• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 136
  • 105
  • 10
  • 10
  • 9
  • 7
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 328
  • 129
  • 90
  • 69
  • 66
  • 51
  • 41
  • 37
  • 37
  • 36
  • 25
  • 24
  • 23
  • 22
  • 21
  • 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.
221

Efeitos da poluição atmosférica na superfície ocular / Effects of air pollution on the ocular surface

Novaes, Priscila 16 December 2011 (has links)
Objetivo: Avaliar os efeitos de diferentes níveis de exposição ambiental sobre a superfície ocular, por meio da análise histológica da superfície ocular e da avaliação de parâmetros clínicos. Métodos: Etapa 1: Foram selecionados 29 voluntários, em duas localidades diferentes: São Paulo (n=13) e Divinolândia (n=16). Foram avaliadas medidas individuais de exposição ao dióxido de Nitrogênio (NO2) atmosférico e a citologia de impressão de conjuntiva tarsal inferior. Avaliou-se a exposição individual ao NO2 por 7 dias consecutivos, usando um sistema de medida passivo. Foram coletados espécimes de citologia de impressão de conjuntiva tarsal inferior. Foram realizados comparações entre o número de células caliciformes e os níveis de NO2 entre os dois grupos e individualmente. Etapa 2: Foram avaliados 55 voluntários, residentes em São Paulo. Foram medidos os níveis de exposição individual ao NO2, e foi realizada uma avaliação subjetiva de sintomas oculares (OSDI e freqüência de sintomas de desconforto ocular); teste de Schirmer I, biomicroscopia, coloração com fluoresceína e rosa bengala, e medida do TRFL, que foram comparados posteriormente por meio de análise estatística. Resultados: Etapa 1: Os níveis de exposição individual ao NO2 em São Paulo(média=32,47 ± 9,83 g/m3) foram 68% mais altos do que em Divinolândia (média =19,33± 5,24 g/m3); (p = 0,005), e houve uma correlação entre o número de células caliciformes e os níveis de NO2 (=0,566, p=0,001), tendo sido observado um padrão dose-resposta relativo à exposição. Etapa 2: Houve associação entre os níveis de NO2 e os escores do OSDI (p<0,05), a freqüência de irritação ocular (p<0,05), e os valores do TRFL (p<0,05, = -0,316). Conclusões: Houve uma associação significativa entre exposição à poluição atmosférica e a hiperplasia de células caliciformes conjuntivais, sintomas de desconforto ocular e maior instabilidade do filme lacrimal. Observou-se uma repercussão tanto clínica quanto histológica da exposição a níveis mais elevados de NO2, o que sugere que essas medidas podem ser usadas como biomarcadores dos efeitos adversos da poluição atmosférica sobre a superfície ocular / The purpose of this study was to assess the effects of different levels of ambient air pollution on the ocular surface, combining determinations of individual exposure with clinical and histological parameters. Methods: Stage 1: A total of 29 volunteers from two locations - São Paulo (n=13) and Divinolândia (n=16) were selected. We assessed mean individual levels of NO2 exposure for 7 days, using a passive sampler. Impression cytology samples were obtained from inferior tarsal conjunctiva. Goblet cell counts and NO2 exposure level were compared between the two groups, and between individual values. Stage 2: A total of 55 volunteers, who lived in São Paulo, were selected. The mean individual levels of nitrogen dioxide (NO2) exposure were assessed, as in Stage 1. All subjects answered the Ocular Symptom Disease Index (OSDI) and a symptoms inventory. Subsequently, subjects underwent Schirmer I test, biomicroscopy, vital staining and tear break-up time (TBUT) assessment. OSDI scores, symptoms frequency and clinical data were compared to individual NO2 exposure values by statistical analysis. Results: Stage 1: The NO2 exposure levels were 68% higher for individuals living in São Paulo (mean = 32.47, SD = ± 9.83) than for those living in Divinolândia (mean 19.33, SD ± 5.24) (p = 0,005). There was a steady increase in goblet cell counts, proportional to NO2 exposure (=0.566, p=0.001). Stage 2: There was a significant association between NO2 levels and OSDI scores (p<0.05), reported ocular irritation (p<0.05) and TBUT (p<0.05, = -0.316). Conclusions: An association between exposure to higher levels of air pollution, goblet cell hyperplasia, ocular discomfort symptoms and tear film instability was detected; indicating that there are clinical and histological effects of NO2 exposure, and that these measurements may be used as biomarkers of the adverse effects of air pollution on the ocular surface
222

