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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.
21

Fatores angiogênicos e antiangiogênicos em pré-termos filhos de mães com e sem pré-eclâmpsia

Hentges, Cláudia Regina January 2014 (has links)
Introdução: Sabe-se que os fatores angiogênicos e antiangiogênicos encontram-se alterados nas gestações com pré-eclâmpsia (PE), mas se desconhece seu comportamento nestes recém-nascidos (RNs). Objetivo: Dosagem do vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFtl-1) e heterodímero vascular endothelial growth factor/placental growth factor (VEGF/PlGF) em pré-termos filhos de mães com PE. Métodos: Incluídos: RNs com peso de nascimento < 2.000 g e idade gestacional (IG) ≤ 34 semanas, divididos em dois grupos: filhos de mães com e sem PE. Excluídos: RNs transferidos de outra instituição com mais de 72 horas de vida, óbito antes da coleta dos exames, malformação congênita maior, erros inatos de metabolismo, gestações múltiplas, mães com infecção do grupo sífilis, toxoplasmose, rubéola, citomegalovírus, herpes (STORCH) ou vírus da imunodeficiência humana (HIV) e doença autoimune. Coletado sangue nas primeiras 72 horas de vida, e nos RNs que permaneceram internados, foi realizada uma segunda coleta com 28 dias. Foi utilizado método ELISA para a dosagem do VEGF, sFlt-1 e VEGF/PlGF. Resultados: Incluídos: 88 pacientes (37 filhos de mães com PE, 51 sem PE) com IG de 29,12 ± 2,96 semanas e peso de nascimento de 1223,80 ± 417,48 g. O VEGF foi menor no grupo com PE [32,45 (6,36-85,75) x 82,38 (35-130,03) pg/mL], p = 0,001 e o sFlt-1 foi maior no grupo com PE [1338,57 (418,8-3472,24) x 318,13 (182,03-453,66) pg/mL], p < 0,001. Na análise multivariada, o VEGF foi 80% menor e sFlt-1 13,48 vezes maior no grupo com PE. O sFlt-1 foi maior nos RNs pequenos para idade gestacional (PIG) do que nos adequados para idade gestacional (AIG) [1044,94 (290,64-3472,24) x 372,67 (236,75-860,14) pg/mL], p = 0,013. No grupo com PE, houve um aumento [≠ 151,71 (76,55-226,86); p < 0,001] entre as dosagens do VEGF entre a primeira e a segunda coleta com 28 dias, já o sFlt-1 diminuiu [≠ 1941,44 (2757,01-1125,87); p < 0,001] entre as duas dosagens. O VEGF/PlGF foi maior nos filhos de mães com PE [20,69 pg/mL (12,79-52,86) x 12,19 pg/mL (0,03 -21,58)], p = 0,003. Esses achados mantiveram-se na análise multivariada, com o VEGF/PlGF 1,05 vezes maior nos filhos de mães com PE. Os níveis de VEGF/PlGF foram inversamente proporcionais ao peso de nascimento, com p < 0,001 e r = - 0,418. Na segunda coleta com 28 dias de vida não houve diferença entre os dois grupos. Conclusão: Os maiores níveis de sFlt-1 e VEGF/PlGF e menores níveis de VEGF no grupo com PE, assim como maiores concentrações de sFlt-1 nos PIG refletem uma predominância dos mecanismos antiangiogênicos na PE e na restrição de crescimento. Os níveis de VEGF/PlGF também foram relacionados ao peso de nascimento, sendo inversamente proporcionais. O estado antiangiogênico da PE tende à normalização com 28 dias de vida. / Background: It is known that angiogenic and antiangiogenic factors are altered in pregnant women with preeclampsia (PE), but the pattern of expression of these factors in their newborn infants remains unknown. Objective: To measure vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and vascular endothelial growth factor/placental growth factor (VEGF/PlGF) heterodimer levels in preterm neonates born to mothers with PE. Methods: Neonates with birth weight < 2,000 g and gestational age ≤ 34 weeks were included and divided into two groups: born to mothers with and without PE. Exclusion criteria were as follows: the neonate was transferred from another institution after 72 hours of life; the neonate died before blood collection; major congenital anomalies; inborn errors of metabolism; congenital infections (STORCH screen); HIV-positive mothers; multiple pregnancies; and mothers with autoimmune disease. Blood was collected from neonates within the first 72 hours of life, and a second sample was collected at 28 days of life from those who remained hospitalized. VEGF, sFlt-1 and VEGF/PlGF levels were measured using the ELISA method. Results: A total of 88 neonates were included (37 born to mothers with and 51 without PE), with mean gestational age of 29.12 ± 2.96 weeks and birth weight of 1223.80 ± 417.48 g. VEGF was lower in the group with PE [32.45 (6.36-85.75) vs. 82.38 (35-130.03) pg/mL] (p = 0.001), and sFlt-1 was higher in the group with PE [1338.57 (418.8-3472.24) vs. 318.13 (182.03-453.66) pg/mL] (p < 0.001). In the multivariate analysis, VEGF was 80% lower and sFlt-1 was 13.48 times higher in the group with PE. sFlt-1 concentration was higher in neonates small for gestational age (SGA) than in those appropriate for gestational age (AGA) [1044.94 (290.64-3472.24) vs. 372.67 (236.75-860.14) pg/mL] (p = 0.013). In the group with PE, VEGF levels increased [≠151.71 (76.55-226.86); p < 0.001) between the first and second collection (at 28 days), while sFlt-1 levels decreased [≠1941.44 (2757.01-1125.87); p < 0.001] between the two measurements. Median VEGF/PlGF levels were significantly higher among infants born to mothers with PE (20.69 pg/mL [12.79-52.86] vs. 12.19 pg/mL [0.03-21.58], p = 0.003). These findings held on multivariate analysis, with VEGF/PlGF levels 1.05-fold higher in the PE group. VEGF/PlGF levels were inversely proportional to birth weight (p < 0.001, r = - 0.418). There were no between-group differences in blood samples collected at age 28 days. Conclusion: Higher sFlt-1 and VEGF/PlGF and lower VEGF levels in the group with PE, as well as higher sFlt-1 levels in SGA neonates, reflect a predominance of antiangiogenic mechanisms in PE and growth restriction. The VEGF/PlGF levels also affected the weight at birth, with VEGF/PlGF levels inversely proportional to birth weight. This antiangiogenic state of PE shows a trend toward normalization within 28 days of life.
22

