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

Patients with severe thalassaemia major suffer endocrine and other abnormalities before their eventual death from iron overload due to repeated blood transfusions. The endocrine status of 31 thalassaemic patients aged 2-5 to 23 years was investigated. Exact data were available on the rate and duration of blood transfusion in all of them and in many the liver iron concentration was also known. Although the patients were euthyroid, the mean serum thyroxine level was significantly lower, and the mean thyrotrophic hormone level significantly higher, compared with the values found in normal children. Forty oral glucose tolerance tests with simultaneous insulin levels were performed in 19 children, of whom 5 developed symptomatic diabetes and one had impaired tolerance. Previous tests on all 6 patients were available and some showed raised insulin levels possibly due to insulin resistance. 2 patients had clinical hypoparathyroidism and are described. The parathyroid hormone levels determined by radioimmunoassay in 25 patients were below the mean for the age group in all and outside the reference range in 16. Nonfasting plasma calcium levels were not reduced. Puberty was delayed in some patients. Concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) measured in urine from 7 girls and 5 boys showed considerable variation. In the boys there was an overall tendency for FSH and LH excretion to be low with regard to age, but with respect to puberty rating FSH exretions were normal or low and LH normal or raised. The girls showed a tendency for LH but not FSH excretion to be raised in relation to puberty rating. The severity of the endocrine changes was related to the degree of iron loading and is discussed in relation to previous work in which the iron loading has rarely been accurately indicated nor parathyroid status assessed.
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PMID:Hormonal changes in thalassaemia major. 100 88

2-3-Dihydroxybenzoic acid was evaluated as a potentially useful, orally effective iron-chelating drug by performing iron balance studies in patients with beta-thalassaemia major. The administration of this substance at 25 mg/kg/d to five patients for 8 d caused an average increase in iron excretion of 4.5 mg/d. When the drug was administered at 25 mg/kg q.i.d. to eight patients for 21 d, iron excretion increased to 6.5 mg/d. Chelation was highly specific for iron with changes in magnesium and calcium excretion being insignificant. The drug was well tolerated with side effects limited to gastrointestinal complaints which ameliorated when the drug was taken with food. These studies provide a rationale for further evaluation of 2,3-dihydroxybenzoic acid in patients with iron overload.
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PMID:Chelation studies with 2,3-dihydroxybenzoic acid in patients with beta-thalassaemia major. 100 20

Because of its high prevalence in Italy, thalassemia is officially considered a disease of major social importance. Several centers have been established for the specific purpose of population screening and treatment of patients with Cooley disease. Survival, in some cases up to 20 years, has been reached by the therapeutic methods adopted, consisting mainly of an intensive transfusion program combined with splenectomy. We now face serious logistic, social, and financial problems, raised by the increasing number of patients living, estimated at around 12,000. The iron overload is not adequately controlled by the routine use of desferrioxamine. Studies of iron kinetics in heterozygotes demonstrate specific alteration of iron metabolism (not related to the exogenous transfusion-induced overload). Therefore, treatment with iron-chelating agents might be indicated in at least some of these subjects.
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PMID:Thalassemia in Italy: treatment of Cooley disease and iron kinetics in heterozygotes. 100 35

During a study of pathogenetic mechanisms in the hepatic cirrhosis of thalassaemia major, 16 liver biopsies were examined by electron microscopy. Previous ultrastructural studies of liver cells during iron overload have shown electron-dense iron as lysosomal haemosiderin, and as lysosomal and cell-sap ferritin. In this study, all biopsies, regardless of the patient's age, showed ferritin molecules within lysosomes in a specific pattern in relationship with regularly arranged lamellae. This membrane-associated lysosomal ferritin is considered to be a stage in the segregation of iron seen in iron overload. The dimensions and electron density of individual ferritin molecules indicate differences between cell sap and lysosomal ferritin. Intracellular ferritin transport and iron-seclusion mechanisms are reconsidered in view of these findings. The liver biopsies of thalassaemic infants also provide information about the causal relationship between iron overload and collagen deposition. Since the collagen deposition precedes any morphological evidence of cellular injury (other than the increased iron content), the primary cirrhotogenic factor in thalassaemia is apparently not cell necrosis but possibly excessive collagen deposition induced by iron.
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PMID:The liver in thalassaemia major: ultrastructural observations. 105 35

Porotic hyperostosis was observed in 34 percent of 539 crania excavated from sites in Arizona and New Mexico. Common causes of this cranial pathology in the Old World (thalassemia, sickel cell anemia, and malargia) do not explain its occurrence in the American Southwest, as malaria and hemoglobinopathies are not known to have existed in the New World prior to European contact. Iron deficiency anemia which may also be assoicated with porotic hyperostosis occurs on a mass level only with hookworm infestation or nutritionally-related iron deficiency. Since hookworm infestation is rare in the American southwest and has not been reported in prehistoric southwestern American Indians, the hypothesis of nutritional anemia was examined. In canyon bottom sites where the diet was heavily dependent on maize, which is low in iron and also contains an inhibitor of iron absorption, significantly more crania had porotic hyperostosis than in sage plain sites, where the diet included ample animal protein rich in easily absorbable iron (p less than .001). Furthermore, canyon bottom children, who were more susceptible to iron deficiency anemia, had a higher incidence of porotic hyperostosis lesions than adults (p less than .0001).
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PMID:The paleoepidemiology of porotic hyperostosis in the American Southwest: Radiological and ecological considerations. 110 84