Protein expression analysis of prostate cancer

Li, He-Chun 08 July 2004 (has links)
Prostate cancer is one of the most common malignant tumors in solid organs of old men. However, the patients are nearly 100 percent survivable if detected early. Prostate-specific antigen (PSA) is a valuable prostate cancer biomarker that is now wildly used for population screening, diagnosis, and monitoring of patients with prostate cancer. But PSA is not good enough for a biomarker because it can not distinguish benign prostate hyperplasia (BPH) from prostate tumor . Recently, there are some tumor marker still in study, for example: free prostate specific antigen¡]fPSA), complexed prostate specific antigen (C-PSA), kallikrein,prostate specific membrane antigen (PSMA). From previously study,we had found many different protein expressions between serum of normal and prostate patients. Mayven is one of the novel proteins that had been identified. The mRNA expression of Mayven in prostate cancer tissue is determined by quantitative RT-PCR. The result shows that the mRNA expression of Mayven in Benign Prostatic Hyperplasia (BPH) is about 5.0-11.3 fold than normal tissue , 12.7 fold in Prostate Cancer (PCa) stage T1 and 0.1- 3.7 fold after cancer stage T2. The Mayven gene expression is predominate in tumor stage T1, decrease after T2 stage. However the expressed pattern of mayven in BPH remains further investigation due to the limited sample size. Furthermore, with 2 dimensional electrophoresis (2¡VDE), we have found 7 differentially expressed proteins between tissue of normal and prostate patients, and these proteins are identified by MALDI-TOF mass spectrometry and MS-Fit. These identified proteins are Keratin 8¡]KRT8¡^, MAPKkinase5¡]MAP2K5¡^, Acid phosphatase (ACPP), Annexin A3¡]ANXA3¡^, Phosphoglycerate mutase 1 (PGAM1), Spindlin-like protein 2 (SPIN2) and Transgelin 2¡]TAGLN2¡^.
223

Comparison of the Clinical Value of Complexed PSA and Total PSA in the Discrimination between Benign Prostatic Hyperplasia and Prostate Cancer

Fröhner, Michael, Hakenberg, Oliver W., Koch, Rainer, Schmidt, Uta, Meye, Axel, Wirth, Manfred P. 14 February 2014 (has links) (PDF)
Background: To compare the clinical value of the measurement of complex and total PSA in the discrimination between benign prostatic hyperplasia (BPH) and prostate cancer. Methods: In serum samples collected from 166 men with histopathologically proven clinically localized prostate cancer and of 97 men with BPH, total prostate-specific antigen (PSA), complexed PSA and the free to total PSA ratio were determined. The statistical analysis was done by the comparison of the receiver operator characteristic (ROC) curves. Results: The areas under the ROC curves were 0.776 for total PSA, 0.799 for complexed PSA (total PSA vs. cPSA: p < 0.0001) and 0.812 for the free to total PSA ratio. With a cut-off of 3.0 ng/ml for complexed PSA, the sensitivity was 90%, the specificity 58%, the positive and the negative predictive values 79 and 78%, respectively. With a cut-off of 4.0 ng/ml for total PSA, the sensitivity was 87%, the specificity 59%, the positive and the negative predictive values were 78 and 72%, respectively. Conclusions: There was a statistically significant advantage for complexed PSA compared to total PSA in the discrimination between BPH and prostate cancer. The difference was, however, small and its clinical relevance is questionable. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
224

Die Rolle des PTEN/PI3K/AKT-Signalweges für die intestinale Immunregulation beim Menschen

Heindl, Mario 18 October 2011 (has links) (PDF)
Der PTEN/PI3K/AKT-Signalweg spielt eine entscheidende Rolle bei der Regulation von Proliferation, Migration und Apoptose. Mäuse mit Defekten innerhalb dieses Signalweges weisen multiple Veränderungen in B- und T-Zell- Homöostase auf, welche zu Thymushyperplasie, Lymphadenopathie, Auto- immunität und Lymphomen führen können. Die Entwicklung und der Erhalt von Foxp3+ regulatorischen T-Zellen ist vom PTEN/PI3K/AKT-Signalweg abhängig. Die immunologischen Konsequenzen von PTEN-Defekten beim Menschen sind bisher nicht verstanden. Aufgrund dieser Tatsache wurden sechs Patienten mit PTEN-Hamartom-Tumor-Syndrom auf immunologische Veränderungen unter- sucht. Die gefundenen Dysregulationen beinhalteten Thymushyperplasie, Tonsillenhypertrophie und ausgedehnte lymphoide Hyperplasien des oberen und unteren Gastrointestinaltraktes. Eine erhöhte Anzahl von naiven Lymphozyten zirkuliert im peripheren Blut und akkumuliert in lymphoiden Organen. Intestinale lymphoide Hyperplasien waren mit einer gesteigerten Phosphorylierung von AKT assoziiert, zeigten jedoch normale Proliferation in T-Zell-Zonen sowie eine normale Verteilung CD3+Foxp3+ T-Zellen. Foxp3+ T-Zellen zeigten jedoch eine gesteigerte Proliferation und Aktivierung des mTORC1-Pfades in situ, was auf einen Schwelleneffekt für PTEN-Aktivität hinweisen könnte. Auffällig war eine reduzierte Apoptose bei gleichzeitig gesteigerter Proliferation und erhöhter mTOR- Aktivität bei CD20+CD10+ B-Zellen des Keimzentrums. Diese Daten zeigen, dass ein Verlust von PTEN-Aktivität auch beim Menschen mit Defekten in B- und T-Zell- Homöostase assoziiert ist. Dies führt zur Akkumulation von Lymphozyten und intestinaler lymphoider Hyperplasie bei weitgehend erhaltener Immunkompetenz.
225

