Since ancient times, indigenous plants have been used by traditional healers for treating various ailments. Sutherlandia frutescens is one of the most commonly used medicinal plants of southern Africa. This widely distributed plant has been traditionally used to treat cancer and HIV patients; however scientific validation is still in high demand. This research aimed to phytochemically characterise the various extracts prepared and to determine if any chemotypes were present. Subsequent biological characterisation was carried out to preliminary ascertain whether this medicinal plant could have anti-cancer and/or immunemodulating properties and which compounds might be responsible for these actions. Various traditional and organic extracts were prepared. Extracts, fractions and compounds generated were analysed and chemical profiles obtained. Column chromatographic techniques were used to isolate and purify compounds and structure elucidation was carried out using various analytical techniques. Sulforhodamine B and cytometric bead array assays were performed to determine the biological activities of samples generated. / Life and Consumer Sciences / (M. Sc. (Life Sciences)

INTRODUÇÃO: O pênfigo foliáceo (PF) caracteriza-se pela síntese de autoanticorpos contra a desmogleína 1 (Dsg1) com acantólise na epiderme superior. As lesões na face e tronco podem evoluir para eritrodermia (PFE), cuja patogênese é pouco conhecida. Estudos prévios sugerem a participação do fator de crescimento endotelial vascular (VEGF) e da endoglina (Eng). OBJETIVOS: Avaliar dados demográficos, expressão tecidual e níveis séricos do VEGF e Eng, bem como o perfil dos imunocomplexos no PFE. PACIENTES, MATERIAIS E MÉTODOS: Foram selecionados pacientes de PFE (n=31) e indivíduos controles com pênfigo vulgar (PV; n=10), psoríase (PSO; n=10) e saudáveis (CS; n=14) com amostras de soro e pele armazenadas. Os níveis séricos do VEGF, receptor solúvel do VEGF (sVEGFR-1), anti-Dsg1 e -Dsg3 foram avaliados por meio da técnica de ELISA, e a presença do VEGF, Eng, e imunocomplexos in situ foi determinada por imuno-histoquímica (IH) em plataforma automatizada (n=19). Após digitalização das lâminas, a reatividade aos anticorpos supracitados foi classificada manualmente em: 0 (ausente), 1 (discreta-moderada) e 2 (intensa), e analisada por software. RESULTADOS: PFE ocorreu no início da doença em 25/31 pacientes (80,6%), com média de idade de 42,7 anos e predomínio feminino (23/31; 74,2%). Os pacientes foram hospitalizados em média por 41,2 dias; infecção bacteriana foi a principal complicação (30/31; 96,8%), com bacteremia em 10/31 (32,3%) causada por Staphylococcus aureus em 7/10 (70%) dos pacientes. Infecção pelo vírus do herpes simples (HSV) em 11/31 (35,5%) doentes determinou internação prolongada. Valores de imunofluorescência indireta, e anti-Dsg1 e VEGF séricos (ELISA) foram superiores no PFE vs. PF não-eritrodérmico (PFNE) (p < 0,05). Níveis do sVEGFR-1 foram semelhantes no PFE e PFNE, e correlacionaram-se fracamente com a anti-Dsg1 no PFNE (p=0,034). A avaliação manual da IH com anti-VEGF no PFE foi estatisticamente diferente do PFNE (p=0,042) e CS (p=0,004), e similar ao PV (p=0,667) e PSO (p=0,667). Já no PFNE, a expressão do VEGF foi estatisticamente diferente do PV (p=0,049) e PSO (p=0,049) e semelhante ao CS (p=0,247). A contagem automatizada dos vasos marcados com anti-Eng no PFE foi similar ao PFNE (p=0,700) e PSO (p=0,133), e diferente do PV (p=0,0009) e CS (p=0,0009). A avaliação de 6 espécimes de PFE mostrou depósitos de imunocomplexos: intercelulares intraepidérmicos com IgG e C3 (n=6), IgA (n=5) e IgM (n=1); nas células inflamatórias com IgG e C3 (n=6), IgM e IgA (n=1); nos vasos com IgG, C3 e IgA (n=6), e IgM (n=5); e nos anexos com IgG e C3 (n=6), IgA (n=3) e IgM (n=1). CONCLUSÕES: O PFE predomina no início da doença e em mulheres, com maior risco de infecção. O aumento do VEGF sérico e tecidual sugere uma resposta reparadora ao dano tecidual causado pelos níveis elevados de autoanticorpos no PFE. A menor expressão de Eng no PFE indica uma desregulação da angiogênese na eritrodermia. De forma pioneira, a IH automatizada demonstrou a presença de imunocomplexos intraepidérmicos e nas estruturas dérmicas / BACKGROUND: Pemphigus foliaceus (PF) is characterized by the production of autoantibodies against desmoglein 1 (Dsg1), triggering superficial acantholysis. Lesions on the face and trunk may evolve to erythroderma (PFE). The pathogenesis of PFE is not fully understood. Previous studies suggest the role of vascular endothelial growth factor (VEGF) and endoglin (Eng). OBJECTIVES: To evaluate demographic data, VEGF and Eng expression, and immune complexes deposition in patients with PFE. METHODS: This study included patients with PFE (n=31) and controls with pemphigus vulgaris (PV; n=10), psoriasis (PSO; n=10), and health individuals (CS; n=14) that had serum and skin samples stored. Serum levels of VEGF, soluble VEGF receptor (sVEGFR-1), anti-Dsg1 and Dsg3 were measured by ELISA, and the in situ expression of VEGF, Eng, and immune complexes was evaluated utilizing an automated immunohistochemistry (IH) platform (n=19). After digitalizing the slides, the reactivity was manually classified as 0 (negative), 1 (mild-to-moderate) and 2 (intense), and also analyzed by software. RESULTS: PFE occurred at the onset of the disease in 25/31 (80.6%) patients, with a mean age of 42.7 years and a female predominance (23/31; 74.2%). Patients were hospitalized with an average length of stay of 41.2 days. Bacterial infection was the main complication (30/31; 96.8%), with bacteremia in 10/31 (32.3%) due to Staphylococcus aureus in 7/10 (70%) patients. Herpes simplex virus infection in 11/31 (35.5%) PFE patients caused prolonged hospitalization. Indirect immunofluorescence titers and serum anti-Dsg1 and VEGF (ELISA) were increased in PFE vs. non-erythrodermic PF (PFNE) (p < 0.05). Serum levels of sVEGFR-1 were similar in PFE and PFNE, and weakly correlated with anti-Dsg1 in PFNE (p=0.0342). Manual analysis of anti-VEGF positivity in PFE was statistically different from PFNE (p=0.042) and CS (p=0.004), and similar to PSO (p=0.667) and PV (p=0.667). VEGF expression in PFNE was statistically different from PSO (p=0.049) and PV (p=0.049) and similar to CS (p=0.247). The automated positive vessel count with anti-Eng was similar between PFE and PFNE (p=0.700) and PSO (p=0.133), but different from PV (p=0.0009). Immune complex deposits were evaluated in 6 specimens obtained during PFE and exhibited: intraepidermal intercellular deposits with IgG and C3 (n=6), IgA (n=5) and IgM (n=1); reactivity to inflammatory cells with IgG e C3 (n=6), IgM and IgA (n=1); vascular deposits with IgG, C3 and IgA (n=6), and IgM (n=5); and adnexal positivity with IgG and C3 (n=6), IgA (n=3) and IgM (n=1). CONCLUSIONS: Erythroderma predominates at the onset of PF, especially in women, with higher infectious risk. Increased expression of serum and in situ VEGF suggests that healing processes are triggered in response to the tissue damage caused by high levels of circulating autoantibodies in PFE. The reduced expression of Eng in PFE demonstrates a dysregulated angiogenesis during erythroderma. To the best of our knowledge, this is the first study that showed intraepidermal and dermal deposits of multiple immune complexes utilizing automated IH analysis

A vascularização tem um papel central na progressão tumoral e representa um alvo terapêutico de grande interesse. A inibição da angiogênese tem potencial de retardar a progressão tumoral e inibir metástase. Em decorrência disto, terapias anti-angiogênicas têm demonstrado ser promissora no controle do crescimento tumoral. Segundo a literatura, interferon-? (IFN?, ativador do sistema imune inato e adaptativo) e p19Arf (supressor de tumor e parceiro funcional de p53), quando estudados individualmente, alteram a vasculatura tumoral. Nosso grupo construiu e utilizou vetores adenovirais recombinantes portadores dos cDNAs de INFbeta e p19Arf e observou que a transferência desta combinação de genes induziu morte celular e diminuiu progressão tumoral, resultados foram observados em modelos murinos de melanoma B16 de terapia genica in situ, vacina profilática e vacina terapêutica. Neste trabalho, exploramos a ideia que a combinação dos vetores adenovirais portadores de INFbeta e p19Arf proporcionam efeitos anti-angiogênicos através de seu impacto em células endoteliais. Para averiguarmos