101 resultados para Kidney failure, chronic


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Improvement of heart failure therapy has led to a far better survival and quality of life of patients. Treatment of the underlying disease, patient education and improvement of compliance and consequent upgrading of medical heart failure therapy often delays further progression to an advanced stage of heart failure. Nevertheless heart failure remains a chronic progressive disease and it is up to the treating clinician to identify the signs of advanced heart failure in a timely manner in order to evaluate patients for further treatment strategies such as heart transplantation. This article should help define advanced heart failure and illustrate how patients are evaluated for further therapy. Outcome of heart transplantation or mechanically assisted circulatory support is strongly associated to proper patient selection and timing.

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Background: In most patients with chronic heart failure (CHF), endurance training improves exercise capacity. However, some patients do not respond favourably. The purpose of this study was to explore the reasons of non-response and to determine their predictive value.Methods: We studied a cohort of 120 consecutive CHF patients with sinus rhythm (mean age 57 ± 12 years, ejection fraction 29.3 ± 9.9%, peak VO2 17.3 ± 5.1 ml/min/kg), participating in a 3-month outpatient cardiac rehabilitation programme. Responders were defined as subjects who improved peak VO2 by more than 5%, work load by more than 10%, or VE/VCO2 slope by more than 5%. Subjects who did not fulfil at least one of the above criteria were characterized as non-responders. Multivariate regression analyses were performed to identify parameters that were predictive for a response. Receiver operating characteristic (ROC) analyses were performed for predictive parameters to identify thresholds for response or non-response.Results: Multivariate regression analyses revealed heart rate (HR) reserve, HR recovery at 1 min, and peak HR as significant predictors for a positive training response. ROC curves revealed the optimal thresholds separating responders from non-responders at less than 30 bpm for HR reserve, less than 6 bpm for HR recovery and less than 101 bpm for peak HR.Conclusions: The presence of impaired chronotropic competence is a major predictor of poor training response in CHF patients with sinus rhythm.

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Exertional oscillatory ventilation (EOV) is an ominous prognostic sign in chronic heart failure (CHF), but little is known about the success of specific therapeutic interventions. Our aim was to study the impact of an exercise training on exercise capacity and cardiopulmonary adaptation in stable CHF patients with left ventricular systolic dysfunction and EOV. 96 stable CHF patients with EOV were included in a retrospective analysis (52 training versus 44 controls). EOV was defined as follows: 1) three or more oscillatory fluctuations in minute ventilation (V'(E)) during exercise; 2) regular oscillations; and 3) minimal average ventilation amplitude ≥5 L. EOV disappeared in 37 (71.2%) out of 52 patients after training, but only in one (2.3%) out of 44 without training (p<0.001). The decrease of EOV amplitude correlated with changes in end-tidal carbon dioxide tension (r= -0.60, p<0.001) at the respiratory compensation point and V'(E)/carbon dioxide production (V'(CO(2))) slope (r=0.50, p<0.001). Training significantly improved resting values of respiratory frequency (f(R)), V'(E), tidal volume (V(T)) and V'(E)/V'(CO(2)) ratio. During exercise, V'(E) and V(T) reached significantly higher values at the peak, while f(R) and V'(E)/V'(CO(2)) ratio were significantly lower at submaximal exercise. No change was noted in the control group. Exercise training leads to a significant decrease of EOV and improves ventilatory efficiency in patients with stable CHF.

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Chronic hepatitis C virus (HCV) infection outcomes include liver failure, hepatocellular carcinoma (HCC), and liver-related death.