Mass Spectrometric Applications for Diagnosing Metabolic and Endocrine Diseases

Kushnir, Mark M. January 2008 (has links)
Disease-specific compounds (biomarkers) are analyzed in clinical laboratories to assist with diagnosing diseases. This thesis describes development and validation of liquid chromatography tandem mass spectrometry (LC-MS/MS) based tests for diagnosing a diverse group of endocrine and metabolic diseases. The analytical methods used on-line and off-line sample extraction and analytical derivatization as means of enhancing the analytical sensitivity, specificity and clinical utility. All developed methods were extensively validated and reference intervals for the biomarker concentrations were established in blood samples of healthy adults and children. Advantages of the LC-MS/MS as an analytical technique include possibility of simultaneous measurement of multiple analytes and ability of confirming their identity. In this thesis we proposed and evaluated approaches for the assessment of the specificity of analysis in the methods that use tandem mass spectrometry detection. To enhance throughput of the LC-MS/MS tests for the biomarkers that have endogenous or exogenous isomers an approach was developed for quantitation of isomers from unresolved chromatographic peaks. Using methods developed in this thesis we performed a study of the steroidogenesis in ovarian follicles of healthy women and women with polycystic ovary syndrome (PCOS). Obtained data on the steroid concentrations and associations between the steroid metabolites in the pathway would be helpful for better understanding of the ovarian pathophysiology. Potential biomarkers of PCOS were identified in the thesis; further studies will be necessary to confirm their clinical utility.
226

Análise histológica e histomorfométrica de carótidas após o implante de stent de cromocobalto sem e com revestimento de polímero : modelo experimental porcino

