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

Using a method involving elution of hemoglobin bands from cellulose acetate strips following electrophoresis of hemolysates, hemoglobin A2 (Ab A2) was quantitated in bloods from 300 healthy individuals and 904 patients. The percentage of Hb A2 was elevated in beta-thalassemia heterozygotes and some patients who had megaloblastic anemia. In the latter, the highest Hb A2 levels were observed in patients with the most severe anemia. Low Hb A2 percentages were found in iron-deficiency anemia, hereditary persistance of fetal hemoglobin, and Hb H disease. In iron-deficiency anemia, the lowest levels of Hb A2 were observed in association with the most severe anemia. Iron and folate deficiency each suppressed Hb A2 levels in beta-thalassemia heterozygotes; however, vitamin B12 deficiency did not alter the percentage of Hb A2 in thalassemia. Malignant tumors, renal and hepatic insufficiency, chronic infections and inflammation, hemolytic disease, lead poisoning, aplastic anemia, leukemia, myelofibrosis, and hypothyroidism did not change Hb A2 levels. The pathogenesis of altered Hb A2 levels and their clinical significance in various diseases are discussed.
 ...
PMID:Hemoglobin A2 levels in health and various hematologic disorders. 26 35

Thalassemia major is a severe and transfusion-dependent anemia that occurs in persons homozygous for a mutation that affects the capacity for synthesis of the beta-globin subunit of hemoglobin. Characterization of the molecular defects that cause beta-thalassemia is providing insight into the mechanism of globin gene regulation. Newer approaches to the management of thalassemia major include more effective chelation by use of subcutaneous desferrioxamine and attempts to obtain young erythrocytes with a longer potential for survival in recipient patients. Development of more effective chelators that may be given orally is an ongoing effort. Noninvasive evaluation of cardiac structure and function in patients with thalassemia major suggests that myocardial iron deposits begin at an early age, causing functional impairment long before the onset of clinical symptoms. Prevention or reversal of these cardiac abnormalities remains the goal of chelation therapy.
 ...
PMID:Thalassemia major: molecular and clinical aspects. NIH Conference. 39 Nov 18

Heterozygous classical beta-thalassemia was found in 13 subjects of pure German descent, 11 of them from the Bergische Land (NW Germany) during the past three years. Clinically it became manifest in a moderate degree of anemia with marked hypochromia and reduced mean corpuscular volume. The number of red blood corpuscles and the value for serum iron were ascertained to be in the upper limits of normal or raised. The diagnosis of Mediterranean anemia was confirmed by hemoglobin electrophoresis with a rise in HbA2 of more than 3%. A slight increase in HbF may also occur. The importance of genetic counseling of thalassemia patients is emphasized. The occurrence of thalassemia even in pure German populations must be increasingly reckoned with.
 ...
PMID:[Thalassemia minor in families of German descent in the Bergische Land (author's transl)]. 40 46

Five cases of HbH disease were discovered in a large family of American Blacks. Anaemia was mild with PCV ranging from 0.275 to 0.405. The amount of HbH was 2--6%. Studies of haemoglobin synthesis in peripheral blood reticulocytes demonstrated marked deficits in alpha globin production with an average alpha/beta ratio of 0.31 (range 0.22--0.36). Eighteen additional family members had evidence of thalassaemia trait and were provisionally classified as either alpha-thal-1 (average MCV 65.2 fl; range 59--70) or alpha-thal-2 (average MCV 79.6 fl; range 74--88). A subject with altha-thal-1 trait had an alpha/beta ratio of 0.56; the average for five cases of alpha-thal-2 was 0.73. One other family member was thought to be homozygous for alpha-thal-2 trait and exhibited an MCV of 65 fl with an alpha/beta ratio of 0.5. These data reconfirm that in Blacks with alpha thalassaemia the proportion of HbH is lower and the severity of anaemia is less than in certain other racial groups, e.g. Southeast Asians. However, the degree of hypochromia and microcytosis and the imbalance in alpha and beta globin synthesis appear to be similar in Blacks and other races. These results suggest that the milder clinical course of HbH disease in Blacks is not a result of greater alpha globin production in that population of thalassaemics.
 ...
PMID:Alpha thalassaemia in American blacks: a study of a family with five cases of haemoglobin H disease. 42 29