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Elevated serum ferritin levels may reflect a systemic inflammatory state as well as increased iron storage, both of which may contribute to an unfavorable outcome of chronic hepatitis C (CHC). We therefore performed a comprehensive analysis of the role of serum ferritin and its genetic determinants in the pathogenesis and treatment of CHC. To this end, serum ferritin levels at baseline of therapy with pegylated interferon-alpha and ribavirin or before biopsy were correlated with clinical and histological features of chronic hepatitis C virus (HCV) infection, including necroinflammatory activity (N = 970), fibrosis (N = 980), steatosis (N = 886), and response to treatment (N = 876). The association between high serum ferritin levels (> median) and the endpoints was assessed by logistic regression. Moreover, a candidate gene as well as a genome-wide association study of serum ferritin were performed. We found that serum ferritin ≥ the sex-specific median was one of the strongest pretreatment predictors of treatment failure (univariate P < 0.0001, odds ratio [OR] = 0.45, 95% confidence interval [CI] = 0.34-0.60). This association remained highly significant in a multivariate analysis (P = 0.0002, OR = 0.35, 95% CI = 0.20-0.61), with an OR comparable to that of interleukin (IL)28B genotype. When patients with the unfavorable IL28B genotypes were stratified according to high versus low ferritin levels, SVR rates differed by > 30% in both HCV genotype 1- and genotype 3-infected patients (P < 0.001). Serum ferritin levels were also independently associated with severe liver fibrosis (P < 0.0001, OR = 2.67, 95% CI = 1.68-4.25) and steatosis (P = 0.002, OR = 2.29, 95% CI = 1.35-3.91), but not with necroinflammatory activity (P = 0.3). Genetic variations had only a limited impact on serum ferritin levels. Conclusion: In patients with CHC, elevated serum ferritin levels are independently associated with advanced liver fibrosis, hepatic steatosis, and poor response to interferon-alpha-based therapy.

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Claudins are major components of tight junctions and contribute to the epithelial-barrier function by restricting free diffusion of solutes through the paracellular pathway. We have mapped a new locus for recessive renal magnesium loss on chromosome 1p34.2 and have identified mutations in CLDN19, a member of the claudin multigene family, in patients affected by hypomagnesemia, renal failure, and severe ocular abnormalities. CLDN19 encodes the tight-junction protein claudin-19, and we demonstrate high expression of CLDN19 in renal tubules and the retina. The identified mutations interfere severely with either cell-membrane trafficking or the assembly of the claudin-19 protein. The identification of CLDN19 mutations in patients with chronic renal failure and severe visual impairment supports the fundamental role of claudin-19 for normal renal tubular function and undisturbed organization and development of the retina.

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Chronic renal allograft rejection is characterized by alterations in the extracellular matrix compartment and in the proliferation of various cell types. These features are controlled, in part by the metzincin superfamily of metallo-endopeptidases, including matrix metalloproteinases (MMPs), a disintegrin and metalloproteinase (ADAM) and meprin. Therefore, we investigated the regulation of metzincins in the established Fisher to Lewis rat kidney transplant model. Studies were performed using frozen homogenates and paraffin sections of rat kidneys at day 0 (healthy controls) and during periods of chronic rejection at day +60 and day +100 following transplantation. The messenger RNA (mRNA) expression was examined by Affymetrix Rat Expression Array 230A GeneChip and by real-time Taqman polymerase chain reaction analyses. Protein expression was studied by zymography, Western blot analyses, and immunohistology. mRNA levels of MMPs (MMP-2/-11/-12/-14), of their inhibitors (tissue inhibitors of metalloproteinase (TIMP)-1/-2), ADAM-17 and transforming growth factor (TGF)-beta1 significantly increased during chronic renal allograft rejection. MMP-2 activity and immunohistological staining were augmented accordingly. The most important mRNA elevation was observed in the case of MMP-12. As expected, Western blot analyses also demonstrated increased production of MMP-12, MMP-14, and TIMP-2 (in the latter two cases as individual proteins and as complexes). In contrast, mRNA levels of MMP-9/-24 and meprin alpha/beta had decreased. Accordingly, MMP-9 protein levels and meprin alpha/beta synthesis and activity were downregulated significantly. Members of metzincin families (MMP, ADAM, and meprin) and of TIMPs are differentially regulated in chronic renal allograft rejection. Thus, an altered pattern of metzincins may represent novel diagnostic markers and possibly may provide novel targets for future therapeutic interventions.