essa hipótese, células endoteliais murinas (tEnd) foram transduzidas com os vetores adenovirais, revelando que o vetor Ad-p19 confere inibição da proliferação, formação de tubos, migração e induz aumento na expressão de genes relacionados a via de p53 e morte celular. O vetor Ad-IFNbeta sozinho ou adicionado em combinação com Ad-p19, não teve impacto significante nestes ensaios. Alternativamente, a influencia indireta, ou parácrina, nas células tEnd cultivadas juntamente com as células B16 transduzidas com os vetores adenovirais também foi investigada. Quando as células B16 foram transduzidas com Ad-IFNbeta ou a co-transdução Ad-IFNbeta+Ad-p19 em co-cultura com a linhagem tEnd, houve inibição da proliferação. Não observamos efeito inibitório na tEnd da co-cultura quando as células da B16 foram transduzidas somente com Ad-p19. Seguindo o ensaio de co-cultura, produzimos meio condicionado da B16 transduzida com os vetores e aplicamos esses meios nas células tEnd. Observamos que Ad-IFN, sozinho ou em combinação com Ad-19, diminuiu a viabilidade, proliferação e levou a morte das células tEnd. Neste trabalho, constamos que inibição de células endoteliais pode ser realizada por transdução direta com Ad-19 ou quando estas células são expostas ao ambiente modulado por células tumorais transduzidas com o vetor Ad-IFNbeta. Mesmo que a transferência gênica de ambos IFNbeta e p19Arf não demonstrou ser uma abordagem superior à aplicação dos genes isolados, observamos que nossa abordagem pode ter um impacto importante na inibição da angiogênese pelas células endoteliais / The vasculature plays a central role in tumor progression and represents a therapeutic target of great interest. Inhibition of angiogenesis has the potential to slow down tumor progression and inhibit metastasis. As a result, anti-angiogenic therapies have been shown to be promising for the control of tumor growth. According to the literature, interferon ? (IFN?, activator of the innate and adaptive immune systems) and p19Arf (tumor suppressor and functional partner of p53) when studied individually alter tumor vasculature. Our group has constructed and used recombinant adenovirus vectors carrying the cDNAs of INFbeta and p19Arf and noted that the transfer of this combination of genes induced cell death and decreased tumor progression, as observed in the B16 murine model of in situ melanoma gene therapy as well as prophylactic and therapeutic vaccine approaches. In this study, we explore the idea that the combination of adenoviral vectors bearing INFbeta and p19Arf produce anti-angiogenic effects due to their impact on endothelial cells. To test this hypothesis, murine endothelial cells (tEnd) were transduced with adenoviral vectors, revealing that Ad-p19 vector confers inhibition of proliferation, tube formation, migration and induces increased expression of genes related to the p53 cell death pathway. The Ad-IFNbeta vector alone had no significant impact on these tests. Alternatively, influences on paracrine effects are evaluated on endothelial cells co-cultured with B16 cells that were previously transduced with adenoviral vectors. When the B16 cells were transduced with Ad-IFNbeta or co-transduced with Ad-IFNbeta + Ad-p19, co-culture resulted in the inhibition of proliferation of the endothelial cells. When B16 cells were transduced with Ad-p19 only, co-culture did alter endothelial cell behavior. Following the co-culture assay, we produce conditioned medium from B16 cells that were transduced with the vectors and applied the media on tEnd cells. We noted that conditioned medium derived from B16 transduced with Ad-IFN alone or in combination with Ad-19 decreased the viability and proliferation and induced cell death of tEnd. In this work, we show that inhibition of endothelial cells can be performed directly by transduction with Ad-19 or when such cells are exposed to the environment modulated by tumor cells transduced with Ad-IFNbeta. Even though the gene transfer of both IFNbeta and p19 was not found to be superior to the application of single genes, we observed that our approach may have an important impact on the inhibition of angiogenesis through endothelial cells