Grudtner, Marco Aurelio January 2009 (has links)
Introdução: Apesar dos avanços significativos no tratamento endovascular das doenças arteriais coronarianas e periféricas, a reestenose intra-stent continua sendo o principal limitante a médio prazo desses procedimentos. O mecanismo da reestenose intra-stent é principalmente a hiperplasia intimal, já que o stent impede a retração elástica aguda e resiste ao remodelamento geométrico negativo tardio. A hiperplasia intimal ocorre basicamente em resposta à formação de trombo local, à inflamação e às dissecções intimais e mediais secundárias à injúria causada pelo stent, sendo o grau de resposta intimal a base dos efeitos a longo prazo. O uso de stents com hastes menores e revestidos com drogas ou polímeros tem sido considerado uma nova alternativa para a prevenção da reestenose intra-stent. Objetivo: Analisar a resposta arterial ao implante de stent de cromo-cobalto sem e com revestimento de polímero Camouflage® em artérias carótidas de suínos, utilizando os seguintes parâmetros histológicos: grau de endotelização, conteúdo de células musculares lisas, grau de angiogênese, conteúdo de fibrina, grau de inflamação e injúria; além da análise histomorfométrica. Método: Stents balões-expansíveis de cromo-cobalto ( 8 stents CC Flex e 5 stents CC Flex Proactive) de 4 x 16 mm foram implantados em artérias carótidas comuns de oito suínos jovens, sendo um stent liberado em cada artéria. Após 30 dias, as artérias contendo os stents foram removidas, fixadas e coradas pelos métodos de hematoxilina/eosina e Verhoeff/Van Giesson. O segmento arterial contendo o stent foi dividido em 3 blocos distintos: proximal, médio e distal. Os cortes histológicos foram obtidos utilizando-se micrótomo de impacto (Polycut S, Leica, Alemanha) equipado com navalha de tungstênio de 16 cm, tipo D (Leica, Alemanha), com 5 ^m de espessura. A navalha de tungstênio mantém as hastes dos stents intactas nas secções transversas, minimizando os artefatos potenciais causados pela retirada dos stents. A avaliação foi realizada através de critérios histológicos e histomorfométricos. Resultados: Todos os stents foram implantados com sucesso e sem dificuldades técnicas. A análise histológica em 30 dias evidenciou alto grau de endotelização em todos os segmentos avaliados e leve à moderada infiltração de células musculares na íntima. Observou-se baixo grau de angiogênese em cerca de 50% dos segmentos avaliados e ausência completa de deposição de fibrina em pelo menos 80%, com distribuição semelhante entre os grupos. A resposta inflamatória e o grau de injúria causadas pelas hastes dos stents também foram discretas e similares entre os grupos e não houve correlação entre resposta inflamatória e injúria e desses parâmetros com a área de neoíntima. O grau de obstrução neo-intimal identificada neste período foi pequeno (15,1% +/- 8,38 CC Flex x 15,5%+/- 5,39 CC Flex ProActive) e estatisticamente não significativo entre os grupos (p=0,785). Conclusão: Os achados deste estudo experimental sugerem que o uso de stents de cromo-cobalto revestidos com polímero Camouflage® em artérias carótidas de suínos parece estar associado, pelo menos no curto prazo, a uma resposta histológica semelhante àquela encontrada após o implante de stents de cromo-cobalto não revestidos. Neste período não se observou uma menor hiperplasia intimal em virtude do revestimento de polímero. / Introduction: Despite all the advances in the endovascular treatment of coronary and peripheral artery diseases, in-stent restenosis is still the main limiting factor of these procedures in the medium and long-term. The mechanism of in-stent restenosis is mainly the intimal hyperplasia, as the stent prevents acute elastic recoil and later negative geometric arterial remodeling. Intimal hyperplasia occurs basically in response to the formation of local thrombus, inflammation and intimal and medial dissections secondary to the injury caused by the stent, with the degree of intimal response being the cause of long-term effects. Coating drug-eluting stents with polymers and drugs with thinner struts have been considered a new alternative for in-stent restenosis prevention. Objective: Analyse the arterial response to the cobalt-chromium stent implant with and without polymer coating Camouflage® in carotid arteries of pigs, using the following histological parameters: degree of endothelialization, smooth muscle cells (SMC) content, degree of angiogenesis, intimal fibrin content, degree of inflammation and injury; plus histomorphometric analysis. Method: Cobaltchromium balloon-expandable stents (8 CC Flex stents and 5 CC Flex Proactive), 4 x 16 mm, were deployed in common carotid arteries of 8 young pigs, with one stent being deployed in each artery. After 30 days, the arteries containing the stents were removed and underwent fixation and staining using the hematoxilin/eosin and Verhoeff /Van Giesson methods. The arterial segment containing the stent was divided into 3 distinct portions: proximal, middle and distal. The histological sections were obtained using impact microtome (Polycut S, Leica, Germany), equipped with a 16 cm, type D, 5 ^m thick tungsten knife (Leica, Germany). The tungsten knife maintains the stent shaft intact in cross sections, minimizing the potential artifacts caused by stent removal. The evaluation was carried out using histological and histomorfometric criteria. Results: All the stents were deployed with success and with no technical difficulties. The histological analysis performed after 30 days showed a high level of endothelialization in all the evaluated portions and mild to moderate infiltration of the SMC in the intima layer. A low level of angiogenesis of about 50% of the evaluated portions was observed and a complete absence of fibrin deposition in at least 80% of the portions, with similar distribution among the groups. The inflammatory response and the level of injury caused by the struts of the stents were also minimum and this was similar among the groups. There was no correlation between inflammatory response and injury and between the two latter parameters and the neo-intima area. The level of neo-intimal obstruction identified in this period was small (15,1% +/- 8,38 CC Flex x 15,5%+/- 5,39 CC Flex ProActive ) and no statistical significance between the groups (p=0,785). Conclusion: The findings of this experimental study suggest the use of balloonexpandable cobalt-chromium stents coated with polymer Camouflage® in carotid arteries of pigs seems to be associated, at least in the short-term, with a similar histological response to that found in the implantation of non-coated cobalt-chromium stents. In this period, a lower intimal hyperplasia was not observed with polymer coating stents.
227

Triagem neonatal pública para hiperplasia adrenal congênita no Rio Grande do Sul : da implantação à caracterização clínico-laboratorial

