e atividade de invadopódios relacionados ao peptídeo. C16 conjugado à rodamina foi encontrando decorando a membrana de células CAL27, sugerindo possível interação com receptores. Diminuição dos níveis de integrina b1 reduzem atividade de invadopódios em amostras tratadas com C16. Nossos dados sugerem que C16 regula invasão e atividade de invadopódios em células CAL27 e HT1080, provavelmente por meio de Src, ERK e integrina b1. / Laminin harbors bioactive peptides released upon tumor-induced proteolysis. Our Laboratory has been studying laminin peptides effects in tumor biology. Here we addressed whether C16 (g1 chain) would regulate invasion and invadopodia activity in cell lines from squamous cell carcinoma (CAL27) and fibrosarcoma (HT1080). C16 increased invasion rate and invadopodia activity compared to control peptide (C16SX). Through time-lapse microscopy, we observed that C16 stimulated invadopodia activity overtime. We searched for signaling pathways related to peptide effects. C16 stimulated Src and ERK 1/2 phosphorylation, and ERK signaling cascade inhibition decreased C16-induced invasion and invadopodia. Next, we addressed how C16 would interact with tumor cells. Rhodamine-conjugated C16 was found decorating CAL27 cell membrane, suggesting an interaction with receptors. Knockdown of b1 integrin reduced invadopodia activity of C16-treated cells. We propose that C16 regulates invasion and invadopodia activity of CAL27 and HT1080 cells through Src, ERK and b1 integrin.
126

Functional Analysis of MicroRNA-10b in Breast Carcinoma: A Dissertation

Moriarty, Charlotte M. Harwood 08 May 2009 (has links)
MicroRNAs (miRNAs) represent a class of small noncoding RNAs that regulate gene expression. Recent studies have shown that miRNAs are mis-expressed in various human cancers and that some miRNAs have the potential to act as tumor suppressors or oncogenes. MiR-10b is one miRNA that has been shown to be deregulated in breast cancer. However, current findings regarding miR-10b’s role in breast cancer are controversial. MiR-10b was originally reported to be downregulated in breast cancer compared to normal breast tissue. Subsequently, miR-10b was argued to be upregulated in metastatic breast cancer cell lines, acting as a potent pro-metastatic agent via regulation of HOXD10. This report was soon challenged by another group who reported that miR-10b expression in a large patient cohort correlated inversely and significantly with tumor size, grade, and vascular invasion, but did not correlate with development of distant metastases or survival. These latter data suggest that miR-10b may impede specific functions associated with breast cancer progression. In this thesis, I present my analysis of miR-10b function in breast carcinoma cells, which revealed that it suppresses their migration and invasion. To define a mechanism that accounts for this suppressive function, I identified T-lymphoma invasion and metastasis 1 (TIAM1), a guanine nucleotide exchange factor for Rac1, as a miR-10b target and demonstrated that miR-10b inhibits TIAM1-dependent Rac1 activation, migration, and invasion. In addition, I identified the VEGF receptor fms-related tyrosine kinase 1 (FLT-1) as a second target of miR-10b and discovered a novel function for FLT-1 in promoting breast carcinoma cell migration and invasion. My results show, for the first time, that Rac activation can be regulated by a specific miRNA and provide a novel mechanism for the regulation of TIAM1 and FLT-1 in breast cancer. These data support the conclusion from clinical data that miR-10b expression correlates inversely with breast cancer progression, and suggest that miR-10b functions to impede breast carcinoma progression by regulating key target genes involved in cell motility.
127

The role of tumoral 1,25 dihydroxyvitamin D3 in inhibition of tumor growth and progression in the PyVMT MMTV#634 transgenic breast cancer model /

Rossdeutscher, Lionel Philip David. January 2007 (has links)
No description available.
128

Differential regulation of c-Cbl and Cbl-b ubiquitin ligases downstream of the Met receptor tyrosine kinase

Durrant, Michael, 1982- January 2007 (has links)
No description available.
129

Influência do grau de especialização médica no diagnóstico de fraturas vertebrais benignas e malignas nas imagens de ressonância magnética / Influence of the degree of medical specialization in the diagnosis of benign and malignant vertebral fractures in magnetic resonance imaging

