A lesão de isquémia/reperfusão em transplante hepático: análise genética, morfológica e correlação clínica

RESUMO: O transplante hepático ortotópico é uma terapêutica aceite para casos selecionados de falência hepática terminal. O procedimento tem-­‐se aperfeiçoado, evidenciado pelo aumento da taxa de sobrevida de 30 para 75% aos 5 anos, mas cerca de 13 a 27% dos enxertos desenvolve falência primária (PNF) ou disfunção primária (DF) após o transplante. As consequências são devastadoras para a sobrevida do doente e do enxerto. A sua etiologia é multifactorial, incluindo factores relacionados com o dador e o receptor, tempos de isquémia, agressões cirúrgicas, bem como características anatomopatológicas do enxerto. A lesão de isquémia/reperfusão mantem-­‐se como um factor de risco intra operatório, com implicações directas sobre toda a evolução do transplante : existe uma relação íntima entre a PNF e a DF, a preservação do enxerto, a lesão de isquémia/reperfusão, e a falência do transplante. Além disso, está comprovada evidência que sugere que a lesão de I/R torna um aloenxerto mais vulnerável por aumento da imunogenicidade, aumentando a probabilidade de episódios de rejeição precoce e tardia. Com base na prática clínica quotidiana do CHBPT HCC, estudaram-­‐se 54 casos de transplante hepático, agrupados segundo grupos por alocação do enxerto respectivo: Grupo 1(n=27): dador cadáver para receptor cirrótico, Grupo 2 (n=15): dador cadáver para receptor PAF, Grupo 3 (n=12): dador PAF para receptor cirrótico. Observaram-­‐se as alterações histológicas e moleculares sobre o enxerto até ao final da operação do receptor, e as suas consequências clínicas,avaliando: -­‐ As diferentes capacidades de resistência e cada enxerto à lesão de isquémia/reperfusão. -­‐ As situações em que os factores do receptor se sobrepõem às do enxerto na definição do prognóstico, e vice versa. -­‐ A relevância das lesões histológicas e moleculares precoces no tecido hepático na evolução do enxerto e do receptor. Foram colhidas biópsias por agulha dos 54 enxertos hepáticos,42 provenientes de cadáver com coração batente(morte cerebral) e 12 provenientes de dador vivo com PAF, em três tempos diferentes do processo de colheita e transplante hepático: ­‐ A primeira(T0)antes da clampagem da aorta do dador -­‐ A segunda (T1) no final da isquémia fria -­‐ A terceira (T2) após a reperfusão do enxerto, durante o encerramento da parede abdominal. A estas amostras foi extraído RNA total, convertido em cDNA por transcrição reversa e feita a análise da expressão dos genes da CTLA4, IL-­‐1β, IL-­‐4, IL-­‐6, IL-­‐13, TNF-­‐α, Perforina, Selectina, (SELE), Fas-­‐ligando, Granzima-­‐B, Heme-­‐Oxigenase 1(HO1)e Óxido Nítrico Sintetase(iNOS2A)por PCR quantitativo segundo o método do Ct comparativo, utilizando como referência a expressão dos genes da amostra não-­‐isquémica –T0. Os fragmentos de todas as biópsias foram seccionados, para envio de amostra comparativa para processamento histológico habitual, sem qualquer alteração ao protocolo seguido habitualmente na Unidade de Transplantação do Hospital Curry Cabral. A presença de alguns parâmetros histológicos definidos, como esteatose, necrose, vacuolização, congestão sinusoidal e infiltração neutrofílica, foi registada e contabilizada numa classificação numérica. O seguimento clínico e laboratorial, bem como o acompanhamento de eventuais complicações, foi registado e correlacionado com os dados das colheitas de órgãos e com os dados das biópsias. Foram consideradas as seguintes variáveis, como as mais relevantes e objectivas para a interpretação da evolução clínica, tendo sido comparadas estatisticamente com os dados recolhidos, laboratoriais e clínicos: disfunção do enxerto, 207 pós operatórias, número de internamentos igual ou superior a 2 e rejeição crónica e/ou morte do receptor. Foram identificadas características clínicas menos favoráveis, a considerar, nalgumas circunstâncias: género feminino do receptor (sobretudo associado a enxerto masculino, p=0,077), isquémia