Earlier studies of persons with deafness (D) and/or deafblindness (DB) have primarily focused on the mobility and communication problems. The purpose of the present study was to develop technology for monitoring aids to improve the ability of persons with D and/or DB to detect, identify, and perceive direction of events that produce sounds in their surroundings. The purpose was achieved stepwise in four studies. In Study I, the focus was on hearing aids for persons with residual low frequency hearing. In Study II-IV, the focus was on vibratory aids for persons with total D. In Study I, six signal processing algorithms (calculation methods) based on two principles, transposition and modulation, were developed and evaluated regarding auditory identification of environmental sounds. Twenty persons with normal hearing listened to 45 environmental sounds processed with the six different algorithms and identified them in three experiments. In Exp. 1, the sounds were unknown and the subjects had to identify them freely. In Exp. 2 and 3, the sounds were known and the subjects had to identify them by choosing one of 45 sounds. The transposing algorithms showed better results (median value in Exp. 3, 64%-69%) than the modulating algorithms (40%-52%) did, and they were good candidates for implementing in a hearing aid for persons with residual low frequency hearing. In Study II, eight algorithms were developed based on three principles, transposition, modulation, and filtration – in addition to No Processing as reference, and evaluated for vibratory identification of environmental sounds. The transposing algorithms and the modulating algorithms were also adapted to the vibratory thresholds of the skin. Nineteen persons with profound D tested the algorithms using a stationary, wideband vibrator and identified them by choosing one of 10 randomly selected from the list of 45 sounds. One transposing algorithm and two modulating algorithms showed better (p&lt;0.05) scores than did the No Processing method. Two transposing and three modulating algorithms showed better (p&lt;0.05) scores than did the filtering algorithm. Adaptation to the vibratory thresholds of the skin did not improve the vibratory identification results. In Study III, the two transposing algorithms and the three modulating algorithms with the best identification scores in Study II, plus their adapted alternative, were evaluated in a laboratory study. Five persons from Study II with profound D tested the algorithms using a portable narrowband vibrator and identified the sounds by choosing one of 45 sounds in three experiments (Exp. 1, 2, and 3). In Exp. 1, the sounds were pre-processed and directly fed to the vibrator. In Exp. 2 and 3, the sounds were presented in an acoustic test room, without or with background noise (SNR=+5 dB), and processed in real time. Five of the algorithms had acceptable results (27%-41%) in the three experiments and constitute candidates for a miniaturized vibratory aid (VA). The algorithms had the same rank order in both tests in the acoustic room (Exp. 2, and 3), and the noise did not worsen the identification results. In Study IV, the portable vibrotactile monitoring aid (with stationary processor) for detection, identification and directional perception of environmental sounds was evaluated in a field study. The same five persons with profound D as in Study III tested the aid using a randomly chosen algorithm, drawn from the five with the best results in Study III, in a home and in a traffic environment. The persons identified 12 events at home and five events in a traffic environment when they were inexperienced (the events were unknown) and later when they were experienced (the events were known). The VA consistently improved the ability with regard to detection, identification and directional perception of environmental sounds for all five persons. It is concluded that the selected algorithms improve the ability to detect, and identify sound emitting events. In future, the algorithms will be implemented in a low frequency hearing aid for persons with low frequency residual hearing or in a fully portable vibratory monitoring aid, for persons with profound D or DB to improve their ability to sense the environment.

No description available.

