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)

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

Pyrimidine 5' nucleotidase (P5'N) acquired deficiency has been found in several hematologic disorders including beta-thalassemia. Our previous studies suggested that the aldehydes produced during membrane lipid peroxidation could play a role in P5'N inactivation in thalassemia. To evaluate the effects of the thalassemic "environment" on transfused red blood cells, we tested P5'N, pyruvate kinase (PK), glucose 6-phosphate dehydrogenase (G-6PD) activity, creatine content, reduced glutathione (GSH) levels and the hexose monophosphate shunt (HMS) in the red cells of homozygous transfusion-dependent thalassemic children, immediately following and again one month after transfusion. In red cells aged in thalassemic plasma, P5'N activity, creatine level, GSH stability and stimulated HMS flux were significantly decreased. These results fit in with the presence in thalassemic plasma of molecules interfering with antioxidant red cell defenses. Normal red cells incubated in thalassemic plasma display a significant stimulation of the basal HMS (p less than 0.01). Transfused red cell metabolic alterations could be explained by the plasma pro-oxidant activity and may contribute to reducing red cell survival in the host plasma.
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PMID:Pyrimidine 5'-nucleotidase and oxidative damage in red blood cells transfused to beta-thalassemic children. 227 76

Pyrimidine 5'-nucleotidase (P5'N) partial deficiency has been described in several hematological disorders and also in the beta-thalassemic trait. To check if the P5'N deficiency in thalassemia was acquired we used thalassemic red cells (from either homo- or heterozygous subjects), whose P5'N activity was lower than in control cells. After separation on a density gradient, activity in lighter cells was similar to controls and less than 50% in denser cells. The most probable mechanism for this faster inactivation involves enzyme -SH groups modification by oxidation and reaction with monofunctional aldehydes produced by membrane lipid peroxidation. In vitro challenge of thiol enzymes as pyruvate kinase (PK), adenylate kinase (AK) and P5'N with increasing concentrations of GSSG, hexanal (HEX) and 4-hydroxynonenal (HNE), showed that HNE is the most powerful among the enzyme inhibitors tested and that P5'N activity is a more sensitive index of -SH groups damage, when compared to PK and AK.
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PMID:Pyrimidine 5'-nucleotidase acquired deficiency in beta-thalassemia: involvement of enzyme-SH groups in the inactivation process. 211 21

Transfusion of young red blood cells (YRBC) with prolonged survival should result in increased intervals between transfusions and, therefore, decreased transfusion-associated iron loading. A prospective clinical trial comparing YRBC transfusions prepared by apheresis versus washed or frozen red cell transfusions was performed in five children with transfusion-dependent thalassemia. A total of 152 YRBC units, evaluated by reticulocyte enrichment and pyruvate kinase activity, were transfused. While a slightly longer interval between transfusions was observed during the time period of YRBC versus the time period after (30.0 +/- 1.5 days versus 27.9 +/- 1.1 days, respectively, p less than 0.02), there was no associated decrease in mg of iron transfused per kg. The effectiveness of transfused YRBC units was less than predicted by in vitro and in vivo studies.
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PMID:Clinical trial of young red blood cells prepared by apheresis. 354 73

The transfusion of young red blood cells (neocytes) is a complementary approach to the present treatment of thalassaemia major patients. Fresh neocytes were harvested from 34 volunteers with the IBM 2991 cell washer (CW). The upper part of 24 units was separated into 6 aliquots (T1-T6) of 15 ml each and the residue homogenized. Four biological criteria were used to evaluate young red cell quality, the erythrocyte pyruvate kinase activity, the mean corpuscular volume, the reticulocyte count and ektacytometry; each sample (T1-T6) showed an enrichment with neocytes as compared with the standard unit. A real efficiency of this technique with the IBM 2991 CW was obtained with the first third of the unit, corresponding to the T1-T4 fractions. The estimation of the theoretical mean life span of T1-T2 was 270 days. The last 10 units were separated into two halves: the enrichment of the first half was worse than in the first third of the previous technique. We concluded that the transfusional program of thalassaemia patients could profit by the use of the most enriched part of a standard blood unit with the IBM 2991 CW.
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PMID:Enrichment of blood units with young red cells (neocytes) with the IBM 2991 cell washer. 367 72