fria superior a 500 minutos (p=0,074), isquémia quente superior a 90 minutos (p=0,099). Na análise laboratorial, distinguiram-­‐se duas características histológicas desfavoráveis e irreversíveis, como índice de mau prognóstico: a necrose e a balonização (p=0,029); no painel genético escolhido neste estudo,a expressão basal de IL-­‐1β(p=0,028), de SELE p=0,013)e de FAS-­‐L (p=0,079)relacionaram-­‐se com pior prognóstico. Algumas características protectoras intrínsecas dos enxertos só se revelaram indirectamente, como menor infiltração neutrofílica e maior expressão de HO1 e de iNOS nos enxertos PAF, não tendo sido possível provar uma interferência directa nos resultados clínicos. Não se obteve expressão mensurável de genes anti-­‐ inflamatórios nas biopsias hepáticas processadas neste estudo, como a IL13 e a I 4: assim, com a metodologia utilizada, não foi possível obter um perfil de expressão genética associado a boa evolução clínica. O perfil inverso foi sugerido apenas pela expressão basal dos 3 genes mencionados (FAS-­‐L,IL-­‐1β e SELE)no mesmo painel, com o protocolo seguido neste conjunto de 54 doentes. As características do receptor sobrepuseram-­‐se às do enxerto no caso de: -­‐ diagnóstico de PAF no receptor, que determinou uma maior predisposição para a disfunção do enxerto, o que, por sua vez, determina uma menor sobrevida. No entanto, o diagnóstico de PAF no receptor exibe uma curva de sobrevida mais favorável. -­‐ receptores com um baixo balanço de risco (BAR)definiram características favoráveis para enxertos com níveis baixos e moderados de esteatose, fazendo que esta característica, definida como um risco acrescido, não só não se manifestasse clinicamente,como parecesse um factor favorável. As características do enxerto sobrepuseram-­‐se às do receptor no caso de: -­‐ tempo de isquémia fria superior a 500 minutos -­‐ balonização, necrose, FAS-­‐L,IL-­‐1β e SELE em T0 A integração dos resultados moleculares e morfológicos com a evolução clínica, realça o papel da mobilização precoce de neutrófilos nos desempenhos menos favoráveis do enxerto hepático. -------------ABSTRACT: Orthotopic liver transplantation is na accepted therapeutic procedure for selected cases of terminal liver failure. The procedure has been improved, evidenced by the rise of survival rates from 30 to 70% at 5 years, but 13 to 27% of the liver grafts develops primary non function (PNF) or primary dysfunction (PDF) after transplantation. The consequences are devastating for the survival of the patient and of the graft. Its etiology is multifactorial, including factos related with the donor and with the recipient, ischemic times, surgical aggressions, as well as the histological characteristics of the graft. The ischemia/reperfusion lesion is still an intraoperative risk factor, with direct implications in the whole transplant outcome: there is a close interrelation between PNF and DF, graft preservation, ischemia / reperfusion lesion and graft failure. Beyond his, there is proved evidence that suggests that I/R lesion turns the allograft more vulnerable by increasing its immunogenity, increasing the probability of precocious and late rejection episodes. Based on the daily clinical practice at CHBPT /HCC, 54 cases of hepatic transplantation have been studied, grouped by allocation of each graft: Group (n=27):deceased do nortocirrhotic recipient, Group 2 (n=15): deceased donor to FAP recipient, Group 3 (n=12): FAP living donor to cirrhotic recipient. The histologic and molecular changes in the liver graft were observed until the end of the recipiente operation,together with its clinical consequences, evaluating:-­‐The different capacity of resistance of each graft to the ischemia / reperfusion lesion -­‐ The situations where the recipiente factos overlap the ones of the graft, in the definition of prognosis, and vice versa.