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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.
11

Desenvolvimento e avaliação da atividade quimiopreventiva de nanopartículas contendo imiquimode em modelo murino de câncer de pele / Development and evaluation of the chemopreventive activity of nanoparticles containing imiquimod in murine model of skin cancer

Dias, Marina França 11 April 2018 (has links)
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-06-22T19:23:21Z No. of bitstreams: 2 Tese - Marina França Dias - 2018.pdf: 4770115 bytes, checksum: 86e73a57e2ce0a02cb1666dfe5988ce3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-06-27T11:09:43Z (GMT) No. of bitstreams: 2 Tese - Marina França Dias - 2018.pdf: 4770115 bytes, checksum: 86e73a57e2ce0a02cb1666dfe5988ce3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-27T11:09:43Z (GMT). No. of bitstreams: 2 Tese - Marina França Dias - 2018.pdf: 4770115 bytes, checksum: 86e73a57e2ce0a02cb1666dfe5988ce3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-04-11 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Skin cancer has the highest incidence among all types of neoplasms and the tendency is the increasing number of new cases in next decades, wich makes necessary new modalities and treatment options. Chemotherapeutic agent imiquimod is used in treatment of disease, but the high occurrence of local and systemic adverse effects associated with its use as well as its low skin permeation impair adherence and therapeutical effectiveness, respectively. The aim of the present work was evaluate the antitumor activity of nanocapsules imiquimod-loaded compared to its commercial product in murine model of skin cancer. Polymeric nanocapsules containing imiquimod, in the absence and presence of chitosan coating, were obtained by the precipitation of preformed polymer technique and characterized by encapsulation efficiency, size, zeta potential, pH, morphology (transmission electron microscopy and scanning), optical scanning spectrophotometry and in vitro release through dialysis membrane in pH 5.6 buffer. Presence of chemical interactions between formulation components was evaluated by thermogravimetric analysis and infrared spectroscopy. Detection of crystalline structures was performed by X-ray diffractometry. The nanocapsules and commercial imiquimod formulation antiagiogenic activity was determined in a chicken embryo chorioallantoic membrane model. Cutaneous permeation of nanocapsules imiquimod-loaded and commercial imiquimod was determined in Swiss albino mice. The chemopreventive activity of colloidal dispersions and the commercial imiquimod was evaluated through the tumoral inhibition promoted by these treatments in a multi- stage model of chemical carcinogenesis in Swiss mice. Encapsulation efficiency, mean diameter, zeta potential and pH of uncoated nanocapsules imiquimod-loaded were 92.5% ± 0.4; 249 ± 22.4 nm; -40.1 mV ± 3.7 and 5.4 ± 0.01 respectively, whereas for nanocapsules with cationic coating the parameters found were: 88.6 ± 2.3%; 287.0 ± 12.6 nm; + 11.3 ± 0.5 mV and 3.7 ± 0.0, respectively. The formulations morphology obtained by scanning and transmission electron microscopy images confirmed the presence of nanocapsules. In the stability analysis by optical scanning spectrophotometry (Turbiscan), all dispersions obtained a backscattering variation less than 2% over 5 weeks and were considered stable. In the in vitro release assay, imiquimod-loaded nanoparticles obtained slower release of the drug compared to free and commercial imiquimod. There were chemical interactions between chitosan and other formulation components evaluated by thermogravimetric and infrared studies. No crystalline structure was detected by the X-ray diffraction technique for the coated and uncoated imiquimod formulation. The dispersion of nanocapsules containing imiquimod presented antiangiogenic activity superior than commercial formulation in chicken embryo chorioallantoic membrane model. Nanocapsules containing imiquimod both uncoated and coated with chitosan presented cutaneous permeation in deep layers of the skin and inhibition in the chemically induced carcinogenicity process superior than tumor control group and groups treated with placebo nanoparticles while the commercial formulation presented retention of the drug in superficial layers of the skin and did not obtain a statistically significant reduction in the number of papillomas formed compared to the carcinogenic control. These results allow to conclude, therefore, that stable nanocarreadores were obtained and the chemopreventive activity and the antiangiogenic effect of these systems represent a promising alternative for the treatment of cutaneous neoplasias. / O câncer de pele é o de maior incidência dentre todos os tipos de neoplasias e a tendência é o aumento crescente do número de novos casos nas próximas décadas, tornando necessárias novas modalidades e opções de tratamento. O agente quimio-terápico imiquimode é utilizado no tratamento da doença, mas a elevada ocorrência de efeitos adversos locais e sistêmicos associados ao seu uso bem como sua baixa permeação cutânea prejudicam a adesão e a efetividade terapêutica, respectiva-mente. O objetivo do presente trabalho foi comparar a atividade quimiopreventiva do imiquimode veiculado em nanocápsulas com a da sua forma comercial, em modelo murino de câncer de pele. Nanocápsulas poliméricas contendo o imiquimode, na ausência e presença de revestimento de quitosana, foram obtidas pela técnica de precipitação do polímero pré-formado e caracterizadas quanto à eficiência de encap-sulação, ao tamanho, ao potencial zeta, ao pH, à morfologia (microscopia eletrônica de transição e varredura), à espectrofotometria de varredura óptica e à liberação in vitro através de membrana de diálise em tampão pH 5,6. A presença de interações entre componentes da formulação foi avaliada por meio de análises termogravimé- tricas e por espectroscopia na região do infravermelho. A detecção de estruturas cristalinas nas formulações foi realizada por difratometria de raios X. A atividade antiangiogênica das nanocápsulas obtidas, bem como da formulação comercial do imiquimode, foi determinada em modelo de membrana corioalantoica de embrião de galinha. A permeação cutânea das nanopartículas e do imiquimode comercial foi determinada em camundongos Swiss. A atividade quimiopreventiva das nanocápsulas obtidas e a do imiquimode comercial foi avaliada por meio da inibição tumoral promovida por esses tratamentos em modelo de carcinogênese química em camundongos Swiss. A eficiência de encapsulação, o diâmetro médio, o potencial zeta e o pH das nanocápsulas não revestidas contendo imiquimode foram respectivamente de 92,5% ± 0,4; 249 ± 22,4 nm; -40,1 mV ± 3,7 e 5,4 ± 0,01. Enquanto que, para as nanocápsulas com recobrimento catiônico os parâmetros encontrados foram 88,6 ± 2,3%; 287,0 ± 12,6 nm; +11,3 ± 0,5 mV e 3,7 ± 0,0, respectivamente. A morfologia das formulações, obtida pelas imagens de microscopia eletrônica de varredura e de transmissão, confirmou a presença de nanocápsulas. Nas análises de estabilidade por espectrofotometria de varredura óptica (Turbiscan), todas as dispersões obtiveram variação de retroespalhamento inferior a 2%, no período de cinco semanas, sendo consideradas estáveis. No ensaio de liberação in vitro, as nanopartículas contendo imiquimode obtiveram liberação mais lenta do fármaco comparativamente ao imiquimode livre (em solução) e ao imiquimode comercial. Foram verificadas interações entre a quitosana e os demais componentes das formulações nos estudos termogravimétricos e na espectroscopia na região do infravermelho. Não foi detectada presença de estrutura cristalina com emprego da técnica de difratometria de raios X para a formulações contendo imiquimode com e sem revestimento. A dispersão de nanocápsulas contendo imiquimode apresentou atividade antiangiogênica superior à da formulação comercial em modelo de membrana corioalantoica de embrião de galinha. As nanocápsulas contendo imi-quimode com e sem revestimento apresentaram permeação cutânea em camadas profundas da pele e inibição no processo de carcinogênese quimicamente induzido superior à do grupo-controle tumoral e à dos grupos tratados com nanopartículas placebo, enquanto a formulação comercial apresentou retenção do fármaco em camadas mais superficiais da pele e não obteve redução estatisticamente significativa no número de papilomas formados em relação ao controle cancerígeno. Esses resultados permitem concluir, portanto, que nanocarreadores estáveis foram obtidos e que a atividade quimiopreventiva e o efeito antiangiogênico desses sistemas representam uma alternativa promissora para o tratamento de neoplasias cutâneas.
12

