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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Normal red blood cells, preincubated for 75 min with 1.15 mM menadione sodium bisulfite lose potassium and water on subsequent incubation at 37 degrees C for 24 h without menadione. The potassium loss is increased by addition of calcium and prevented by addition of glucose. Since normal red cells treated with menadione behave like untreated hypochromic cells, both from beta-thalassaemia or iron deficiency anaemia in respect to membrane permeability to potassium, it may be supposed that menadione induces in normal red cells an abnormality similar to that naturally occurring in hypochromic cells.
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PMID:Increased potassium permeability induced in vitro by menadione in normal human red cells. 84 Dec 69

To study the potential of multivariate classification methods in order to obtain more insight into abnormal laboratory data from patients with sickle cell disease, we investigated standard haematological and clinical chemical variables of 18 controls and 37 apparently healthy persons with heterozygous sickle cell disease (Hb AS), all women, using both univariate and multivariate classification methods. In the univariate method, those with Hb AS showed decreased serum log aspartate aminotransferase (log AST) activity, mean corpuscular volume and mean corpuscular haemoglobin (MCH) and increased sodium concentration. The multivariate method identified sodium, potassium, urea, uric acid, log AST, alanine aminotransferase and MCH as the variables that produced maximal separation between persons with Hb As and controls. It increased the 'non-error rate' for classification of persons with Hb AS by 16.4% compared with classification based on the variable, MCH, that produced maximal separation by the univariate method. The frequency distribution of percentage Hb S in the Hb AS group proved bimodal with maximal separation at 37.0% Hb S. The subgroup with 37.0% or less (n = 16) was considered to have concomitant heterozygous alpha-thalassaemia-2. In the univariate method the subgroup characterized by greater than 37.0% Hb S (n = 21) had increased serum sodium and uric acid concentrations, perhaps related to sickle cell nephropathy, whereas the subgroup with less than or equal to 37% Hb S did not. The multivariate method added information to the univariate method by additionally identifying abnormalities in serum potassium and urea concentrations in the former subgroup.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Potential of descriptive linear discriminant analysis for studying clinical chemical and haematological data from persons with heterozygous sickle cell disease. 189 49

Pythium infection (pythiosis) in humans has not previously been described, even in areas endemic for animal pythiosis. We report five patients with a unique presentation of fungal arteritis. The medium- to large-sized arteries were involved, and in some cases this involvement led to gangrene of the limbs, aneurysm formation, and ultimately fatal arterial leakage. All five patients were farmers. All patients, with the possible exception of one who had hemoglobin typing performed after receiving a blood transfusion, had thalassemia hemoglobinopathy syndrome. Fungal isolation was difficult. Amphotericin B treatment seemed to be ineffective. Radical surgical removal of infected tissues and oral administration of a saturated solution of potassium iodide are proposed therapy. In the tropics, where Pythium is ubiquitous, one should actively look for this fungal infection in patients with unexplained arterial occlusion, especially in the case of patients with thalassemia hemoglobinopathy syndrome.
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PMID:Human pythiosis associated with thalassemia hemoglobinopathy syndrome. 264 70

During a study of clinical and laboratory features in 83 patients with sickle cell disease in the Netherlands, serum creatinine, sodium, potassium, uric acid and osmolality were determined and reported for 65: 39 with homozygous sickle cell (SS) disease, 5 with beta degrees thalassaemia (S beta degrees thal), with sickle cell beta + thalassaemia (S beta degrees + thal) and 17 with sickle cell haemoglobin C (SC) disease. Data on history of hyposthenuria was unreliable. Haematuria was reported in 6 (7%) of the 83 patients. Four of the six patients with a history of haematuria, two of whom had elevated creatinine levels, had SS disease. Lower mean levels of serum sodium and higher levels of serum potassium were observed in SS's than in the other genotypes (p less than 0.001). Hyperkalaemia of greater than 5 mmol/l was seen in 50% of SS disease cases and in 33% of paediatric SC disease cases. Some high potassium levels must be ascribed to in vitro haemolysis. The rate of hyperuricaemia ranged from 24% to 40% among the various genotypes. Clinical gout was not observed.
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PMID:Renal and electrolyte profile in steady state sickle cell disease: observations in patients with sickle cell disease in The Netherlands. 276 58

