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

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

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

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.

Signaling pathways of regulated necrosis, such as necroptosis and ferroptosis, contribute to acute kidney injury (AKI), but the role of pyroptosis is unclear. Pyroptosis is mediated by the pore-forming protein gasdermin D (GSDMD). Here, we report a specific pattern of GSDMD-protein expression in the peritubular compartment of mice that underwent bilateral ischemia and reperfusion injury (IRI). Along similar lines, the GSDMD-protein expression in whole kidney lysates increased during the first 84 h following cisplatin-induced AKI. Importantly, unlike whole kidney lysates, no GSDMD-protein expression was detectable in isolated kidney tubules. In IRI and cisplatin-induced AKI, GSDMD-deficient mice exhibited hypersensitivity to injury as assessed by tubular damage, elevated markers of serum urea, and serum creatinine. This hypersensitivity was reversed by a combined deficiency of GSDMD and the necroptosis mediator mixed lineage kinase domain-like (MLKL). In conclusion, we demonstrate a non-cell autonomous role for GSDMD in protecting the tubular compartment from necroptosis-mediated damage in IRI.

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Yes / Acute kidney injury (AKI) can occur rarely in patients exposed to iodinated contrast and result in contrast-induced AKI (CI-AKI). A key risk factor is the presence of pre-existing chronic kidney disease (CKD), therefore it is important to assess patient risk and obtain kidney function measurement prior to administration. Point of care (PoC) testing provides an alternative strategy but there remains uncertainty, with respect to diagnostic accuracy and clinical utility. A device study compared three PoC analysers (Nova StatSensor, Abbott i-STAT, Radiometer ABL800 FLEX) with a reference laboratory standard (Roche Cobas 8000 series, enzymatic creatinine). Three hundred adult patients attending a UK hospital phlebotomy department were recruited to have additional blood samples for analysis on the PoC devices. The ABL800 FLEX had the strongest concordance with laboratory measured serum creatinine (mean bias=-0.86, 95% limits of agreement = -9.6 to 7.9) followed by the i-STAT (average bias=3.88, 95% limits of agreement = -8.8 to 16.6) and StatSensor (average bias=3.56, 95% limits of agreement = -27.7 to 34.8). In risk classification, the ABL800 FLEX and i-STAT identified all patients with an eGFR≤30, whereas the StatSensor resulted in a small number of missed high-risk cases (n=4/13) and also operated outside of the established performance goals. The screening of patients at risk of CI-AKI may be feasible with PoC technology. However in this study it was identified that the analyser concordance with the laboratory reference varies. It is proposed that further research exploring PoC implementation in imaging department pathways is needed. / Yorkshire and Humber Academic Health Science Network (Grant Number: YHP0318)