Bone antiresorptive or antiangiogenic medication and dental implant treatment in osteoporotic patients : A systematic review

Al-Azzawi, Tara Ali Ziad, Kurtanovic, Amina January 2022 (has links)
Aim: The overall aim is to (i) analyze the prognosis of dental implant treatment concerning marginal bone loss (MBL) in patients undergoing or have undergone treatment with bone antiresorptive or antiangiogenic medication for osteoporosis (ii) and additional purpose to assess the available scientific literature in the first aim concerning the risk of getting medication-related osteonecrosis of the jaw (MRONJ) associated with dental implant installation.  Material and methods: A systematic literature search was conducted in October 2021 in the following three databases; MEDLINE/PubMed, Cochrane Library and Web of Science. PRISMA 2009 Flow Diagram were used for the selection process, whereas the included studies were evaluated for quality assessment using Newcastle Ottawa Scale (NOS).  Results: The search resulted in four included studies considering the eligibility criteria. The studies evaluated MBL in osteoporotic patients undergoing or have undergone oral bisphosphonate (BP) treatment before and/or during implant placement. MRONJ was also assessed in all four articles.  Conclusions: The results of this present study do not indicate that patients undergoing or have undergone antiresorptive or antiangiogenic medication for osteoporosis are at an increased risk of MBL in dental implants during follow-up periods. The present data assessing the risk for developing MRONJ remains low for osteoporotic patients. Therefore, dental implant surgery is considered possible with success in osteoporotic patients receiving earlier mentioned medications. However additional studies are required to evaluate the effects on this patient group concerning osseointegration of dental implant regarding MBL. / Syfte: Syftet med denna studie är att analysera prognosen för implantatbehandling avseende marginell benförlust (MBL) hos patienter som genomgår eller har genomgått behandling med benantiresorptiv eller antiangiogen medicin för osteoporos. Ytterligare utförs en bedömning av tillgänglig vetenskaplig litteratur gällande risken för läkemedelsrelaterad käkbensnekros (MRONJ) associerat med implantatinstallation hos patienter som genomgår eller har genomgått behandling med benantiresorptiv eller antiangiogen medicin. Material och metod: En systematisk elektronisk litteratursökning genomfördes i oktober 2021 i följande tre databaser; MEDLINE/PubMed, Cochrane Library och Web of Science. PRISMA 2009 Flow Diagram användes för urvalsprocessen, varav de inkluderande studierna kvalitetsgranskades enligt Newcastle Ottawa Scale (NOS). Resultat: Sökningen resulterade i fyra studier, enligt inklusions- och exklusionskriterier. Studierna utvärderade MBL hos osteoporospatienter som går eller har gått behandling med orala bisfosfonater före eller under implantatinstallationen. MRONJ fastställdes i alla fyra artiklar. Slutsats: Resultatet av denna studie indikerar inte att patienter som genomgår eller har genomgått behandling med benantiresorptiv eller antiangiogen medicin för osteoporos löper en ökad risk för MBL av dentala implantat under uppföljningsperioder. Nuvarande data bedömer att risken för att utveckla MRONJ är fortfarande låg för osteoporos patienter. Därför antas implantatkirurgi kunna utföras på osteoporos patienter som står på denna medicinering. Dock krävs ytterligare studier för att utvärdera effekterna av denna patientgrupp gällande osseointegration av dentala implantat avseende MBL.
13

