Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The plasma clearance rate of heat denatured human serum albumin (DHAI-125, 5 mg/kg body weight) was studied in 20 children with homozygous-beta-thalassemia before and 7--10 days after blood transfusion. A significant increase of the DHAI-125 clearance rate (P less than 0.02) was found 7--10 days after blood transfusion while the spleen presented its minimum size. This finding may be relevant to the improved intrasplenic blood circulation after blood transfusion due to the release of the blood trapped within the spleen.
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PMID:Colloid clearance rate changes in children with homozygous-beta-thalassemia in relation to blood transfusion. 721 64

"Free" iron, a potentially radical-generating low mass iron, and not found in normal human blood, was increased in the serum of blood-transfused thalassemia major patients seen in the Yangon General Hospital, Yangon, Myanmar (Burma). The low mass iron was detected by the bleomycin assay. Fifty-one blood samples were analyzed (from 28 males and 23 females). High "free" iron was detected in 47 sera samples from thalassemia patients. Serum ferritin, which reflects the body store iron, was higher than the normal range (10-200 ng/ml) in 49 patients. On the other hand, serum iron of 39 sera samples fell within the normal range (50-150 micrograms/dl). Four were less than 50 micrograms/dl and eight were more than 150 micrograms/dl. Almost all the patients' sera of normal or higher serum iron level contained "free" iron. Thus, almost all the sera from thalassemic patients from Myanmar contain bleomycin-detectable iron, even when serum iron is within the normal range. In developing countries where undernutrition is prevalent (serum albumin in these patients was 3.6 +/- 0.4 g/dl, P < 0.0001 vs. control value of 4.0 - 4.8 g/dl), normal serum iron does not preclude the presence of free iron in the serum.
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PMID:Serum bleomycin-detectable iron in patients with thalassemia major with normal range of serum iron. 754 60

Pulmonary microthromboembolism is one of the serious complications found in patients with thalassemia. The pathogenesis is undetermined. The thrombotic risk in 44 patients (26 males, 18 females) with beta-thalassemia/hemoglobin E disease and without clinical symptoms of thrombosis were studied. The age ranged from 3-19 yr (X +/- SD = 10 +/- 4). Neither of them had chronic hepatitis B infection. They were divided into three groups according to clinical manifestations as follows: (1) Mild form (n = 12). They did not require blood transfusion. The mean +/- SD of hematocrit was 23.3 per cent +/- 2.3; (2) Severe form (n = 19). They required frequent blood transfusion. The mean +/- SD of hematocrit was 17.7 per cent +/- 1.5; (3) Severe form with splenectomy (n = 13). They seldom required blood transfusion. The mean +/- SD of hematocrit was 21.8 per cent +/- 3.5. Most of the patients had delayed growth. They had high serum ferritin reflecting iron overload status which was prominent in the severe groups (group 2 & 3). The prothrombin time and serum albumin were slightly decreased, and the serum alanine transaminase were slightly increased; all of which reflected mild alteration of liver function. The plasma AT III, PC and PS antigen in the three groups were similar. The mean +/- SD of AT III antigen was 106.7 per cent +/- 22.2 which is normal. The mean +/- SD of PC antigen was 44.2 per cent +/- 14.2 and PS antigen level was 77.2 per cent +/- 17.8.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Thrombotic risk of children with thalassemia. 782 10

Alpha-thalassaemic erythrocytes develop a specific membrane skeletal defect that is manifest as a loss of normal spectrin-binding sites on the inner surface of the thalassaemic membranes. To test whether this lesion could be caused by the excess free beta-globin chains that accumulate in alpha-thalassaemic red cells, we incubated normal red cell membranes with native, haem-containing alpha or beta globin chains or with haemoglobin A. Spectrin-depleted inside-out membrane vesicles (IOVs) derived from membranes incubated with beta-globin chains bound only 9 +/- 3% as much spectrin as IOVs from control membranes incubated with bovine serum albumin. In contrast. IOVs from membranes incubated with alpha-globin chains or haemoglobin A were nearly normal (79 +/- 3% and 86 +/- 5% of controls, respectively). This differential effect of globin chains was not seen when membranes were first transformed into spectrin-depleted IOVs and then incubated with the isolated globin chains. Under these conditions, both alpha and beta globin chains reduced the spectrin-binding capacity of the IOVs by approximately 45% (alpha 46 +/- 7%, beta 43 +/- 6%) whereas haemoglobin A had no effect. Unlike IOVs, spectrin isolated from membranes exposed to alpha or beta globin chains bound normally to IOVs and to actin (in the presence of protein 4.1). These studies show that isolated beta-globin chains (but not alpha-globin chains) can produce a spectrin-binding defect in normal red cell membranes similar to that seen in alpha thalassaemia. The existence of similar defects in the membrane skeletons of red cells from other diseases with unstable beta globins suggests a common pathophysiology for the premature destruction of these cells.
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PMID:Isolated beta-globin chains reproduce, in normal red cell membranes, the defective binding of spectrin to alpha-thalassaemic membranes. 875 86

