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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cardiac cachexia is divided into two types, i.e., the classic type, which occurs in patients with severe heart failure, and the nosocomial type, which develops in the postoperative state. Cardiac cachexia is due both to a decrease in nutrient intake (anorexia, malabsorption) and to specific metabolic alterations (hypercatabolism with increased energy expenditure, response to hypoxia, inflammatory status, etc). Among the various mechanisms involved in the pathogenesis of cachexia, cellular hypoxia has long been recognized. The chronic activation of the endogenous neurohormonal system is another specific feature of such patients; a striking relationship was found between cardiac cachexia and hormonal levels which correlate better than the classical parameters of cardiac failure severity. Finally, inflammatory syndrome has been known to occur frequently in patients with cardiac cachexia. Several studies have shown that tumor necrosis factor-alpha was significantly increased in cachectic patients and that chronic activation of the systemic immune response might be a common and unifying factor.
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PMID:Metabolic and nutritional disorders in cardiac cachexia. 1152 73

Patients with heart failure are predisposed to infections and anemia, possibly due to reduced hematopoiesis. The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is increased in heart failure, and it inhibits normal hematopoiesis, partly due to apoptosis through the effector molecule Fas. We examined bone marrow progenitor cells of mice with heart failure induced by acute myocardial infarction. The fraction of progenitor cells in mice with heart failure was only approximately 40% of control. Measured with in vitro clonal assays, the proliferative capacity of the progenitor cells in mice with heart failure was reduced to approximately 50% of control. Flow cytometry with specific markers revealed a threefold increase in apoptosis among progenitor cells from mice with heart failure. In these mice, TNF-alpha/Fas expression was increased in bone marrow natural killer (NK) and T cells, and these lymphocytes showed increased cytolytic activity in vitro against progenitor cells. We conclude that the TNF-alpha/Fas pathway in lymphocytes is activated in the bone marrow during heart failure, which may play a pathogenic role in the observed decrease in hematopoiesis.
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PMID:Decreased hematopoiesis in bone marrow of mice with congestive heart failure. 1174 35

Clinical and experimental evidence demonstrating the effects of tumor necrosis factor-alpha (TNF-alpha) in patients with heart failure continues to accumulate. It is well established that high concentrations of TNF-alpha appear in the circulation of patients with heart failure and that these levels have a directly proportional correlation with the patient's functional class. TNF-alpha levels also show a linear relation with prognosis. These circulating levels are responsible for the decreased expression of myocardial TNF-alpha receptors observed in heart failure. As a result of extrapolation of findings from experimental animals, we assume that TNF-alpha is deleterious to myocardial function in humans because it induces a negative inotropic state in patients who have not undergone heart transplant. Supporting this assumption is the fact that the resolution or improvement of pressure overload (obstructive hypertrophic myocardiopathy, by ethanol ablation) and volume overload (terminal dilated myocardiopathy, by ventricular assistance) states is accompanied by a decrease in myocardial TNF-alpha expression. The use of specific antagonists of circulating TNF-alpha in patients with symptomatic heart failure has been demonstrated to be safe and possibly effective. At present, multicenter studies are under way to assess the efficacy of this antagonism in a larger number of patients. If the results of these studies are favorable, we will have new therapeutic elements for managing patients with advanced hear failure. The transplanted heart behaves differently from the native heart. From the early stages of HTx, myocardial TNF-alpha expression is greatly increased (much more than in patients with heart failure) and not associated with contractile dysfunction, in contrast with what occurs in the native heart. However, we know that the transplanted heart soon develops ventricular hypertrophy, fibrosis, diastolic dysfunction, and late graft failure, even in the presence of normal epicardial coronary arteries. Clinical evidence suggests that TNF-alpha may be involved in these processes.
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PMID:[Importance of tumor necrosis factor-alpha in the pathogenesis of heart failure]. 1178 25

Chronic heart failure is a complex disorder with interactions among the cardiovascular, immune, and neurohormonal systems. The concept that the progression of heart failure is due to neurohormonal abnormalities has received the greatest attention to date, leading to substantial therapeutic benefits. Although many current therapies are also thought to exert a variety of immunologic effects, this has been much less studied. In this review, the authors discuss a number of interactions among immune pathways and neurohormonal abnormalities relevant to heart failure. Cytokines, in particular tumor necrosis factor-alpha, have tremendous interactive opportunities within a regulatory network of energy metabolism, immune function, and neuroendocrine and hormonal function. Inflammatory cytokines are known to contribute to the progression of heart failure, and have been related to patients' prognosis. Advanced heart failure can be considered a state of chronic (low-grade) inflammation, and there are many reasons to suggest that anticytokine therapy could be successful in these patients. These novel approaches are certainly not without some risk, and many of them are very expensive, which may limit their application to certain subgroups of patients. In the future, it may not be enough to monitor cardiac function alone. Rather, the immune and neurohormonal status of patients may also need to be included in the performance of a complete assessment.
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PMID:Immune and neurohormonal pathways in chronic heart failure. 1182 25