Our paper describes two Sardinian families with alpha-beta thalassaemia interaction. In the first (family S), the propositus, whose haemoglobin pattern at birth consisted of about 25% Hb Bart's and 75% Hb F, successively developed a clinical and haematological picture typical of Cooleys anaemia. Haematological and globin chain synthesis studies together with these findings suggest that he is homozygous for beta 0 thalassaemia and heterozygous for alpha thalassaemia-1 and alpha thalassaemia-2. This conclusion is further substantiated by the finding of various combination of alpha and beta thalassaemia among his family members. In the P family two twins whose haemoglobin pattern and synthesis data at birth were similar to those of the proband of family S died in the neonatal period. The mother was assumed to be a compound heterozygte for alpha thalassaemia-2 and beta 0 thalassaemia and the father for alpha thalassaemia-1 and beta 0 thalassaemia. The homozygous state for beta 0 thalassaemia in association with the alpha thalassaemia 1 and alpha thalassaemia 2 genes results in a severe clinical picture similar to that of a homozygous beta 0 thalassaemia. The interaction between the heterozygous state for beta 0 thalassaemia and the alpha thalassaemia 1 or alpha thalassaemia 2 genes, or the combination of both, results in a haematological picture similar to that of a beta thalassaemia heterozygote.
 ...
PMID:Interaction of alpha and beta thalassaemia genes in two Sardinian families. 42 30

The mean serum and adjusted red cell folate levels, as measured by microassay using Lactobacillus casei, respectively were 8.87 +/- SD 3.28 microgram/l and 436 +/- SD 107 microgram/l in 76 normal subjects, 4.22 +/- SD 2.70 microgram/l and 182 +/- SD 114 microgram/l in 55 patients with beta-thalassaemia/Hb E disease and 6.36 +/- SD 2.95 microgram/l and 320 +/- 158 microgram/l in 37 patients with Hb H disease. The mean serum and adjusted red cell folate values of the patients with beta-thalassaemia/Hb E disease and the mean serum folate value of the patients with Hb H disease were significantly lower than those of the normal subjects (P less than 0.001). 33% of the beta-thalassaemia/Hb E patients and 8% of the Hb H patients showed low serum folate levels (less than 3 microgram/l) whereas 84% of the former and 45% of the latter showed low adjusted red cell folate levels (less than 270 microgram/l). The group of beta-thalassaemia/Hb E disease with low serum folate levels had lower mean haemoglobin concentration and lower mean adjusted red cell folate level than the group with normal serum folate levels. Since the Thai diets have high folate content, the observed low serum and erythrocyte folate levels in thalassaemic patients most likely occur from massively increased erythropoiesis. Folate, 5 mg/d, is now routinely prescribed to such patients especially to those with severe anaemia.
 ...
PMID:Serum erythrocyte folate levels in thalassaemic patients in Thailand. 45 55

The red cell indices and results of globin chain synthesis in peripheral blood of obligate beta 0 thalassemia (beta 0 thal) carriers (parents of homozygous beta 0 thal children) and beta thalassemia (beta thal) carriers identified during mass screening are reported. Red cell indices were similar in obligate beta 0 carriers and in carriers diagnosed during mass screening. However there was a higher incidence of anemia in female obligate beta 0 thal carriers. In Sardinia the beta 0 thal carrier showed the usual hematological characteristics of the high Hb A2 beta thal carrier with microcytosis, hypochromia, reduced osmotic fragility; Hb F greater than 1% was found in 30% of the carriers. With MCV, MCH, osmotic fragility test (OFT) and Shine and Lal discriminant function we found 3.5%, 1.5%, 3.5% and 4.0% respectively false negatives in carrier identification. A part from one subject, all obligate carriers had elevated Hb A2 levels. The alpha/beta ratio in obligate carriers (mean +/- SD) was 1.83 +/- 0.26 (N = 30).
 ...
PMID:Beta 0 thalassemia trait in Sardinia. 45 22

