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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathogenesis of cirrhotic cardiomyopathy remains unclear. Because ventricular contractility is dependent on the interplay of stimulatory beta-adrenergic and inhibitory muscarinic receptors, we aimed to examine a possible role of muscarinic M2 receptor overactivity in a rat model of cirrhotic cardiomyopathy. Cirrhosis was induced by bile duct ligation (BDL), while controls underwent sham operations. Contractile responses to the muscarinic agonist carbachol were measured in situ in the autonomic-denervated pithed rat and in vitro in isolated ventricular papillary muscles. Ventricular sarcolemmal plasma membranes were isolated by sucrose density gradients, and muscarinic receptor characteristics were studied using 1-[N-methyl-3H]scopolamine (NMS). Membrane adenylyl cyclase activity was tested by a protein binding assay. Maximum first time derivative of peak ventricular systolic pressure (+dP/dt) for sham-operated and cirrhotic rats at baseline was 3,599 +/- 296 versus 1,226 +/- 63 mm Hg/sec (P < .01). Maximum first time derivative of ventricular diastolic relaxation (-dP/dt) for sham and cirrhotic rats at basal levels was -3,040 +/- 235 versus -864 +/- 59 (P < .01). The +dP/dt(max), and -dP/dt(max) responses to carbachol were blunted in the cirrhotic rats. The cirrhotic papillary muscles showed significantly less inhibition to incremental doses of carbachol than control rat muscles. Likewise, isoproterenol-stimulated membrane adenylyl cyclase activity was significantly less inhibited by carbachol doses in the cirrhotic rats. Membrane M2 receptor density and binding affinity in cirrhotic rat hearts were similar to controls. We conclude that muscarinic responsiveness was blunted in cirrhotic hearts, but this was not caused by receptor down-regulation, suggesting changes in postreceptor factors. These changes in muscarinic function are likely compensatory, and M2 receptor overactivity is not involved in the genesis of cirrhotic cardiomyopathy.
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PMID:Cardiac muscarinic receptor function in rats with cirrhotic cardiomyopathy. 918 53

Visceral changes were studied by histological and electron-microscopic methods in cadavers of 18 subjects dead from hemochromatosis. Pronounced visceral changes in all cases represented a characteristic tetrad of signs: bronze-colored skin, pigmentary cirrhosis of the liver, involvement of the pancreas, and cardiomyopathy. In forensic medical practice hemochromatosis can be found in subjects who were probably genetically predisposed to it and, as a rule, had a history of alcohol abuse. Among the numerous complications of the disease, the most incident are cardiac pathology (dilatation cardiomyopathy) and diabetes mellitus with concomitant intoxications caused by various inflammations.
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PMID:[The morphological changes in the internal organs in hemochromatosis]. 960 56

Hepatitis C infection is common in patients receiving life-long blood transfusion therapy. Interferon-alpha induces long-term viral clearance in 25-30% of patients suffering from Cooley's anemia. Ribavirin, an orally active guanoside analogue together with interferon-alpha produces a sustained response in up to 40% of patients with cirrhosis, who had previously failed single agent treatment. Growth retardation in iron-overloaded patients is the result of growth hormone deficiency in up to 30% of patients. Height gain can be successfully achieved in these patients with growth hormone treatment. Pregnancy in women with Cooley's anemia is now a reality, and over 100 pregnancies have been documented. Conception may be spontaneous or the result of ovulation induction. Cardiomyopathy and diabetes require careful assessment in these patients before a decision is made to treat with gonadotrophins to induce ovulation.
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PMID:New approaches to the management of hepatitis and endocrine disorders in Cooley's anemia. 966 45

Hereditary hemochromatosis (HH) is a common autosomal recessive disorder that can result in iron overload and a wide range of clinical complications, including hepatic cirrhosis, diabetes mellitus, hypopituitarism, hypogonadism, arthritis, and cardiomyopathy. People with HH can be detected at an asymptomatic stage of the disease by abnormalities in serum iron measures. Early detection is desirable, because periodic phlebotomy provides effective treatment for iron overload and may prevent complications of the disorder. The natural history of HH is poorly understood, however, and the proportion of people detected by screening who will develop serious complications of HH is unknown. The genetics of HH may help to resolve these questions. The gene, HFE, and two mutations, C282Y and H63D, have been identified: the C282Y mutation has a higher penetrance than the H63D mutation, and appears to result in a greater loss of HFE protein function. Most people with HH are C282Y homozygotes, a small proportion are compound heterozygotes or H63D homozygotes, and some have no identifiable HFE mutation or are HFE heterozygotes, suggesting that additional mutations associated with HH are yet to be found. Gender and environmental agents, such as alcohol and dietary iron, influence phenotypic expression of HH. The severity of HH is thus determined by an interaction between genotype and modifying factors. HFE mutations also appear to increase the likelihood of iron overload in inherited anemias and to promote the clinical manifestations of porphyria cutanea tarda. HH is an important paradigm for medical genetics because it offers an opportunity to explore the complexity of gene gene and gene environment interactions.
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PMID:Hemochromatosis: genetics helps to define a multifactorial disease. 972 31