Many complex forces are at work during adolescence which can contribute to the occurrence of anemia. Careful consideration of the entire patient should enable a physician to identify the unusual as well as the more common causes of anemia in this age group. Anemia in teenage girls is primarily due to menstrual iron loss. In boys, borderline diets and the demands of rapid growth predominate as causative factors. Hemoglobinopathies (thalassemia, sickle cell disease), G6PD deficiency, infectious mononucleosis, and illicit drug use account for small proportions of cases.
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PMID:Anemia in adolescence. 2. Hemoglobinopathies and other causes. 110 36

Thalassaemia minor has been diagnosed in 12 members of two Norwegian families. Haematological data from 23 family members are reported. The diagnosis was based on estimation of Hb A(2) by polyacrylamide gel disc electrophoresis. All patients having high Hb A(2) levels had confirmatory evidence of thalassaemia minor (hypochromic anaemia, marked variation in size and shape of the red cells, target cells, basophilic stippling, decreased osmotic fragility, normal or high serum iron level). The majority of the patients had previously been treated with iron without effect.
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PMID:Thalassaemia minor. Twelve patients in two Norwegian families. 112 58

Urinary iron excretion was measured in patients with sickle cell anemia and relateddiseases. Iron concentration in urine was determined by atomic absorption spectrophotometry and daily total iron excretion was calculated from this and total daily urine volume. Normal subjects excreted a mean of 88 pg Fe per day (95 per cent confidence limitsof 0 to 120 pg). Nine persons with sickle cell trait had normal Fe excretion rates.However, abnormally high iron excretion was present in the first urine sample obtainedfrom 27/31 patients with SS, 3/7 with SC, 1/2 with CC, and 1 with S-thalassemia. Iron excretion varied very significantly from day-to-day in individual patients. The results of studies attemting to relate this to increase excretion during activityas compared to rest were negative. No clear relationship of iron excretion to painfulcrisis could be shown, but remarkable rises in urine iron occurred in two patients who developed a hyperhemolytic crisis. These studies suggest that urinary iron reflects intravascular hemolysis primarily. No correlation was evident between urine iron and the patients' age, transfusion history, or serum iron values suggesting increased urinary iron excretion cannot be attributed to iron overload in sickle cell anemia.
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PMID:Urinary iron in patients with sickle cell anamia. 115 Nov 37

The interrelationships between liver iron concentration, the duration of iron-loading, and hepatic fibrosis, assessed morphometrically, have been studied in 32 specimens of liver obtained from 19 heavily transfused patients with thalassaemia major whose age ranged from 4 to 19 yr. Similar observations were made in a matched group of thalassaemic patients treated with long-term chelation therapy. The degree of liver damage ranged from very slight increase in fibrous tissue to severe fibrosis and cirrhosis. The severity of the fibrosis was closely correlated both with liver iron concentration and with age. While the relationship between fibrosis and age was linear, both the severity and the rate of fibrosis were exponentially related to liver iron concentration, damage accelerating as liver iron concentration exceeded 3 per cent, dry weight. By producing a modest but significant reduction in liver iron concentration chelation therapy resulted in a disproportionate but predictable retardation in the progression of the fibrosis. The factors affecting the distribution of iron between parenchymal and reticuloendothelial cells were also examined. In general stainable iron was uniformly distributed between parenchymal and reticuloendothelial cells from the early stages of iron-loading. Parenchymal siderosis was relatively heavier in splenectomised patients and in patients with liver iron concentrations above 3 per cent, dry weight than in non-splenectomised patients or patients with liver iron levels of less than 3 per cent, dry weight, but this did not affect the severity of the fibrosis. The relevance of these findings to the traditional concepts of the pathology of transfusional siderosis is discussed.
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PMID:Transfusional iron overload: the relationship between tissue iron concentration and hepatic fibrosis in thalassaemia. 115 28

Small erythrocytes (mean corpuscular volume less than 80 mu-3 by the Coulter Model S) were found in 222 (2.75%) of 8,086 consecutive patients admitted to a large suburban general hospital. Forty-five (20.3%) of these 222 patients had laboratory findings consistent with thalassemia. Seventy-six (31.2%) were found to be iron deficient. Patients whose hemoglobin values were below 9.0 Gm. per 100 ml. were more likely to be iron deficient. The hemoglobin A2 values were significantly lower in iron-deficient than in non-iron-deficient patients. Although the mean corpuscular volume is much lower and the erythrocyte count is higher in thalassemia than in iron deficiency, hematologic values obtainable from the Counlter S (such as MCV, erythrocyte count, and hemoglobin) alone are not valuable in differentiating thalassemia from iron deficiency.
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PMID:The significance of small erythrocytes. 115 74


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