Myocardial extracellular matrix remodeling regulated by matrix metalloproteinases (MMPs) is implicated in the progression of heart failure. We hypothesized that MMP inhibition may modulate extracellular matrix remodeling and prevent the progression of heart failure. The effects of the MMP inhibitor BB-94 (also known as batimastat) on MMP expression, collagen expression, collagen deposition, collagen denaturation, and left ventricular structure and function in transgenic mice with cardiac-restricted overexpression of tumor necrosis factor-alpha (TNF-alpha) (TNF1.6) were assessed. The results showed that BB-94 reduced the expression of collagens, increased insoluble collagen and the ratio of undenatured to total soluble collagen, and prevented myocardial hypertrophy and diastolic dysfunction in young TNF1.6 mice. Furthermore, the treatment significantly improved cumulative survival of TNF1.6 mice. However, MMP inhibition did not have salutary effects on ventricular size and function in old mice with established heart failure. The results suggest that MMP activation may play a critical role in changes of myocardial function through the remodeling of extracellular matrix, and MMP inhibition may serve as a potential therapeutic strategy for heart failure, albeit within a narrow window during the development of heart failure.
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PMID:MMP inhibition modulates TNF-alpha transgenic mouse phenotype early in the development of heart failure. 1183 96

Heart failure is generally believed to begin with myocyte damage caused by a variety of insults, including ischemia, toxin or myocardial infection. The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), has been hypothesized to play a pathogenetic role in the transition from compensated to decompensated heart failure. Interleukin-18 (IL-18), a recently cloned cytokine synthesized by Kupffer cells, activates macrophages. We examined the therapeutic effect of IL-18 on the modulation of TNF-alpha gene expression in failing heart in a murine model of heart failure caused by viral myocarditis. The heart weight (HW)/ body weight (BW) ratio in IL-18 treated mice 7 days after viral inoculation was significantly lower (P<0.01) than in the untreated controls. Myocardial necrosis and inflammatory cell infiltration were significantly lower in IL-18 treated mice than untreated mice 5 and 7 days after inoculation. The expression of TNF-alpha mRNA in the myocardium was significantly lower on days 5 and 7 in IL-18 treated mice than in infected untreated mice. We conclude that concurrent systemic administration of IL-18 is beneficial in mice with myocarditis, and may be mediated through reduced expression of TNF-alpha in the heart.
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PMID:Interleukin-18 reduces expression of cardiac tumor necrosis factor-alpha and atrial natriuretic peptide in a murine model of viral myocarditis. 1188 1

The cytokine tumor necrosis factor (TNF)-alpha has been causally linked to left ventricular (LV) remodeling, but the molecular basis for this effect is unknown. Matrix metalloproteinases (MMPs) have been implicated in cardiac remodeling and can be regulated by TNF-alpha. This study tested the central hypothesis that administration of a TNF-alpha blocking protein would prevent the induction of MMPs and alter the course of myocardial remodeling in developing LV failure. Adult dogs were randomly assigned to the following groups: 1) chronic pacing (250 beats/min, 28 days, n = 12), 2) chronic pacing with concomitant administration of a TNF-alpha blocking protein (TNF block) using a soluble p75 TNF receptor fusion protein (TNFR:Fc; administered at 0.5 mg/kg twice a week subcutaneously, n = 7), and 3) normal controls (n = 10). LV end-diastolic volume increased from control with chronic pacing (83 +/- 12 vs. 118 +/- 10 ml, P < 0.05) and was reduced with TNF block (97 +/- 9 ml, P < 0.05). MMP zymographic levels (92 kDa, pixels) increased from control with chronic pacing (36,848 +/- 9,593 vs. 87,247 +/- 12,912, P < 0.05) and was normalized by TNF block. Myocardial MMP-9 and MMP-13 levels by immunoblot increased with chronic pacing relative to controls (130 +/- 10% and 118 +/- 6%, P < 0.05) and was normalized by TNF block. These results provide evidence to suggest that TNF-alpha contributes to the myocardial remodeling process in evolving heart failure through the local induction of specific MMPs.
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PMID:TNF-alpha and myocardial matrix metalloproteinases in heart failure: relationship to LV remodeling. 1189 63