Hemoglobin's physiologic properties depend on the orderly assembly of its subunits in erythropoietic cells. The biosynthesis of alpha- and beta-globin polypeptide chains is normally balanced. Heme rapidly binds to the globin subunit, either during translation or shortly thereafter. The formation of the alpha beta-dimer is facilitated by electrostatic attraction of a positively charged alpha-subunit to a negatively charged beta-subunit. The alpha beta-dimer dissociates extremely slowly. The difference between the rate of dissociation of alpha beta- and alpha gamma-dimers with increasing pH explains the well-known alkaline resistance of Hb F. Two dimers combine to form the functioning alpha 2 beta 2-tetramer. This model of hemoglobin assembly explains the different levels of positively charged and negatively charged mutant hemoglobins that are encountered in heterozygotes and the effect of alpha-thalassemia and heme deficiency states in modifying the level of the variant hemoglobin as well as Hb A2. Electrostatic interactions also affect the binding of hemoglobin to the cytoplasmic surface of the red cell membrane and may underlie the formation of target cells. Enhanced binding of positively charged variants such as S and C trigger a normally dormant pathway for potassium and water loss. Thus, the positive charge on beta c is responsible for the two major contributors to the pathogenesis of Hb SC disease: increased proportion of Hb S and increased intracellular hemoglobin concentration. It is likely that electrostatic interactions play an important role in the assembly of a number of other multisubunit macromolecules, including membrane receptors, cytoskeletal proteins, and DNA binding proteins.
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PMID:Subunit assembly of hemoglobin: an important determinant of hematologic phenotype. 353 23

It has been suggested that the less severe anemia that exists in patients with sickle cell anemia who also have alpha-thalassemia is related to an effect on the sickling of erythrocytes. To test this hypothesis, we used as a measure of sickling the change in sickle erythrocyte sodium and potassium content that occurs during deoxygenation. Sickle cells from individuals with four, three, or two alpha-globin genes were deoxygenated, and the change in monovalent cation content measured to determine whether a relationship exists between alpha-globin gene number and sickling. In samples of cells depleted of irreversibly sickled cells, the alpha-globin gene number was directly related to the magnitude of mean cation change and inversely related to the ratio of membrane surface area to cell volume. These data indicate that alpha-thalassemia is associated with a diminished degree of sickling in individuals with sickle cell anemia. They also suggest that excess cell membrane may play a role in this protective effect.
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PMID:Monovalent cation changes in sickle erythrocytes: a direct reflection of alpha-globin gene number. 400 25

Certain aspects of the metabolism of centrifuged young and old erythrocytes in hemoglobin H disease have been examined and compared with similar studies of beta thalassemia and normal cells. Glycolysis, hexose monophosphate shunt activity (HMPS), potassium flux, and glutathione (GSH) content were measured. The distributions of hemoglobins H and F, as well as the activities of erythrocyte glucose-6-phosphate dehydrogenase (G6PD) and glutamic oxalacetic transaminase (GOT), were utilized for estimations of the relative ages of the cell samples. The young erythrocytes in hemoglobin H disease differed in several respects from older hemoglobin H cells. They contained more soluble hemoglobin H and GSH and, after splenectomy, fewer inclusions. HMPS activity was subnormal in hemoglobin H young cells and rose to normal activity in old cells. Potassium flux tended to increase in old cells when inclusions were present.Beta thalassemia young cells contained less hemoglobin F and, after splenectomy, more inclusions than old cells. In addition, they had markedly increased glycolysis and HMPS activity. GSH was randomly distributed. Potassium flux was increased in younger cells and particularly increased when inclusions appeared in younger cells after splenectomy. The results are interpreted to indicate that inclusion formation is associated with increased erythrocyte cation permeability in the thalassemia syndromes. This is not related to the level of intracellular GSH. The decreased HMPS activity in young hemoglobin H cells may be due to the presence of the extra thiols of soluble hemoglobin H which can act as a reducing agent. The substitution of hemoglobin H for glutathione in this capacity would then spare the NADPH-requiring glutathione reductase system. As a consequence, HMPS activity would decline. However, in older cells the oxidized hemoglobin H precipitates; these must rely upon GSH and glutathione reductase activity for thiol reduction capacity. Accordingly, HMPS activity increases to normal in the old cell population.
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PMID:Influence of hemoglobin precipitation on erythrocyte metabolism in alpha and beta thalassemia. 576 25

