Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic hemochromatosis is an autosomal recessive disease, characterized by an increased iron absorption, leading to progressive iron overload. The fully expressed phenotype comprises fatigue, skin pigmentation, liver disease with hepatomegaly, cirrhosis and hepatocellular carcinoma, and diabetes. Arthralgias are frequent, cardiopathy or impotence may occur. This presentation is now unfrequent with earlier diagnosis, and patients are often asymptomatic--with only biochemical expression--or pauci-symptomatic (mild fatigue, arthralgias or increased transaminases). Transferrin saturation is always increased. Serum ferritin is proportional to iron burden. Diagnosis is now easy, since most patients are homozygote for the C282Y mutation of the HFE gene. Liver biopsy can be useful to quantify iron overload and assess liver fibrosis. The disease can be lethal due to liver disease, carcinoma or heart disease, but life expectancy goes to normal if patients are treated before the occurrence of cirrhosis. Treatment relies on regular venesections. Familial screening is essential.
 ...
PMID:[Diagnosis and treatment of genetic hemochromatosis]. 1086 97

Hereditary hemochromatosis is an inherited autosomal recessive disease, associated to a mutation in the recently described HFE gene, which is located on the short arm of chromosome 6. The product of this gene combines with the beta-2-microglobulin and the ferritin receptor, and regulates the iron absorption in the small intestine crypt cells. It is possible that the mutation may cause the increased iron uptake by the intestinal cells. The disease is very much common in men after the forties, and its expression is influenced by concomitant alcoholism, iron rich diet, oral and parenteral iron administration, menstrual blood loss or abnormal hemorrhages, blood donations, pregnancy, lactation, and iron malabsorption clinical conditions, like celiac disease. Many patients are asymptomatic, and the diagnosis may be suspected by hepatomegaly of unknown cause, abnormal iron metabolism tests, increased serum aminotransferase levels, diabetes mellitus, and anonymous arthropathy. Less commonly hereditary hemochromatosis presented by symptoms and signs of chronic liver disease, or by the classic triad described by Trousseau skin pigmentation, hepatomegaly and diabetes mellitus. The diagnosis is confirmed by the increased serum ferritin levels and transferrin saturation, and the stainable iron in hepatocytes, measured by scale devised by Scheuer et al, or the measurement of the hepatic iron. The C282Y mutation was found in 64 to 100% of patients; eventually, subjects with hepatic iron overload identical to hereditary hemochromatosis has no mutation, and homozygous for the C282Y mutation do not express iron overload. Iron is best and quickly removed by weekly or twice-weekly phlebotomy of 500 ml, containing approximately 250 mg iron. One to 3 years of weekly phlebotomy may be required to reduce stores to normal. As a guide to long-term maintenance therapy, is recommended phlebotomy every 3 months and the serum ferritin level should be maintained by less than 50 ng/ml.
 ...
PMID:[Hereditary hemochromatosis]. 1217 Feb 86

Iron overload in body tissues can cause complications such as cirrhosis, cardiomyopathy, diabetes, hypogonadism and arthritis. In populations of northern European descent, most iron overload is due to hereditary haemochromatosis (HHC), a genetic condition that causes increased iron absorption. HHC can be treated or prevented by regular phlebotomy treatments. Some experts have called for population screening for HHC, so that early phlebotomy treatment can be initiated. Two screening tests are available: measurement of the serum iron transferrin saturation (Tf%) and genetic testing for HFE mutations. However, both methods have low positive predictive values. Current data suggest that most people at risk are unlikely to develop clinical symptoms and that the population prevalence of clinical complications of HHC is low, arguing against population screening. Two other prevention strategies are available. (1) Health provider education, to heighten awareness of HHC as an explanation for symptoms and signs seen in early iron overload including unexplained fatigue, joint pain, palpitations, abdominal pain, elevated liver function tests, hepatomegaly and elevated serum ferritin. (2) Family-based testing after a diagnosis of HHC, to ensure that relatives are evaluated for evidence of iron overload. More research is also needed to identify the factors that increase risk for disease in persons with excess iron uptake, to determine whether moderate iron overload is a health risk and to evaluate the causes of iron overload other than HHC.
 ...
PMID:Hereditary haemochromatosis: a realistic approach to prevention of iron overload disease in the population. 1240 10