Estudo comparativo entre o Bevacizumabe intravitreo e a fotocoagulação a laser com oftalmoscopio binocular indireto na retinopatia da prematuridade / Comparative study between intravitreal Bevacizumab or laser photocoagulation with binocular indirect ophthalmoscope in retinopathy of prematurity

Marquez, Tatiana Vieira de Brito 06 July 2010 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-02-20T15:09:52Z No. of bitstreams: 2 Dissertação - Tatiana Vieira de Brito Marquez - 2010.pdf: 2722177 bytes, checksum: d3f571bcc9c3e44cf51b9d4539e6191d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-02-20T15:10:12Z (GMT) No. of bitstreams: 2 Dissertação - Tatiana Vieira de Brito Marquez - 2010.pdf: 2722177 bytes, checksum: d3f571bcc9c3e44cf51b9d4539e6191d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-02-20T15:10:12Z (GMT). No. of bitstreams: 2 Dissertação - Tatiana Vieira de Brito Marquez - 2010.pdf: 2722177 bytes, checksum: d3f571bcc9c3e44cf51b9d4539e6191d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2010-07-06 / OBJECTIVES: To compare the response of bevacizumab and the response of the laser photocoagulation with indirect binocular ophthalmoscope (IBO) in infants with retinopathy of prematurity (ROP) stages II or III. METHODS: Data collection was performed in the neonatal intensive care unit of the Hospital Materno Infantil, from May to November 2009. Preterm infants with ROP stages II or III, with or without the plus disease were included. They were divided into two groups: on group I, an intra-vitreous injection of bevacizumab was performed and on group II, laser photocoagulation with IBO was performed. RESULTS: In group I, from the 20 eyes that underwent the application of bevacizumab, there was total regression of ROP with one application in 14 eyes, being 4 eyes with complete regression with two doses of bevacizumab, and 2 eyes with total regression after two applications of bevacizumab and one application of laser. On group II, from the 20 eyes treated with laser photocoagulation with IBO, there was total regression of ROP with laser therapy in 14 eyes and there was total regression with two laser sessions in 6 eyes. CONCLUSION: Bevacizumab is effective if compared to laser photocoagulation in ROP stages II and III. / OBJETIVOS: Comparar a resposta terapêutica do bevacizumabe intravítreo com à resposta da fotocoagulação a laser com oftalmoscópio binocular indireto, em prematuros portadores de retinopatia da prematuridade estágios II ou III. MÉTODOS: A coleta de dados foi realizada na UTI neonatal do Hospital Materno Infantil, no período de maio a novembro de 2009. Foram incluídos os prematuros com retinopatia da prematuridade graus II ou III, com ou sem doença plus. Estes foram divididos em dois grupos: no grupo I foi realizada a injeção intra-vitrea de bevacizumabe, no grupo II foi realizada a fotocoagulação a laser com oftalmoscópio binocular indireto. RESULTADOS: No grupo I, dos 20 olhos incluídos, houve regressão total da retinopatia da prematuridade com uma aplicação de bevacizumabe em 14 olhos, regressão total com duas aplicações em 4 olhos e regressão total após duas aplicações de bevacizumabe e uma aplicação de laser em 2 olhos. No grupo II, dos 20 olhos tratados com fotocoagulação a laser com oftalmoscópio binocular indireto, houve regressão total da retinopatia da prematuridade com uma sessão em 14 olhos e houve regressão total com duas sessões em 6 olhos. CONCLUSÃO: O bevacizumabe é tão eficiente quanto a fotocoagulação a laser na retinopatia da prematuridade nos estágios II e III.
14

Avaliação da eficácia e segurança do uso de radioterapia intraocular com estrôncio 90 e bevacizumabe no tratamento de pacientes portadores de degeneração macular relacionada à idade, forma exsudativa / Three-year safety and visual acuity results of epimacular straontium-90*ytrium90 brachytherapy with bevacizumab for the treatment of sobfoveal chorodoidal neovascularization secondary to agerelated macular degerenation