Santos, Iranilson Medeiros Germano dos 02 June 2017 (has links)
As fraturas benignas osteoporóticas e malignas da coluna vertebral representam um desafio diagnóstico para os médicos especialistas. As fraturas benignas osteoporóticas ocorrem em virtude da fragilidade óssea da osteoporose e as fraturas malignas são secundárias a infiltração neoplásica. Estes dois grupos tem em comum o fato de acometerem predominantemente a população idosa. Alguns sinais radiológicos favorecem o diagnóstico de fraturas benignas osteoporóticas enquanto outros sinais de imagem favorecem o diagnóstico de fraturas malignas, no entanto nenhum sinal identificado nas imagens é específico. O propósito de realizar esse estudo foi identificar se o nível de formação médica dos radiologistas e ortopedistas (cirurgiões da coluna vertebral) exerce influência para o diagnóstico etiológico dessas fraturas nos exames de RM da coluna lombar, assim como avaliar o grau de concordância intra e interobservador para o diagnóstico de fraturas benignas por osteoporose e fraturas malignas. Foram incluídos no estudo de forma retrospectiva os exames de 63 pacientes consecutivos da rotina clínica do HCRP, realizados previamente por indicação clínica e com diagnóstico de fratura não traumática de corpo vertebral. Para avaliar a influência do nível de formação médica, quatro radiologistas e dois cirurgiões da coluna vertebral com diferentes níveis de formação realizaram avaliações de forma independente e as cegas em relação as demais leituras e em relação às informações do prontuário clínico. As imagens de RM anonimizadas e no formato DICOM foram avaliadas em workstation OsiriX. Os médicos observadores fizeram as leituras classificando cada vértebra da região lombar da seguinte forma: sem fratura, com fratura de características benignas ou com fratura de características malignas. Cada observador realizou duas leituras, com intervalo de 15 dias entre as leituras. O padrão de referência foi obtido a partir da avaliação pormenorizada do prontuário eletrônico de cada paciente realizada por médico radiologista sênior, a partir do Sistema de Informações do Hospital (HIS) e do Sistema Informatizado da radiologia (RIS), incluindo a biópsia com confirmação histopatológica nos casos de neoplasia e o seguimento clinico e laboratorial por pelo menos dois anos nos casos em que não houve indicação clínica de biópsia. Utilizando este padrão de referência foram calculadas para cada leitura, a sensibilidade, a especificidade, acurácia, valor preditivo positivo e negativo com intervalo de confiança (IC) 95%. Os resultados demonstram uma excelente concordância intraobservador e uma boa concordância interobservador, porém sem relevância estatística. Além disso, de uma forma geral a sensibilidade dos observadores para a detecção de fraturas malignas foi boa. A especificidade, acurácia e valor preditivo negativo foram elevados para todos os observadores. O valor preditivo positivo variou de moderado a substancial. Portanto, não houve influência do nível de formação médica para o desempenho diagnóstico na detecção de fraturas benignas osteoporóticas e fraturas malignas nas imagens de ressonância magnética. / Benign osteoporotic and malignant spinal fractures represent a diagnostic challenge for medical specialists. Osteoporotic benign fractures occur because of the bone fragility of osteoporosis and malignant fractures are secondary to neoplastic infiltration. These two groups have in common the fact that they affect predominantly the elderly population. Some radiological signs favor the diagnosis of benign osteoporotic fractures while other imaging signs favor the diagnosis of malignant fractures, however no signs identified in the images are specific. The purpose of this study was to identify whether the level of medical training of radiologists and orthopedists (spine surgeons) influences the etiological diagnosis of these fractures in lumbar spinal MRI (magnetic resonance imaging), as well as to evaluate the degree of intra and interobserver agreement for the diagnosis of benign fractures due to osteoporosis and malignant fractures. We retrospectively included the exams of 63 consecutive patients from the clinical routine of the HCRP, performed previously by clinical indication and with diagnosis of non-traumatic vertebral body fracture. To evaluate the influence of the level of medical training, four radiologists and two spine surgeons with different levels of training performed evaluations independently, without knowing the other readings and without the information in the medical record. The anonymized MRI in the DICOM format were evaluated in OsiriX workstation. Observer doctors did the readings by classifying each vertebra in the lumbar region as follows: no fracture, with fracture of benign features or with fracture of malignant characteristics. Each observer performed two readings, with a 15-day interval between readings. The reference standard was obtained from the detailed evaluation of each patient\'s electronic medical record by a senior radiologist, with the Hospital Information System (HIS) and the Computerized Radiology System, including biopsy with histopathological confirmation in cases of neoplasia and clinical and laboratory follow-up for at least two years in cases in which there was no clinical indication of biopsy. Using this reference standard, sensitivity, specificity, accuracy, positive and negative predictive value with 95% confidence interval (CI) were calculated for each reading. The results demonstrate excellent intraobserver agreement and good interobserver agreement, but without statistical relevance. In addition, the sensitivity of the observers for the detection of malignant fractures was generally good. The specificity, accuracy and negative predictive value were high for all observers. The positive predictive value ranged from moderate to substantial. Therefore, there was no influence of the level of medical training for diagnostic performance in the detection of benign osteoporotic fractures and malignant fractures in magnetic resonance imaging.
130

Gene expression patterns in human ovarian cancer and mouse embryos.

