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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.
141

Insulina regula a translocação nuclear de NF-κB p65, inflamação e morte celular em modelo experimental de sepse em camundongos diabéticos / Insulin regulates NF-κB p65 nuclear translocation, inflammation and cell death in septic diabetic mice

Eduardo Lima Nolasco 19 May 2017 (has links)
Sepse é uma resposta sistêmica e deletéria do indivíduo a uma infecção, sendo um importante problema de saúde pública. Pacientes diabéticos são bastante afetados representando cerca de 22% de todos os pacientes sépticos. A suscetibilidade para o desenvolvimento de sepse no diabetes, bem como a ação da insulina em modular alguns parâmetros imunológicos necessitam de maiores esclarecimentos O objetivo deste estudo foi avaliar os efeitos do tratamento com insulina em um modelo murino de diabetes e sepse. Camundongos C57BL/6 foram tornados diabéticos por administração de aloxana. Os seguintes parâmetros foram analisados vinte e quatro horas após a ligadura cecal e punção (CLP): (a) interleukine (IL)-6, IL-10, chemokine (C -C motif) ligand 2 (CCL2) e tumor necrosis fator (TNF ) -α no soro; (b) os níveis de IL-1β, IL-6, TNF-&#945, IL-10, chemokine (C -X-C motif) ligand (CXCL)-1 e CXCL2 no lavado peritoneal (LPe) e broncoalveolar (LBA), bem como nos rins e fígado; (c) contagens celulares totais e diferenciais em LPe e LBA; (d) capacidade endocítica de neutrófilos e produção de espécies reactivas de oxigénio (ERO); (e) níveis de apoptose e necrose no baço e níveis relativos de células CD4+ e CD8+; (f) resultados histopatológicos de pulmão, rim e fígado; e (g) níveis de translocação nuclear de NF-κB p65. Camundongos diabéticos-CLP exibiram concentrações séricas aumentadas de TNF-α, IL-6, CCL2, IL-1, IL-6, CXCL1, CXCL2 e IL-10 e contagens de neutrófilos em LPe. A capacidade endocítica dos neutrófilos e a produção de ERO apresentavam-se reduzidas em animais CLP-diabéticos e os níveis de IL-6, TNF-α, CXCL1 e CXCL2 em LBA e IL-1β, IL-6, CXCL1 e CXCL2 nos homogenados renais aumentaram diabéticos -CLP. O tratamento destes com insulina reduziu os nívies de citocinas séricas, aumentou a concentração de citocinas e a migração celular para o Lpe, restaurou a capacidade endocítica e a produção de ERO e reduziu a translocação nuclear NF-κB p65 no tecido renal. Estes dados sugerem que a insulina modula a produção/libertação de citocinas, regula a migração celular, a apoptose, a necrose e a translocação nuclear de NF-κB p65 na sepse induzida por CLP em camundongos diabéticos. / Sepsis is a systemic and harmful response of the individual to infection and is an important public health problem. Diabetic patients are greatly affected representing about 22% of all septic patients. The susceptibility to sepsis development in diabetic individuals and insulin action in modulating some immunological parameters require further clarification. The aim of this study was to evaluate the effects of insulin treatment in a mouse model of diabetes and sepsis. C57BL/6 mice were rendered diabetic by alloxan administration. The following parameters were analyzed twenty-four hours after a cecal ligation and puncture (CLP): (a) interleukin (IL)-6, IL-10, chemokine (C-C motif) ligand 2 (CCL2), and tumor necrosis factor (TNF) - α levels in serum; (b) IL-1β, IL-6, TNF-α, IL-10, chemokine (C-X-C motif) ligand (CXCL)1 and CXCL2 levels in peritoneal lavage (PeL) and bronchoalveolar lavage (BAL) fluid, as well as in the kidneys and liver; (c) total and differential cell counts in PeL and BAL fluid; (d) neutrophil endocytic capacity and reactive oxygen species (ROS) production; (e) spleen cell apoptosis and necrosis levels and relative CD4+ and CD8+ T cell levels; (f) lung, kidney, and liver histopathological results; and (g) NF-kB p65 nuclear translocation levels. Diabetic-CLP mice exhibited increased serum TNF-α, IL-6, CCL2, IL-1, IL-6, CXCL1, CXCL2 and IL-10 concentrations and neutrophil counts in PeL fluid. Neutrophil endocytic capacity and ROS production were decreased in diabetic-CLP mice, and IL-6, TNF- α, CXCL1 and CXCL2 leves in BAL fluid and IL-1β, IL-6, CXCL1 and CXCL2 levels in kidney homogenates were increased in diabetic-CLP mice. Treatment of these mice with insulin reduced serum cytokine levels increased cytokine and cell migration into PeL fluid, and restored neutrophil endocytic capacity and ROS production and NF-kB p65 nuclear translocation in the kidney. These data suggest that insulin modulates cytokine production/release, regulates cellular migration, apoptosis, necrosis and NF-kB p65 nuclear translocation in CLP-induced sepsis in diabetic mice.
142