BIANCHI, Lívia Carla de Souza Nassar 27 March 2012 (has links)
Made available in DSpace on 2014-07-29T15:29:14Z (GMT). No. of bitstreams: 1 Dissertacao Livia C de S N Bianchi - Oftalmologia.pdf: 3291987 bytes, checksum: bf690044678ae1c1ecf40768b3ef062a (MD5) Previous issue date: 2012-03-27 / Purpose: To evaluate the efficacy and safety of strontium-90 epimacular brachytherapy combined with intravitreal bevacizumab for treating subfoveal choroidal neovascularization secondary to exudative age-related macular degeneration. Its effects on visual acuity and macular thickness at 36 months of follow up were also studied. Methods: Sixteen patients with predominantly classic, minimally classic and occult choroidal neovascularization were treated with a single 24 Gy dose of radiation during pars plana vitrectomy, associated to two injections of bevacizumab at baseline and one injection at the one-month visit. The patients underwent a complete ophthalmologic examination, which included fluorescein angiography and optical coherence tomography, at the initial visit, every three months during the first year, and every six months during the second and third years of follow up. Results: Of the 16 cases, 2 patients (12.5%) lost more than 15 letters at the end of 36 months, and 3 (18.75%) lost fewer than 15 letters. Among the patients with improved visual acuity, 3 (18.75%) gained less than 15 letters and 8 (50%) gained more than 15 letters at the end of treatment. The mean best corrected visual acuity showed a gain of 16.0 letters at 12 months. After 36 months (n = 16), the mean best corrected visual acuity showed a gain of 10.4 letters. Of the 16 eyes included in the study, six required further therapy. The evaluation of macular thickness showed decreased thickness in 10, among the 16 patients (62.5%). Three eyes (18.75%) had similar values at the beginning and the end of 36 months, and 3 eyes (18.75%) showed increased macular thickness. Conclusion: Epimacular brachytherapy combined with bevacizumab may be considered a possible therapeutic option for choroidal neovascularization in age-related macular degeneration. The procedure was thought to be safe and was well tolerated by the patients. The treatment resulted in anatomical and functional improvements, compatible with currently available therapies. / Objetivo: Avaliar a eficácia e segurança da braquiterapia epimacular com estrôncio 90 e bevacizumabe intravítreo para tratamento da neovascularização coróidea subfoveal secundária à degeneração macular relacionada à idade exsudativa, e observar seus efeitos na acuidade visual e espessura macular, em 36 meses de seguimento. Metodologia: Foram estudados 16 pacientes portadores de neovascularização coróidea, (predominantemente clássicas, minimamente clássicas e ocultas) tratados com dose única de radiação de 24Gray, durante vitrectomia via pars plana, associada a duas injeções de bevacizumabe uma no início do tratamento e a outra um mês após. Foram realizados exame oftalmológico completo, angiofluoresceinografia e tomografia de coerência óptica na visita inicial, a cada três meses durante o primeiro ano e a cada seis meses durante o segundo e o terceiro anos de seguimento. Resultados: Dos 16 casos, 2 (12,5%) perderam mais de 15 letras ao final de 36 meses, e 3 pacientes (18,75%) perderam menos de 15 letras. Dentre os pacientes que melhoraram a acuidade visual, 3 (18,75%) ganharam menos de 15 letras e 8 (50%) ganharam mais de 15 letras ao final do tratamento. A média da melhor acuidade visual corrigida demonstrou ganho de 16,0 letras ao final de 12 meses. Após 36 meses (n = 16), a média da melhor acuidade visual corrigida apresentou um ganho de 10,4 letras pela tabela ETDRS. Dos 16 olhos observados, 6 necessitaram de tratamento adicional. Na avaliação da espessura macular, 10 (62,5%) dos 16 pacientes apresentaram diminuição da espessura, 3 olhos (18,75%) mantiveram valores semelhantes no início e ao final de 36 meses, e 3 olhos (18,75%) apresentaram aumento da espessura macular. Conclusão: A braquiterapia epimacular combinada ao uso de bevacizumabe se mostra como uma possível opção terapêutica para a neovascularização de coróide na degeneração macular relacionada à idade. O procedimento foi considerado seguro e bem tolerado, com melhora antômica-funcional compatível aos tratamentos atualmente disponíveis.
15

Pharmacologie des antiangiogéniques : effet sur les propriétés élastiques des grosses artères / Antiangiogenic drugs pharmacology : effect on large arteries elastic properties