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BACKGROUND: Renal hypodysplasia, characterized by a decrease in nephron number, small overall kidney size, and maldeveloped renal tissue, is a leading cause of chronic renal failure in young children. Familial clustering and renal hypodysplasia phenotypes observed in transgenic animal models suggest a genetic contribution. Uroplakin IIIa (encoded by UPIIIA) is an integral membrane protein present in urothelial plaques, and the murine UPIIIa knockout is associated with urothelial anomalies and vesicoureteral reflux. De novo UPIIIA mutations recently were identified in 4 of 17 patients with severe bilateral renal adysplasia. METHODS: To evaluate the overall role of UPIIIA in human renal hypodysplasia pathogenesis, we performed UPIIIA mutation analysis in a cohort of 170 pediatric patients affected by severe unilateral or bilateral renal hypodysplasia. Eighty-one patients were affected by bilateral nonobstructive renal hypodysplasia; of these, 61 were without vesicoureteral reflux. Eighty-four patients presented with unilateral nonobstructive renal hypodysplasia, including 24 patients with unilateral multicystic dysplastic kidneys. Family history was positive in 11%. RESULTS: Mutation analysis showed 2 heterozygous mutations not observed in 200 race-matched control chromosomes. In only 1 family was distribution of the UPIIIA mutation consistent with a disease-causing effect. This de novo missense mutation (Gly202Asp) was identified in a patient with unilateral multicystic dysplastic kidneys. The second (intronically located) mutation appeared unlikely to be disease causing because it did not segregate with an obvious disease phenotype in the affected family. CONCLUSION: Our results indicate that de novo mutations in UPIIIA can be involved in defective early kidney development, but probably constitute only a rare cause of human renal hypodysplasia in a minor subset of individuals.

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OBJECTIVE: Generation and maintenance of pain in chronic pancreatitis (CP) have been shown to be partially attributable to neuroimmune interactions, which involve neuropeptides such as substance P (SP). So far, expression of SP receptors NK-2R, NK-3R, the SP-encoding gene preprotachykinin A (PPT-A), and the SP degradation enzyme neutral endopeptidase (NEP) and their relation to pain in CP have not been determined. METHODS: Tissue samples from patients with CP (n = 25) and from healthy donors (n = 20) were analyzed for PPT-A, NK-2R, NK-3R, and NEP expression using quantitative RT-PCR. NEP protein levels were examined by immunoblot analysis and its localization was determined using immunohistochemistry. A scoring system was used to grade the extent of fibrosis on hematoxylin and eosin- and Masson-Trichrome-stained sections. Messenger RNA levels and the extent of pain were analyzed for correlations. RESULTS: In CP tissues, NK-2R and PPT-A expression was increased, whereas NK-3R and NEP mRNA levels were comparable with normal pancreas. Overexpression of NK-2R was related to the intensity, frequency, and duration of pain in CP patients. NK-1R and NEP expression was significantly related to the extent of fibrosis. CONCLUSIONS: Expression of NK-2R and PPT-A is increased in CP and is associated with pain. Failure to up-regulate NEP may contribute to the disruption of the neuropeptides loop balance in CP and thus may exacerbate the severe pain syndrome.

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BACKGROUND: Clinical outcomes of chronic hepatitis C infection in patients with advanced fibrosis include liver failure, hepatocellular carcinoma, and death. OBJECTIVE: To investigate whether sustained virologic response to treatment for hepatitis C is associated with improved clinical outcomes. DESIGN: Retrospective cohort study. SETTING: 5 hepatology units of tertiary care centers in Europe and Canada caring for patients with chronic hepatitis C treated between 1990 and 2003. PATIENTS: Consecutively treated patients with chronic hepatitis C who had biopsy-proven advanced fibrosis or cirrhosis (Ishak score, 4 to 6). MEASUREMENTS: Sustained virologic response, defined as absence of detectable hepatitis C virus RNA at 24 weeks after the end of treatment, and clinical outcomes, defined as death (liver-related or non-liver-related), liver failure, and hepatocellular carcinoma. RESULTS: Of 479 patients, 29.6% had sustained virologic response and 70.3% did not. Median follow-up was 2.1 years (interquartile range, 0.8 to 4.9 years). Four patients with and 83 without sustained virologic response had at least 1 outcome event. Sustained virologic response was associated with a statistically significant reduction in the hazard of events (adjusted hazard ratio, 0.21 [95% CI, 0.07 to 0.58]; P = 0.003). The effect was largely attributable to a reduction in liver failure, which developed in no patients with and 42 patients without sustained virologic response (5-year occurrence, 0% vs. 13.3% [CI, 8.4% to 18.2%]; unadjusted hazard ratio, 0.03 [CI, 0.00 to 0.91]). LIMITATIONS: Because few events occurred in the sustained virologic response group, the study had limited ability to detect differences between groups in individual outcomes. In addition, the study was retrospective; selection and survival biases may therefore influence estimates of effect. CONCLUSION: Sustained virologic response to treatment is associated with improved clinical outcomes, mainly prevention of liver failure, in patients with chronic hepatitis C and advanced fibrosis.

