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 outcomes of 72 pregnancies in 20 women with either hemoglobin CC or C-beta-thalassemia are described. Except for mild to moderate hemolytic anemia, maternal complications caused by the hemoglobinopathy were infrequent and perinatal outcomes were generally good. In eight women, blood volume expansion determined by 51chromium-tagged erythrocytes was similar to that for normally pregnant women. Mean red-cell survival was determined 11 times in eight women, and the red-cell half-life of 22 days was significantly shorter than that of 35 days for normally pregnant women.
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PMID:Pregnancy complicated by hemoglobin CC and C-beta-thalassemia disease. 238 8

Forty women with a major sickle hemoglobinopathy (hemoglobin SS, SC, or S-beta-thalassemia) were given red blood cell transfusions prophylactically during pregnancy. A mean of 13.6 units of erythrocytes per woman was given and none received more than 28 units. Direct-vision needle biopsy of the liver was performed in conjunction with cesarean section or puerperal sterilization. Although iron deposition in hepatocytes and Kupffer cells was identified commonly, neither cirrhosis nor widespread hepatocellular necrosis was found. We conclude that the risk of irreversible hepatic damage is negligible in women with sickle hemoglobinopathies who are given erythrocytes prophylactically during one pregnancy.
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PMID:Liver histopathologic findings in women with sickle cell disease given prophylactic transfusion during pregnancy. 240 75

We believe that on the basis of all available data, severe oxidative damage occurs in alpha- and beta-thalassemic RBCs, as depicted schematically in Fig 6. The differences in the severity and pattern of the oxidative damage may be related to the type and, perhaps, quantity of precipitated globin chains. The detrimental effect of the excess chains is multifold. In the process of globin-chain precipitation, free radicals are generated. The end product of the precipitated hemoglobin chains is heme, from which eventually iron and globin are liberated. Globin chains have been found to interact and disrupt the RBC membrane, damaging the cytoskeleton. The role of heme has not yet been studied in detail in thalassemic RBCs. However, there is some evidence that it participates in damaging RBCs in other types of hemoglobinopathies. Excess of iron is known to be a catalyst of peroxidation via the Fenton reaction, causing damage to the various RBC membrane components (lipids, proteins, etc). The denatured hemaglobin, in the form of hemichromes, aggregates with protein 3, forming Actual proof of excessive free radical production in thalassemia is still warranted. It will not be easy to document since the amount of superoxide dismutase in RBCs is above and beyond that required for neutralizing excess amount of superoxide. The more active radicals, particularly hydroxyl free radical, are difficult to measure because they are so active an interact immediately with any given substrate in their vicinity. In addition, we have to better understand the finding of excess membrane lipids in thalassemic RBCs and whether there are changes in the formation and propagation of lipid peroxidation in these cells compared with normal RBCs. Regarding the proteins, further understanding is required concerning the exact type and sites of oxidation that occurs in the beta-thalassemia 4.1 protein, and whether the damage found in alpha-thalassemia is due to oxidation of ankyrin itself or its entrapment within the complex of the precipitated hemichromes of beta chains. What is the role of the different globin chain oxidation and precipitation in generating such different cytoskeletal protein alterations? Another point that needs to be elucidated is the role of different kinds of antibodies that are attached to the newly exposed antigenic sites on the thalassemic RBC membranes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Oxidative denaturation of red blood cells in thalassemia. 240 97

Splenic function in sickle hemoglobinopathy syndromes was assessed to determine the developmental pattern of splenic dysfunction. Nonvisualization of the spleen using technetium-99 metastable (99mTc) spleen scans correlated strongly with pocked (vesiculated) RBCs greater than or equal to 3.5%. Cross-sectional analysis of pocked RBC data from 2,086 patients showed differences in the developmental pattern of splenic dysfunction between several disorders. In hemoglobin SS disease (sickle cell anemia) and hemoglobin S beta(0) thalassemia, splenic dysfunction (greater than or equal to 3.5% pocked RBCs) often occurred in the first 6 to 12 months of life. In hemoglobin S beta(+) thalassemia, splenic dysfunction occurred less frequently and later. Splenic dysfunction in hemoglobin SC disease (sickle cell-hemoglobin C) was intermediate. The level of pocked RBCs was inversely associated with fetal hemoglobin (P less than .007) and directly associated with age (P less than or equal to .001). These patterns of splenic dysfunction reflect the known severity of hemolysis and intravascular sickling and are consistent with the epidemiology of severe bacterial meningitis and sepsis in these diseases. Serial measurement of pocked RBCs permits determination of the onset of splenic dysfunction and the time of increased susceptibility to severe bacterial infections.
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PMID:Developmental pattern of splenic dysfunction in sickle cell disorders. 241