January 1997 (has links)
by Cheung Kwok Kuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 111-130). / Chapter Chapter 1 --- General introduction of human ovarian cancer / Chapter 1.1 --- Epidemiology --- p.1 / Chapter 1.2 --- Symptoms and diagnosis --- p.4 / Chapter 1.3 --- Etiology --- p.5 / Chapter 1.3.1 --- Factors associated with decreased risks --- p.6 / Chapter 1.3.2 --- Factors associated with increased risks --- p.8 / Chapter 1.4 --- Classification of ovarian cancer --- p.12 / Chapter 1.5 --- Molecular basis of ovarian cancer --- p.18 / Chapter 1.6 --- Project aim --- p.29 / Chapter Chaper 2 --- "DOC-2, a differentially expressed gene in human ovarian cancer" / Chapter 2.1 --- Introduction --- p.32 / Chapter 2.2 --- Materials and Methods --- p.35 / Chapter 2.2.1 --- Expression of DOC-2 in human ovarian tissues --- p.35 / Chapter 2.2.1.1 --- Preparation of specimen --- p.35 / Chapter 2.2.1.2 --- Immunohistochemical studies of the expression of DOC-2 protein in human ovarian tissues --- p.35 / Chapter 2.2.1.3 --- Quantitation of immunoreactivity --- p.38 / Chapter 2.2.2 --- Effect of DOC-2 transfection on growth rate of the ovarian cancer cell lineSKOV3 --- p.39 / Chapter 2.2.2.1 --- Cell line --- p.39 / Chapter 2.2.2.2 --- Transfection of DOC-2 to SKOV3 ovarian carcinoma cell line --- p.39 / Chapter 2.2.2.3 --- Growth curve of the transfected ovarian carcinoma cell lines --- p.40 / Chapter 2.2.3 --- In vivo tumorigenicity study --- p.42 / Chapter 2.3 --- Results --- p.44 / Chapter 2.3.1 --- Expression of DOC-2 in human ovarian tissues --- p.44 / Chapter 2.3.2 --- Effects of DOC-2 transfected gene on the growth rate of the human ovarian cancer cell line SKOV3 --- p.46 / Chapter 2.3.2.1 --- Standard curves for calculating cell density from absorbance --- p.46 / Chapter 2.3.2.2 --- The effect of DOC-2 transfection on the growth rate of the human ovarian cancer cell line SKOV3 --- p.47 / Chapter 2.3.3 --- In vivo tumorigenicity --- p.48 / Chapter 2.4 --- Discussion --- p.50 / Chapter Chapter 3 --- DOC-2 expression in mouse embryonic development / Chapter 3.1 --- Introduction --- p.56 / Chapter 3.2 --- Materials and Methods --- p.60 / Chapter 3.2.1 --- Expression of murine homolog of DOC-2 (p96) during mouse embryonic development --- p.60 / Chapter 3.2.1.1 --- Preparation of paraffin-embedded mouse embryo sections --- p.60 / Chapter 3.2.1.2 --- Preparation of OCT-embedded mouse embryo sections --- p.61 / Chapter 3.2.1.3 --- Immunohistochemistry of murine homolog of DOC-2 (p96) on mouse embryos --- p.61 / Chapter 3.2.2 --- Effect of antibody blocking for DOC-2 protein on the growth of embryonic kidney in vitro --- p.62 / Chapter 3.3 --- Results --- p.64 / Chapter 3.4 --- Discussion --- p.69 / Chapter Chapter 4 --- Apoptosis / Chapter 4.1 --- Introduction --- p.72 / Chapter 4.1.1 --- Current methods for the detection of apoptosis --- p.74 / Chapter 4.1.1.1 --- Agarose gel electrophoresis --- p.75 / Chapter 4.1.1.2 --- Flow cytometric analysis --- p.76 / Chapter 4.1.1.3 --- 3-OH end labelling --- p.77 / Chapter 4.1.1.4 --- Nuclease assay --- p.78 / Chapter 4.1.2 --- Apoptosis in normal physiology and oncogenesis --- p.78 / Chapter 4.1.3 --- p53 and apoptosis --- p.80 / Chapter 4.1.4 --- bcl-2 and apoptosis --- p.83 / Chapter 4.2 --- Materials and Methods --- p.92 / Chapter 4.2.1 --- Expression of p53 and bcl-2 in human ovarian tissues --- p.92 / Chapter 4.2.1.1 --- Preparation of specimens --- p.92 / Chapter 4.2.1.2 --- Immunohistochemical studies of the expression of p53 and bcl-2 proteins in ovarian tissue --- p.92 / Chapter 4.2.2 --- In stiu terminal transferase-mediated dUTP nick and labelling (TUNEL) --- p.94 / Chapter 4.3 --- Results --- p.96 / Chapter 4.3.1 --- Expression of p53 and bcl-2 in human ovarian tissues --- p.96 / Chapter 4.3.2 --- Apoptosis in human ovarian tissues --- p.99 / Chapter 4.4 --- Discussion --- p.101 / Chapter Chapter 5 --- Concluding Remarks --- p.108 / References --- p.111 / Appendix --- p.131 / Figures and legend --- p.138

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