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

The effect of the iron chelator deferoxamine (DFO) on resistance to infection with Listeria monocytogenes in mice with a condition analogous to human beta-thalassemia was studied. Intraperitoneal injection of 10 mg DFO resulted in significantly increased mortality when given one, three and six days before infection with L. monocytogenes (for all three time points, p less than 0.02). There were no significant differences in hematocrit, plasma iron, or splenic iron content between the two groups of mice during these time periods. In addition, splenic counts of L. monocytogenes were not significantly higher in DFO-treated compared to saline-treated mice three days after infection. Moreover, background C57Bl/6J mice were not more susceptible to Listeria infection after receiving DFO than were saline-treated controls. In conclusion, acute administration of DFO increases the susceptibility of beta-thalassemic mice to L. monocytogenes. The effect is not seen in background mice and suggests that DFO increases susceptibility to Listeria infection only in animals with iron overload.
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PMID:Deferoxamine increases the susceptibility of beta-thalassemic, iron-overloaded mice to infection with Listeria monocytogenes. 156 Jul 32

In patients with thalassemia intermedia in whom hyperabsorption of iron may result in serious organ dysfunction, an orally effective iron-chelating drug would have major therapeutic advantages, especially for the many patients with thalassemia intermedia in the Third World. We report reduction in tissue iron stores and normalization of serum ferritin concentration after 9-month therapy with the oral chelator 1,2-dimethyl-3-hydroxypyrid-4-one (L1) in a 29-year-old man with thalassemia intermedia and clinically significant iron overload (SF 2,174 micrograms/L, transferrin saturation 100%; elevated AST and ALT, abnormal cardiac radionuclide angiogram) who was enrolled in the study with L1 75 mg/kg/day after he refused deferoxamine therapy. L1-Induced 24-hour urinary iron excretion during the first 6 months of therapy was (mean +/- SD, range) 53 +/- 30 (11 to 109) mg (0.77 mg/kg), declining during the last 3 months of L1 to 24 +/- 14 (13-40) mg (0.36 mg/kg), as serum ferritin decreased steadily to normal range (present value, 251 micrograms/L). Dramatic improvement in signal intensity of the liver and mild improvement in that of the heart was shown by comparison of T1-weighted spin echo magnetic resonance imaging with images obtained immediately before L1 administration was observed after 9 months of L1 therapy. Hepatic iron concentration decreased from 14.6 mg/g dry weight of liver before L1 therapy to 1.9 mg/g liver after 9 months of therapy. This constitutes the first report of normalization of serum ferritin concentration in parallel with demonstrated reduction in tissue iron stores as a result of treatment with L1. Use of L1 as a therapeutic option in patients with thalassemia intermedia and iron overload appears warranted.
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PMID:Reduction of tissue iron stores and normalization of serum ferritin during treatment with the oral iron chelator L1 in thalassemia intermedia. 158 21

174 serum ferritin assays in 121 patients with various haemolytic disorders have been performed. The mean serum ferritin levels were significantly increased in all these disorders in contrast to healthy controls. The highest serum ferritin levels were found in pyruvate kinase (PK) deficiency, moderate increase was observed in hereditary sphaerocytosis (HS) and in autoimmune haemolytic anaemia (AIHA) with massive haemolysis and in glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. Mild elevation of serum ferritin levels was depicted in paroxysmal nocturnal haemoglobinuria (PNH), in beta thalassaemia minor and in other types of haemoglobinopathies. The range of values was associated with a degree of haemolysis and its relation to duration of the disease was not apparent in most cases. Highly significant differences between serum ferritin levels in splenectomized and non-splenectomized patients with HS and between serum ferritin levels in patients with AIHA with massive haemolysis or in remission were found. As compared to normal controls, significant increase of serum ferritin levels was observed even in patients with AIHA in remission or in splenectomized patients with HS. In two patients with PK deficiency the levels exceeding 2,000 micrograms/l indicated manifest iron overload. A reliability of serum ferritin assay as an index of iron stores in haemolytic disorders has been discussed.
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PMID:Serum ferritin in patients with various haemolytic disorders. 169 23

We report two cases of intermediate beta-thalassemia diagnosed at the age of 2 years and 3 1/2 years respectively. Characteristic features of this disease include delayed onset, moderate blood transfusion requirements, and frequent development of hypersplenism. Major iron overload develops even in patients who have received no transfusions. This disease is further characterized by significant genetic heterogeneity and by a reduction in the imbalance between produced chains and deficient chains.
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PMID:[Thalassemia intermedia. Report of two cases]. 170 19

A patient with thalassemia minor (TM) is reported who ingested 80 g of alcohol/day and presented an important overload of iron with deposits and a hepatic iron ratio compatible with primary hemochromatosis. The results obtained from the study of histocompatibility antigens, clinical manifestations and family analysis discarded the possibility of two genetic diseases, beta-thalassemia and primary hemochromatosis, being concomitantly present in the same progeny. Thalassemia minor and alcoholic hepatopathy are considered as having acted together and being responsible for the iron overload. The relation between alcohol ingested, TM and iron deposits is discussed.
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PMID:[Thalassemia minor with iron overload: genetic and clinical study of a family]. 176 61