-­‐ The relevance of the precocious histologic and molecular lesions of the hepatic tissue in the clinical outcome of the graft and the recipient. Needle biopsies were obtained from 54 liver grafts, 42 deceased brain dead donors and 12 from FAP living donors, at three diferente times of the harvesting and the hepatic transplantation: The first one (T0) before clamping the donor aorta -­‐ The second one (T2) in the end of cold ischemia time -­‐ The third one (T) after the reperfusion of the graft, during the closure of the abdominal wall. Total RNAwas extracted to these samples, converted to cDNA by reverse transcription and the analysis of gene expression was made for CTLA4,IL-­‐1β,IL-­‐4,IL-­‐6,IL-­‐13,TNF-­‐α,Perforin,E Selectin (SELE),Fas-­‐ligand,Granzyme-­‐B,Heme-­‐oxigenase 1 (HO1) and Nitric Oxide Sintetase (iNOS2A) by quantitative PCR, according with the Ct comparative method, using the expression of the non ischemic sample – T0. The fragments of all the biopsies were divided, to send a comparative sample to the usual histologic processement, keeping the same usual protocol at the Transplantation Unit of Curry Cabral Hospital. The presence of some defined histologic parameters, such as steatosis, necrosis, vacuolization, sinusoidal congestion and neutrophilic infiltration, was registered and catalogued in a numeric classification. The clinical and laboratory follow-­‐up, as well as the following of eventual complications, was registered and correlated with the data from organ procurement operations and with the data from the biopsies. The following variables were considered as the most relevant and objective ones, to the interpretation of the clinical evolution, being statistically compared with the clinical and laboratorial collected data: graft dysfunction, post-­‐operative complications, number of readmissions of 2 or more and chronic rejection and /or recipiente death. There were identified some unfavorable clinical characteristics, to be considered under certain circumstances: recipiente female gender (specially associated with malegraft, p=0,077), cold ischemia time of more than 500 minutes (p=0,074), warm ischemia time of more than 90 minutes (p=0,099). In the laboratory analysis, two histologic characteristics were identified as unfavorable and irreversible, associated with bad prognosis: necrosis and balonization (p=0,029); in the gene panel selected in this study, the basal expression of IL-­‐1β (p=0,028), SELE (p=0,013) and FAS-­‐L (p=0,079)were related with worse prognosis.Some intrinsic protective characteristics of the grafts were only indirectly revealed, such as less neutrophilic infiltration and bigger expression of HO1 and iNOS in FAP grafts, being impossible to prove any direct inte ference in the clinical results. A relevant and measurable expression of the anti inflammatory genes IL13 and IL4 was not obtained: with the used methodology, it was impossible to obtain a gene expression profile associated with a favorable clinical outcome.The inverse profile was suggested only by the basal expression of the three mentioned genes (FAS-­‐L, IL-­‐ 1β e SELE) in the same gene panel, according with the followed protocol in this group of 54 patients. The characteristics of the recipient overlapped those from the graft, in the case of :-­‐ FAP diagnosis in the recipient, which determined a bigger predisposition to graft dysfunction, which by itself determines a shorter survival. However, FAP diagnosis in the recipiente depicts a more favorable survival curve. -­‐ Recipients with a low balance risk índex (BAR) defined favorable characteristics to grafts with low and moderate grades of steatosis, making that this characteristic, associated with bad prognosis, looked like a favorable factor, and with no clinical interference. The graft characteristics overlapped those from the receptor in the case of: -­‐ Cold ischemic time more than 500 minutes -­‐ Balonization, necrosis, FAS-­‐L, IL-­‐1β and SELE at T0. The integration of molecular and morphologic results with the clinical evolution, stresses the role of a precocious neutrophils mobilization in the worse outcomes of liver grafts.