The zeta (zeta) and various gamma (gamma) chains of Hb Portland I have been separated and isolated from blood samples obtained from neonates with hydrops fetalis due to homozygous alpha-thalassemia. By using developers containing acetonitrile, methanol, and potassium phosphate and either an analytical (3.9 mm x 30 cm) or a preparative (7.8 mm x 30 cm) muBondapak C-18 column (Waters), globin chains from 200 micrograms to 5.0 mg have been isolated in pure forms. Analytical and preparative procedures using short (50-min duration) and extended (186-min duration) gradient programs have been developed. In addition to the type of column and developer conditions, the following factors are found to be important: (a) preparation of sample, (b) sample loading, and (c) cleaning of the column. Preliminary studies indicate that the yield ranges from 40 to 60% depending on the type of globin sample and the age of the column. This procedure also permits the separation of alpha, beta, and various gamma globin chains from fetal and adult samples.
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PMID:Separation of zeta (zeta) and various gamma (gamma) chains of human embryonic hemoglobin Portland I by reverse-phase high-performance liquid chromatography. 668 87

Osmotically resistant red cells associated with some haemolytic anaemias, including hereditary xerocytosis, sickle-cell disease and beta thalassaemia minor, are more sensitive than normal red cells to exogenous in vitro hydrogen peroxide (H2O2). This sensitivity is manifested by a rapid loss of intracellular potassium, shape change, protein aggregation, and methaemoglobin formation at lower concentrations of H2O2 (225 microM) than are required to induce similar effects in normal red cells (450 microM). Malonyldialdehyde (MDA) formation occurs later than the other effects and can be inhibited by the antioxidant, butylated hydroxytoluene (BHT), without affecting protein aggregation or potassium leak. Incubation of normal red cells directly with MDA induces protein aggregation, but only after 1 h of incubation. Although nystatin-sucrose treated normal cells which are dehydrated with altered cation content, and therefore osmotically resistant, do not display abnormal H2O2 hypersensitivity as manifested by excessive potassium permeability, they do show an increase in methaemoglobin formation and protein aggregation similar to xerocytes. These data indicate that membrane protein cross-linking occurring immediately following H2O2 exposure seems independent of either the sulfhydryl or MDA mechanisms, and that the membrane permeability of the abnormal red cells predisposes them to oxidative damage.
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PMID:Red cell membrane response to hydrogen peroxide-sensitivity in hereditary xerocytosis and in other abnormal red cells. 725 92

Pythium insidiosum is a protoctista and causes diseases in plants and animals. In Thailand it can cause a unique human infection of three types. The first type is a subcutaneous lesion in thalassaemic patients, with the pathological findings of a granulomatous reaction, diffuse infiltration, and oedema of the vessel walls. The patients responded to a saturated solution of potassium iodide. The second type is chronic inflammation and occlusion of blood vessels mainly in the lower extremities which results in gangrene or aneurysm formation. This type of infection is only found in thalassaemic patients and leads to amputation of the affected extremities or resection of the involved arteries. The third type is keratitis. This type of infection may or may not be associated with thalassaemia. The clinical signs and symptoms do not differentiate it from other types of myocotic keratitis. The patients end up with keratoplasty, evisceration or enucleation. Thailand is an agricultural country, and there are plenty of swampy areas and several plants to support the life cycle of Pythium. Moreover, many people suffer from thalassaemia, and there is no drug available for Pythium. Pythiosis plays an important role in medicine in Thailand.
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PMID:Human pythiosis in Thailand. 793 48


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