Kopacek, Cristiane January 2016 (has links)
A hiperplasia adrenal congênita (HAC) é um grupo de doenças hereditárias causadas por uma deficiência em uma das enzimas necessárias para a síntese de cortisol no cortex adrenal. Mais de 95% de todos os casos de HAC são devidos a 21-Hidroxilase (21-OHD). Existem 3 formas principais, duas com manifestações clínicas no período neonatal, a forma mais grave perdedora de sal (HAC-PS) e a forma virilizante simples (HAC-VS). Além da perda salina, o excesso de andrógenos leva à virilização de recém nascidas femininas. As formas neonatais são chamadas de clássicas, atividade enzimática da 21-OH bastante reduzida, de < 2% na HAC-PS e de 2-10% na HAC-VS. A forma parcial de início tardio é chamada de HAC não clássica (HAC-NC) e a principal manifestação na infância é a adrenarca precoce. Nesta forma a atividade da 21-OH é de 20-60%. Os programas de triagem para HAC visam, principalmente, ao diagnóstico precoce da forma clássica perdedora de sal, mais grave e potencialmente letal. No Brasil, a triagem pública é realizada no Estado de Goiás desde 1997 e em Santa Catarina desde 2001. No Rio Grande do Sul (RS) foi implantada em maio de 2014 na fase IV do Programa Nacional de Triagem Neonatal. A inclusão da HAC trouxe consigo muitos desafios e a exigência de um fluxo de triagem e diagnóstico bem estruturados. O diagnóstico precoce é crucial para prevenir o óbito de lactentes por insuficiência adrenal. Dosa-se, em papelfiltro, a 17OH progesterona (17-OHP). Elevações podem ocorrer em recém-nascidos sem HAC (falso-positivos), devido a situações de estresse perinatal e por prematuridade. Após avaliação dos dados do primeiro ano de triagem para HAC neste estudo, a mediana da idade da coleta nos casos diagnosticados foi de 8 dias (4.25-15.75). Dos 8 casos diagnosticados de maio de 2014 a abril de 2015, 6 casos com forma perdedora de sal (incluindo 1 caso de óbito por coleta tardia do TP aos 38 dias de vida). A incidência encontrada em nosso meio no primeiro ano foi de 1:13.551 casos. Com a estratégia do uso de pontos de corte estratificados pelo peso de nascimento18, o índice total de resultados positivos em nosso meio foi de 0,5% da amostra avaliada (“n” total de 514 bebês), sendo mais frequente em recém nascidos com menos de 2000g de peso ao nascer. Além da confirmação clínica e laboratorial, o genótipo é importante, além de confirmar, para estabelecer gravidade da doença e também para ratificar o diagnostico dos falsos positivos na ausência de uma mutação do gene CYP21A2. Um dos casos confirmados de HAC-PS foi associado a múltiplas malformações e craniossinostose severa, suscitando a hipótese de um a associação com defeito de FGFR2. A correlação genótipo- fenótipo na avaliação dos casos em dois anos da triagem alcançou um alto nível de concordância de 87%. Diagnosticada, portanto, de forma assertiva a HAC forma clássica, instituise a terapia glicocorticóide para as formas virilizante simples e acrescenta-se mineralocorticóide para as formas perdedoras de sal. A triagem neonatal é um importante programa de saúde populacional e visa ao diagnóstico precoce de uma patologia com potencial risco à vida pela perda de sal, além de permitir adequada atribuição de sexo nas meninas com virilização genital e à saúde da criança. Estabelecer os fluxos adequados de triagem e manejo, além de ampliar o conhecimento sobre a HAC, com o reconhecimento dos desfechos e tratamentos adequados é essencial para minimizar as possíveis complicações nesta população de maior vulnerabilidade. / Congenital adrenal hyperplasia (CAH) is a group of inherited diseases caused by a deficiency in one of the enzymes required for the cortisol synthesis by the adrenal cortex. More than 95% of all CAH cases are due to 21-hydroxylase (21-OHD). There are 3 forms, two with neonatal clinical manifestation: salt-wasting CAH (SW-CAH\) and the simple virilizing form (HAC-VS). In addition to salt loss, androgens excess lead to the virilization of female newborn. Neonatal forms are defined as classical CAH. The 21-OHD enzymatic activity in SWCAH is less than <2% and in the SV-CAH 2-10%. A late-onset form, with partial enzymatic defect (20-60%) is called non-classical HAC (NC-CAH) and the main manifestation in childhood is early adrenarche. In Brazil, public health screening has been conducted in the State of Goiás since 1997 and in te Sate of Santa Catarina since 2001. In Rio Grande do Sul (RS) it was implemented in May 2014, in phase IV of the National Neonatal Screening Program. The inclusion of CAH in the local screening program brought many challenges and the need of a well structured screening and diagnosis flowchart. Early diagnosis is crucial to prevent infant death due to adrenal insufficiency. Around de world, the screening programs for CAH main purpose is the early diagnosis of the more severe classical forms, especially SW-CAH. The cortisol precursor 17OH progesterone (17-OHP) is the main disease marker and is measured on filter paper. Elevations may occur in infants without CAH (false positive) due to perinatal stress and prematurity. Of newborns screened in the first year, median age of collection in diagnosed cases was 8 days (4.25-15.75) and 8 patients were diagnosed with CAH (four males, four females). The incidence of CAH in the state was 1:13,551. Six cases were identified as classic salt-was-ting CAH and two were cases of virilizing CAH. The overall rate of positive results was 0.5% (n = 514 infants). The number of false positive results was higher among newborns with birth weight < 2,000 g. In addition to clinical and laboratory confirmation, the genotype is important to confirme 21-OH deficiency, to establish disease severity and also in the absence of a mutation of the CYP21A2 gene to more precise exclude the diagnosis of suspected false positives. One of the confirmed cases of SW-CAH was associated with multiple malformations and severe craniosynostosis, raising the hypothesis of an association with FGFR2 mutation. A high genotype- phenotype correlation of 87% was found in the cases after two years of screening. Once the classic CAH is diagnosed, glucocorticoid therapy is instituted and mineralocorticoid is added for SW-CAH. CAH neonatal screening is an important population health program and aims to the early diagnosis of a pathology with a potential risk due to salt loss crisis. The early detection of cases also allows to adequate sex assignment in girls with genital virilization. Establishing adequate screening flows, proper diagnosis and management, in addition to increase knowledge about the disease, with the appropriate recognition of outcomes and treatments is essential to minimize complications in this population of greater vulnerability.
228