Prevalence of Trypanosoma cruzi antibodies and inflammatory markers in uncompensated heart failure

INTRODUCTION: Heart failure (HF) represents the final stage of chronic chagasic cardiomyopathy (CChC). The diagnosis of CChC is based on the demonstration of anti-Trypanosoma cruzi antibodies (aTcAg) and clinical and epidemiological data. In Venezuela, there are no data about the prevalence of chagasic HF. The aim of this study was to determine the epidemiological, clinical, and inflammatory risk factors associated with seronegative or seropositive HF patients. METHODS: We performed a cross-sectional study in the Venezuelan central-west states among a healthy rural population and in patients admitted to the emergency room with uncompensated HF. RESULTS: The seroprevalence rates of Trypanosoma cruzi antibodies were 11.2% and 40.1% in the healthy population and in HF patients, respectively. Seropositivity in healthy individuals was associated with age, knowledge on triatomine vectors, and having seen wild reservoirs in the house; in HF patients, with contact with the vector and previous clinical diagnosis of Chagas' disease; and in both groups taken together, with age, knowledge on triatomines, and HF. Seropositive patients had prolonged QRS, decreased ejection fraction, and high serum magnesium, all significant as compared with HF seronegative cases. Left atrium enlargement and ventricular hypertrophy were most frequently observed in HF seronegative patients. CRP, IL6, ILβ1, IL2, and FNTα were elevated in 94.5%, 48%, 17.8%, 13.7%, and 6.9% of HF patients, respectively, but only IL2 levels were associated with chagasic HF. CONCLUSIONS: There is a high prevalence of aTcAg in HF patients from the central-west region of Venezuela, and their epidemiological, clinical, and inflammatory features are discreetly different as compared with those of seronegative cases.

Is autonomic function associated with left ventricular systolic function in Chagas heart disease patients undergoing treatment for heart failure?

Introduction The association between cardiac autonomic and left ventricular (LV) dysfunction in Chagas disease (ChD) is controversial. Methods A standardized protocol that includes the Valsalva maneuver, a respiratory sinus arrhythmia (RSA) test, and an echocardiographic examination was used. Spearman correlation coefficients (rho) were used to investigate associations. Results The study population consisted of 118 ChD patients undergoing current medical treatment, with an average LV ejection fraction of 51.4±2.6%. The LV ejection fraction and diastolic dimension were correlated with the Valsalva index (rho=0.358, p<0.001 and rho=-0.266, p=0.004, respectively) and the RSA (rho=0.391, p<0.001 and rho=-0.311, p<0.001, respectively). Conclusions The impairment of LV function is directly associated with a reduction of cardiac autonomic modulation in ChD.

An unusual case of heart failure due to Plasmodium vivax infection with a favorable outcome

Although malaria is one of the oldest types of parasitic infection, we have recently witnessed substantial changes in the outcome of malarial infections. Severe Plasmodium vivax infections have recently become more frequent, and are occasionally associated with fatal outcomes. Cardiac arrhythmia and myocardial failure have also been reported, typically in association with Plasmodium falciparum infections. We report a case of myocarditis and heart failure, due to Plasmodium vivaxinfection, along with the favorable outcome.

Acute renal failure due to abdominal compartment syndrome: report on four cases and literature review

We report on 4 cases of abdominal compartment syndrome complicated by acute renal failure that were promptly reversed by different abdominal decompression methods. Case 1: A 57-year-old obese woman in the post-operative period after giant incisional hernia correction with an intra-abdominal pressure of 24 mm Hg. She was sedated and curarized, and the intra-abdominal pressure fell to 15 mm Hg. Case 2: A 73-year-old woman with acute inflammatory abdomen was undergoing exploratory laparotomy when a hypertensive pneumoperitoneum was noticed. During the surgery, enhancement of urinary output was observed. Case 3: An 18-year-old man who underwent hepatectomy and developed coagulopathy and hepatic bleeding that required abdominal packing, developed oliguria with a transvesical intra-abdominal pressure of 22 mm Hg. During reoperation, the compresses were removed with a prompt improvement in urinary flow. Case 4: A 46-year-old man with hepatic cirrhosis was admitted after incisional hernia repair with intra-abdominal pressure of 16 mm Hg. After paracentesis, the intra-abdominal pressure fell to 11 mm Hg.