A survey of hemoglobinopathies in northern Sardinia revealed a high frequency (0.3%) of carriers of a hematologic condition characterized by increased expression of fetal hemoglobin during adult life (hereditary persistence of fetal hemoglobin or HPFH). In spite of a normal hematologic phenotype, the heterozygous carriers for this condition display about 12% HbF, almost exclusively of the A gamma type; compound heterozygotes with beta-thalassemia have 20%-26% HbF and run a very mild clinical course. The sequence analysis of the cloned A gamma gene linked to the HPFH determinant revealed the presence of a G----A substitution at position -117 of the A gamma-globin gene promoter; the same mutation occurs also in Greek HPFH, although associated with different restriction polymorphisms. Another hereditary condition characterized by increased HbF (alpha 2 A gamma 2) level and a mild thalassemia phenotype in Sardinia is associated with the -196C----T substitution in the A gamma-globin gene promoter (Sardinian delta beta-thalassemia). Population studies using oligonucleotides complementary both to the -117 G----A and -196C----T mutations and the corresponding normal sequences confirm the presence of these mutations only in HPFH and delta beta-thalassemia chromosomes and exclude these changes being common DNA polymorphisms.
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PMID:A frequent A gamma-hereditary persistence of fetal hemoglobin in northern Sardinia: its molecular basis and hematologic phenotype in heterozygotes and compound heterozygotes with beta-thalassemia. 245 84

An isoelectricfocusing method has been developed to enable large scale screening of newborn blood for hemoglobinopathies. The method utilizes a thin layer agarose gel containing carrier ampholytes in the pH range 6-8. The gradient is non linear allowing increased resolution in the pH region 6.8-7.8 where most hemoglobin variants are isoelectric. The increased resolution between Hb A and Hb Fac enables screening for beta-thalassemia by densitometric analysis. By calculating the ratio of Hb A/Hb Fac or Hb F/Hb A it is possible to detect newborns heterozygous for beta(+)- or beta(0)-thalassemia. Structural variants, unresolved by other electrophoretic methods, are easily detected. Seventy-two samples can be analyzed on a single gel in 90 minutes. Traces of hemoglobin variants can be detected by a heme-specific stain requiring no destain step.
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PMID:An isoelectricfocusing method to detect hemoglobin variants in newborn blood samples including the beta-thalassemias. 246 35

A 73 year-old man suffering from marked anemia for several years admitted in our hospital. Diagnosis was immediately made of refractory anemia with ringed sideroblasts by the existence of ringed sideroblasts. Hemoglobin analysis revealed a high fetal hemoglobin, a low hemoglobin A2, a decreased beta/alpha synthetic ratio, and a decreased G gamma/A gamma synthetic ratio. This acquired hemoglobinopathy resembled delta beta-thalassemia. His anemia was remarkably improved because of the responsiveness to anabolic steroid hormone, and this abnormal globin synthetic pattern was identical as those of the normal adult. We consider this hemoglobinopathy may due to an abnormal expression of globin mRNA.
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PMID:[Refractory anemia with ringed sideroblasts complicated with delta beta-thalassemia-like hemoglobinopathy]. 247 63

Data on distribution of various types of hemoglobinopathies in the Krasnodar region are presented. This region was unfavourable, due to malaria in the past. The results obtained allow to conclude that the territory needs more attention as a possible focus of beta-thalassemia in our country.
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PMID:[Medico-genetic study of the residents of Krasnodar territory. Incidence of hemoglobinopathies]. 253 Jan 33

In the normal fetus, a switch from production of hemoglobin F (alpha 2 gamma 2) to hemoglobin A (alpha 2 beta 2) occurs at 28 to 34 weeks of gestation. In the fetus with beta-hemoglobinopathy or beta-thalassemia, this switch proceeds despite the morbidity that results when production of beta-globin is abnormal or reduced. Since insulin has recently been shown to induce renewed expression of some inactive genes, we studied globin biosynthesis during the natural evolution of the fetal globin switch under conditions of hyperinsulinemia, which occurs in infants of diabetic mothers. Such infants develop in a hyperglycemic environment, which produces reactive hyperinsulinemia. The normal increase in beta-globin production from pre-switch levels did not occur in 9 of 10 such infants at term, as compared with 11 normal infants, in whom the switch occurred by 36 to 39 weeks of gestation (P less than 0.0001). The delay in the switch from gamma-globin to beta-globin in this unique clinical setting may allow identification of physiologic factors that can modulate developmental gene suppression.
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PMID:Delay in the fetal globin switch in infants of diabetic mothers. 257 9

One hundred and thirty one different hemoglobin (Hb) variants and 134 families with thalassemia syndrome were reported during 30 years search for hemoglobinopathy in Japan. Studies on their molecular pathology and gene abnormalities have elucidated the effects of base substitution in the genomic DNA. The expression of the abnormal gene products decreases in a graded manner as follows: hemoglobinopathies due to stable Hb variants----unstable Hb disorder----hyperunstable Hb disorder----thalassemic expression of Hb variants----thalassemia syndrome without abnormal gene product.
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PMID:[Hemoglobinopathies in Japan]. 260 Oct 23


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