Análise histológica e histomorfométrica de carótidas após o implante de stent de cromocobalto sem e com revestimento de polímero : modelo experimental porcino

Grudtner, Marco Aurelio January 2009 (has links)
Introdução: Apesar dos avanços significativos no tratamento endovascular das doenças arteriais coronarianas e periféricas, a reestenose intra-stent continua sendo o principal limitante a médio prazo desses procedimentos. O mecanismo da reestenose intra-stent é principalmente a hiperplasia intimal, já que o stent impede a retração elástica aguda e resiste ao remodelamento geométrico negativo tardio. A hiperplasia intimal ocorre basicamente em resposta à formação de trombo local, à inflamação e às dissecções intimais e mediais secundárias à injúria causada pelo stent, sendo o grau de resposta intimal a base dos efeitos a longo prazo. O uso de stents com hastes menores e revestidos com drogas ou polímeros tem sido considerado uma nova alternativa para a prevenção da reestenose intra-stent. Objetivo: Analisar a resposta arterial ao implante de stent de cromo-cobalto sem e com revestimento de polímero Camouflage® em artérias carótidas de suínos, utilizando os seguintes parâmetros histológicos: grau de endotelização, conteúdo de células musculares lisas, grau de angiogênese, conteúdo de fibrina, grau de inflamação e injúria; além da análise histomorfométrica. Método: Stents balões-expansíveis de cromo-cobalto ( 8 stents CC Flex e 5 stents CC Flex Proactive) de 4 x 16 mm foram implantados em artérias carótidas comuns de oito suínos jovens, sendo um stent liberado em cada artéria. Após 30 dias, as artérias contendo os stents foram removidas, fixadas e coradas pelos métodos de hematoxilina/eosina e Verhoeff/Van Giesson. O segmento arterial contendo o stent foi dividido em 3 blocos distintos: proximal, médio e distal. Os cortes histológicos foram obtidos utilizando-se micrótomo de impacto (Polycut S, Leica, Alemanha) equipado com navalha de tungstênio de 16 cm, tipo D (Leica, Alemanha), com 5 ^m de espessura. A navalha de tungstênio mantém as hastes dos stents intactas nas secções transversas, minimizando os artefatos potenciais causados pela retirada dos stents. A avaliação foi realizada através de critérios histológicos e histomorfométricos. Resultados: Todos os stents foram implantados com sucesso e sem dificuldades técnicas. A análise histológica em 30 dias evidenciou alto grau de endotelização em todos os segmentos avaliados e leve à moderada infiltração de células musculares na íntima. Observou-se baixo grau de angiogênese em cerca de 50% dos segmentos avaliados e ausência completa de deposição de fibrina em pelo menos 80%, com distribuição semelhante entre os grupos. A resposta inflamatória e o grau de injúria causadas pelas hastes dos stents também foram discretas e similares entre os grupos e não houve correlação entre resposta inflamatória e injúria e desses parâmetros com a área de neoíntima. O grau de obstrução neo-intimal identificada neste período foi pequeno (15,1% +/- 8,38 CC Flex x 15,5%+/- 5,39 CC Flex ProActive) e estatisticamente não significativo entre os grupos (p=0,785). Conclusão: Os achados deste estudo experimental sugerem que o uso de stents de cromo-cobalto revestidos com polímero Camouflage® em artérias carótidas de suínos parece estar associado, pelo menos no curto prazo, a uma resposta histológica semelhante àquela encontrada após o implante de stents de cromo-cobalto não revestidos. Neste período não se observou uma menor hiperplasia intimal em virtude do revestimento de polímero. / Introduction: Despite all the advances in the endovascular treatment of coronary and peripheral artery diseases, in-stent restenosis is still the main limiting factor of these procedures in the medium and long-term. The mechanism of in-stent restenosis is mainly the intimal hyperplasia, as the stent prevents acute elastic recoil and later negative geometric arterial remodeling. Intimal hyperplasia occurs basically in response to the formation of local thrombus, inflammation and intimal and medial dissections secondary to the injury caused by the stent, with the degree of intimal response being the cause of long-term effects. Coating drug-eluting stents with polymers and drugs with thinner struts have been considered a new alternative for in-stent restenosis prevention. Objective: Analyse the arterial response to the cobalt-chromium stent implant with and without polymer coating Camouflage® in carotid arteries of pigs, using the following histological parameters: degree of endothelialization, smooth muscle cells (SMC) content, degree of angiogenesis, intimal fibrin content, degree of inflammation and injury; plus histomorphometric analysis. Method: Cobaltchromium balloon-expandable stents (8 CC Flex stents and 5 CC Flex Proactive), 4 x 16 mm, were deployed in common carotid arteries of 8 young pigs, with one stent being deployed in each artery. After 30 days, the arteries containing the stents were removed and underwent fixation and staining using the hematoxilin/eosin and Verhoeff /Van Giesson methods. The arterial segment containing the stent was divided into 3 distinct portions: proximal, middle and distal. The histological sections were obtained using impact microtome (Polycut S, Leica, Germany), equipped with a 16 cm, type D, 5 ^m thick tungsten knife (Leica, Germany). The tungsten knife maintains the stent shaft intact in cross sections, minimizing the potential artifacts caused by stent removal. The evaluation was carried out using histological and histomorfometric criteria. Results: All the stents were deployed with success and with no technical difficulties. The histological analysis performed after 30 days showed a high level of endothelialization in all the evaluated portions and mild to moderate infiltration of the SMC in the intima layer. A low level of angiogenesis of about 50% of the evaluated portions was observed and a complete absence of fibrin deposition in at least 80% of the portions, with similar distribution among the groups. The inflammatory response and the level of injury caused by the struts of the stents were also minimum and this was similar among the groups. There was no correlation between inflammatory response and injury and between the two latter parameters and the neo-intima area. The level of neo-intimal obstruction identified in this period was small (15,1% +/- 8,38 CC Flex x 15,5%+/- 5,39 CC Flex ProActive ) and no statistical significance between the groups (p=0,785). Conclusion: The findings of this experimental study suggest the use of balloonexpandable cobalt-chromium stents coated with polymer Camouflage® in carotid arteries of pigs seems to be associated, at least in the short-term, with a similar histological response to that found in the implantation of non-coated cobalt-chromium stents. In this period, a lower intimal hyperplasia was not observed with polymer coating stents.
229