Recent treatment for patients with thalassemia and chronic anemia involves transfusion of young red cells (YRBCs) or "neocytes." We developed a technique enabling YRBCs to be separated based on their buoyant density in autologous plasma during centrifugation. Following this procedure, measurement of pyruvate kinase (PK), an age-dependent red cell enzyme, showed neocyte enrichment in the top one-third of the RBC layer corresponding to a mean of 47.5 percent of the total PK present in the unfractionated unit. To provide a neocyte transfusion preparation with an acceptable hemoglobin content, the top one-third fraction from each of three bags of blood was pooled. Leukocytes were removed from this "neocyte unit" by an initial sedimentation with 6 percent hydroxyethyl starch (HES) followed by filtration through a filter (IG 500, Imugard). This process resulted in removal of 99.3 +/- 0.5 percent (mean +/- SD) of the leukocytes with a mean RBC recovery of 89.5 +/- 5.5 percent and a final hemoglobin content of 53.4 +/- 2.3 g. Tests for plasma-free hemoglobin and HES in the supernatant of the final transfusion product gave acceptable mean values of 28 mg per dl and 3.0 mg per ml. Autologous mean RBC survival of Cr51-labeled YRBC fractions was 41.8 +/- 2.9 days (n = 5). This technique yields neocyte enrichment superior to that achieved using a cell processor (model 2991, IBM) and has the added advantage of being less costly to prepare ($45.00 [1984] U.S. per YRBC unit as compared to an estimated $135.00 [1984] U.S., IBM) and more economical in terms of blood use.
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PMID:A simple method for preparing neocyte-enriched leukocyte-poor blood for transfusion-dependent patients. 370 44

At present the treatment of thalassaemia major consists of regular blood transfusions coupled with chelation therapy using deferoxamine. A complementary approach to the problem is the use of blood units enriched with young red cells (neocytes), which reduce the transfusional frequency and thereby diminish the risk of iron overload. Young red cell units were collected from blood from 60 volunteer donors using a cell separator (IBM 2997). Donors' blood was anticoagulated and the young red cell harvesting carried out over 4 h at a constant rotor speed of 500 rpm. Three biological criteria were used to evaluate young red cell quality: the number of reticulocytes, the pyruvate kinase activity and the mean corpuscular volume, all of which show an enrichment of young red cells as compared to standard donor units. The 51Cr young red cell survival in four normal donors and in two splenectomized patients showed an increased red cell half-life compared to the same study performed with standard blood units. Blood consumption was diminished significantly when the two patients were transfused with young red cell units. It must be emphasized that, despite the high cost of this blood product, the efficiency of this transfusion technique, by reducing blood consumption, represents important progress and a hopeful treatment for chronic anaemia.
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PMID:Neocytopheresis: a new approach for the transfusion of patients with thalassaemia major. 373 11

The frequencies of glucose-6-phosphate dehydrogenase (G-6-PD), pyruvate kinase (PK) and hexokinase (HK) deficiency were determined in different regions of Saudi Arabia. G-6-PD deficiency was found to range from 0.045 to 0.220 for the male and 0.020 to 0.125 for the female population. The highest frequencies were found to exist in the regions which are endemic to malarial parasite and have high frequencies of sickle cell and thalassaemia genes. Partial deficiencies of PK and HK were encountered in each region, however, no case of complete deficiency of these enzymes was identified. Further investigations are in progress to determine the clinical manifestations of enzyme deficiencies in the Saudi population.
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PMID:Frequency of glucose-6-phosphate dehydrogenase, pyruvate kinase and hexokinase deficiency in the Saudi population. 394 60

A 12-year-old male of Chinese ancestry had life-long hemolytic anemia attributed to alpha-thalassemia. Restriction endonuclease mapping of his DNA revealed that in reality, he had three alpha-globin loci, but he was homozygous for pyruvate kinase deficiency. The new pyruvate kinase variant carried by this patient was characterized and designated PK Fukien.
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PMID:Coexistence of alpha-thalassemia and a new pyruvate kinase variant: PK Fukien. 629 20

The activity of 18 red blood cell (RBC) enzymes and reduced glutathione (GSH) content were measured in 70 normal subjects, in 50 heterozygous beta-thalassaemia carriers and in 50 non-thalassaemic patients with haemolytic anaemia and high reticulocyte counts. In addition, pyrimidine 5'nucleotidase (P5N) activity was also determined in 34 patients with hypochromic, microcytic, iron deficiency anaemia. beta-Thalassaemia trait was associated with an increase in almost all of the enzyme activities, except for 2,3-bisphosphoglycerate synthetase (BPGS) and glutathione reductase (GR) which were normal and for acetylcholinesterase (AChE) and P5N which were slightly and markedly decreased respectively. The increases in enzyme activities were similar to those observed in patients with non-thalassaemic reticulocytosis except for glyceraldehydephosphate dehydrogenase (GAPD), phosphoglyceratekinase (PGK), pyruvate kinase (PK), glutathione peroxidase (GPX) and adenylate kinase (AK) which were higher than in non-thalassaemic group of patients with increased number of reticulocytes. No correlation was found between the severity of P5N deficiency and the intensity of basophilic stippling which was present in 46 of 50 thalassaemic carriers here studied. In addition, GSH content and UV absorption spectra of deproteinized thalassaemic RBC extracts were also found to be normal. The present findings provide further information on the metabolic status of RBC in beta-thalassaemia trait and suggest a possible molecular explanation for the frequently observed basophilic stippling in this disease.
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PMID:Pyrimidine 5'nucleotidase and several other red cell enzyme activities in beta-thalassaemia trait. 632 Aug 62


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