La question prioritaire de constitutionnalité (QPC), instaurée en 2008, permet au Conseil constitutionnel de se prononcer sur la conformité d’une disposition législative déjà entrée en vigueur, aux « droits et libertés que la Constitution garantit ». Les effets substantiels des décisions QPC, c'est-à-dire la suppression ou la modification d’une disposition législative par le prononcé d’une inconstitutionnalité ou d’une réserve d’interprétation, peuvent se révéler importants compte tenu de la portée erga omnes de ces décisions. C’est alors par la maîtrise de leur application temporelle que les effets substantiels vont être encadrés voire modérés. Certains effets temporels revêtent un caractère automatique : la décision QPC en tant qu’elle porte sur une norme (la disposition législative en cause), s’insère dans l’ordonnancement juridique et, à ce titre, génère des conflits de normes. Par ailleurs, les effets temporels peuvent également, et surtout, être choisis par le Conseil constitutionnel, par l’utilisation de son pouvoir de modulation. Ce pouvoir a été conçu de manière à laisser une grande liberté au Conseil constitutionnel. Dans une démarche d’efficacité, le juge constitutionnel s’est fixé l’objectif de faire bénéficier le justiciable d’un« effet utile » de ses décisions et a par conséquent valorisé l’usage de la rétroactivité. Cependant, la liberté seule n’assure pas une pleine maîtrise de ce pouvoir de modulation et ce même pouvoir est parfois insuffisant pour régir les effets substantiels des décisions QPC. La thèse contribue, sur la base d’une analyse exhaustive de l’ensemble des décisions QPC du Conseil et de trèsnombreuses décisions dites « retour de QPC » des juridictions ordinaires, à étudier ces insuffisances et notamment le manque de réflexion sur la compatibilité entre la technique de la modulation et l’office du juge constitutionnel et sur la nécessité d’une collaboration avec les juridictions ordinaires. / The priority question of constitutionality (QPC), created in 2008, allows the french Constitutional Council to operate a judicial review of an adopted law. The substantial effects of a QPC decision, ie the abolition or the modification of a legislation by pronouncing its unconstitutionality or by interpreting it in accordance with the Constitution, can be considerable given the erga omnes impact of these decisions. These substantial effects can however be controlled or moderated by the temporal effects. Some temporal effects are inevitable: the QPCdecision since it concerns a norm (the law), integrates with the legal order and generates norms’ conflicts. Otherwise the temporal effects can be chosen by the Constitutional Council thanks to the ability of modulating the temporal effects of its decisions. This jurisdictional technical lets total liberty to the Constitutional Council. The court, in an efficacy perspective, sets the objectiveof giving a « useful effect » to the litigant and thus accords value to retroactivity. Yet this liberty alone isn’t enough to provide a complete control of this modulating ability and this ability can’t regulate all the substantial effects. This thesis, based on an exhaustive jurisprudential analysis ofthe QPC decisions, aims to study these difficulties and especially the lack of reflection about the compatibility of the technical into the judicial office of the court and about the essential collaboration with the ordinary jurisdictions.

Introdução: A correção anatômica da transposição das grandes artérias após o período neonatal demanda a preparação prévia do ventrículo subpulmonar, com bandagem do tronco pulmonar, para induzir a hipertrofia ventricular. Estudos experimentais prévios demonstraram que a sobrecarga sistólica intermitente determina uma hipertrofia ventricular mais eficiente, em relação à bandagem convencional (fixa) do tronco pulmonar. Os mecanismos adaptativos envolvidos no retreinamento do ventrículo subpulmonar ainda não estão completamente estabelecidos, pois se sabe que, além da hipertrofia e hiperplasia das células contráteis, também células do interstício e vasos sofrem alterações fenotípicas. Permanece indefinida a taxa ideal de incremento, tanto da matriz extracelular quanto da vascularização do miocárdio na situação do retreinamento ventricular, para suportar a resistência sistêmica. Objetivo: Avaliar a adaptação do ventrículo subpulmonar no que se refere a apoptose e estímulo à neovascularização miocárdica em resposta à sobrecarga pressórica contínua versus intermitente, obtida pela bandagem ajustável do tronco pulmonar de cabritos jovens. Método: Foram utilizados 21 cabritos hígidos, com idade de 30 a 60 dias e pesos comparáveis, divididos em três grupos: Controle (n = 7, sem sobrecarga sistólica), Contínuo (n = 7, sobrecarga sistólica contínua do VD), Intermitente (n = 7, 12 horas/dia