Express?o imuno-histoqu?mica da triptase em mast?citos nos fibromas de c?lulas gigantes e hiperplasias fibrosas de mucosa oral

Santos, Pedro Paulo de Andrade 27 February 2008 (has links)
Made available in DSpace on 2014-12-17T15:32:16Z (GMT). No. of bitstreams: 1 PedroPAS.pdf: 6126862 bytes, checksum: 3ae3ec2483d9e09d3a05fcd73782e862 (MD5) Previous issue date: 2008-02-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The giant cell fibroma is a benign neoplasm characterized by the presence of mono, bi or multinucleate cells, which can have a connection to the presence of mast cells. This research aims to analyze, descriptively and comparatively, the immunohystochemistry expression of the tryptase in mast cells of the giant cell f ibroma, f ibrous hyperplasia and samples of the normal oral mucosa. Thirty cases of giant cell fibroma, ten cases of fibrous hyperplasia and ten cases of normal oral mucosa were selected for the analysis of the immunohistochemistry expression, determination of the number of present mast cells, as well as their location and shape. It could be stated that there was a statistically signif icant difference (p<0,001) in relation to the quantity of mast cells among other samples analyzed where the giant cell f ibroma presented lesser quantity of mast cell and the hyperplasia showed higher concentration of this cellular type. Although the oral mucosa has presented a higher quantity of mast cells when compared to the giant cells fibroma, these were found in usual locations in the connective tissue in normal tissues. There could be noticed a statistically significant difference in relation to the number of non-granulated mast cells (p<0,001). On the areas of fibrosis, we could observe a statistically signif icant difference (p<0,006) among the samples. In relation to the present mast cells in perivascular location, no statistically signif icant difference was found. On the morphological analysis there was a predominance of oval mast cells. It was concluded that despite of the fact there was a lesser quantity of mast cells present in cases of giant cell f ibroma, they appeared to have a stronger relation to the present giant fibroblasts in this lesions, around 59,62%, being also evidenced a strong relation between these cells and the fibrosis areas in both cases of giant cell f ibroma and f ibrous hyperplasias and samples of normal oral mucosa, used as control group in our study, confirming, this way, the role of the mast cells as fibrinogenous inductor / O fibroma de c?lulas gigantes constitui-se de uma neoplasia benigna, caracterizada pela presen?a de c?lulas gigantes, mono, bi ou multinucleadas, c?lulas estas que podem guardar rela??o com a presen?a de mast?citos. O prop?sito desta pesquisa consistiu em analisar descritiva e comparativamente a express?o imuno-histoqu?mica da triptase em mast?citos de fibroma de c?lulas gigantes, hiperplasia fibrosa e esp?cimes de mucosa oral normal. Foram selecionados 30 casos de fibroma de c?lulas gigantes, 10 casos de hiperplasia fibrosa e 10 casos de mucosa oral normal, para a an?lise da express?o imuno-histoqu?mica, determina??o do n?mero de mast?citos presentes, bem como a sua forma e localiza??o. Constatou-se diferen?a estatisticamente significativa (p<0,001) em rela??o a quantidade de mast?citos entre os esp?cimes analisados, onde o fibroma de c?lulas gigantes apresentou a menor quantidade de mast?citos e a hiperplasia exibiu a maior concentra??o deste tipo celular. Embora a mucosa oral tenha apresentado uma maior quantidade de mast?citos quando comparado com os casos de f ibroma de c?lulas gigantes, estes se encontravam em localiza??es usuais no tecido conjuntivo em tecidos normais. Verif icou-se, diferen?a estatisticamente significativa, no que diz respeito ao n?mero de mast?citos n?o degranulados (p<0,001). Nas ?reas de fibrose, observamos diferen?a estatisticamente signif icativa (p<0,006) entre os esp?cimes. Com rela??o aos mast?citos presentes em localiza??o perivascular n?o se observou diferen?a estatisticamente significativa. Na an?lise morfol?gica verif icou-se uma predomin?ncia de mast?citos ovais. Concluiu-se que embora uma menor quantidade de mast?citos estivesse presente nos casos de fibroma de c?lulas gigantes, estes exibiam maior rela??o com os fibroblastos gigantes presentes nestas les?es em torno de 59,62%, sendo evidenciada tamb?m uma forte rela??o entre estas c?lulas e ?reas de fibrose tanto nos casos de fibroma de c?lulas gigantes como de hiperplasias fibrosas e esp?cimes de mucosa oral normal, utilizados como controle em nosso estudo, confirmando desta forma, o papel dos mast?citos como indutor fibrinog?nico
230