Corporate governance failure at PT

The following case study depicts the bitter transfiguration of Portugal Telecom, SGPS (PT), a multinational telecommunications company that was once an honourable flag of innovation, corporate governance standards in Portugal and overseas. It scrutinises the controversial episodes that paved the way for the pitiful condition in which PT is nowadays: a company that carries the weight of a ruinous €897 million investment in a defaulted company and no more than a 25.6% stake in a heavily indebted Brazilian carrier. The free-fall is made, ironically, of a complete disregard for best corporate governance practices, allowing for PT’s major shareholders to take over the helm of the company, using it selfishly as a cash cow.

Lightweight adjustable partition system: evaluation of resistance to horizontal loads and functional failure from impacts

This paper presents and discusses the results of the serviciability and use condition tests carried on an innovative solution for partitions, designated AdjustMembrane developed within a research project. The proposed system is a modular non-loadbearing wall, tensioned between the pavements and ceiling slabs, which are used as anchoring elements. It allows several advantages, related with the weight reduction to achieve a good sustainable performance, such as the reduction of construction costs, energy, and materials, and it is easy to recycle and to reuse, allowing self-construction. Apart from a general presentation of the partition technology, this paper presents and discusses the results of experimental tests carried out. From the results obtained, it is possible to conclude that the solution fulfils the requirements for this typology of wall in terms of resistance to horizontal loads induced by soft and hard body impacts.

Nonparametric estimation of the survival function for ordered multivariate failure time data: a comparative study

In longitudinal studies of disease, patients may experience several events through a follow-up period. In these studies, the sequentially ordered events are often of interest and lead to problems that have received much attention recently. Issues of interest include the estimation of bivariate survival, marginal distributions and the conditional distribution of gap times. In this work we consider the estimation of the survival function conditional to a previous event. Different nonparametric approaches will be considered for estimating these quantities, all based on the Kaplan-Meier estimator of the survival function. We explore the finite sample behavior of the estimators through simulations. The different methods proposed in this article are applied to a data set from a German Breast Cancer Study. The methods are used to obtain predictors for the conditional survival probabilities as well as to study the influence of recurrence in overall survival.

Plataforma de suporte à decisão médica para transplante de órgãos baseada em Business Intelligence

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Informática Médica)

Assessment of inotropic and vasodilating effects of milrinone lactate in patients with dilated cardiomyopathy and severe heart failure

OBJECTIVE: To assess the hemodynamic and vasodilating effects of milrinone lactate (ML) in patients with dilated cardiomyopathy (DCM) and New York Heart Association (NYHA) class III and IV heart failure. METHODS: Twenty patients with DCM and NYHA class III and IV heart failure were studied. The hemodynamic and vasodilating effects of ML, administered intravenously, were evaluated. The following variables were compared before and during drug infusion: cardiac output (CO) and cardiac index (CI); pulmonary capillary wedge pressure (PCWP); mean aortic pressure (MAP); mean pulmonary artery pressure (MPAP); mean right atrial pressure (MRAP); left ventricular systolic and end-diastolic pressures (LVSP and LVEDP, respectively); peak rate of left ventricular pressure rise (dP/dt); systemic vascular resistance (SVR); pulmonary vascular resistance (PVR); and heart rate (HR). RESULTS: All patients showed a significant improvement of the analysed parameters of cardiac performance with an increase of CO and CI; a significant improvement in myocardial contractility (dP/dt) and reduction of the LVEDP; PCWP; PAP; MAP; MRAP; SVR; PVR. Were observed no significant increase in HR occurred. CONCLUSION: Milrinone lactate is an inotropic dilating drug that, when administered intravenously, has beneficial effects on cardiac performance and myocardial contractility. It also promotes reduction of SVR and PVR in patients with DCM and NYHA class III and IV of heart failure.