The complications of iron overload in hemochromatosis can be avoided by early diagnosis and appropriate management. Therapeutic phlebotomy is used to remove excess iron and maintain low normal body iron stores, and it should be initiated in men with serum ferritin levels of 300 microg/L or more and in women with serum ferritin levels of 200 microg/L or more, regardless of the presence or absence of symptoms. Typically, therapeutic phlebotomy consists of 1) removal of 1 unit (450 to 500 mL) of blood weekly until the serum ferritin level is 10 to 20 microg/L and 2) maintenance of the serum ferritin level at 50 microg/L or less thereafter by periodic removal of blood. Hyperferritinemia attributable to iron overload is resolved by therapeutic phlebotomy. When applied before iron overload becomes severe, this treatment also prevents complications of iron overload, including hepatic cirrhosis, primary liver cancer, diabetes mellitus, hypogonadotrophic hypogonadism, joint disease, and cardiomyopathy. In patients with established iron overload disease, weakness, fatigue, increased hepatic enzyme concentrations, right upper quadrant pain, and hyperpigmentation are often substantially alleviated by therapeutic phlebotomy. Patients with liver disease, joint disease, diabetes mellitus and other endocrinopathic abnormalities, and cardiac abnormalities often require additional, specific management. Dietary management of hemochromatosis includes avoidance of medicinal iron, mineral supplements, excess vitamin C, and uncooked seafoods. This can reduce the rate of iron reaccumulation; reduce retention of nonferrous metals; and help reduce complications of liver disease, diabetes mellitus, and Vibrio infection. This comprehensive approach to the management of hemochromatosis can decrease the frequency and severity of iron overload, improve quality of life, and increase longevity.
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PMID:Management of hemochromatosis. Hemochromatosis Management Working Group. 986 45

As advances in cancer therapy improve the prognosis of patients with childhood malignancies, awareness of the consequences of treatment methods assumes increasing importance. All cancer treatment modalities are associated with toxic effects, and the spectrum of therapy-induced complications involves all organ systems. Radiologists have a pivotal role in detecting these sequelae, which can be categorized by the affected organ system and by whether they occur (a) at diagnosis or during initial therapy or (b) after the completion of treatment. The first group consists of oncologic emergencies, infectious complications, and irritant effects. Oncologic emergencies can be further categorized as space-occupying lesions (e.g., superior vena cava syndrome or spinal cord compression), vascular abnormalities (e.g., hyperleukocytosis, anemia, coagulopathy), and metabolic emergencies (e.g., tumor lysis syndrome). Common complications developing after completion of treatment include leukoencephalopathy and neurocognitive defects; cataract formation; cardiomyopathy and congestive heart failure; hepatic dysfunction, fibrosis, and cirrhosis; radiation enteritis; renal dysfunction or failure; scoliosis and short stature; hypothyroidism; gonadal dysfunction; graft-versus-host disease; and development of secondary malignancies. Physician awareness of these complications will permit more effective patient surveillance, which may afford patients the opportunity for earlier intervention in these situations and improved quality of life.
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PMID:Complications of cancer therapy in children: a radiologist's guide. 1019 80

Cirrhosis is associated with several circulatory abnormalities. These include hyperkinetic systemic and splanchnic circulation, hepatopulmonary syndromes including pulmonary hypertension, and cirrhotic cardiomyopathy. Hepatopulmonary syndrome generally refers to hypoxaemia seen in patients with chronic liver disease and appears to be relatively common, although often subclinical. However, significant pulmonary hypertension occurs in 0.2-0.7% of cirrhotic patients. Nitric oxide and/or other vasodilators appear to be involved in the pathogenesis of hepatopulmonary syndrome through induction of pulmonary capillary dilatation which increases the alveolar-arterial oxygen gradient. Cirrhotic cardiomyopathy refers to abnormal left ventricular function which is manifested under conditions of physiological or pharmacological stress. The emergence of liver transplantation as an effective treatment for end-stage liver disease has led to recognition of previously subclinical cardiomyopathy and congestive heart failure accounts for significant morbidity and mortality after this procedure. Diminished myocardial beta-adrenergic receptor function has been shown to play an important role in the pathogenesis of this condition. The contributions of other factors including nitric oxide, catecholamines and membrane fluidity changes are under investigation. Cirrhotic patients also have an increased incidence of other cardiac abnormalities, such as endocarditis and pericardial effusions.
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PMID:Cardiopulmonary dysfunction in cirrhosis. 1038 72