Clinical evidence demonstrates participation of several cytokines in cardiac heart failure pathogenesis, in particular tumor necrosis factor-alpha (TNF-alpha), which induces left ventricular dysfunction, acute pulmonary edema and congestive cardiomyopathy. Increased levels of TNF-alpha in patients with heart failure were proved and may have prognostic significance. Absent in normal myocardium, produced in the myocardium in response to volume overload, TNF-alpha can depress cardiac function directly and indirectly by induction of nitric oxide synthase produced by macrophages, cardiac myocytes and other cells. The most of TNF-alpha effects are performed by two receptors termed as TNF-RI and TNF-RII identified on the surface of many cells. The extracellular domain fragments of both receptors shed from cell surface can be detected as soluble forms sTNF-RI and sTNF-RII in the urine and blood, and their blood levels in patients with severe heart failure are elevated. There are various pharmacological agents that block the biological effects of TNF-alpha, however only two of them have been used in patients with heart failure: pentoxifylline and etanercept. Encouraging effects of this studies must be regarded as provisional because of relatively small numbers of treated patients. Preliminary results of other randomized, multicenter and in large patients populations trials, planned till 2002 year indicate the possibility of novel anti-TNF strategies in heart failure; treatment is well tolerated and can be effective. It is thought, that recombinantly produced TNF-alpha soluble receptor being now evaluated clinically can determine the progress in heart failure treatment.
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PMID:[The role of TNF-alpha in the etiopathogenesis of heart failure]. 1195 9

Transgenic mice are widely used to study cardiac function, but strain-dependent differences in autonomic nervous system activity (ANSA) have not been explored. We compared 1) short-term pharmacological responses of cardiac rhythm in FVB vs. C57Black6/SV129 wild-type mice and 2) long-term physiological dynamics of cardiac rhythm and survival in tumor necrosis factor (TNF)-alpha transgenic mice with heart failure (TNF-alpha mice) on defined backgrounds. Ambulatory telemetry electrocardiographic recordings and response to saline, adrenergic, and cholinergic agents were examined in FVB and C57Black6/SV129 mice. In FVB mice, baseline heart rate (HR) was higher and did not change after injection of isoproterenol or atropine but decreased with propranolol. In C57Black6/SV129 mice, HR did not change with propranolol but increased with isoproterenol or atropine. Mean HR, but not indexes of HR variability, was an excellent predictor of response to autonomic agents. The proportion of surviving animals was higher in TNF-alpha mice on an FVB background than on a mixed FVB/C57Black6 background. The homeostatic states of ANSA are strain specific, which can explain the interstrain differences in mean HR, pharmacological responses, and survival of animals with congestive heart failure. Strain-specific differences should be considered in selecting the strains of mice used for transgenic and gene targeting experiments.
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PMID:Strain-specific patterns of autonomic nervous system activity and heart failure susceptibility in mice. 1200 14

To investigate how cardiac hypertrophy and heart failure develop, we isolated and characterized a candidate initiator, the soluble 12-kDa protein myotrophin, from rat and human hearts. Myotrophin stimulates protein synthesis and myocardial cell growth associated with increased levels of hypertrophy marker genes. Recombinant myotrophin from the cloned gene showed structural/functional motifs, including ankyrin repeats and putative phosphorylation sites for protein kinase C (PKC) and casein kinase II. One repeat, homologous with I kappaB, interacts with rel/NF-kappaB in vitro. We analyzed the interaction of recombinant myotrophin and nuclear extracts prepared from neonatal and adult cardiomyocytes; gel mobility shift assay showed that myotrophin bound to kappaB DNA. To define PKC's role in myotrophin-induced myocyte growth, we incubated neonatal rat myocytes (normal and stretch) with specific inhibitors and found that myotrophin inhibits [3H]leucine incorporation into myocytes and different hypertrophic gene expression in neonatal myocytes. Using confocal microscopy, we observed that a basal level of myotrophin was present in both cytoplasm and nucleus under normal conditions, but under cyclic stretch, myotrophin levels became elevated in the nucleus. Myotrophin gene levels were upregulated when myocytes underwent cyclic stretch or were treated with tumor necrosis factor-alpha (TNF-alpha) or interleukin-1beta and also when excised beating hearts were exposed to high pressure. Our data showed that the myotrophin-kappaB interaction was increased with age in spontaneously hypertensive rats (SHRs) only. Our data provide evidence that myotrophin-kappaB DNA interaction may be an important step in initiating cardiac hypertrophy.
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PMID:Myotrophin-kappaB DNA interaction in the initiation process of cardiac hypertrophy. 1203 92


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