Células-tronco provenientes de cordão umbilical humano atenuam a senescência renal induzida por injúria renal aguda secundária à lesão de isquemia e reperfusão em ratos / Human umbilical cord derived stem cells attenuate ischemic acute kidney injury-induced premature senescence in rats

Camila Eleuterio Rodrigues 28 April 2015 (has links)
A injúria renal aguda representa um estado de senescência precoce induzida por estresse, e as células-tronco mesenquimais podem ser uma alternativa para seu tratamento. Células-tronco jovens reduzem o fenótipo de envelhecimento em rins quando comparadas a células idosas. O objetivo deste estudo foi avaliar se o tratamento com jovens células-tronco mesenquimais derivadas de cordão umbilical humano podem interferir na senescência renal induzida por lesão de isquemia-reperfusão em ratos. Ratos machos foram submetidos ao modelo de isquemia de artérias renais bilateralmente por 45 minutos, com reperfusão após, e alguns animais receberam 1 X 106 células por via intraperitoneal após 6 horas da indução da lesão. Os animais foram eutanasiados no segundo ou no sétimo dia pós-isquêmico. No segundo dia após a lesão de isquemia-reperfusão, o tratamento com as células melhorou a filtração glomerular e a função tubular, melhorou a expressão renal de aquaporina-2 e reduziu a infiltração de macrófagos nos rins. Proteínas relacionadas à senescência (-galactosidase, p21, p16 e fator de transformação do crescimento ) e microRNAs (mir-29a e miR-34a) estiveram com a expressão aumentada após a isquemia-reperfusão, e houve redução nesses parâmetros com o tratamento. A redução na expressão de Klotho e o estado pró-oxidativo gerados pela isquemia-reperfusão também foram revertidos pelo tratamento. A senescência induzida pela injúria renal aguda é um processo independente de telômeros. Ao sétimo dia pós-lesão, os ratos isquêmicos mantinham defeito de concentração urinária, que foi revertido nos animais tratados. Além disso, o tratamento reduziu o índice de necrose tubular aguda em tecido renal e reduziu o infiltrado macrofágico túbulo-intersticial. O marcador pró-senescência p16 foi completamente restabelecido nos animais tratados. Nossos dados demonstram que o tratamento com jovens células-tronco mesenquimais derivadas de cordão umbilical humano atenua a resposta inflamatória e de estresse oxidativo que ocorre na injúria renal aguda, e reduz a expressão de proteínas e microRNAs relacionados à senescência. Nossos achados expandem as perspecivas para o tratamento da injúria renal aguda / Acute kidney injury represents a status of premature stress-induced senescence, and mesenchymal stem cells are an alternative for treatment. Young stem cells reduce aging phenotype in kidneys when compared to old cells. The objective of this study was to evaluate if treatment with young human umbilical cord mesenchymal stem cells could interfere in kidney senescence induced by renal ischemia-reperfusion in rats. Male rats were induced to ischemia-reperfusion injury by 45-minutes clamping of both renal arteries; some rats received 1X106 cells intraperitonally six hours later. Rats were euthanatized on post-renal ischemia reperfusion days two and seven. At day 2 after ischemia-reperfusion injury, treatment with cells improved glomerular filtration, tubular function, improved renal expression of aquaporin 2 and decreased macrophage kidney infiltration. Senescence-related proteins (?-galactosidase, p21, p16 and transforming growth factor ?) and microRNAs (miR-29a and miRNA-34a) were overexpressed after ischemia-reperfusion, and reversed by the treatment. The Klotho reduced expression and the pro-oxidative status induced by ischemia-reperfusion were reversed by the treatment. Senescence induced acute kidney injury is a telomere-independent process. At day 7, ischemic rats maintained urinary concentrating defect, which is reversed in treated animals. Moreover, treatment decreased the index of acute tubular necrosis in kidney tissue and decreased macrophage kidney infiltration. Senescence marker p16 was completely restored in treated animals. Our data demonstrate that young human umbilical mesenchymal stem cells treatment attenuates the inflammatory and oxidative stress response occurring in acute kidney injury, and reduces the protein and microRNA expression related to senescence. Our findings broaden the perspectives for the treatment of AKI
143

Influência da sobrecarga de sódio em ratos submetidos à  isquemia e reperfusão renal: tratamento com N-acetilcisteína / Influence of sodium overload in rats submitted to renal ischemia and reperfusion; N -acetylcysteine treatment