A leptina regula a proliferação celular e a apoptose na próstata humana / The lepitin regulate the celular proliferation and apoptosis in human prostate

Eduardo Moussa de Jabur Leze 22 June 2011 (has links)
A hiperplasia prostática benigna (HPB) é a doença na qual a próstata demonstra um crescimento anormal e sua prevalência aumenta com o envelhecimento. Leptina, a adipocina mais notável, tem um importante papel na regulação do sistema reprodutivo. Esse trabalho tem por fim avaliar o papel da leptina no tecido prostático humano, utilizando a cultura de tecido in vitro, avaliando a proliferação celular e a expressão dos genes do fator de crescimento do fibroblasto 2 (FGF2), da enzima aromatase e dos genes apoptóticos. De 2009 a 2011, amostras de tecido hiperplásico humano foram obtidas pela prostatectomia transvesical em quinze pacientes com próstatas de volume aumentadas. Cada amostra foi dividida em quatro partes simétricas, mantidas no meio RPMI suplementado com soro fetal bovino a 10%, e 1ng/mL de gentamicina, adicionados a 16 ng/mL de leptina (Leptina) ou não (Controle). Após três horas a expressão dos genes de FGF2, aromatase, Bax, Bcl-x e Bcl-2 foram avaliados por RT-PCR em tempo real. A proliferação celular foi avaliada por imunohistoquímica para PCNA. O tratamento com leptina levou a um aumento na expressão de Bax (C=0.40.1; L=0.90.2; p<0.05), enquanto as expressões de Bcl-2 (C=19.95.6; L=5.61.8; p< 0.05) e Bcl-x (C=0.20.06; L=0.070.02; p<0.05) foram significativamente reduzidas. Não houve alteração significativa na expressão de FGF2, enquanto a expressão da aromatase foi significativamente (C=1.90.6; L=0.40.1; p<0.04) reduzida. A leptina também levou a um aumento na proliferação celular (C=21.80.5; L=64.80.9; p<0.0001). Dessa forma, concluímos que a leptina tem um importante papel na manutenção do crescimento fisiológico da próstata, desde que estimula tanto a proliferação celular como a apoptose, com diminuição na expressão do gene da aromatase. / The benign prostate hyperplasia (BPH) is the disease in which the prostate shows an abnormal growth and its prevalence rise up with aging. Leptin, the most well characterized adipokine, has an important role regulating the reproductive system. This paper aimed to evaluate the leptin role in the human prostate tissue, using an in vitro tissue culture system, on the cellular proliferation and the expression of fibroblast growth factor 2, aromatase enzyme and apoptotic genes. From 2009 to 2011, hyperplasic prostate tissue samples obtained by transvesical prostatectomy in fifteen patients with enlarged prostates were used. Each sample was divided in four symmetric parts which were maintained in RPMI medium supplemented with 10% fetal bovine serum, 1 ng/mL of gentamicin and added with 16 ng/mL leptin (L) or not (C). After 3 hours gene expression of FGF2, aromatase, Bax, Bcl-x and Bcl-2 were evaluated by Real Time RT-PCR. Cellular proliferation was evaluated by imunohistochemistry for PCNA. The leptin treatment led to an increase in the expression of Bax (C=0.40.1; L=0.90.2; p<0.05) while Bcl-2 (C=19.95.6; L=5.61.8; p< 0.05) and Bcl-x (C=0.20.06; L=0.070.02; p<0.05) expressions were significantly reduced. There was no significant alteration in the FGF2 expression, while the aromatase expression was significantly (C=1.90.6; L=0.40.1; p<0.04) reduced. Leptin also resulted in an increase in cellular proliferation (C=21.80.5; L=64.80.9; p<0.0001). The conclusion is that leptin has an important role in maintaining the physiological growth of the prostate since it stimulates both cellular proliferation and apoptosis, with the decrement in the aromatase gene expression

Page generated in 0.0692 seconds