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BACKGROUND: Increased activity of single ventricular L-type Ca(2+)-channels (L-VDCC) is a hallmark in human heart failure. Recent findings suggest differential modulation by several auxiliary beta-subunits as a possible explanation. METHODS AND RESULTS: By molecular and functional analyses of human and murine ventricles, we find that enhanced L-VDCC activity is accompanied by altered expression pattern of auxiliary L-VDCC beta-subunit gene products. In HEK293-cells we show differential modulation of single L-VDCC activity by coexpression of several human cardiac beta-subunits: Unlike beta(1) or beta(3) isoforms, beta(2a) and beta(2b) induce a high-activity channel behavior typical of failing myocytes. In accordance, beta(2)-subunit mRNA and protein are up-regulated in failing human myocardium. In a model of heart failure we find that mice overexpressing the human cardiac Ca(V)1.2 also reveal increased single-channel activity and sarcolemmal beta(2) expression when entering into the maladaptive stage of heart failure. Interestingly, these animals, when still young and non-failing ("Adaptive Phase"), reveal the opposite phenotype, viz: reduced single-channel activity accompanied by lowered beta(2) expression. Additional evidence for the cause-effect relationship between beta(2)-subunit expression and single L-VDCC activity is provided by newly engineered, double-transgenic mice bearing both constitutive Ca(V)1.2 and inducible beta(2) cardiac overexpression. Here in non-failing hearts induction of beta(2)-subunit overexpression mimicked the increase of single L-VDCC activity observed in murine and human chronic heart failure. CONCLUSIONS: Our study presents evidence of the pathobiochemical relevance of beta(2)-subunits for the electrophysiological phenotype of cardiac L-VDCC and thus provides an explanation for the single L-VDCC gating observed in human and murine heart failure.

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Mucosal pH (pHi) is influenced by local perfusion and metabolism (mucosal-arterial Pco2 gradient, DeltaPco2), systemic metabolic acidosis (arterial bicarbonate), and respiration (arterial Pco2). We determined these components of pHi and their relation to outcome during the first 24 h of intensive care. We studied 103 patients with acute respiratory or circulatory failure (age, 63 +/- 2 [mean +/- SEM]; Acute Physiology and Chronic Health Evaluation II score, 20 +/- 1; Sequential Organ Failure Assessment score, 8 +/- 0). pHi, and the effects of bicarbonate and arterial and mucosal Pco2 on pHi, were assessed at admission, 6, and 24 h. pHi was reduced (at admission, 7.27 +/- 0.01) due to low arterial bicarbonate and increased DeltaPco2. Low pHi (<7.32) at admission (n = 58; mortality, 29% vs. 13% in those with pHi >/=7.32 at admission; P = 0.061) was associated with an increased DeltaPco2 in 59% of patients (mortality, 47% vs. 4% for patients with low pHi and normal DeltaPco2; P = 0.0003). An increased versus normal DeltaPco2, regardless of pHi, was associated with increased mortality at admission (51% vs. 5%; P < 0.0001; n = 39) and at 6 h (34% vs. 13%; P = 0.016; n = 45). A delayed normalization or persistently low pHi (n = 47) or high DeltaPco2 (n = 25) was associated with high mortality (low pHi [34%] vs. high DeltaPco2 [60%]; P = 0.046). In nonsurvivors, hypocapnia increased pHi at baseline, 6, and 24 h (all P