Rafael Canavel Pereira 30 May 2018 (has links)
A injúria renal aguda (IRA) é uma complicação renal que necessita de tratamento com urgência, gerando gastos de bilhões de dólares na saúde pública de diversos países. Dentre os tipos mais comuns de IRA é a IRA isquêmica causada por perfusão abaixo do normal ao tecido renal, gerando maior produção de espécies reativas de oxigênio (ROS), ativação do sistema renina angiotensina aldosterona (SRAA) local, necrose tubular aguda (NTA). O tratamento com o antioxidante N-acetilcisteína (NAC) tem resultados positivos em diversos modelos de lesão renal. Ao reestabelecer a função renal após a IRA, os pacientes devem seguir dietas restritas quanto a quantidade de proteínas e de sal, entretanto, sabe-se que o sal é um dos maiores causadores de doenças renais e é encontrado de forma exacerbada em diversos tipos de alimentos comumente consumidos no dia a dia. OBJETIVOS: Avaliar os efeitos da sobrecarga de sódio sobre a isquemia e reperfusão renal e verificar se o tratamento com NAC é capaz de mitigar os danos causados pela isquemia e reperfusão renal bilateral associada ao alto consumo de sódio. ANIMAIS: Ratos Wistar machos com seis semanas de vida foram divididos em dois tipos de dieta normossódica (NR) com 2,3% de NaCl e hipersódica (HR) com 8% e submetidos ou não (SHAM) à isquemia e reperfusão renal bilateral e tratados ou não com NAC (600 mg/L) VARIÁVEIS: Peso corpóreo, pressão arterial caudal, consumo hídrico e de ração, volume urinário, fração de excreção de sódio e potássio, sódio, potássio, creatinina e uréia sérica, clearance de creatinina, proteinúria e albuminúria, massas cardíaca e renal, diâmetro transverso glomerular e diâmetro transverso do cardiomiócito, fibrose intersticial renal e cardíaca, TAS,TBARS e ácido úrico, expressão gênica de renina, atividade da renina plasmática e renal, taxa de sobrevida. RESULTADOS E DISCUSSÃO: A dieta hipersódica associada à isquemia e reperfusão induziu ao aumento da albuminúria, das massas renal e cardíaca e ao desenvolvimento de fibrose intersticial cardíaca e renal, não houve diferença na atividade da renina plasmática e renal, e também no estado REDOX destes animais. NAC foi capaz de prevenir o desenvolvimento de albuminúria, o aumento das massas renal e cardíaca e formação de fibrose / ABSTRACT: Acute kidney injury (AKI) is a renal complication that requires urgent treatment and the most common types is ischemic AKI caused by below normal perfusion to renal tissue, generating high production of reactive oxygen species (ROS), tissue renin angiotensin aldosterone system (RAAS) activation, and acute tubular necrosis (NTA). The antioxidant N-acetylcysteine (NAC) treatment have shown positive results in several renal injury models. After reestablishment of renal function, patients should be submitted to protein and salt restriction diet. Salt is known to be a major cause of kidney disease. OBJECTIVES: To evaluate the effects of sodium overload on renal ischemia and reperfusion and to verify if NAC treatment was able to mitigate the damage caused by bilateral renal ischemia and reperfusion associated with high sodium consumption in diet. ANIMALS: Six-week-old male Wistar rats were divided in normal sodium (NS - 1.3% NaCl) or high sodium (HS - 8.0% NaCl) diet group. Both diet group were submitted to bilateral renal reperfusion and ischemia or not (SHAM), treated or not with NAC (600mg/L). VARIABLES: Body weight, tail blood pressure, water and feed intake, urinary volume excretion, sodium and potassium excretion, sodium, potassium, serum creatinine and urea, creatinine clearance, proteinuria and albuminuria, cardiac and renal masses, transverse diameter glomerular and transverse diameter of the cardiomyocyte, renal and cardiac interstitial fibrosis, TAS, TBARS and serum uric acid, renin gene expression, plasma and renal renin activity, survival curve. RESULTS AND DISCUSSION: The high sodium diet associated to ischemia and reperfusion induced to albuminuria; increased renal and cardiac mass and to development of cardiac and renal interstitial fibrosis. However, plasma and renal renin activity and REDOX status were not changed. NAC was able to prevent the albuminuria, renal and cardiac hypertrophy, and fibrosis formation
144

Efeito protetor de fitomedicamento Vitis Vinifera L na lesão renal aguda induzida pelo Tacrolimus / Protective effect of the phytomedicine Vitis Vinifera L in acute kidney injury by Tacrolimus

