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Biomedical subjects

P Pootrakul

Publications and source records attributed to P Pootrakul.

At least 37 records · Page 2Linked to original sources
PubMed1990

Beta-thalassaemia/haemoglobin E tissue ferritins. I: Purification and partial characterization of liver and spleen ferritins.

Ferritins from liver and spleen of both beta-thalassaemia/haemoglobin E (HbE) and non-thalassaemic patients were purified by heating a methanol-treated homogenate, followed by molecular exclusion chromatography. The concentrations of ferritins in the beta-thalassaemia/HbE liver and spleen were calculated as 3.8 and 2.0 mg/g wet tissue. The beta-thalassaemia/HbE ferritin iron/protein ratios were higher than those of normal ferritins. On PAGE, all ferritins gave a single major monomeric band with only very small differences in their mobility. Ferritins from thalassaemic patients also possessed bands corresponding to oligomers. On SDS/PAGE, all ferritins were resolved into two major subunits: H and L with L subunit predominating. While the isoferritin profiles of ferritins from beta-thalassaemia/HbE liver and spleen were similar to each other and to those of normal liver and spleen, some extra bands were present in the acidic region. The microstructure of these pathological ferritins appears to result, to a large degree, from the particular nature and amount of iron loading present.

Electrophoresis, Polyacrylamide Gel↗
PubMed1990

Beta-thalassaemia/haemoglobin E tissue ferritins. II: A comparison of heart and pancreas ferritins with those of liver and spleen.

Tissue ferritins from beta-thalassaemia/haemoglobin E heart and pancreas were characterized by native PAGE, SDS/PAGE and isoelectric focussing, and compared with those isolated from corresponding liver and spleen tissue. On PAGE, all ferritins consisted of a single band assigned to the protein monomer. Small differences in electrophoretic mobility were found between the bands. The ferritins were resolved by SDS/PAGE into two major subunits, H and L, corresponding to molecular masses of 22.5 kDa and 19 kDa, respectively. The L subunit was predominant in all cases. The isoferritin profiles of all tissue ferritins were remarkably similar, consisting of a complex pattern of bands which were appreciably more basic than those obtained for horse spleen ferritin. The subunit composition and isoferritin profiles of the four tissue ferritins almost certainly reflect the defense mechanism of the body in synthesizing in all four tissue types a more stable long-term iron-storage isoferritin in order to detoxify and store the excess iron present due to the pathological condition of beta-thalassaemia/HbE.

Electrophoresis, Polyacrylamide Gel↗
PubMed1989

Analysis of hematological data of thalassemia cases in Thailand.

We analyzed the complete blood count (CBC) obtained from patients with various types of thalassemia in Thailand. As a control, samples from healthy donors and patients with iron deficiency anemia were also collected. Most cases of thalassemia could be differentiated from iron deficiency anemia by using a discrimination function equation. This screening method is applicable for mass-screening of patients with latent thalassemia in Thailand.

Erythrocyte Count↗
PubMed1988

A WHO collaborative study on iron supplementation in Burma and in Thailand.

Studies on the treatment and prevention of iron deficiency anemia, in pregnant and nonpregnant women and in men, were conducted in Thailand and Burma. The effects of the dose of Fe, duration of Fe administration, additional supplementation with folate, mode of supplement delivery (either supervised or unsupervised), and the presence of Hb(AE) were studied. The frequency and severity of side effects were also recorded. Fe administration resulted in an increase in hemoglobin concentration in all anemic individuals but approximately 20% failed to reach normality. The length of administration and the dose influenced the results. Frequency and severity of side effects increased with the dose of Fe administered. Folate supplementation did not affect the results. It appears possible to integrate a program of prevention and treatment of Fe deficiency anemia in a primary health-care system but the constraints and limitations of achievable results should be recognized.

Adult↗
PubMed1988

Investigation of the causes of suboptimal haemoglobin response to iron supplementation.

The investigation concerned 572 children, 6-11 years of age, who were divided into three groups: urban control, rural control and rural study. During the first phase of supplementation, each child received 120 mg of elemental iron (as ferrous sulphate) with 0.50 mg of folic acid daily for 60 school days (five days a week) which resulted in a suboptimal haemoglobin concentration. During the second phase, all groups continued to take iron-folate tablets for 60 school days while the children in the study group also received protein, vitamins and minerals. Final blood examinations showed no significant difference in mean haemoglobin concentrations between the rural study and rural control groups. Only 1.5% of all children had haemoglobin below 12 g/dl. It can therefore be concluded that strict supervision of iron tablet intake and long-term supplementation with iron are essential for optimal haemoglobin response.