Význam antiangiogenní terapie u lymfomu z plášťových buněk / The Role of Antiangiogenic Therapy in Mantle Cell Lymphoma

Kovaříková, Petra January 2022 (has links)
Mantle cell lymphoma (MCL) is a subtype of B-non-Hodgkin's lymphoma, characterized by often relapses. Despite an Ibrutinib (a Bruton's kinase inhibitor) implementation into salvage therapy, these patients often relapse with biologically highly aggressive disease and very poor prognosis. An increased activation of alternative metabolic pathways was described as one of ibrutinib-resistance mechanisms. Some of these pathways have also significant proangiogenic activity (e.g. PI3K-AKT-mTOR). In presented study, we established and standardized a real-time ultrasound and photoacoustic imaging of neovascularization and tissue oxygenation of subcutaneous MCL tumors in mice. Ultrasound and photoacoustic imaging is a fast, non-invasive method for angiogenesis evaluation in subcutaneous tumors with huge preclinical potential. Using MCL mice models, we also demonstrated the importance of CD31/PECAM-1 expression for engraftment, growth and spread of MCL cells in vivo. The level of CD31 expression in primary MCL cell (obtained directly from MCL patients) positively correlates with extent of extranodal involvement. CD31 facilitates survival and regulates extranodal spread of mantle cell lymphoma. We found that increased VEGFA expression causes not only increased microvessel density due to higher sprouting...
23

Avaliação “in vitro” do efeito antitumoral e antiangiogênico de uma metaloprotease isolada da peçonha de Bothrops pauloensis

Guimarães, Denise de Oliveira 16 September 2016 (has links)
O câncer de mama é uma neoplasia altamente maligna e continua a ser a segunda principal causa de mortalidade entre as mulheres. Os efeitos antitumorais de metaloproteinases e desintegrinas de veneno de serpentes têm sido investigados em vários tipos de células tumorais. Neste estudo, foram avaliados os efeitos antitumorais e anti-angiogênicos induzidos pela Bothropoidina, uma metaloproteinase desintegrina-like isolada da peçonha de Bothrops pauloensis em células de câncer de mama humano MDA-MB-231 e células endoteliais. Após 24 horas de tratamento com 100pg/mL de Bothropoidina foi constatado um efeito citotóxico moderado de 30% em MDA-MB-231 contra 10% de citotoxicidade em MCF10A (uma linha de células da mama não tumorigênica), uma diferença significativa que sugere uma possível preferência desta proteína por alvos em células tumorais. Observou-se apoptose e apoptose tardia após tratamento com Bothropoidina (10pg/mL e 40pg/mL) em células MDA-MB-231. Além disso, esta toxina não só inibiu a adesão de células MDA-MB-231 de uma forma dose dependente, como a migração celular em aproximadamente 45%. Bothropoidina reduziu a viabilidade e adesão de células endoteliais em Matrigel e inibiu a angiogênese in vitro estimulada por bFGF em Matrigel, mostrando um número de vasos formados significativamente menor em relação ao controle. Os resultados demonstraram que Bothropoidina tem um potente efeito antitumoral e antiangiogênico in vitro, representando uma ferramenta biotecnológica para elucidar o efeito antitumoral de metaloproteinases desintegrinas-like em células cancerígenas. / Breast cancer is a highly malignant carcinoma and remains the second leading cause of mortality among women. The antitumor effects of metalloproteinases and disintegrins from snake venom on various types of cancer cells have been investigated. In this study, we evaluated the antitumor and antiangiogenic effects on MDA-MB-231 human breast cancer cells and endothelial cells induced by Bothropoidin, a disintegrin-like metalloproteinase isolated from Bothrops pauloensis snake venom. At 24h after treatment at 100pg/mL, Bothropoidin exerted a moderate cytotoxic effect of 30% on MDA-MB-231 versus 10% cytotoxicity against MCF10A (a non-tumorigenic breast cell line), a significant difference that suggests a possible preference by this protein for targets in cancer cells. Early and late apoptosis of MDA-MB-231 was observed after Bothropoidin treatment (10gg/mL and 40gg/mL). Furthermore, this toxin inhibited not only the adhesion of MDA-MB-231 cells in a dose-dependent manner but also cell migration by approximately 45%. In addition, Bothropoidin decreased endothelial cells viability and adhesion in Matrigel and inhibited in vitro angiogenesis in Matrigel stimulated by bFGF, showing significantly fewer formed vessels. The results demonstrated that Bothropoidin has potent in vitro antitumor and antiangiogenic effect and represents a biotechnological tool for elucidating the antitumor effect of disintegrins-like metalloproteinases in cancer cells. / Dissertação (Mestrado)

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