Contexte: la survenue d’IRA chez les patients ayant subi un traumatisme est une problématique qui a été peu étudiée jusqu’à ce jour. La présence de cette atteinte rénale a été démontrée comme étant associée à un risque accru de morbidités et de mortalité chez les sujets atteints. Objectifs: identifier les facteurs prédictifs d’insuffisance rénale ou plus récemment appelée atteinte rénale dans cette population particulière et tenter de trouver des facteurs qui peuvent être mesurés dans les premières heures de la prise en charge du patient. Aussi, nous avons cherché à savoir si l’injection de produit de contraste est associée à un risque accru d’insuffisance rénale aiguë dans cette population. Méthodes et résultats: la recherche a eu lieu à l’Hôpital du Sacré-Coeur de Montréal, un centre de traumatologie tertiaire en milieu urbain. Nous avons utilisé le registre des patients hospitalisés en traumatologie dans notre centre hospitalier entre 2002 et mars 2007 de même que les banques de données de laboratoire et de radiologie pour obtenir les données sur la créatinine et les examens avec produits de contraste. Finalement, une revue de dossiers structurée fut conduite pour recueillir le reste de l’information requise. L’incidence d’IRA dans la population étudiée est estimée à environ 5 %. Une analyse cas témoins fut conduite pour identifier les facteurs prédictifs d’IRA. Quarante-neuf cas d’IRA diagnostiqués par le médecin traitant et 101 témoins sélectionnés au hasard ont été analysés. Les facteurs prédictifs suivants ont été identifiés à l’analyse univariée : la première valeur de créatinine obtenue (p<0,001), l’instabilité hémodynamique (p<0,001), les antécédents d’insuffisance rénale chronique tels que notés dans le dossier par le médecin traitant (p=0,009), une maladie cardiaque (p=0,007), une chirurgie dans les 48 premières heures suivant le traumatisme (p=0,053), le niveau de gravité du traumatisme (Injury Severity Score) (p=0,046) et l’injection de produit de contraste au cours des 48 heures suivant le trauma (p=0,077). Parmi ces facteurs, deux ont été identifiés comme prédicteurs indépendants d’IRA à l’analyse multivariée. Une des valeurs était la première valeur de créatinine obtenue RC = 6,17 (p<0,001, IC95 % 2,81 – 13,53) pour chaque augmentation de 0.5mg/dL de créatinine. L’autre facteur était la présence d’instabilité hémodynamique RC 11,61 (p<0,001, IC95 % 3,71 – 36,29). Conclusion: des informations obtenues tôt dans la prise en charge du patient permettent de prédire le risque d’IRA chez ces patients. L’administration de contraste (intraveineuse ou intra-artérielle) ne s’est pas avérée un facteur indépendant de prédiction d’insuffisance rénale aiguë dans cette population dans le modèle multivarié. / Background: acute kidney injury (AKI) has important mortality and morbidity complications. Few studies have looked at predictors of acute renal failure in a trauma patient population. Objectives: we sought to identify factors associated with AKI that can be assessed in the early hospital stay of trauma patients. We also specifically assessed if the administration of radiological contrast was a predictor of AKI. Methods: we conducted a nested case-control study from the trauma registry of an urban Level I trauma center which includes data on more than 6 000 subjects. The cases consisted of 49 patients with a diagnosis of AKI by their treating physician in the first 7 days following their trauma between 2002 and 2007 (March 2007). The controls were randomly selected for a 1:2 case to control ratio. Data were retrieved from the prospective trauma registry database. Additional data were also obtained via the hospital laboratory and radiology databases. Finally, a structured chart review was conducted to obtain the remaining information. Univariate analyses were conducted. Elements with a significance level of <0.1 were included in a multivariate logistic regression model. Results: predictors identified in the univariate analysis were: the first creatinine value obtained (p<0,001), hemodynamic instability (p<0,001), history of coronary artery disease (p=0,007), history of chronic renal insufficiency as per physician’s diagnosis in the chart (p=0,009), surgery in the 48 hours following the trauma (p=0,053), and, injection of contrast in the 48 hours following the trauma (p=0,077). In the final multivariate model, two factors were statistically significant. One factor was the first creatinine value p<0,001, OR 6,17 CI95 % (2,81 – 13,53) for each increase of creatinine by 0,5mg/dL. The other factor was the presence of hemodynamic instability p<0,001 OR 11,61 CI95 % (3,71 – 36,29). Conclusion: easily obtained information in the emergency department can aid in predicting the risk of AKI in a trauma population. Early administration of radiological contrast was not an independant predictor of AKI in this population.