Alivon, Maureen 11 September 2014 (has links)
Les antiangiogéniques (AAD) représentent une classe relativement récente d’anticancéreux indiqués dans un nombre croissant de cancers solides avancés. Ces traitements inhibent la voie du VEGF en amont avec le bevacizumab, un anticorps monoclonal dirigé contre le VEGF et en aval avec les inhibiteurs des tyrosines kinases des récepteurs impliqués dans cette voie de signalisation (sorafenib et sunitinib). Les AAD s’accompagnent d’effets secondaires dont le plus fréquent est l’hypertension artérielle. Ma thèse a pour objectif de mieux comprendre la physiopathologie de l’hypertension artérielle iatrogène induite par les AAD, notamment en mesurant l’effet des AAD sur les grosses artères. Le deuxième objectif est de déterminer des marqueurs précoces d’efficacité et d’optimisation de ces traitements, notamment avec un suivi thérapeutique pharmacologique (STP). Pour remplir ces objectifs nous avons mis en place une étude clinique prospective, observationnelle monocentrique dans laquelle nous avons suivi l’évolution de paramètres artériels au cours du traitement AAD avec des techniques non-invasives chez des patients atteints d’un cancer. Dans un premier travail nous avons montré qu’il y avait une augmentation précoce et cliniquement significative de la pression brachiale et centrale, de la rigidité artérielle et du diamètre carotidien sous AAD et que ces modifications étaient en partie indépendantes de la pression artérielle. Nous avons également montré que la présence d’ondes de réflexion amples et d’une rigidité aortique basse de base avant l’introduction des AAD prédisaient une augmentation de pression artérielle systolique (PAS) à un stade précoce d’exposition (coefficients de régression : 0.37[0.04-0.70] et -1.27[-2.43 ; -0.11], p<0.05 respectivement) alors qu’après une exposition chronique aux AAD, seule une rigidité artérielle basse de base prédisait une augmentation de la PAS (-2.46 [-4.02 ; -0.90], p<0.01). L’atteinte des grosses artères est positivement associée à l’évolution carcinologique. En effet une augmentation précoce de la rigidité aortique et carotidienne sous AAD étaient associées à un haut risque de progression (HR : 1.24 [1.01 ; 1.51], p=0.042 et 1.34 [1.03-1.73], p=0.027 respectivement). Dans la deuxième partie, nous avons montré à l’aide d’un modèle pharmacocinétique de population, que l’atteinte artérielle observée lors de la prise d’AAD était due à un effet pharmacologique des AAD sur les grosses artères indépendamment de l’augmentation de pression induite par les AAD. L’augmentation de rigidité artérielle était proportionnelle à la concentration plasmatique d’AAD et à l’augmentation de la pression artérielle (coefficient de corrélation standardisé : 0.37 et 0.35, p<0.01, respectivement), expliquant respectivement 13% et 11% de la variance. Nous avons également montré que la progression et la mortalité liées au cancer étaient moindre chez les patients les plus exposés aux AAD (HR : 0.60 [0.38 ; 0.97], p=0.035 et HR=0.38 [0.19-0.79], P=0.01 respectivement) et enfin, nous avons pu déterminer une concentration sérique cible qui permettra aux cliniciens d’avoir un objectif à atteindre pour optimiser l’efficacité des AAD. En conclusion, nous avons pu démontrer l’existence d’une atteinte précoce des grosses artères se traduisant par une augmentation de la rigidité artérielle et un remodelage carotidien sous traitement AAD. Cette atteinte artérielle est directement liée à un effet pharmacologique des AAD de manière indépendante de l’augmentation de pression induite par ces traitements. Nous avons montré que les altérations de la paroi artérielle ainsi que le suivi thérapeutique pharmacologique prédisaient le pronostic carcinologique. Le suivi des propriétés artérielles combinée au STP des AAD pourraient optimiser les chances d’efficacité de ces traitements. / Antiangiogenic drugs (AAD) are a relatively new class of anti-cancer therapy indicated in an increasing number of advanced solid tumors. By inhibiting the VEGF pathway, upstream with an anti-VEGF monoclonal antibody, bévacizumab, and downstream with tyrosine kinase inhibitors of receptors involved in this signaling pathway (sorafenib and sunitinib), AAD induce arterial hypertension which is the most common side effect. The principal objective of my thesis is to improve the understanding of the pathophysiology of hypertension induced by AAD, by determining the effect of AAD on large arteries. The second objective is to determine early marker of efficacy and optimization of AAD, by the use of therapeutic drug monitoring. To fulfill those objectives, we set up a clinical prospective, observational, single center study in which we followed the time-course of several arterial parameters after AAD by the use of non-invasive techniques in patients with metastatic solid tumors. In a first work we showed that brachial and central blood pressure, arterial stiffness and carotid diameter significantly increased after AAD, partly independently of blood pressure changes. We also showed that high reflection waves and low aortic stiffness at baseline (i.e. before AAD initiation) predicted early systolic blood pressure (SBP) increase (regression coefficients: 0.37[0.04; 0.70] and -1.27[-2.43; -0.11], P<0.05 respectively) while only low aortic stiffness predicted SBP increase after chronic AAD exposure (-2.46 [-4.02 ; -0.90], P<0.01). Large arteries damage under AAD is positively associated with cancer progression. Indeed, early increase of aortic and carotid stiffness after AAD were associated with a higher risk of cancer progression (HR: 1.24 [1.01; 1.51], P=0.042 and 1.34 [1.03; 1.73], P=0.027 respectively). In a second part, using a pharmacokinetic model of population, we showed that large arteries damage observed after AAD was partly due to a pharmacological effect of AAD on large arteries independently of blood pressure increase. Arterial stiffness increase was proportional to AAD blood concentration and blood pressure increase (standardized correlation coefficients: 0.37 and 0.35, P<0.01, respectively), explaining 13% and 11% of the variance respectively. We also showed that progression and mortality related to cancer were lower in patients high AAD blood concentrations (HR: 0.60 [0.38; 0.97], P=0.035 and HR=0.38 [0.19; 0.79], P=0.01 respectively). And finally, we determined a target AAD blood concentration which will allow the clinicians to have an objective to reach in order to optimize the efficacy of AAD. In conclusion, we were able to demonstrate the existence of large arteries damage translated by large arteries stiffening and a remodeling of carotid artery after AAD. This arterial damage is directly related to a pharmacological effect of AAD independently of blood pressure changes induced by these treatments. We showed that infringement of the arterial wall and the therapeutic drug monitoring predicted tumor prognosis. Thus, the monitoring of arterial properties monitoring and the therapeutic drug monitoring might optimize the chances of efficiency of AAD.
16

Les variants d'épissage du VEGF-A : leur rôle dans la progression et la réponse aux thérapies anti-angiogéniques des carcinomes pulmonaires / VEGF-A splicing variants : their role in lung carcinoma response to antiangiogenic therappies