Ferrokinetic studies were carried out in 8 patients with heterozygous beta-thalassaemia with anaemia of varying severity. Effective and ineffective erythropoiesis, mean red cell lifespan and non-erythroid iron turnover were estimated from the experimental data through a mathematical model of iron kinetics. Erythropoietic activity was markedly increased in all patients, but was variably ineffective (from 10 to 74%). A negative correlation (r = 0.855, P less than 0.01) was found between the amount of ineffective erythropoiesis and Hb level. Red cell lifespan was variably shortened and there was a negative correlation between the degree of daily peripheral haemolysis and Hb level (r = 0.733, P less than 0.05). Non-erythroid iron turnover was increased in most patients. The results provide quantitative measurements of the mechanisms responsible for the wide variation of the Hb level in heterozygous beta-thalaeeaemia. Ineffective erythropoiesis seems to be the major reason for the anaemia. Peripheral haemolysis contributes to it, especially in the most severely affected patients. The increased non-erythroid iron turnover may be responsible for the pathology which characterizes heterozygotes in the adult life.
 ...
PMID:Quantitative evaluation of the mechanisms of the anaemia in heterozygous beta-thalassaemia. 49 74

Hb J Calabria is a fast moving hemoglobin variant which was found in an Italian family by Vecchio et al (1), and in a French family by Blouquit et al. who studied its functional properties (2). The original family described by Vecchio et al. in which both Hb J Calabria and beta-thalassemia were present has been reexamined and is the subject of the present study. Hematological and clinical features of the carriers are described. The heterozygous carriers of Hb J Calabria showed only mild variable subclinical anemia and levels of the abnormal hemoglobin ranging from about 33 to 42%. The Hb J Calabria/beta-thalassemia double heterozygote showed a moderate chronic hemolytic anemia with alterations of the RBC indices and morphology in addition to splenomegaly. The relationship between structural abnormality, functional properties and clinical expression of Hb J Calabria is discussed.
 ...
PMID:Studies on a family with Hb J Calabria (alpha 2 beta 2 64 (E8) Gly replaced by Asp). 50 Mar 75

A total of 4939 apparently healthy Fijian and Indian subjects living in Fiji were tested for anaemia by determination of the microhaematocrit of a sample of capillary blood. The prevalence of anaemia during childhood varied with age but was similar for Fijians and Indians of either sex. The overall prevalences were: 0-4 years, 20.3%; 5-9 years, 3.7%; 10-14 years, 23.5%. The prevalence of anaemia among Indian women (33.3%) was substantially higher than that for Indian men (6.9%), Fijian women (8.1%) or Fijian men (6.8%). Iron deficiency was the most common cause of anaemia and was established by laboratory studies in 203 (68%) of 298 anaemic subjects who were followed up. Iron deficiency was an important aetiological factor in 91 (93%) of 98 subjects with moderate or severe anaemia. Folate deficiency was found, usually in combination with iron deficiency, in 44 or 141 anaemic indian adults were followed up. Folate deficiency was uncommon in Fijian adults and among children of either race. Two cases of nutritional vitamin B12 deficiency, one case of pernicious anaemia, 6 cases of heterozygous thalassaemia and one case of heterozygous haemoglobin E were found among the anaemic Indian subjects. No cases of vitamin B12 deficiency anaemia, thalassaemia or haemoglobinopathy were detected among the Fijians. In 5 Indians and 7 Fijians the anaemia was associated with an underlying chronic disorder. This study emphasizes that in Fiji, as in other developing countries, nutritional anaemia is prevalent among asymptomatic subjects. Iron deficiency is by far the most common cause.
 ...
PMID:The prevalence and nature of anemia among apparently normal subjects in Fiji. 52 78


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>