de sobrecarga sistólica intermitente do VD). A sobrecarga sistólica do VD foi mantida por 96 horas no grupo Contínuo e por quatro períodos de 12 horas, alternados com 12 horas de descanso, no grupo intermitente. Os animais do grupo Controle foram submetidos ao implante do dispositivo de bandagem, o qual foi mantido desinsuflado. As medidas hemodinâmicas foram tomadas diariamente, antes e após o ajuste da sobrecarga sistólica. Avaliações ecocardiográficas foram realizadas no pré-operatório e no final do protocolo de estudo. Após 96 horas de estudo, os animais foram mortos para avaliação dos parâmetros morfológicos (peso e conteúdo de água das massas cardíacas e análise imuno-histoquímica da apoptose e da expressão do VEGF). Resultados: Ao final do protocolo, o ecocardiograma revelou uma diferença significativa da espessura do VD no grupo Intermitente (+129,2%), quando comparado ao grupo Contínuo (+58,2%; p < 0,001) e de ambos os grupos de estudo quando comparados ao grupo Controle (p < 0,001). Sob a análise morfológica, ambos os grupos de estudo apresentaram ganho de magnitude semelhante nas massas do VD (Intermitente: + 115,8%; Contínuo: + 90,8%; p < 0,0001) e do septo (Intermitente: +55,8%; Contínuo: + 45,4%; p < 0,047), em relação ao grupo Controle, apesar do menor tempo de sobrecarga pressórica no grupo Intermitente. O protocolo de sobrecarga sistólica do VD não influenciou a massa muscular do VE. Houve um discreto aumento do conteúdo de água do VD (Contínuo: +3,5%, Intermitente: +4,6%) e do septo (ambos os grupos de estudo: +3,5%) em relação ao grupo Controle (p < 0,002). A expressão do VEGF foi maior no VD do grupo Intermitente (2,89% ± 0,41%; p=0,005) em relação ao VD dos demais grupos (Controle: 1,43% ± 0,18%; Contínuo: 1,80% ± 0,19%). A expressão desta molécula no miocárdio do VD do grupo Intermitente foi também maior que o do VE e septo dentro do mesmo grupo (p < 0,050). Não houve diferença na expressão do VEGF das demais massas cardíacas (VE: p > 0,252; Septo: p > 0,740). Em relação à apoptose, não foram observadas diferenças significativas no miocárdio do VD dos três grupos (Caspase: p=0,784; TUNEL: p=0,374). Conclusões: Ambos os grupos de estudo desenvolveram hipertrofia miocárdica do VD, não acompanhada de edema miocárdico importante ou apoptose. No entanto, a sobrecarga sistólica intermitente promoveu maior expressão do VEGF no miocárdio do VD. Esta associação entre sinalização de proliferação vascular e hipertrofia tem implicações importantes quando se objetiva preparar um ventrículo para suportar pressões sistêmicas, uma vez que o desejável é que a proliferação vascular ocorra de forma sustentada, permitindo uma hipertrofia do VD mais eficiente / Introduction: Surgical correction of transposition of the great arteries beyond the neonatal period needs a previous pulmonary artery band to promote left ventricular hypertrophy thereby preparing the ventricle. Experimental studies have demonstrated that intermittent systolic overload causes a more efficient ventricular hypertrophy, as compared to traditional pulmonary artery banding. The adaptive mechanisms involved in the subpulmonary ventricle retraining are not completely established. Nevertheless, besides the hypertrophy and/or hyperplasia of the contractile cardiomyocytes, noncontractile cells (vascular and interstitial) from the stimulated ventricle also present structural phenotype changes. It remains unclear the ideal increasing rate of the myocardial interstitium as well as capillary vessel proliferation in the process of ventricular retraining before undertaking the arterial switch. Objective: This study sought to assess adaptive changes of the subpulmonary ventricle in regards to vascular endothelial growth factor (VEGF) expression and apoptosis in young goats submitted to continuous versus intermittent systolic overload by means of an adjustable pulmonary artery band. Methods: 21 young goats were separated into 3 groups: Control (no systolic overload), Continuous (96-hour continuous systolic overload), and Intermittent (four 12-hour periods of systolic overload paired with a 12-hour resting period). Systolic overload was adjusted to achieve a 0.7 RV / aortic pressure ratio. Hemodynamic evaluations were performed before and after systolic overload every day postoperatively. Echocardiograms were obtained preoperatively and at the end of protocol. After the study period, the animals were humanely killed for morphologic assessment, apoptosis and vascular endothelial growth factor (VEGF) expression. Results: Echocardiography revealed a marked increase in RV wall thickness in the Intermittent group (+129.2%), compared with the Continuous group (+58.2%; p<0.001), as well as both trained groups compared to Control group (p < 0.001). Regardless of the shorter systolic overload exposure of Intermittent