Thirty prepubertal patients with thalassaemia major (15 boys and 15 girls) aged from 9.3 to 17.2 years (mean 12.9) who had successfully undergone allogenic bone marrow transplantation were studied. Before the transplant all patients were given short courses of high doses of busulphan (total dose 14 mg/kg) followed by cyclophosphamide (total dose 200 mg/kg). Pituitary gonadal function was assessed between 0.7 and 5.1 years (mean 2.3) after bone marrow transplantation. Increased gonadotrophin concentrations indicating gonadal damage were found in 80% of the girls, probably as a result of the chemotherapy. In all the prepubertal boys the basal follicle stimulating hormone and luteinising hormone concentrations were normal. Most of the boys had reduced gonadotrophin and testosterone responses after gonadotrophin releasing hormone and human chorionic gonadotrophin tests. This could have been the result of iron overload but the effect of cytotoxic agents cannot be excluded. These findings emphasise the need for vigilant long term follow up of thalassaemic patients treated with cytotoxic chemotherapy for bone marrow transplantation so that those requiring hormone replacement can be identified and treated.
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PMID:Gonadal function after allogenic bone marrow transplantation for thalassaemia. 175 59

The cores of ferritins isolated from different organs of human subjects with beta-thalassemia/hemoglobin E (beta-thal/HbE) disease have different size distributions and crystallinities depending on the source organ. These patients have not been treated by hypertransfusion regimen or iron chelation therapy. beta-Thal/HbE spleens and livers yield ferritin cores which are less crystalline than those isolated from normal spleens and livers, reflecting the more rapid deposition of iron in the diseased state. Ferritins isolated from the hearts and pancreases of beta-thal/HbE subjects were found to have larger, more crystalline cores than those from the beta-thal/HbE livers and spleens, possibly as a consequence of the role of the heart and pancreas as long-term iron deposition sites in this iron overload pathology.
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PMID:Organ-specific crystalline structures of ferritin cores in beta-thalassemia/hemoglobin E. 193 35

This report describes a patient with thalassemia intermedia-like phenotype born to normal parents in whom globin gene sequencing detected a novel abnormal hemoglobin (Hb) due to a T to A substitution at codon 60 of the beta-globin gene arising as a de novo mutation. Normal sequences were detected at the homologous beta-globin locus. This mutation results in the substitution of a polar (glutamic acid) for a nonpolar (valine) residue near the corner of the heme pocket of the beta-globin chain. The novel variant has been designated Hb Cagliari, from the place of birth of the propositus. Kinetics of globin synthesis performed following splenectomy suggest that this new Hb variant is synthesized at a near normal rate but undergoes rapid breakdown. The extreme lability of the variant explains the clinical and hematologic picture characterized by marked ineffective erythropoiesis, thalassemia-like bone changes, iron overload, high proportion of Hb F in the peripheral blood, reduced beta/alpha-globin chain synthesis ratio in peripheral blood reticulocytes, and absence of the abnormal Hb in peripheral blood at extensive protein structural analysis before splenectomy. This case indicates that a thalassemic hemoglobinopathy should be suspected in the presence of a patient with a thalassemia intermedia-like phenotype born to normal parents, even when protein structural analysis fails to detect an abnormal Hb. DNA sequencing may allow to define the mutation, thus making the proper diagnosis.
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PMID:Hemoglobin Cagliari (beta 60 [E4] Val----Glu): a novel unstable thalassemic hemoglobinopathy. 198 2

In patients with thalassemia treated by long-term chronic blood transfusions who survive beyond the first ten or twenty years of life but received no or inadequate chelating therapy during the first years, evaluation of iron overload and its consequences on tissues may prove an arduous task. MRI is a non-invasive means of measuring the amount of iron in the liver and the consequences of the iron overload on the heart and other tissues. For this purpose, MRI is more satisfactory than CT scan studies. In this investigation, 20 patients with thalassemia major underwent MRI. Multiple spin echos were used to allow determination of the transversal relaxation constant T2. This constant, expressed in ms, is related to the concentration of iron in the liver as in the following expression: (C) = 5 410/T2-110. MRI studies disclosed a discrepancy between the severity of hepatic hemosiderosis and development of decompensated iron overload cardiomyopathy. In a unique case, in which a heart transplant and two MRI studies were performed, the severe iron overload that failed to respond to several years of subcutaneous chelating therapy was more than halved by intensive intravenous chelation through a central catheter. MRI studies of the heart provide valuable morphologic and functional data. Although the amount of iron in the myocardium cannot as yet be quantified, modifications of the transversal relaxation time provide information on the severity of the overload and the presence of other myocardial alterations.
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PMID:[The value of nuclear magnetic resonance in the study of iron overload in thalassemia patients]. 203 85

Depending upon the transferrin saturation value, 214 serum samples were divided into three groups--iron overloaded (46 cases), iron deficient (61 cases) and normal (107 cases)--and tested with a micromethod based upon detection of unsaturated iron binding capacity. All the samples with iron overload could be distinguished from the other two groups, the results of the normal and iron deficient groups showing wide scatter and overlap. The high prevalence of iron deficiency anaemia and thalassaemia (iron overload) syndromes in India and other developing countries emphasises the need to differentiate these disorders at the earliest opportunity. The micromethod can be of immense help as it is a simple, rapid and inexpensive.
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PMID:Iron overload: detection using a micromethod for iron-binding capacity. 206 80


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