Wanessa Teixeira Silva 04 November 2010 (has links)
As lesões renais agudas (LRAs) nefrotóxicas correspondem a 30% dos casos de LRA. A nefrotoxicidade é efeito indesejável de diversos fármacos de uso rotineiro na clínica, entre eles as drogas imunossupressoras. A nefrotoxicidade do Tracolimus (Fk 506) é uma das causas de LRA após o transplante renal. Com a ampla utilização do Fk 506 nas terapias imunossupressoras e devido ao seu potencial nefrotóxico que pode levar à perda do enxerto, o objetivo desse estudo foi avaliar o efeito renoprotetor do extrato de Vitis vinifera L, um fitomedicamento com efeito antiinflamatório e antioxidante, na nefrotoxicidade induzida pelo Tacrolimus em ratos. Foram utilizados ratos Wistar, machos, adultos, pesando entre 250 - 300g, todos tratados 1x/dia por 5 dias, conforme os seguintes grupos: Salina (grupo controle) (NaCl 0,9%, 0,1ml por gavagem); Vitis (Vitis vinifera L 3mg/kg por gavagem), Fk (Tacrolimus 0,5mg/kg por gavagem) e Fk+Vitis (Tacrolimus 0,5mg/kg + 3mg/kg por gavagem). Foram avaliados a função renal (FR) (clearance de creatinina, método Jaffé); os peróxidos urinários (PU) (FOX-2), o malondealdeído (MDA-TBARS) e a histologia renal. Os dados desse estudo confirmaram a lesão nefrotóxica de caráter oxidativo induzida pelo Tacrolimus. A Vitis vinifera L demonstrou efeito renoprotetor significativo, com melhora na FR, redução dos níveis de peroxidação lipídica e proteção histológica. Esse estudo confirmou a renoproteção da Vitis vinifera L na LRA induzida pelo Tacrolimus. / The nephrotoxic injury corresponds to 30% of the acute kidney injury (AKI) cases. Nephrotoxicity is an undesirable effect of several drugs used in the clinic, among them, the imunossupressoras drugs. The Tacrolimus (FK 506) nephrotoxicity is the main cause of AKI after kidney transplantation. Being Fk 506 widely used in the immunessupressive therapies and due to its nephrotoxic effect that can lead to the loss of graft, the aim of this study was evaluate the renoprotective action of Vitis Vinifera L extract , a phitomedicine with antioxidant and antinflammatory effects in the nephrotoxicity induced by FK 506 in rats. Wistar rats, male, adults, weight ranging from 250-300g were used, all treated once/day for 5 days, as the following groups: Saline (control group) (NaCl 0.9%, 0,1ml per gavage), Vitis (Vitis vinifera L, 3mg/Kg per gavage), FK (Tacrolimus 0.5mg/Kg per gavage) and FK+Vitis (Tacrolimus 0.5mg/Kg per gavage + Vitis vinifera L, 3mg/Kg per gavage). Renal Function (RF) (creatinine clearance, Jaffé method), urinary peroxides (FOX-2), malondialdehyde (MDA-TBARS) and the kidney histological were evaluated. The data of this study confirmed the oxidative kidney injury by Tacrolimus. The Vitis vinifera L showed significant renoprotective effect, with improvement in the RF, a reductin in lipid peroxidation and histological protection. This study confirmed the renoprotective effect of Vitis Vinifera in the AKI by Tacrolimus.
145

Rôle de miR-21 au cours de la réponse à une agression rénale / Role of miR-21-5p in the response after a renal damage