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A variety of chronic kidney diseases tend to progress towards end-stage kidney disease. Progression is largely due to factors unrelated to the initial disease, including systemic hypertension and proteinuria. Drugs that block the renin-angiotensin II-aldosterone system, either ACE inhibitors or angiotensin II receptor antagonists, reduce both BP and proteinuria and appear superior to a more conventional antihypertensive treatment regimen in preventing progression to end-stage kidney disease. The most recent recommendations state that the BP goal in children with chronic kidney disease is the corresponding 90th centile for body height, age, and gender.Since satisfactory BP control is often not achieved, the mnemonic acronym DELTAREPROSI was generated to recall the following tips for the practical management of hypertension and proteinuria in childhood chronic renal parenchymal disease: DEfinition of hypertension and Low blood pressure TArget in REnal disease (90th centile calculated by means of simple formulas), potential of drugs inhibiting the REnin-angiotensin II-aldosterone system in hypertension and PROteinuria, advantages of SImplified treatment regimens and escalating the doses every SIx weeks.

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Although experimental prevention studies have suggested therapeutic potential of endothelin (ET) antagonists for the treatment of heart failure, the results of clinical trials using ET antagonists on top of standard heart failure medications have been largely disappointing. This experimental study investigated the effects of chronic ET(A) receptor blockade in long-term survivors of myocardial infarction who had developed stable chronic heart failure in the absence of other treatments. Systolic blood pressure, heart rate, organ weights of the right atrium and ventricle, and the lungs were determined, and tissue ET-1 peptide levels were measured in cardiac tissue, lung, and aorta. The results show that chronic blockade of ET(A) receptors stabilizes systolic blood pressure and reverses the heart failure-induced weight increases of right heart chambers and lung. The changes observed occurred independently of tissue ET-1 concentrations and heart rate, suggesting mechanisms independent of local cardiac or pulmonary ET-1 synthesis, which are yet to be identified.

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BACKGROUND: Simultaneous pancreas/kidney transplantation (SPK) should be the procedure of choice for (pre)uremic patients with type 1 diabetes. All standard immunosuppressive protocols for SPK include a calcineurin-inhibitor. Both calcineurin inhibitors, cyclosporine (CyA) and probably tacrolimus (FK506) too, are associated with the occurrence of cholelithiasis due to their metabolic side effects. PATIENTS AND METHODS: We evaluated the prevalence of cholelithiasis in 83 kidney/pancreas transplanted type I-diabetic patients (46 males, 37 females, mean age 42.8 +/- 7.5 years) by conventional B-mode ultrasound 5 years after transplantation. 56 patients received CyA (group 1) and 27 received tacrolimus (group 2) as first-line-immunosuppressive drug. Additional immunosuppression consisted of steroids, azathioprine or mycophenolate mofetil. Additionally, laboratory analyses of cholestasis parameters (gamma-GT and alcalic phosphatasis) were performed. RESULTS: In total, 23 patients (28%) revealed gallstones and 52 patients (62%) revealed a completely normal gallbladder. In eight patients (10%) a cholecystectomy was performed before or during transplantation because of already known gallstones. No concrements in the biliary ducts (choledocholithiasis) could be detected. In group 2 the number of patients with gallstones was slightly lower (22%) compared with group 1 patients (30%), but without statistical significance. - Cholestasis parameters were not increased and HbA1c values were normal in both groups of patients. CONCLUSION: The prevalence of biliary disease in kidney/pancreas transplanted type I-diabetic patients with 28% is increased in comparison to the general population (10-15%). Lithogenicity under tacrolimus seems to be lower as under cyclosporine based immunosuppressive drug treatment. We recommend regular sonographical examinations to detect an acute or chronic cholecystis as early as possible, which may develop occultly in these patients.