We report clinical and genetic characteristics of seven juvenile hemochromatosis (JH) patients (six females, one male) in two unrelated kinships from the southeastern U.S. All had severe iron overload. Mean age at diagnosis was 20 +/- 5 years (range 8-23 years). In six patients, the mean age at onset of signs and symptoms attributable to iron overload was 15 +/- 2 years (12-18 years); an 8-year-old girl had no symptoms. Six of the seven patients had hypogonadotrophic hypogonadism, two had severe cardiomyopathy, seven had hepatomegaly, two had hepatic cirrhosis, and five had hyperpigmentation. Two of four siblings with JH also had Hashimoto thyroiditis. One patient with severe cardiomyopathy improved with therapeutic phlebotomy, medical therapy for congestive heart failure, and a permanent pacemaker; the other died before phlebotomy was initiated. Estimates of average daily iron absorption before phlebotomy-induced iron depletion were 2.3, 3.1, and 1.7 mg in a male and two females, respectively. Both parents of four siblings with JH were heterozygous at two Ch1q loci (D1S1156, D1S2344); each of the four affected siblings was homozygous at both loci. An unaffected sib was heterozygous at D1S1156. One patient was heterozygous for HFE H63D, five others did not have HFE C282Y or H63D, and one was unavailable for testing. We conclude that JH occurs in the southeastern U.S. It is likely that JH allele(s) in at least one of the present kinships occur(s) on Ch1q, and presumably this represents a mutation(s) of the same gene localized to Ch1q in Italian and Greek JH kindreds. The present cases do not have HFE genotypes typical of hemochromatosis diagnosed in adults. Hashimoto thyroiditis, linked to Ch6p in many kinships, did not segregate with JH alleles on Ch1q in the present kinship.
 ...
PMID:Juvenile hemochromatosis in the southeastern United States: a report of seven cases in two kinships. 1248 11

A four-fold increase in the iron content of normal subjects was detected in plasma after 5 hours of iron administration. Iron supplementation had a surprisingly erratic effect on four patients with hepatomegaly secondary to heart insufficiency, since the increase in the iron content in the plasma after iron-dextran administration was either within the control range or significantly lower, independently of the initial values. Thiobarbituric acid reactive substances (TBARS) content was 2.5 +/- 0.2 and 4.3 +/- 0.4 microM for control and hepatomegalic subjects, respectively. The TBARS basal level was increased by iron supplementation. The difference between TBARS content in hepatomegalic and control subjects, after 5 hours of iron administration, was increased by 50% as compared to the difference in the basal content of TBARS. alpha-Tocopherol (alpha-T) content in plasma from subjects with hepatomegaly showed a significant decrease (-41%) as compared to control subjects. No significant difference over the basal level of alpha-T was measured after 5 hours of iron administration in any subject. The data presented here suggest that abnormal liver condition affects iron-dependent oxidative stress in plasma. Moreover, alpha-T does not seem to be the main antioxidant to control iron-dependent oxidative stress in plasma.
 ...
PMID:Does hepatomegaly alter iron-dependent oxidative effects in human plasma? 1292 30

Hereditary hemochromatosis (HH) is the most common autosomal recessive disorder in populations of caucasian origin with a prevalence of 1 : 200-400 for homozygous patients. Currently, 4 types of HH are distinguished. The classical and most common form is type 1 hemochromatosis which is characterized by HFE gene mutations on chromosome 6. The disease results from an excessive iron absorption leading to multiple manifestations such as hepatomegaly, diabetes mellitus, cardiomyopathy, infertility, and hepatic fibrosis/cirrhosis if untreated. A distinct clinical feature of hemochromatosis is represented by involvement of the joints (arthropathy of hemochromatosis) which occurs frequently and often before iron overload is present. Severity of arthropathy usually does not correlate with the extent of iron overload. In contrast to most other manifestations, it is not improved by iron depletion but can be treated symptomatically. This review outlines clinical aspects as well as pathogenesis, diagnosis and therapy of the disease.
 ...
PMID:[Arthropathy of hereditary hemochromatosis]. 1499 Dec 75