Because of continuous blood transfusions, thalassemia patients are subjected to peroxidative tissue injury by the secondary iron overload. In accordance, analysis of serum from 42 beta-thalassemia patients, aged 4 to 40 years, showed that the mean concentrations of conjugated diene lipid hydroperoxides (CD), lipoperoxides evaluated as malondialdehyde/ thiobarbituric acid (MDA/TBA) adducts, and protein carbonyls increased about twofold with respect to control. Ferritin levels were positively correlated with the amount of MDA (r = .41; P = .007) and showed a positive trend with CD (r = .31; P = .07) and protein carbonyls (r = .35; P = .054), as further evidence of the deleterious effects of high tissue iron levels. Marked changes in the antioxidant pattern were also observed in all patients. Evidence is presented of a net drop in the concentration of ascorbate (-44%), vitamin E (-42%), vitamin A(-44%), beta-carotene (-29%), and lycopene (-67%). On the other hand, an increase of uric acid and bilirubin was observed, whereas serum albumin and glutathione were in the normal range in all patients. As a result, the total serum antioxidant potential, measured as trolox equivalent antioxidant capacity appeared significantly decreased by 14%. Serum levels of vitamin E were inversely correlated with ferritin (r = -.45; P = .003), suggesting a major consumption of this antioxidant under iron overload. Nontransferrin bound iron (NTBI) was in the range 4.5 to 54.8 micrograms/dL (mean, 21.8 +/- 13.9). Although NTBI had a positive trend with ferritin (r = .37, P = .03), no clear correlation was found with either MDA or vitamin E. A mild to severe hepatic damage, as assessed by serum transaminases, was shown in 24 of 42 patients. Serum levels of vitamin E (r = -.49, P = .015), vitamin A (r = -.48, P = .016) and lycopene (r = -.47, P = .020), were inversely correlated with the levels of transminases. On the other hand, lipid-soluble antioxidants in thalassemia patients were depleted to the same extent in hepatitis C virus (HCV)-infected (31 subjects) and in HCV-uninfected (10 subjects), while in the normal range in serum from 30 nonthalassemic patients with HCV-related chronic hepatitis. These results point out that the iron-induced liver damage in thalassemia may play a major role in the depletion of lipid-soluble antioxidants. The variations of the parameters evaluated in the present study were not correlated with the age of the patients. Our results suggest that the measurement of peroxidation products, matched with evaluation of antioxidants, may be a simple measure of iron toxicity in thalessemia, in addition to the conventional indices of iron status.
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PMID:Oxidative stress and antioxidant status in beta-thalassemia major: iron overload and depletion of lipid-soluble antioxidants. 889 30

Reverse allele specific oligonucleotide assays provide a robust method for the molecular characterization of high-mutation spectrum disorders. Commercial test have been developed for human leukocyte antigens class I and class II regions of human chromosome 6, the cystic fibrosis transmembrane conductance regulator at 7q31 and strains of human Hepatitis B and C virus. In their most developed form, these assays rely upon highly multiplexed PCR reactions containing biotinylated primers providing a substrate for nonradioactive detection systems. Sophisticated reverse dot-blot technology involves mechanized covalent attachment of activated primary amine-conjugated oligonucleotides to carboxylated nylon membranes or bovine serum albumin. Subsequent to line or dot printing, membranes are stored or sold dry in preparation for hybridization. Circular spots or lines are visualized colorimetrically after hybridization through the use of streptavidin horseradish peroxidase incubation followed by development using tetramethylbenzidine and hydrogen peroxide, or via chemiluminescence after incubation with avidin alkaline phosphatase conjugate and a luminous substrate susceptible to enzyme activation, such as CSPD, followed by exposure to x-ray film. The entire procedure from blood specimen receipt to result usually requires less than 1 day. Because of the simplicity, speed, and generally high sensitivity and specificity, large numbers of individuals can be rapidly screened using this technology. Rapid turnaround is often required in prenatal diagnosis of cystic fibrosis, beta-thalassemia and hemoglobinopathies, giving this technology has special applicability in those genetic diseases. Commercial instruments are available which automate the hybridization and color development. In addition, scanning software can capture the probe reactivity pattern and interpret it in terms of a genotype.
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PMID:Origin and utility of the reverse dot-blot. 1264 92