Boudria, Asma 13 June 2014 (has links)
Le VEGF-A est l'un des facteurs de croissance les plus importants au cours de la néo-angiogénèse tumorale. Ce rôle en a fait une cible de choix pour le développement de thérapies. Ainsi, différents médicaments le ciblant (Bevacizumab, AvastinR) ou ciblant ses voies de signalisation (inhibiteurs des récepteurs VEGFR) sont actuellement utilisés en clinique, notamment dans les adénocarcinomes pulmonaires. Cependant, malgré des résultats initiaux prometteurs, un grand nombre de patients apparaissent d'emblée résistants ou échappent à ces thérapies, voir même développent des tumeurs plus agressives. A ce jour, il n'existe aucun moyen d'identifier les patients susceptibles de répondre à ces thérapies. Récemment, de nouveaux variants d'épissage du VEGF-A issus d'un épissage alternatif différentiel au niveau du dernier exon ont été identifiés, les isoformes VEGFxxxb. A l'inverse des VEGFxxx, ces variants sont anti-angiogéniques. Si les effets paracrines des isoformes du VEGF-A sur les cellules endothéliales ont été bien caractérisés, bien peu d'études se sont penchées sur leurs effets autocrines sur les cellules tumorales qui expriment à leur surface les récepteurs VEGFR1 et VEGFR2. Dans ce contexte, le but principal de notre étude était de déterminer le statut d'expression et les fonctions biologiques de l'isoforme VEGF165b dans les tumeurs primaires et dans des modèles cellulaires dérivés de Carcinomes Pulmonaires Non à Petites Cellules (CBnPCs). Nos résultats identifient des profils d'expression variables du VEGF165b chez les patients atteints de CBnPCs, et montrent que de hauts niveaux intratumoraux de VEGF165b sont associés à un envahissement ganglionnaire. De plus, nos résultats identifient une boucle autocrine au travers de laquelle l'activation des récepteurs VEGFR1/VEGFR2 par le VEGF165b conduit à l'apparition de cellules tumorales présentant un phénotype plus invasif. Finalement, nous montrons que le traitement des cellules tumorales par le Bevacizumab (BVZ) mais aussi par les sels de platine auquel il est associé en clinique augmente l'expression du VEGF165b, la signalisation autocrine qu'il active et conduit à l'apparition de cellules tumorales plus agressives et résistantes à l'apoptose induite par le cisplatine. Ces résultats sont la première démonstration de la capacité du VEGF165b à signaliser sur les cellules tumorales. Dans une seconde étape de notre travail, nous avons étudié le rôle que pourraient jouer les intégrine β1 et β3 dans le maintien de la signalisation induite par le VEGF165b dans les cellules de CBnPCs. Nous montrons que le VEGF165b active l'intégrine β1. Cette activation aboutit à un réarrangement du cytosquelette d'actine en fibres de stress, ce qui pourrait favoriser la migration de ces cellules. De manière intéressante, le BVZ est capable d'induire ce même phénotype par un mécanisme nécessitant l'expression du VEGF165b, de l'intégrine β1, mais aussi de l'intégrine β3. La formation de ces fibres de stress est associée à l'activation de voies de signalisation d'aval mettant en jeu la phosphorylation des protéines FAK et cofiline. De plus, nous mettons en évidence l'existence de complexes entre la neuropiline 2 et l'intégrine β1 dans les cellules de CBnPCs qui seraient susceptibles de participer à l'activation de ces voies. Ainsi, le VEGF165b et le BVZ apparaissent capable de signaliser à travers les intégrines β1 et β3 dans les cellules de CBnPCs, suggérant un rôle de ces intégrines dans la réponse des cellules tumorales aux thérapies anti-angiogéniques. En conclusion, nos résultats identifient un rôle du variant VEGF165b dans la progression des CBnPCs et la réponse aux thérapies anti-angiogéniques et aux chimiothérapies, ce qui suggère que le VEGF165b pourrait être un marqueur réponse au BVZ dans les CBnPCs. / VEGF-A is one of the most important factors during tumor neoangiogenesis. This role has made it a prime target for the development of therapies. Thus, various drugs targeting VEGF-A (Bevacizumab, Avastin®) or its signaling pathways (VEGFR inhibitors) are currently used in clinical practice, especially in lung adenocarcinomas treatment. However, despite promising initial results, many patients are refractory or escape these therapies, and sometimes, even develop more aggressive tumors. To date, there is no means to identify patients who are likely to respond these treatments. Recently, new splicing variants of VEGF-A resulting from an alternative splicing at the last exon, were identified and called VEGFxxxb. Unlike VEGFxxx, these variants are antiangiogenic. If paracrine effects of VEGF-A isoforms on endothelial cells have been well characterized, few studies have examined their autocrine effects on tumor cells expressing VEGFR1 and VEGFR2. In this context, the main aim of our study was to determine the expression status and biological functions of VEGF165b in primary tumors and derived cell models of non small cell lung carcinoma (NSCLC). Our results identify variable expression profiles of VEGF165b in NSCLC patients, and show that high levels of intratumoral VEGF165b are associated with lymph node metastases. Furthermore, our results identify an autocrine loop through which the VEGFR1/VEGFR2 activation by VEGF165b leads to the appearance a more invasive phenotype on tumor cells. Finally, our results show that treatment of tumor cells by Bevacizumab (BVZ) but also platinum salts, with which it is associated clinics, increases VEGF165b expression and autocrine signaling, which leads to appearance of tumor cells that are more aggressive and resistant to cisplatin-induced apoptosis. These results are the first evidence of the VEGF165b ability to signalize on tumor cells. In a second stage of our work, we investigated the potential role of β1 and β3 integrins in maintaining VEGF165b signaling in NSCLC cells. We show that VEGF165b activates beta1 integrin. This activation leads to a rearrangement of the actin cytoskeleton in stress fibers, which may promote tumor cell migration. Interestingly, BVZ is able to induce this same phenotype by a mechanism requiring the expression of VEGF165b , beta1 integrin and beta3 integrin. The formation of these stress fibers is associated with the activation of downstream signaling pathways involving proteins phosphorylation of FAK and cofilin. In addition, we highlight the existence of neuropilin-2/β1 integrin complexes in NSCLC cells, which are likely to participate in these pathways activation. Thus, VEGF165b and especially BVZ appear able to signal through beata1 and beta3 integrins NSCLC cells, suggesting a role of these integrins in tumor cells response to antiangiogenic therapies. In conclusion, our results are the first evidence of a role of VEGF165b in NSCLC progression and response to antiangiogenic therapies and chemotherapies; they suggest that VEGF165b could be a marker of response to BVZ in NSCLC.
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EVALUATION DE L’INHIBITION DE L’ANGIOGENESE DANS LE NEUROBLASTOME ET CARACTERISATION DE MECANISMES DE RESISTANCE / EXPLORATION OF ANGIOGENESIS INHIBITION IN NEUROBLASTOMA AND CHARACTERIZATION OF ESCAPE MECHANISMS