group, both study groups had a similar increase in RV mass (Intermittent: + 115.8%; Continuous: +90.8%; p < 0.001), and septal mass (Intermittent: + 55.8%; Continuous: + 45.4%; p < 0.047), compared with the Control group. No significant changes in the left ventricle mass were seen. There was a negligible but significant increase in water content of RV (Continuous: +3.5%, Intermittent: +4.6%) and septal masses (both study groups: +3.5%) compared with that in the Control group (p < 0.002). RV VEGF expression was greater in the Intermittent group (2.89% ± 0.41%) than in the Continuous (1.80% ± 0.19%) and Control (1.43% ± 0.18%) groups (p < 0.023). VEGF expression in the myocardium of the right ventricle in the Intermittent group was also greater than that in the left ventricle and septum within the same group (p < 0.050). There was no significant difference in VEGF expression between the other cardiac sections or within the Control and Continuous groups. Regarding apoptosis, there were no significant changes in the RV myocardium of the three groups (Caspase: p=0,784; TUNEL: p=0,374). Conclusions: Both study groups have developed RV hypertrophy with no apoptosis or relevant myocardial edema. Nevertheless, intermittent systolic overload causes upregulation of VEGF expression in the subpulmonary ventricle, an adaptation that provides a mechanism for increased myocardial perfusion during the rapid myocardial hypertrophy of young goats. The association of the marked increase in RV mass and increased angiogenesis signaling has an important implication on the subpulmonary ventricle retraining protocol by promoting a compensatory growth of the coronary vasculature, allowing for a more efficient hypertrophy

Introdução: A correção anatômica da transposição das grandes artérias após o período neonatal demanda a preparação prévia do ventrículo subpulmonar, com bandagem do tronco pulmonar, para induzir a hipertrofia ventricular. Estudos experimentais prévios demonstraram que a sobrecarga sistólica intermitente determina uma hipertrofia ventricular mais eficiente, em relação à bandagem convencional (fixa) do tronco pulmonar. Os mecanismos adaptativos envolvidos no retreinamento do ventrículo subpulmonar ainda não estão completamente estabelecidos, pois se sabe que, além da hipertrofia e hiperplasia das células contráteis, também células do interstício e vasos sofrem alterações fenotípicas. Permanece indefinida a taxa ideal de incremento, tanto da matriz extracelular quanto da vascularização do miocárdio na situação do retreinamento ventricular, para suportar a resistência sistêmica. Objetivo: Avaliar a adaptação do ventrículo subpulmonar no que se refere a apoptose e estímulo à neovascularização miocárdica em resposta à sobrecarga pressórica contínua versus intermitente, obtida pela bandagem ajustável do tronco pulmonar de cabritos jovens. Método: Foram utilizados 21 cabritos hígidos, com idade de 30 a 60 dias e pesos comparáveis, divididos em três grupos: Controle (n = 7, sem sobrecarga sistólica), Contínuo (n = 7, sobrecarga sistólica contínua do VD), Intermitente (n = 7, 12 horas/dia de sobrecarga sistólica intermitente do VD). A sobrecarga sistólica do VD foi mantida por 96 horas no grupo Contínuo e por quatro períodos de 12 horas, alternados com 12 horas de descanso, no grupo intermitente. Os animais do grupo Controle foram submetidos ao implante do dispositivo de bandagem, o qual foi mantido desinsuflado. As medidas hemodinâmicas foram tomadas diariamente, antes e após o ajuste da sobrecarga sistólica. Avaliações ecocardiográficas foram realizadas no pré-operatório e no final do protocolo de estudo. Após 96 horas de estudo, os animais foram mortos para avaliação dos parâmetros morfológicos (peso e conteúdo de água das massas cardíacas e análise imuno-histoquímica da apoptose e da expressão do VEGF). Resultados: Ao final do protocolo, o ecocardiograma revelou uma diferença significativa da espessura do VD no grupo Intermitente (+129,2%), quando comparado ao grupo Contínuo (+58,2%; p < 0,001) e de ambos os grupos de estudo quando comparados ao grupo Controle (p < 0,001). Sob a análise morfológica, ambos os grupos de estudo apresentaram ganho de magnitude semelhante nas massas do VD (Intermitente: + 115,8%; Contínuo: + 90,8%; p < 0,0001) e do septo (Intermitente: +55,8%; Contínuo: + 45,4%; p < 0,047), em relação ao grupo Controle, apesar do menor tempo de sobrecarga pressórica no grupo Intermitente. O protocolo de sobrecarga sistólica do VD não influenciou a massa muscular do VE. Houve um discreto aumento do conteúdo de água do VD (Contínuo: +3,5%, Intermitente: +4,6%) e do septo (ambos os grupos de estudo: +3,5%) em relação ao grupo Controle (p < 0,002). A expressão do VEGF foi maior no VD do grupo Intermitente (2,89% ± 0,41%; p=0,005) em relação ao VD dos demais grupos (Controle: 1,43% ± 0,18%; Contínuo: 1,80% ± 0,19%). A expressão desta molécula no miocárdio do VD do grupo Intermitente foi também maior que o do VE e septo dentro do mesmo grupo (p < 0,050). Não houve diferença na expressão do VEGF das demais massas cardíacas (VE: p > 0,252; Septo: p > 0,740). Em relação à apoptose, não foram observadas diferenças significativas no miocárdio do VD dos três grupos (Caspase: p=0,784; TUNEL: p=0,374). Conclusões: Ambos os grupos de estudo desenvolveram hipertrofia miocárdica do VD, não acompanhada de edema miocárdico importante ou apoptose. No entanto, a sobrecarga sistólica intermitente promoveu maior expressão do VEGF no miocárdio do VD. Esta associação entre sinalização de proliferação vascular e hipertrofia tem implicações importantes quando se objetiva preparar um ventrículo para suportar pressões sistêmicas, uma vez que o desejável é que a proliferação vascular ocorra de forma sustentada, permitindo uma hipertrofia do VD mais eficiente / Introduction: Surgical correction of transposition of the great arteries beyond the neonatal period needs a previous pulmonary artery band to promote left ventricular hypertrophy thereby preparing the ventricle. Experimental studies have demonstrated that intermittent systolic overload causes a more efficient ventricular hypertrophy, as compared to traditional pulmonary artery banding. The adaptive mechanisms involved in the subpulmonary ventricle retraining are not completely established. Nevertheless, besides the hypertrophy and/or hyperplasia of the contractile cardiomyocytes, noncontractile cells (vascular and interstitial) from the stimulated ventricle also present structural phenotype changes. It remains unclear the ideal increasing rate of the myocardial interstitium as well as capillary vessel proliferation in the process of ventricular retraining before undertaking the arterial switch. Objective: This study sought to assess adaptive changes of the subpulmonary ventricle in regards to vascular endothelial growth factor (VEGF) expression and apoptosis in young goats submitted to continuous versus intermittent systolic overload by means of an adjustable pulmonary artery band. Methods: 21 young goats were separated into 3 groups: Control (no systolic overload), Continuous (96-hour continuous systolic overload), and Intermittent (four 12-hour periods of systolic overload paired with a 12-hour resting period). Systolic overload was adjusted to achieve a 0.7 RV / aortic pressure ratio. Hemodynamic evaluations were performed before and after systolic overload every day postoperatively. Echocardiograms were obtained preoperatively and at the end of protocol. After the study period, the animals were humanely killed for morphologic assessment, apoptosis and vascular endothelial growth factor (VEGF) expression. Results: Echocardiography revealed a marked increase in RV wall thickness in the Intermittent group (+129.2%), compared with the Continuous group (+58.2%; p<0.001), as well as both trained groups compared to Control group (p < 0.001). Regardless of the shorter systolic overload exposure of Intermittent group, both study groups had a similar increase in RV mass (Intermittent: + 115.8%; Continuous: +90.8%; p < 0.001), and septal mass (Intermittent: + 55.8%; Continuous: + 45.4%; p < 0.047), compared with the Control group. No significant changes in the left ventricle mass were seen. There was a negligible but significant increase in water content of RV (Continuous: +3.5%, Intermittent: +4.6%) and septal masses (both study groups: +3.5%) compared with that in the Control group (p < 0.002). RV VEGF expression was greater in the Intermittent group (2.89% ± 0.41%) than in the Continuous (1.80% ± 0.19%) and Control (1.43% ± 0.18%) groups (p < 0.023). VEGF expression in the myocardium of the right ventricle in the Intermittent group was also greater than that in the left ventricle and septum within the same group (p < 0.050). There was no significant difference in VEGF expression between the other cardiac sections or within the Control and Continuous groups. Regarding apoptosis, there were no significant changes in the RV myocardium of the three groups (Caspase: p=0,784; TUNEL: p=0,374). Conclusions: Both study groups have developed RV hypertrophy with no apoptosis or relevant myocardial edema. Nevertheless, intermittent systolic overload causes upregulation of VEGF expression in the subpulmonary ventricle, an adaptation that provides a mechanism for increased myocardial perfusion during the rapid myocardial hypertrophy of young goats. The association of the marked increase in RV mass and increased angiogenesis signaling has an important implication on the subpulmonary ventricle retraining protocol by promoting a compensatory growth of the coronary vasculature, allowing for a more efficient hypertrophy