Ethanol is one of the few nutrients that is profoundly toxic. Alcohol causes both whole-body and tissue-specific changes in protein metabolism. Chronic ethanol missuse increases nitrogen excretion with concomitant loss of lean tissue mass. Even acute doses of alcohol elicit increased nitrogen excretion. The loss of skeletal muscle protein (i.e., chronic alcoholic myopathy) is one of several adverse reactions to alcohol and occurs in up to two-thirds of all ethanol misusers. There are a variety of other diseases and tissue abnormalities that are entirely due to ethanol-induced changes in the amounts of individual proteins or groups of tissue proteins; for example, increased hepatic collagen in cirrhosis, reduction in myosin in cardiomyopathy, and loss of skeletal collagen in osteoporosis. Ethanol induces changes in protein metabolism in probably all organ or tissue systems. Clinical studies in alcoholic patients without overt liver disease show reduced rates of skeletal muscle protein synthesis though whole-body protein turnover does not appear to be significantly affected. Protein turnover studies in alcohol misusers are, however, subject to artifactual misinterpretations due to non-abstinence, dual substance misuse (e.g., cocaine or tobacco), specific nutritional deficiencies, or the presence of overt organ dysfunction. As a consequence, the most reliable data examining the effects of alcohol on protein metabolism is derived from animal studies, where nutritional elements of the dosing regimen can be strictly controlled. These studies indicate that, both chronically and acutely, alcohol causes reductions in skeletal muscle protein synthesis, as well as of skin, bone, and the small intestine. Chronically, animal studies also show increased urinary nitrogen excretion and loss of skeletal muscle protein. With respect to skeletal muscle, the reductions in protein synthesis do not appear to be due to the generation of reactive oxygen species, are not prevented with nitric oxide synthase inhibitors, and may be indirectly mediated by the reactive metabolite acetaldehyde. Changes in skeletal muscle protein metabolism have profound implications for whole body physiology, while protein turnover changes in organs such as the heart (exemplified by complex alterations in protein profiles) have important implications for cardiovascular function and morbidity.
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PMID:Protein metabolism in alcoholism: effects on specific tissues and the whole body. 1042 97

The aim of this study was to assess the relationship between subtle cardiovascular abnormalities and abnormal sodium handling in cirrhosis. A total of 35 biopsy-proven patients with cirrhosis with or without ascites and 14 age-matched controls underwent two-dimensional echocardiography and radionuclide angiography for assessment of cardiac volumes, structural changes and systolic and diastolic functions under strict metabolic conditions of a sodium intake of 22 mmol/day. Cardiac output, systemic vascular resistance and pressure/volume relationship (an index of cardiac contractility) were calculated. Eight controls and 14 patients with non-ascitic cirrhosis underwent repeat volume measurements and the pressure/volume relationship was re-evaluated after consuming a diet containing 200 mmol of sodium/day for 7 days. Ascitic cirrhotic patients had significant reductions in (i) cardiac pre-load (end diastolic volume 106+/-9 ml; P<0.05 compared with controls), due to relatively thicker left ventricular wall and septum (P<0.05); (ii) afterload (systemic vascular resistance 992+/-84 dyn.s.cm(-5); P<0. 05 compared with controls) due to systemic arterial vasodilatation; and (iii) reversal of the pressure/volume relationship, indicating contractility dysfunction. Increased cardiac output (6.12+/-0.45 litres/min; P<0.05 compared with controls) was due to a significantly increased heart rate. Pre-ascitic cirrhotic patients had contractile dysfunction, which was accentuated when challenged with a dietary sodium load, associated with renal sodium retention (urinary sodium excretion 162+/-12 mmol/day, compared with 197+/-12 mmol/day in controls; P<0.05). Cardiac output was maintained, since the pre-load was normal or increased, despite a mild degree of ventricular thickening, indicating some diastolic dysfunction. We conclude that: (i) contractile dysfunction is present in cirrhosis and is aggravated by a sodium load; (ii) an increased pre-load in the pre-ascitic patients compensates for the cardiac dysfunction; and (iii) in ascitic patients, a reduced afterload, manifested as systemic arterial vasodilatation, compensates for a reduced pre-load and contractile dysfunction. Cirrhotic cardiomyopathy may well play a pathogenic role in the complications of cirrhosis.
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PMID:Role of cardiac structural and functional abnormalities in the pathogenesis of hyperdynamic circulation and renal sodium retention in cirrhosis. 1046 50

The iron content of the body is normally tightly controlled by regulation of iron absorption. In hereditary hemochromatosis, mutation of an HLA class 1 gene, designated HFE, results in excessive iron absorption. Over many years, accumulating iron produces tissue damage, most notably cirrhosis, cardiomyopathy, diabetes, and arthropathies. Hereditary hemochromatosis is the most common hereditary disease of Northern Europeans with a prevalence of approximately 5 per 1000. The most sensitive screening test for hemochromatosis is saturation of the transferrin with iron; a fasting value greater than 50% is strongly suggestive of the disease. Confirmation of increased iron storage can be achieved most readily by serial phlebotomy. We do not regard liver biopsy to be indicated, except in unusual circumstances. Early diagnosis and treatment by phlebotomy before tissue damage has occurred is essential, because life span seems to be normal in treated patients but markedly shortened in those who are not. Therefore, genetic counseling with evaluation of first-degree relatives is mandatory.
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PMID:New developments in hereditary hemochromatosis. 1052 53


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