Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to reveal changes in the myocardium at the preclinical stage of heart failure, 34 patients with hereditary hemochromatosis (HHC) underwent echocardiography in the M-mode. There were 26 men and 8 women aged 24 to 59 years. The control group was made up of 20 healthy persons. The HHC patients over 35 years of age (49.5 years on the average) manifested enlargement of the left ventricular cavity, an increase of the thickness of the interventricular septum and of the posterior heart wall, and reduction of pump function of the left ventricle.
 ...
PMID:[Myocardial function in patients with hereditary hemochromatosis based on echocardiographic data]. 225 45

Hereditary hemochromatosis is the most common cause of iron overload in adults and is probably the second most common cause of iron overload in children in the United States next to transfusional overload. Serious morbidity from this disorder of iron absorption can occur in early as well as in middle and advanced age, iron overload having been reported in children with hereditary hemochromatosis as early as 2 years of age. Younger persons differ from older persons in that the risk for iron loading in females appears to be equal to the risk for males, in contrast to a preponderance of males among older patients. Also, younger patients frequently demonstrate cardiac and gonadal involvement, with cardiac failure commonly leading to death, whereas older patients are more likely to have liver involvement and diabetes mellitus, with liver failure and hepatoma commonly leading to death. Because early diagnosis and treatment can prevent the toxicities of iron overload, appropriate screening can be lifesaving. Transferrin saturation is the most reliable screening test. Liver biopsy with objective measurement of hepatic iron stores is the most important diagnostic criterion at present, although reliable noninvasive methods for quantitating body iron are being developed. Young individuals who should be screened for iron overload include patients with cardiac myopathies, hypogonadism, amenorrhea, loss of libido, diabetes mellitus, other endocrine disorders, cirrhosis of the liver, and arthritis, as well as the siblings, parents, and children of patients with hereditary hemochromatosis or iron loading of unknown cause.
 ...
PMID:Hereditary hemochromatosis in children, adolescents, and young adults. 305 60

Approximately 1.5 million persons in the United States are affected by iron overload diseases, which are primarily caused by hereditary hemochromatosis--the most common genetic disorder in the United States. Hereditary hemochromatosis is characterized by increased iron absorption in the gastrointestinal tract, which may cause lifelong excessive iron absorption and accumulation and serious health effects, including arthritis, cirrhosis, diabetes, impotence, heart failure, and death. Hereditary hemochromatosis is an autosomal recessive disease; the estimated prevalence of the homozygous genotype is 1:200 - 1:250 persons, and 10% of persons are carriers. Although the disease was previously believed to affect primarily white males of northern European descent, recent data indicate hereditary hemochromatosis also occurs among blacks. Moreover, iron overload diseases are underdiagnosed among whites and may not be considered in other racial/ethnic groups (e.g., Hispanics) even when compatible symptoms and clinical findings are present. As part of a joint demonstration project during August-October 1995 to determine the overall prevalence of iron overload, CDC reviewed data from a health-maintenance organization (HMO) in San Diego, California; the prevalence among Hispanics appeared similar to that for non-Hispanic whites. This report presents the preliminary findings of an analysis of the prevalence of iron overload among Hispanics and compares these findings with nationally representative data from the Third National Health and Nutrition Examination Survey (NHANES III). These findings indicate that the prevalence of possible iron overload among Hispanic clients of the HMO based on initial screening was consistent with the nationwide prevalence of possible iron overload based on a single screening test for Hispanics of Mexican descent and non-Hispanic whites.
 ...
PMID:Iron overload disorders among Hispanics--San Diego, California, 1995. 900 7