Hepatomegaly is commonly observed in hepatic iron overload due to human hemochromatosis and in animal models of iron loading, but the mechanisms underlying liver enlargement in these conditions have received scant attention. In this study, male rats were treated with iron dextran or dextran alone for 6 months. Chronic iron loading resulted in a > 50-fold increase in hepatic iron concentration. Both liver weights and liver/body weight ratios were increased approximately 2-fold in the iron-loaded rats (P < 0.001 for both). Hepatocyte nuclei expressing proliferating cell nuclear antigen (PCNA), a marker of S phase, were significantly increased in the iron-loaded livers, suggesting enhanced proliferation. To assess the mechanisms by which iron promotes proliferation, the expression of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, hepatocyte growth factor (HGF), and transforming growth factor-alpha (TGF-alpha) were assessed by reverse transcription-polymerase chain reaction (RT-PCR). Of these growth-associated factors, only TNF-alpha messenger RNA (mRNA) was significantly increased by iron loading (about 3-fold; P = 0.005). Because cyclin D1 is required for entry of hepatocytes into the cell cycle after partial hepatectomy or treatment with direct mitogens, levels of immunoreactive cyclin D1 were examined and found to be significantly increased in the iron-loaded livers. The increase in cyclin D1 protein in the iron-loaded livers was paralleled by an increase in the abundance of its transcript as measured by real-time PCR. Taken together, these results suggest that iron is a direct mitogen in the liver and raise the possibility that chronic stimulation of hepatocyte proliferation may play a role in the pathophysiology of iron overload states.
 ...
PMID:Chronic iron overload stimulates hepatocyte proliferation and cyclin D1 expression in rodent liver. 1689 Jan 45

Liver pathology occurring in patients with sickle cell disease is commonly related to viral hepatitis or hepatic iron deposition due to repeated transfusions; cholestasis and cirrhosis may also occur. Consequently, the differential diagnosis of abnormal liver tests in patients with sickle cell anemia is often complicated. We report the case of a patient presenting with jaundice and abnormal liver biochemistries, without typical evidence of the liver diseases associated with sickle cell anemia. Biochemical markers for viral hepatitis were negative. CT scan only showed hepatomegaly. The liver biopsy revealed marked sinusoidal congestion with red blood cells without significant steatosis or increased iron deposition. The patient's medical history corroborated with biochemical tests and histological examination of the liver suggested that worsening hemolysis related to increased sickling of erythrocytes intrahepatically led to sinusoidal dilatation and probably caused the abnormal liver tests.
 ...
PMID:Exacerbation of sickle cell disease itself as a cause of abnormal liver chemistry tests. 1717 33

Beta thalassaemia major is a common hereditary haematological disease in southern Chinese. Advances in transfusion and iron chelation improve survival but haematopoietic stem cell transplantation (HSCT) is still the only curative treatment. Due to repeated blood transfusion and iron overload, thalassaemia patients undergoing HSCT are at a higher risk of graft rejection and transplant-related mortality. The prognostic factors identified to be affecting transplant outcome include hepatomegaly, hepatic fibrosis, and compliance to chelation therapy. Patients can be classified into three classes and conditioning regimens are modified according to the risk. Early stage patients have 85 to 90% chance of disease-free survival, whereas advance stage only has 60% disease-free survival. Mixed chimerism is common after HSCT but majority have satisfactory erythropoiesis without need for further transfusion. Sibling cord blood and bone marrow transplantation has similar outcome. Recently alternative donor transplant has been performed in patients without human leukocyte antigen (HLA)-identical siblings. The result of unrelated-donor bone marrow transplantation is in general inferior but extended HLA matching may improve outcome. The use of unrelated cord blood transplant from a single-centre study showed promising result. The survivors require iron depletion to remove excessive iron store and some may require hormonal replacement therapy. Most of the patients have good quality of life after successful HSCT.
 ...
PMID:Haematopoietic stem cell transplantation for thalassaemia in Chinese patients. 1949 96

A patient is reported who presented in the newborn period with an unusual combination of congenital lactic acidosis and bilateral calcifications in the adrenal medulla, visible on standard abdominal x-ray and ultrasound examination. At birth, the proband was hypotonic and dystrophic. She developed respiratory insufficiency, cardiomegaly, and hepatomegaly and died at the age of 38 d. Examination of postmortem heart muscle revealed multiple areas of myocardial infarction with dystrophic calcifications. In the medulla of the adrenal glands, foci of necrosis and calcifications, and in the liver, multiple zones of necrosis and iron deposition were detected. Biochemical analysis in heart muscle revealed a decreased activity of complex IV of the oxidative phosphorylation (OXPHOS) and in liver a combined deficiency involving the complexes I, III, IV, and V. The findings were suggestive of a defect in biosynthesis of the mitochondrially encoded subunits of the OXPHOS complexes. Extensive analysis of the proband's mitochondrial DNA revealed neither pathogenic deletions and point mutations nor copy number alterations. Relative amounts of mitochondrial transcripts for the ribosomal mitochondrial 12S rRNA (12S) and mitochondrial 16S rRNA (16S) were significantly increased suggesting a compensatory mechanism involving the transcription machinery to low levels of translation. The underlying molecular defect has not been identified yet.
 ...
PMID:Lactic acidosis in a newborn with adrenal calcifications. 1958 30


<< Previous 1 2 3 4 5 Next >>