Les patients en état critique nécessitant une ventilation artificielle sont particulièrement exposés au risque d'une agression rénale ischémique. L'apparition d'une insuffisance rénale aiguë (IRA) dans ce contexte est responsable d'une surmortalité. L'objectif de ce travail était l'optimisation de la prévention de l'IRA incluant deux axes de recherche. D'une part l'évaluation de mesures de protection rénale visant au maintien de la délivrance rénale en oxygène et d'autre part l'étude de la performance des outils d'évaluation de la fonction rénale pour la détection et la caractérisation d'une agression.La principale mesure de prévention de l'IRA proposée en pratique clinique pour la restauration et le maintien d'une perfusion rénale est l'expansion volémique mais avec un risque d'altération de la fonction pulmonaire. Nos travaux ont permis de montrer que le pronostic rénal au cours de la réanimation liquidienne dépend du type de soluté administré. L'incidence de l'IRA est plus élevée lorsque des colloïdes à base d'hydroxyéthylamidons et/ou ayant un pouvoir oncotique élevé sont utilisés. Contrairement au rein, l'évolution de la fonction respiratoire ne dépend pas de l'effet oncotique du soluté utilisé mais des volumes administrés. La degradation de la fonction respiratoire semble survenir pour un volume moindre de colloïdes que de cristalloïdes, sans doute du fait d'une efficacité plus importante sur l'augmentation du volume intravasculaire.Associé à la restauration de la perfusion rénale, le maintien de l'oxygénation artérielle est un autre déterminant potentiel de l'oxygénation rénale. Nous avons évalué la réponse rénale à une hypoxémie modérée, habituelle au cours du syndrome de détresse respiratoire aiguë. Une baisse de la FiO2 est en effet recommandée pour la prévention des lésions pulmonaires induites par l'oxygène. Une ventilation de 2 heures à un niveau de SaO2 entre 88 et 92% engendre une réponse diurétique et une augmentation des résistances artérielles rénales mesurées par la méthode Doppler. Cette réponse rénale est indépendante des modifications ventilatoires et hémodynamiques, elle est rapidement réversible avec la réoxygénation. En plus de sa capacité à détecter une modification de la vascularisation rénale, nous avons retrouvé que la mesure de l'index de résistance prédisait de façon satisfaisante la persistance d'une IRA, performance meilleure que celle de certains indices biochimiques urinaires habituellement recommandés.Ces différents travaux ont permis de mieux appréhender les interactions physiopathologiques entre la prévention des dysfonctions rénale et pulmonaire et soulignent les antagonismes qui peuvent exister entre ces deux organes. La réanimation liquidienne peut être optimisée par le choix d'un soluté hypo-oncotique pour réduire le risque d'IRA sans altérer la fonction respiratoire. La réponse rénale à une hypoxémie modérée suggère que la préservation de l'oxygénation artérielle puisse avoir un rôle dans la préservation de la fonction rénale. Enfin, le Doppler rénal est un outil prometteur pour la sélection, l'évaluation et l'optimisation des mesures de protection rénales. / Critically ill patients needing mechanical ventilation are particularly exposed to ischemic renal injury leading for acute kidney injury (AKI) occurrence is associated and poor outcome. The aim of this work was to optimize AKI prevention. We evaluated protective measures for renal oxygen delivery on one hand and the performance of usual tools for the detection and characterization of renal injury on the other hand.The main measure in preventing AKI is the correction and the preservation of blood volume; fluid resuscitation is, however, associated with an increased risk of pulmonary oedema. Our results show that renal outcome depends on the type of fluid used with an increased risk of AKI using hydroxyethylstarches and/or hyper-oncotic colloids while pulmonary function is not influenced by the type of fluids used but depends on the volume infused. Pulmonary worsening seems to occure for a lower volume of colloids than crystalloids, probably because of a higher efficiency to increase intravascular volume.In addition to the restoration of renal perfusion, arterial oxygenation is a potential determinant of renal oxygenation. Because the use of a low FiO2 level is recommended to avoid oxygen related pulmonary lesions, we assessed the renal response to a moderate hypoxemia, usually applied in patient with acute respiratory distress syndrome. Two hours of mechanical ventilation with a SaO2 between 88% and 92% induces renal diuretic and vascular response identified by Doppler. This response is independent from ventilator and hemodynamic changes. Renal response is rapidly reversible with the correction of hypoxemia. In addition to the ability in detecting changes of intra-renal vascular resistances, we found that Doppler resistive index is helpful in predicting the persistence of AKI, better than most of the usual urinary indices.Our works allow a better approach of the intricate mechanisms in preventing renal and pulmonary functions. Fluid resuscitation can be optimized preferring hypo-oncotic fluids for reducing AKI incidence without apparent negative impact on pulmonary function. Renal response to a moderate hypoxemia suggests that arterial oxygen preservation might be essential for renal function preservation. Renal Doppler is a promising tool for the selection and the evaluation of AKI preventive measures.