Effects of propranolol on the QT dispersion in congestive heart failure

OBJECTIVE - Studies have shown that therapy with beta-blockers reduces mortality in patients with heart failure. However, there are no studies describing the effects of propranolol on the QT dispersion in this population. The objective of this study was to assess the electrophysiological profile, mainly QT dispersion, of patients with heart failure regularly using propranolol. METHODS - Fifteen patients with heart failure and using propranolol were assessed over a period of 12 months. Twelve-lead electrocardiograms (ECG) were recorded prior to the onset of beta-blocker therapy and after 3 months of drug use. RESULTS - A significant reduction in heart rate, in QT dispersion and in QTc dispersion was observed, as was also an increase in the PR interval and in the QT interval, after the use of propranolol in an average dosage of 100 mg/day. CONCLUSION - Reduction in QT dispersion in patients with heart failure using propranolol may explain the reduction in the risk of sudden cardiac death with beta-blocker therapy, in this specific group of patients.

Exercise and heart failure. Relation of the severity of the disease to the anaerobic threshold and the respiratory compensation point

OBJECTIVE - To identify, the anaerobic threshold and respiratory compensation point in patients with heart failure. METHODS - The study comprised 42 Men,divided according to the functional class (FC) as follows: group I (GI) - 15 patients in FC I; group II (GII) - 15 patients in FC II; and group III (GIII) - 12 patients in FC III. Patients underwent a treadmill cardiopulmonary exercise test, where the expired gases were analyzed. RESULTS - The values for the heart rate (in bpm) at the anaerobic threshold were the following: GI, 122±27; GII, 117±17; GIII, 114±22. At the respiratory compensation point, the heart rates (in bpm) were as follows: GI, 145±33; GII, 133±14; GIII 123±22. The values for the heart rates at the respiratory compensation point in GI and GIII showed statistical difference. The values of oxygen consumption (VO2) at the anaerobic threshold were the following (in ml/kg/min): GI, 13.6±3.25; GII, 10.77±1.89; GIII, 8.7±1.44 and, at the respiratory compensation point, they were as follows: GI, 19.1±2.2; GII, 14.22±2.63; GIII, 10.27±1.85. CONCLUSION - Patients with stable functional class I, II, and III heart failure reached the anaerobic threshold and the respiratory compensation point at different levels of oxygen consumption and heart rate. The role played by these thresholds in physical activity for this group of patients needs to be better clarified.

Growth hormone for optimization of refractory heart failure treatment

It has been reported that growth hormone may benefit selected patients with congestive heart failure. A 63-year-old man with refractory congestive heart failure waiting for heart transplantation, depending on intravenous drugs (dobutamine) and presenting with progressive worsening of the clinical status and cachexia, despite standard treatment, received growth hormone replacement (8 units per day) for optimization of congestive heart failure management. Increase in both serum growth hormone levels (from 0.3 to 0.8 mg/l) and serum IGF-1 levels (from 130 to 300ng/ml) was noted, in association with clinical status improvement, better optimization of heart failure treatment and discontinuation of dobutamine infusion. Left ventricular ejection fraction (by MUGA) increased from 13 % to 18 % and to 28 % later, in association with reduction of pulmonary pressures and increase in exercise capacity (rise in peak VO2 to 13.4 and to 16.2ml/kg/min later). The patient was "de-listed" for heart transplantation. Growth hormone may benefit selected patients with refractory heart failure.