Daudigeos -Dubus, Estelle 16 December 2014 (has links)
Adulte ou pédiatrique, les tumeurs solides ont besoin d’oxygène et de nutriments pour se développer et métastaser. Leur apport est assuré par la néo-vascularisation tumorale issue d’un processus multifactoriel appelé l’angiogénèse. Son équilibre est maintenu par une balance entre facteurs pro- et anti-angiogéniques. Elle fait partie des principales cibles pour traiter les cancers et l’inhibition de la voie VEGF en est un facteur clé. Cependant, la réponse aux agents anti-angiogéniques a montré, malgré des résultats encourageants, un effet transitoire associé à l’apparition d’une résistance adaptative de la tumeur.Nous avons étudié l’inhibition de l’angiogénèse et les mécanismes potentiels d’échappement dans les tumeurs pédiatriques solides, et principalement dans le neuroblastome. Le neuroblastome est une tumeur originaire de la crête neurale et atteint généralement l’enfant jeune. Nous avons exploré l’effet anti-tumoral de l’inhibition sélective des récepteurs 1, 2, 3 du VEGF à l’aide de l’inhibiteur à tyrosine kinase axitinib dans divers modèles précliniques de neuroblastome. L’axitinib a montré une activité anti-tumorale modérée associée à une inhibition de la vascularisation. Néanmoins, après un traitement prolongé in vitro, les cellules tumorales IGR-N91-Luc deviennent résistantes à l’axitinib. Elles prolifèrent normalement mais secrètent de «l’ hepatocyte growth factor» (HGF) et activent la voie MAPK. In vivo, le traitement prolongé par axitinib entraîne le développement d’un phénotype plus agressif de la tumeur avec l’augmentation du nombre d’animaux présentant des métastases, associée à une activation de la voie SRC. Ceci nous a conduit à explorer l’effet d’une inhibition ciblant principalement VEGFR2 et MET (récepteur à l’HGF) avec le cabozantinib. Ainsi nous avons contrôlé le développement tumoral en inhibant la néo-vascularisation et l’activation de SRC, et induit la mort cellulaire dans le modèle orthotopique IGR-N91-Luc et inhibé le développement métastatique dans le modèle systémique IMR-32-Luc. Par ailleurs, nous avons étendu notre exploration à d’autres facteurs jouant un rôle dans l’angiogénèse comme FGFR ou PDGFR car ils représentent, comme MET, de puissants oncogènes. Pour cibler simultanément VEGFR et PDGFR, nous avons utilisé l’inhibiteur multi-kinase regorafenib. In vivo, à des doses bien tolérées qui permettent un traitement prolongé, le regorafenib a montré une activité anti-tumorale significative. Cet effet a été associé principalement à une forte inhibition de la vascularisation mais également à l’induction de la mort cellulaire. En élargissant notre étude à d’autres modèles de tumeurs pédiatriques, nous avons observé que son activité est indépendante du type histologique. Compte tenu du caractère oncogénique de PDGFR, nous avons évalué cet inhibiteur dans des modèles présentant une amplification du gène PDGFRA, qui entraine une surexpression et une activation forte du récepteur. Combiné avec des thérapies standards capables d’induire des dommages à l’ADN telles que l’irradiation ou l’irinotecan, l’effet du regorafenib a été potentialisé, notamment dans les modèles amplifiés pour le gène PDGFRA se traduisant par des régressions tumorales. Ces évaluations précliniques soutiennent le développement d’une nouvelle stratégie thérapeutique pour les enfants atteints de tumeurs solides. / Solid tumors either adult or pediatric need oxygen and nutrients to grow and metastasize. Their input is provided by tumor neovascularization after a multifactorial process called angiogenesis. Balance is maintained by equilibrium between pro and anti-angiogenic factors. It is one of the main targets for treating cancers and the inhibition of the VEGF pathway is a key factor. However, despite encouraging results, the response to anti-angiogenic agents showed a transient effect associated with the development of an adaptive tumor resistance. We studied the inhibition of angiogenesis and potential escape mechanisms in solid pediatric tumors, mainly in neuroblastoma. Neuroblastoma is a solid tumor derived from the neural crest and it usually affects childhood. We investigated the anti-tumor effect of selective inhibition of VEGF receptors 1, 2, 3 using the tyrosine kinase inhibitor axitinib in various preclinical neuroblastoma l models. Axitinib showed a moderate anti-tumor activity associated with the inhibition of vascularization. However, after prolonged treatment in vitro, tumor cells IGR-N91-Luc become resistant to axitinib. They proliferate normally but secrete the "hepatocyte growth factor" (HGF) and activate the MAPK pathway. In vivo, prolonged treatment by axitinib results in the development of a more aggressive tumor phenotype with an increase in the number of animals exhibiting metastases associated with an activation of SRC signaling. This led us to explore the effect of inhibiting concomitant VEGFR2 and MET (HGF receptor), main cabozantinib targets. So we stabilized tumor growth by inhibiting the neovascularization and activation of SRC, induced cell death in the orthotopic model IGR-N91-Luc and inhibited metastatic development in the IMR-32-Luc systemic model. In addition, we extended our exploration of other factors that play a role in angiogenesis like FGFR or PDGFR because they represent, like MET, powerful oncogenes. To simultaneously target VEGFR and PDGFR, we used the multi-kinase inhibitor regorafenib. In vivo, at well-tolerated doses that allow prolonged treatment, regorafenib showed significant anti-tumor activity. This effect was mainly associated with a strong inhibition of vascularization, but also (with) induction of cell death. By expanding our study to other models of pediatric tumors, we observed that its activity was independent of histologic type. Given the oncogenic character of PDGFR, we evaluated the inhibitor in models which present a PDGFRA gene amplification, which results in a strong activation of the receptor. Combined with standard therapies that can induce DNA damages such as irinotecan or radiation, the effect of regorafenib was potentiated, mainly in PDGFRA gene amplified models, where tumor regressions were obtained. These preclinical evaluations support the development of a new therapeutic strategy for children with solid tumors.
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BEVACIZUMABE INTRA-VÍTREO: ANÁLISE DA TOXICIDADE RETINIANA APÓS 3 MESES EM OLHOS DE COELHOS NÃO ALBINOS / Bevacizumab INTRA-VITREOUS: ANALYSIS OF RETINAL TOXICITY AFTER 3 MONTHS IN EYES OF RABBITS NOT ALBINO