Hennino, Marie-Flore 28 April 2017 (has links)
Toute maladie rénale chronique (MRC) se caractérise par le développement de lésions de fibrose rénale et d’une perte de fonction qui peut, à terme conduire vers l’insuffisance rénale chronique terminale. miR-21-5p est un microARN ubiquitaire impliqué dans le processus de fibrose, notamment rénale. Toutefois, des données expérimentales contradictoires suggèrent que miR-21-5p joue un rôle ambivalent dans la constitution des lésions rénales de fibrose.L’objectif de ce travail est de préciser l’implication de miR-21 au cours des lésions rénales aigües, en s’appuyant sur un modèle murin de toxicité rénale du cisplatine, ou chroniques chez l’homme au cours de la néphropahtie à dépôts mésangiaux d’IgA (maladie de Berger).Dans un premier travail, une cohorte rétrospective de patients porteurs d’une néphropathie à dépôts mésangiaux d’IgA a été caractérisée de façon systématique sur le plan clinico-biologique et anatomo-pathologique (classification d’Oxford). L’expression rénale de trois fibromiR (miR-21-5p, miR-199a-5p et miR-214-3p) est associée aux lésions de fibrose rénale (p ≤ 0,02). Parmi ces microARN, miR-21-5p semble le plus pertinent car il présente des amplitudes de variation d’expression plus importantes selon le niveau de fibrose, il est également associé aux lésions de sclérose glomérulaire (p = 0,001) et son niveau d’expression tissulaire rénale est associée à une moins bonne survie rénale.Un second travail a été mené en utilisant un modèle murin d’insuffisance rénale aiguë secondaire à l’injection intra-péritonéale de cisplatine chez des animaux invalidé pour miR-21a-5p. Deux schémas d’injections ont été réalisés afin explorer le rôle de miR-21a-5p au cours de lésions rénales aiguës (injection d’une dose unique de 10mg/kg de cisplatine) ou subaiguës (injections répétées de 7 mg/kg de cisplatine). Les souris ayant reçu une injection unique de cisplatine ne présentent pas de différence significative d’urée sanguine, de marqueurs de souffrance rénale (NGAL, KIM-1), d’inflammation (TNF-α, IL-6) et de stress oxydant (HO-1, NRF2), ni d’activité apoptotique selon leur statut sauvage ou invalidé pour miR-21a-5p. Le modèle d’injections répétées de cisplatine a, quant à lui, permis de mettre en évidence des lésions plus importantes chez les souris miR-21-/-. En effet, les souris miR-21-/- cisplatine présentent une urée sanguine plus élevée (1,92 g/l ±, 0,72 versus 0,66 g/l ± 0,15 p = 0,014) et une expression rénale de NGAL plus importante (RQ = 118,1 ± 44,8 versus RQ = 45,4 ± 37,7, p= 0,018) que le souris sauvages cisplatine. Enfin les lésions rénales de nécrose tubulaire aiguë observées sont plus sévères chez les souris miR-21-/-.Ainsi ces résultats montrent qu’une forte expression rénale de miR-21-5p est associée à la fibrose et au pronostic rénal chez des patients porteurs d’une néphropathie à dépôts mésangiaux d’IgA. Dans notre modèle expérimental, les souris déficientes pour miR-21a-5p présentent une sensibilité variable au développement de lésions rénales induites par le cisplatine en fonction du type d’administration, aigu ou subaigu. Ces résultats confirment que miR-21-5p joue un rôle ambivalent au cours des lésions rénales, protecteur à la phase précoce d’une agression rénale aiguë et délétère lorsque le processus se prolonge dans le temps. miR-21-5p est présent dans les fluides biologiques, et constitue ainsi un candidat potentiel en tant que biomarqueur de la fibrose rénale. De plus, miR-21-5p constitue une cible thérapeutique innovante, ayant montré son efficacité dans différents modèles murins de fibrose rénale. / Independently of the cause, active CKD leads to the development of fibrotic lesions, responsible for a loss of renal function and ultimately, end-stage renal failure. MiR-21-5p is a ubiquitous microRNA involved in the process of fibrosis, especially renal fibrosis. However, contradictory experimental data suggest that miR-21-5p plays an ambivalent role in the regulation of renal fibrosis.The aim of this work was to investigate the involvement of miR-21 in chronic renal lesions based on human renal samples and in acute lesions by using a murine model of renal toxicity induced by cisplatin.In a first part of the work, a retrospective cohort of patients with IgA nephropathy has been systematically characterized clinically, biologically and pathologically (according to Oxford classification). The renal expression of three FibromiRs (miR-21-5p, miR-199a-5p and miR-214-3p) is associated with renal fibrosis lesions (p ≤ 0.02). Among these microRNAs, miR-21 appears to be the most relevant as it displayed larger amplitudes of variation, it was also associated with glomerular sclerosis (p = 0.001) and its strong expression was associated with lower renal survival.A second part of the work was carried out on a murine model of acute renal failure secondary to the intraperitoneal injection of cisplatin. Two injections schemes were established to investigate the role of miR-21-5p in acute renal lesions (injection of a single dose of 10 mg/kg cisplatin) or subacute (repeated injections of 7 mg/kg cisplatin). After a single injection of cisplatin, no significant difference in blood urea, renal (NGAL, KIM-1), inflammation (TNF-α, IL-6) and oxidative stress (HO-1, NRF2) nor apoptotic activity was observed in miR21-/- mice compared to wild-type mice. In a model of repeated injections of cisplatin, we observed more renal lesions in miR-21-/- mice. Indeed, miR-21-/- mice treated with cisplatin exhibited higher blood urea (1.92 g / l ±, 0.72 versus 0.66 g / l ± 0.15 p = 0.014) and an increased renal expression of NGAL (RQ = 118.1 ± 44.8 versus RQ = 45.4 ± 37.7, p = 0.018) compared to wild-type mice.Thus, these results demonstrate that an increased renal expression of miR-21-5p is associated with fibrosis and renal prognosis in patients with IgA nephropathy. In an experimental model, of cisplatin-induced renal injury, mice deficient for miR-21a-5p exhibit a higher sensitivity when cisplatin was administered several times. These results confirm that miR-21-5p plays an ambivalent role in renal lesions and seems to be protective at an early stage, or deleterious when the process is prolonged over time. As miR-21-5p is present in biological fluids, it might be an efficient biomarker of renal fibrosis. Moreover, miR-21-5p is an innovative therapeutic target validated in several murine models of renal fibrosis.
146

Réparation de l'épithélium tubulaire après agression rénale aiguë. Etude du programme cellulaire et modifications épigénétiques / Tubular epithelium repair after acute kidney injury. Cellular reprogramming & epigenetics modifications