Chronic mild liver enzyme abnormalities are attributable to hereditary hemochromatosis in at least 3% of cases. Hemochromatosis formerly was diagnosed late with diabetes and hepatic and cardiac failure. Only recently have the autosomal recessive inheritance and subtle early presentations been understood. However, patients still wait many years and see many physicians before receiving a correct diagnosis. Increased serum transferrin saturation is currently the best test for detection of those likely to accumulate iron. Serum ferritin identifies those requiring treatment. When liver biopsy (controversial in asymptomatic individuals) is indicated, chemical measurement of liver iron content is helpful and therapeutic phlebotomy is the only effective treatment. Caucasian-type hemochromatosis (prevalence of 0.005) is associated with genetic abnormalities in HLA-H but also occurs in other ethnic groups. Those of African descent may have a different but also heritable iron-loading disease. Caucasian-type and to a lesser extent African iron loading are detectable early by laboratory testing. Early treatment restores normal expectations of length and quality of life in the Caucasian disease. Long-term treatment data are not yet available in African iron loading. Laboratory-initiated screening programs using unsaturated iron-binding capacity can eliminate symptomatic hemochromatosis.
 ...
PMID:Mild liver enzyme abnormalities: eliminating hemochromatosis as cause. 926 5

Universal screening for hereditary hemochromatosis (HH) has been proposed by many experts, with understandable enthusiasm: HH can cause fatal complications, which are preventable with early treatment. The disorder involves excess iron accumulation that can result in tissue iron overload, with secondary cirrhosis, diabetes, heart failure, impotence and arthritis. These complications are preceded by years of iron accumulation, and most are believed to be preventable by removal of excess iron by phlebotomy. Thus, early identification and treatment - the quintessential functions of health screening - seem to make sense for HH. However, the available screening tests are imperfect. While they can identify many persons at increased risk from HH, the proportion that will develop serious clinical manifestations related to iron overload is not known with certainty. DNA-based tests do not provide a simple resolution to these questions.
 ...
PMID:Screening for hereditary hemochromatosis: are DNA-based tests the answer? 1049 10

During the last decades efforts regarding dietary iron supply focused mostly on the prevention of deficiencies, especially during growth and pregnancy. Correspondingly, homeostatic mechanisms increase intestinal iron absorption in iron deficiency, but its downregulation at high intake levels seems insufficient to prevent accumulation of high iron stores at high intake. There is no regulated iron excretion in overload. Excess of pharmaceutical iron may cause toxicity and therapeutic doses may cause gastrointestinal side effects. Chronic iron excess, e.g. in primary and secondary hemochromatosis, may lead to hepatic fibrosis, diabetes mellitus and cardiac failure. Chronic intake of 50-100 mg Fe/day of highly bioavailable iron with home-brewed beer in sub-Saharan Africans lead to cirrhosis and diabetes. Applying a safety factor of 2 would lead to an upper safe level of 25-50 mg Fe/day for this endpoint of conventional iron toxicity. However, beyond this kind of damage iron is known to catalyze the generation of hydroxyl radicals from superoxide anions and to increase oxidative stress which, in turn, increases free iron concentration. This self-amplifying process may cause damage to lipid membranes and proteins, which relates radical generation and organ damage after ischemia-reperfusion events to available free iron in clinical and experimental settings. Correspondingly, epidemiological studies as well as observations in heterozygotes for hereditary hemochromatosis suggest that the risk of atherosclerosis and acute myocardial infarction is related to body iron stores, though there is conflicting epidemiological evidence as well. The most recent and best controlled studies, however, support the hypothesis that iron stores are related to cardiovascular risk. Iron-amplified oxidative stress may also increase DNA damage, oxidative activation of precancerogens and support tumor cell growth. This is supported by experimental, clinical and epidemiological observations. Due to these mechanisms high iron stores may present a health hazard. Though this has not been finally proven, available evidence strongly recommends not to increase iron intake beyond physiological requirements. To avoid iron deficiency symptoms, on the other hand, care must be taken to meet recommended daily intake.
 ...
PMID:Safety aspects of iron in food. 1142

Individuals with primary or secondary abnormalities of iron metabolism, such as hereditary hemochromatosis and transfusional iron loading, may develop potentially lethal systemic iron overload. Over time, this excess iron is progressively deposited in the liver, heart, pancreas, and other organs, resulting in cirrhosis, heart disease, diabetes and other disorders. Unless treated, death usually results from cardiac failure. The amount of iron in the liver is the best indicator of the amount of iron in the whole body. At present, the only sure way to measure the amount of iron in the liver is to remove a sample of the liver by biopsy. Iron stored in the liver can be magnetized to a small degree when placed in a magnetic field. The amount of magnetization is measured by our instrument, called a superconducting quantum interference device (SQUID) susceptometer. In patients with iron overload, our previous studies have shown that magnetic measurements of liver iron in patients with iron overload are quantitatively equivalent to biochemical determinations on tissue obtained by biopsy. The safety, ease, rapidity, and comfort of magnetic measurements make frequent, serial studies technically feasible and practically acceptable to patients.
 ...
PMID:SQUID biosusceptometry in the measurement of hepatic iron. 1276 53