Hepatitis C virus (HCV) infection is a common cause of liver disease in thalassemia major patients in Western, especially Mediterranean, countries. Its significance in thalassemic patients from Southeast Asia has not been critically evaluated. In this report, we describe our study of the prevalence of HCV infection among Thai patients with thalassemia. The relationships of the infection to blood transfusion and the infection's effects on liver function have also been determined. Of the 104 patients studied, 21 (20.2%) tested positively by enzyme immunoassay for anti-HCV antibody, whereas only 2 patients (2%) had the hepatitis B surface antigen. There was no significant relationship between the presence of anti-HCV antibodies and the number and frequency of blood transfusions. In fact, 2 patients (10%) who tested positive for anti-HCV antibodies had never received transfusions. Patients with anti-HCV antibodies had significantly abnormal liver functions, such as higher levels of serum aspartate aminotransferase (SGOT) and alanine aminotransferase (SGPT) and lower levels of serum albumin, compared with patients without anti-HCV antibodies (P = .021, .017, and .004, respectively). However, there were also significant correlations between iron status as indicated by transferrin saturation or serum ferritin levels and SGOT, SGPT, and gamma-glutamyltransferase (GGT) levels. Moreover, abnormal liver function as represented by elevated levels of SGOT, SGPT, GGT, and serum alkaline phosphatase was observed more frequently in patients with iron overload than in patients with a lower degree of iron burden. The presence of HCV did not alter the effects of iron overload on liver function. The findings suggest that both HCV and iron overload are the main causes of abnormal liver function in Thai patients with thalassemia. The treatment of both problems, if coexisting in patients with thalassemia, is required to prevent progression to chronic liver disease.
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PMID:Prevalence and clinical significance of hepatitis C virus infection in Thai patients with thalassemia. 1468 98

Thalassemia results from an imbalance between two proteins in hemoglobin called alpha and beta globin that interferes with cell maturation and function resulting in an ineffective erythropoeisis and hemolysis. Zinc is an essential element that supports normal growth and development. In thalassemia, the expected low serum zinc level is due to hemolysis, loss in urine and inadequate dietary intake. To evaluate serum zinc levels among thalassemia patients and study its relation to nutritional status and growth, a case control study was conducted at Damanhour Medical National Institute. Forty-six thalassemia patients were randomly selected from the attendants of the Hematology Unit and were compared to 20 control children. They were subjected to medical history and examination, anthropometric measurements, assessment of dietary profile, laboratory investigations for CBC, total serum protein, serum albumin, serum zinc. The mean age was 8.29 +/- 3.96 years for cases and 8.45 +/- 3.52 years for controls. Thalassemia patients showed significant lower serum zinc level when compared to and 8.45 +/- 3.52 years for controls. Thalassemia patients showed significant lower serum zinc level when compared to control (88.28 +/- 17.76 microg/dl), and (113.5 +/- 15.39 microg/dl) respectively A positive correlation was found between their serum level and height/age (r = 0.392). Zinc supplementation and nutrition education program are recommended to improve growth rate among thalassemia patients with retarded growth ad low serum zinc levels.
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PMID:Study of serum zinc in relation to nutritional status among thalassemia patients in Damanhour Medical National Institute. 1721 12

The size of gold nanoparticles is shown here to gradually decrease if it is allowed to grow on a protein template, and the protein is subjected to unfolding by a nonionic denaturant. The correlation between size of the gold nanoparticle formed and the plasmon frequency observed remains linear, except at stages where protein folding intermediates are formed. Higher population of exposed tyrosine residues, number of sulfhydryl groups of the protein, and the overall exposition of the inner hydrophobic core may lead to the generation of smaller particles. The method provides a simple colorimetric sensing of protein conformation and has been tested for both nonheme and heme proteins (hemoglobin and bovine serum albumin). Similarly, protein variants with defects in folding (caused by subunit misassembly or mutation) can also be classified. Possible application of this approach in hemoglobinopathy (e.g., thalassemia carrier detection) is discussed in the text.
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PMID:Gold nanoparticle-based tool to study protein conformational variants: implications in hemoglobinopathy. 1737 65

Beta-thalassemia is an inherited anemia in which synthesis of the hemoglobin beta-chain is decreased. Clinical features of beta-thalassemia include variably severe anemia and iron overload due to increased intestinal iron absorption, which may result in damage to vital organs. The hepatic peptide; hepcidin is a key regulator of iron metabolism in mammals. The present study aimed to determine the relationship between hepcidin expression and iron status in beta-thalassemia patients with hepatitis C virus infection. The study included 50 patients diagnosed as beta-thalassemia major (21 of them were HCV infected and 29 were HCV negative), in addition, 20 healthy subjects were enrolled in the study. The hepatic iron and hepcidin mRNA concentration in liver biopsy samples were measured, as well as serum ferritin, serum iron, hemoglobin and levels and serum hepcidin. Result showed remarkable decrease of serum and liver hepcidin mRNA expression in thalassemic patients as compared to controls, and showed a positive correlation with hemoglobin concentration, but negatively correlated with serum ferritin level and hepatic iron index (HII). In HCV infected patients, serum and liver hepcidin mRNA were markedly depressed in HCV positive beta-thalassemia cases, and positively correlated serum albumin and prothrombin concentrations, but inversely correlated with HII and fibrosis score. In HCV positive beta-thalassemia major patients, the hepcidin mRNA level was positively correlated with the synthetic function of the liver (namely serum albumin and prothrombin concentration) and with serum hepcidin level. While, both serum and hepcidin mRNA level was inversely correlated with HII and fibrosis score in these patients. These results suggest a possible role of hepcidin expression in iron overload in beta-thalassemia major, consequent disease progression and development of liver fibrosis.
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PMID:Hepcidin levels and iron status in beta-thalassemia major patients with hepatitis C virus infection. 2308 85


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