Bataille, Aurélien 28 October 2016 (has links)
L’insuffisance rénale aiguë (IRA) est une dysfonction d’organe fréquente. Alors que la fonction rénale récupère le plus souvent, on sait depuis 2009 que le pronostic rénal est malgré tout engagé à long terme. L’objectif de ce travail est d’étudier les mécanismes de réparation pathologique de l’épithélium tubulaire afin de mieux comprendre les conséquences à long terme d’un épisode d’IRA.Le parcours des patients après IRA a été transposé dans un modèle à deux agressions (souris C57Bl6/J) : ischémie-reperfusion rénale, suivie à distance par l’administration continue d’angiotensine 2. L’agression aiguë a été calibrée pour obtenir une récupération fonctionnelle et une histologique (microarchitecture normale à la fin du processus de réparation). La fibrose rénale sous angiotensine 2 était plus importante après un antécédent de nécrose tubulaire ischémique résolutive. En isolant les cellules du tube proximal différenciées, une reprogrammation durable du métabolisme et une probable compartimentalisation de la fibrogénèse ont été mises en évidence.L’hypothèse d’un mécanisme épigénétique, faisant le lien entre ischémie-reperfusion et fibrose à distance, a été explorée. Des modifications d’acétylation des histones dans les cellules tubulaires ont été constatées sur des biopsies des greffons humains en post-IRA. Ces modifications ont été reproduites chez la souris et modélisées in vitro après hypoxie-réoxygénation sur une culture primaire de cellules tubulaires. L’acétylation du locus du gène du micro-ARN miR21, dont les cibles sont impliquées dans la progression de la fibrose, est augmentée après ischémie-reperfusion et associée à son induction. / Acute kidney injury (AKI) is a frequent organ dysfunction. While renal function generally recovers, it has been shown since 2009 that AKI carries a poor long-term renal prognosis. The objective of this study was to investigate the maladaptive repair of the tubular epithelium in order to better understand the long-term consequences of AKI. The course of patients after AKI was transposed into a two-hit animal model (C57Bl6/J mice): renal ischemia-reperfusion, followed by continuous administration of angiotensin 2. AKI was calibrated so as to obtain full functional recovery and normal microarchitecture after ischemic tubular necrosis. There was greater renal fibrosis under angiotensin 2 after a history of resolving ischemic tubular necrosis. By isolating differentiated proximal tubular cells, sustained metabolism reprogramming and compartmentalization of fibrogenesis were highlighted. The hypothesis of an underlying epigenetic mechanism, linking ischemia-reperfusion to fibrosis, was explored. Histone post-translational modifications (H3K18 acetylation) in tubular cells were found in human graft biopsies. These changes were reproduced in mice and modeled in vitro after hypoxia-reoxygenation on a primary culture of tubular cells. Histone acetylation peaked at the locus of the miR21 microRNA gene, whose targets are involved in the progression of fibrosis, and was implicated in miR21 expression following our model of AKI.
147

Renal perfusion in experimental sepsis: impact on kidney metabolism and the role of renal autoregulation

Post, Elmar 20 February 2018 (has links)
The etiology of renal dysfunction in sepsis is currently attributed to altered perfusion, microcirculatory abnormalities and cellular alterations. To clarify these mechanisms, we characterized the changes in renal perfusion and cortex metabolism in a large animal model of sepsis. In this model, sepsis was associated with metabolic alterations that may reflect early induction of cortical glycolysis. Septic shock was associated with reduced renal perfusion and decreased cortical and medullary blood flow, followed by signs of anaerobic metabolism in the cortex when flow reductions became critical. Attempts to correct renal hypoperfusion and alleviate the associated perfusion/metabolism mismatch with fenoldopam or renal denervation were unsuccessful. In the final study we focussed on the role of renal autoregulation in experimental sepsis and septic shock. Evidence suggests that higher blood pressure targets are needed in patients with impaired renal autoregulation and septic shock, but the effects of vasopressors should also be considered. We therefore investigated the effects of arginine vasopressin and norepinephrine on renal autoregulation in ovine septic shock. In experimental septic shock, arginine vasopressin was associated with a lower autoregulatory threshold than norepinephrine. As vasopressors may have different effects on renal autoregulation, individualized therapy of blood pressure management in patients with septic shock should take into account drug-specific effects. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished
148

Relação do estresse oxidativo com a excreção de cisplatina e nefrotoxicidade em pacientes com câncer de cabeça e pescoço tratados com altas doses de cisplatina e radioterapia / Relationship between oxidative stress, excretion of cisplatin and nephrotoxicity in patients with head and neck cancer treated with high-dose cisplatin and radiotherapy