ARRAES, João Carlos Diniz 19 June 2009 (has links)
Made available in DSpace on 2014-07-29T15:25:22Z (GMT). No. of bitstreams: 1 tese joao arraes ciencias saude.pdf: 3252483 bytes, checksum: be116024cf6d2b2b6cef094fc736420d (MD5) Previous issue date: 2009-06-19 / Antiangiogenesis therapy has become a first-line treatment for neovascular age-related macular degeneration (AMD). Bevacizumab has proven to be efficient and cost effective, however its use in AMD is still off-label. PURPOSES: Evaluating the histological toxicity of bevacizumab on the neurosensorial retina (NSR) and the retinal pigmented epithelium (RPE) in pigmented rabbit eyes; evaluating if a fast increase in vitreous volume after a 0.1 ml balanced saline solution (BSS) intravitreal injection (IVI) in a rabbit eye will lead to histological damages in the NSR and RPE; and evaluating postoperative clinical complications after an IVI in rabbits eyes. METHODS: Eighteen pigmented rabbits (36 eyes) were divided into 4 groups a Control Group (3 rabbits - 6 eyes), which did not receive any IVI; the rabbits were sacrificed at the beginning of the study. Thirty eyes of the fifteen remaining rabbits were distributed to three groups: a sham group (S), that received a 0.1 ml balanced saline solution (BSS) IVI (ten eyes); group 1, that received a 1.25 mg (0.1 ml) bevacizumab IVI (ten eyes); and group 2, that received a 2.5 mg (0.1 ml) bevacizumab IVI (ten eyes). Postoperative clinical evaluation included inspection of the anterior segment and indirect binocular ophthalmoscopy. The rabbits were sacrificed 90 days after the procedure and both eyes of all the rabbits were enucleated. Histological examination of the NSR and RPE were performed and their morphological features and layer thickness were analyzed. RESULTS: No significant postoperative clinical complications were observed either in the neurossensorial retina or in the RPE. Histological morphology and thickness of the NSR and RPE layers did not differ significantly between BBS-injected eyes and bevacizumab-injected eyes. CONCLUSIONS: A rapid increase in vitreous volume, after 0.1 ml BSS IVI did not lead to any histological damage in the NSR and RPE in rabbit eyes. After a 90-day follow-up period, a single Bevacizumab 1.25 and 2.5 mg intravitreal injection did not lead any toxic damage in the NSR and RPE. No important postoperative complications in pigmented rabbit eyes were observed and it appears to be a safe procedure for the treatment of retinal neovascular diseases / A terapia anti-angiogênica tornou-se o tratamento de primeira linha para a forma neovascular da degeneração macular relacionada à idade. O Bevacizumabe é uma droga com boa eficácia e custo-efetividade, porém seu uso nesta doença ainda é considerado off-label. OBJETIVOS: Avaliar a toxicidade sobre a retina neurossensorial (RNS) e epitélio pigmentado da retina (EPR) da injeção intra-vítrea (IV) de bevacizumabe em olhos de coelhos não albinos; avaliar se o aumento súbito do volume vítreo após a injeção IV de 0,1ml de solução salina balanceada (SSB) no olho do coelho leva a danos histológicos na RNS e EPR; e avaliar as complicações clínicas pós-operatórias após a injeção IV em olhos de coelhos. MÉTODOS: 18 coelhos não albinos (36 olhos) foram distribuídos em 4 grupos. O grupo controle (3 coelhos 6 olhos), o qual não recebeu injeção IV, foi sacrificado no início do estudo. Os trinta olhos dos 15 coelhos restantes foram distribuídos em 3 grupos (1:1:1): Grupo Placebo (injeção IV de 0,1ml de SSB); Grupo 1 (injeção IV de 1,25mg/0,1ml de bevacizumabe); e Grupo 2 (injeção IV de 2,5mg/0,1ml de bevacizumabe). Os coelhos foram acompanhados por um período de 90 dias após o procedimento, quando então foram submetidos a eutanásia. Todos os coelhos tiveram seus olhos enucleados e avaliados histologicamente. Foram realizadas avaliação clínica pós-operatória (inspeção do segmento anterior e oftalmoscopia binocular indireta) e avaliação histológica da morfologia e da espessura das camadas da RNS e EPR. RESULTADOS: Não foram observadas complicações clínicas pós-operatórias significantes. A morfologia histológica e espessura das camadas da RNS e EPR não apresentou diferença significante entre os grupos controle e placebo, grupo placebo e grupo 1 e grupo placebo e grupo 2. CONCLUSÕES: A injeção IV de 1,25mg/0,1ml e 2,5mg/0,1ml bevacizumabe não leva a alterações histológicas tóxicas na RNS e EPR, nem a complicações clínicas pós-operatórias importantes em olhos de coelhos não albinos. A injeção IV de 0,1ml de SSB não leva a danos histológicos ao RNS e ao EPR em olhos de coelhos não albinos
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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.
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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.

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