The case of a 43-year-old male is presented, with diagnosed diabetes mellitus,heart failure, skin pigmentation, hepatic cirhosis, and hereditary hemochromatosis confirmed by liver biopsy. The objective of this publication is to have hemochromatosis in mind as a differential diagnosis in a middle-aged patient with several pathologies and organs involved.
 ...
PMID:[Hereditary hemochromatosis]. 1471 26

Transferrin receptor 2 (TfR2) is a type 2 transmembrane protein expressed in hepatocytes that binds iron-bound transferrin (Tf). Mutations in TfR2 cause one form of hereditary hemochromatosis, a disease in which excessive absorption of dietary iron can lead to liver cirrhosis, diabetes, arthritis, and heart failure. The function of TfR2 in iron homeostasis is unknown. We have studied the regulation of TfR2 in HepG2 cells. Western blot analysis shows that TfR2 increases in a time- and dose-dependent manner after diferric Tf is added to the culture medium. In cells exposed to diferric Tf, the amount of TfR2 returns to control levels within 8 hours after the removal of diferric Tf from the medium. However, TfR2 does not increase when non-Tf-bound iron (FeNTA) or apo Tf is added to the medium. The response to diferric Tf appears to be hepatocyte specific. Real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis shows that TfR2 mRNA levels do not change in cells exposed to diferric Tf. Rather, the increase in TfR2 is attributed to an increase in the half-life of TfR2 protein in cells exposed to diferric Tf. Our results support a role for TfR2 in monitoring iron levels by sensing changes in the concentration of diferric Tf.
 ...
PMID:Diferric transferrin regulates transferrin receptor 2 protein stability. 1531 90

Since the discovery of HFE gene in 1996, considerable progress has been made concerning the iron-metabolism and its major abnormalities. Five types of hereditary hemochromatosis are actually known: type 1 (HFE gene), type 2A (HJV gene), type 2B (HAMP gene), type 3 (TfR2 gene), type 4 (SLC40A1 gene). The HFE C282Y +/+ mutation is responsible for the most frequent type of hemochromatosis in France. Various secondary causes can lead to iron-overload: associated genetic diseases, exogenous iron intake, thalassaemia and refractory anaemia, hepatic siderosis, alcoholic hepatitis, cutaneous porphyria and cirrhosis. The deleterious consequences of iron-overload are due to the interactions of the environmental factors. The role of HFE heterozygote mutations is still discussed. In clinical practice, the interpretation of a serum ferritin increase is a frequent problem that needs a careful evaluation based on the tranferrin saturation measurement. Significant increase of both these factors is in favour of an HFE C282Y +/+ hemochromatosis, after exclusion of a hepatocellular insufficiency or a refractory anaemia. Nevertheless, high ferritin is not always a marker of iron-overload. Thus, there are many disorders increasing the serum ferritin levels without iron overload : cytolysis (hepatic...), inflammatory or infectious syndromes, high alcohol intake, neoplasia... Looking for HFE mutations help to separate type 1 hemochromatosis from other conditions mainly hepatic siderosis (metabolic disorders). The identification of rare types of hemochromatosis (types 2-4) is only required in particular cases. The evaluation of the iron overload is now based on hepatic MRI determination rather than liver biopsy. Repeated phlebotomies remain the essential way to decrease the iron overload in HFE hemochromatosis and to prevent the occurrence of severe and irreversible complications (cirrhosis, arthropathies, cardiac failure, and diabetes). Because of the link established between the amount of iron-overload and the occurrence of complications and the mortality over-risk in HFE C282Y +/+ hemochromatosis, venesections must be started when serum ferritin is higher than 300 microg/l in man and 200 microg/l in woman, whatever the clinical manifestations are and obviously before the symptomatic phase of the disease.
 ...
PMID:[Hereditary and acquired iron overload]. 1737 75


1 2 Next >>