Tuan, Bruna Taliani, 1988- 11 April 2014 (has links)
Orientador: Patricia Moriel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T16:28:35Z (GMT). No. of bitstreams: 1 Tuan_BrunaTaliani_M.pdf: 5204136 bytes, checksum: aae37ded0ab8bc9e6059c1b65b9860dd (MD5) Previous issue date: 2014 / Resumo: A cisplatina (CDDP) é um agente antitumoral potente e citotóxico, indicado para o tratamento de carcinoma de células escamosas de cabeça e pescoço (CCECP), concomitante a radioterapia. Seu uso está limitado devido ao surgimento de intensos efeitos adversos, como exemplo a nefrotoxicidade. O objetivo deste trabalho foi avaliar o estresse oxidativo antes e após a quimioterapia com CDDP (fase 1), e correlacioná-lo com a excreção de CDDP na urina (fase 2), avaliando a nefrotoxicidade. Foi realizado um estudo clínico observacional, longitudinal prospectivo, quantitativo, com amostragem consecutiva, realizado de agosto de 2011 a dezembro de 2013 no Hospital de Clínicas/UNICAMP. Foram incluídos sujeitos de ambos os sexos, entre 18 e 80 anos, com diagnóstico de CCECP, em seu primeiro dia (caso novo) no Ambulatório de Oncologia Clínica, que receberam como conduta terapêutica 3 ciclos de quimioterapia com altas doses de CDDP e radioterapia concomitante. Os sujeitos foram acompanhados pela equipe de farmácia clínica no dia do caso novo, em todos os retornos com a equipe médica (pré quimioterapia, após os 3 ciclos de quimioterapia), como também nos dias das quimioterapias. Foram investigados biomarcadores de estresse oxidativo (através dos testes de TBARS, FOX-2 e Nitrito) e excreção de CDDP (0-12, 12-24 e 24-48 horas após a quimioterapia), ambos na urina, como também a nefrotoxicidade (variação de creatinina, Cr e clearance de creatinina, ClCr). Para todas as análises considerou-se significativo p < 0,05. Na fase 1 (n = 33) os sujeitos apresentaram idade média de 55 anos, sendo a maioria homens, brancos, tabagistas e etilistas acentuados, com tumores localizados na faringe, e com pico de estresse oxidativo no período 0-12h após a administração de CDDP. A excreção de CDDP também apresentou maiores valores no período 0-12h, evidenciando uma relação entre eles. Pode-se observar que houve relação entre o período basal e 0-12h dos testes de FOX-2 e nitrito, demonstrando que após a administração de CDDP existe aumento do estresse oxidativo, porém este não se relaciona com os parâmetros de nefrotoxicidade. Na fase 2 (n= 95) os sujeitos apresentaram características semelhantes à fase 1, e não houve relação significativa entre estresse oxidativo, excreção de CDDP e parâmetros de nefrotoxicidade. Portanto este estudo sugere que existe o aumento de estresse nitrosativo e oxidativo após a administração de CDDP em pacientes com câncer de cabeça e pescoço / Abstract: Cisplatin (CDDP) is a potent cytotoxic and anticancer agent, indicated for the treatment of head and neck squamous cell carcinoma (HNSCC), concomitant radiotherapy. Its use is limited owing of severe side effects, mainly nephrotoxicity. The aim of this study was to evaluate oxidative stress before and after chemotherapy with CDDP (phase 1), and correlate it with urinary excretion (phase 2), and nephrotoxicity of CDDP. An observational clinical study, prospective longitudinal, and quantitative, with consecutive sampling during August 2011 to December 2013 at the Hospital de Clínicas/UNICAMP was performed. We included patients of both sexes, between 18 and 80 years, diagnosed with HNSCC, on his first day (new case) at the Clinical Oncology, who received a therapeutic conduct of 3 cycles of chemotherapy with high-dose cisplatin concomitant radiotherapy. The patients were followed up by clinical pharmacy staff in the new case and all returns with the medical team (pre chemotherapy, after 3 cycles of chemotherapy), and in the days of chemotherapy. Biomarkers of oxidative stress (using the TBARS test, FOX-2 and nitrite in urine) and excretion of CDDP (0-12, 12-24 and 24-48 hours after chemotherapy), both in urine, were investigated, as well as nephrotoxicity (creatinine variation, Cr and creatinine clearance, CrCl). A p value less than 0.05 were considered significant. In phase 1 (n = 33) patients had a mean age of 55 years, mostly white men, smokers and alcoholics accented with tumors located in the pharynx, and with a increased in oxidative stress in 0-12h after administration of CDDP. The excretion of CDDP also showed higher values during 0-12h, showing a relationship between them. It can be seen that there was a relationship between the baseline and the 0-12h of FOX-2 and nitrite test, indicating that after administration of CDDP there is increase in oxidative stress, but this is not related to the parameters of nephrotoxicity. In phase 2 (n = 95) patients showed characteristics similar to phase 1, and there was no significant relationship between oxidative stress parameters, excretion of CDDP, and nephrotoxicity. Therefore, this study suggests that there is an increase of nitrosative and oxidative stress after administration of cisplatin in patients with head and neck cancer / Mestrado / Ciencias Biomedicas / Mestra em Ciências Médicas
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Avaliação do hidroxietilamido de terceira geração (Tetrastarch) em relação ao Ringer Lactato como fluido de reposição volêmica em cães submetidos à hemodiluição normovolêmica aguda

Diniz, Miriely Steim. January 2017 (has links)
Orientador: Francisco José Teixeira Neto / Resumo: Justificativa: Coloides sintéticos como o “Tetrastarch“ (TS), quando comparados aos cristaloides isotônicos, são expansores volêmicos mais eficazes e minimizam o risco de edema tecidual. Entretanto, o TS pode causar efeitos adversos sobre a coagulação e, em pacientes sépticos, pode aumentar o risco de injúria renal aguda e morte. Hipóteses: Formularam-se as hipóteses de que, em cães sadios, a HNA com TS não resultaria em evidência de IRA; enquanto que a inibição da coagulação induzida por este coloide seria ao menos equivalente a produzida pelo Ringer Lactato (RL). A HNA com TS, quando comparada a HNA com RL, resultaria em menor acúmulo de água extravascular pulmonar e menor incidência de edema periférico. Materiais e Métodos: Seis cães (19,7–35,3 kg) foram anestesiados durante 7 horas com isoflurano/remifentanil em 3 ocasiões. Na primeira ocasião (Fase I), os animais não foram submetidos a HNA (controle). Na Fase II, iniciada após intervalo > 2 semanas do término da Fase I, os cães foram anestesiados em 2 ocasiões para realização de HNA, em um modelo experimental randomizado (intervalo > 8 semanas). Em cada procedimento, o sangue removido foi reposto com RL ou TS, (3 mL de RL ou 1 mL de TS para cada 1 mL de sangue removido), durante 60 minutos, visando reduzir o hematócrito para 33%. A anestesia foi mantida por 4 horas após a reposição volêmica (RV). As variáveis cardiorrespiratórias foram coletadas no momento BL (basal, antes da HNA), 0,5, 1, 2, 3 e 4 horas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Rationale: Synthetic colloids such as tetrastarch solution (TS), when compared to crystalloids, are more effective plasma expanders and minimize the risk of edema. However, TS may cause adverse effects on coagulation and, in septic patients, may increase the risk of acute kidney injury (AKI) and death. Hypotheses: The first hypothesis was that, in healthy dogs, acute normovolemic hemodilution (ANH) with TS would not induce AKI; while the coagulation impairment induced by this colloid would be at least equivalent to that induced by lactated Ringer´s solution (LRS). The second hypothesis was that ANH with TS, when compared to ANH with LRS, would cause less extravascular lung water accumulation and less evidence of peripheral edema. Material and Methods: Six dogs (19.7–35.3 kg) were anesthetized with isoflurane/remifentanil on 3 occasions. During the first occasion (Phase I), animals did not undergo ANH (control). During Phase II, initiated after an interval of at least 2-weeks, the same dogs underwent anesthesia for ANH on 2 occasions, in a ramdomized crossover design (washout interval > 8-weeks). During both procedures, the blood withdrawn was replaced with LRS or TS (3 mL of LRS or 1 mL of TS for each 1 mL of blood removed), during 60 minutes, aiming to decrease the hematocrit to 33%. Anesthesia was maintained for 4 hours after volume replacement (VR). Cardiorespiratory variables were recorded at BL (before ANH), 0.5, 1, 2, 3, and 4 hours after VR. Biomarkers ... (Complete abstract click electronic access below) / Doutor
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Pathophysiology of Unilateral Ischemia-Reperfusion Injury: Importance of Renal Counterbalance and Implications for the AKI-CKD Transition

Polichnowski, Aaron J., Griffin, Karen A., Licea-Vargas, Hector, Lan, Rongpei, Picken, Maria M., Long, Jainrui, Williamson, Geoffrey A., Rosenberger, Christian, Mathia, Susanne, Venkatachalam, Manjeri A., Bidani, Anil K. 01 May 2020 (has links)
Unilateral ischemia-reperfusion (UIR) injury leads to progressive renal atrophy and tubulointerstitial fibrosis (TIF) and is commonly used to investigate the pathogenesis of the acute kidney injury-chronic kidney disease transition. Although it is well known that contralateral nephrectomy (CNX), even 2 wk post-UIR injury, can improve recovery, the physiological mechanisms and tubular signaling pathways mediating such improved recovery remain poorly defined. Here, we examined the renal hemodynamic and tubular signaling pathways associated with UIR injury and its reversal by CNX. Male Sprague-Dawley rats underwent left UIR or sham UIR and 2 wk later CNX or sham CNX. Blood pressure, left renal blood flow (RBF), and total glomerular filtration rate were assessed in conscious rats for 3 days before and over 2 wk after CNX or sham CNX. In the presence of a contralateral uninjured kidney, left RBF was lower (P < 0.05) from 2 to 4 wk following UIR (3.6 + 0.3 mL/min) versus sham UIR (9.6 + 0.3 mL/min). Without CNX, extensive renal atrophy, TIF, and tubule dedifferentiation, but minimal pimonidazole and hypoxia-inducible factor-1α positivity in tubules, were present at 4 wk post-UIR injury. Conversely, CNX led (P < 0.05) to sustained increases in left RBF (6.2 ∓ 0.6 mL/min) that preceded the increases in glomerular filtration rate. The CNX-induced improvement in renal function was associated with renal hypertrophy, more redifferentiated tubules, less TIF, and robust pimonidazole and hypoxia-inducible factor-1α staining in UIR injured kidneys. Thus, contrary to expectations, indexes of hypoxia are not observed with the extensive TIF at 4 wk post-UIR injury in the absence of CNX but are rather associated with the improved recovery of renal function and structure following CNX.

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