Child↗
PubMed1988

Quantitation of ferritin iron in plasma, an explanation for non-transferrin iron.

In 33 patients with thalassemia and idiopathic hemochromatosis, plasma ferritin protein levels ranged from 36 to 5,850 micrograms/L. The iron content of this ferritin as determined by immunoprecipitation ranged from undetectable amounts to 507 micrograms/L. The mean iron content of ferritin protein in those and other subjects with plasma ferritin concentrations of over 1,000 was 6.8% +/- 2.7%. Plasma transferrin was usually saturated with iron in patients with measurable ferritin iron, but exceptions occurred. In studies using electrophoretic separation, it was shown that some ferritin iron moved to transferrin during in vitro incubation, whereas exchange in the opposite direction was extremely limited. Because some plasma ferritin iron was measured by the standard colorimetric plasma iron determination, these observations (a) indicate that plasma ferritin contains a significant amount of iron (b) indicate that a significant proportion of nontransferrin iron in individuals with nontransferrin iron as detected by standard plasma iron and total iron-binding capacity measurements is due to the presence of ferritin, and (c) suggest that large amounts of ferritin iron may affect the saturation of plasma transferrin.

Child↗
PubMed1988

The effect of erythroid hyperplasia on iron balance.

Measurements of erythropoiesis and iron balance were made in eight normal and 32 anemic subjects. The latter consisted of 12 individuals with ineffective erythropoiesis (beta-thalassemia/hemoglobin E), 13 subjects with ineffective erythropoiesis and hemolytic anemia (hemoglobin H), and seven subjects with hemolytic anemia (hereditary spherocytosis). A consistent relationship within each group existed between the degree of erythropoiesis and radioiron absorption. Although the effect of erythropoiesis on iron absorption was of similar magnitude in the two thalassemia groups, the effect in hereditary spherocytosis was much less. There was agreement between absorption and ferritin or magnetic susceptibility (SQUID) measurements of iron stores in thalassemia, but in hereditary spherocytosis a discrepancy existed between absorption and ferritin. It is concluded that, although increased erythropoiesis is associated with increased iron absorption, some additional factor associated with red cell breakdown is more directly responsible for the positive iron balance in thalassemia.

Adolescent↗
PubMed1987

A mild uncompensated alkalosis in anemia.

Blood, pH and bicarbonate were examined in 40 normal subjects and in 53 patients with anemia. Included were 28 patients with thalassemia, 18 with aplastic anemia and seven with iron deficiency anemia. Mean increases in pH of 0-0.04 and decreases in HCO3 of 2.3-3.5 mEq/L were observed. Changes were not significantly affected by the degree of erythropoiesis or by the severity of the anemia and were essentially the same in the three groups of patients studied. Typical changes of a mild, uncompensated alkalosis were also produced on four occasions in one transfused thalassemic patient.

Adolescent↗
PubMed1987

Erythroid marrow function in anemic patients.

Erythropoietic activity is known to be closely associated with marrow iron uptake. A modification of the standard measure of plasma iron turnover has been developed in which erythron transferrin uptake (ETU) rather than iron uptake has been calculated. The ETU has the advantage of providing a parameter of erythroid marrow activity independent of change produced by plasma iron and transferrin saturation. Measurements in 80 patients with anemia were compared to the normal value of 60 +/- 12 mumol/L whole blood/d. The mean ETU for ten patients with severe aplastic anemia and for six patients with pure red-cell aplasia were 12 +/- 8 and 12 +/- 11 mumol/L whole blood/d, respectively. In ten transfusion-dependent patients with renal failure under dialysis therapy, the mean value was 35 +/- 11, while ten other dialyzed patients who were transfusion independent had a mean ETU of 73 +/- 21 mumol/L whole blood/d. Sixteen patients with hemolytic anemia had an average ETU of 400 +/- 130, while 28 patients with ineffective erythropoiesis had a mean value of 474 +/- 147 mumol/L whole blood/d. While patients with hypoproliferative anemia showed no relation between the severity of anemia and ETU, those with hyperproliferative erythroid marrow showed increasing values as the anemia became more severe. Sequential measurements in patients with aplastic anemia under treatment and in thalassemic patients under transfusion therapy showed the value of this measurement in monitoring the effects of treatment on erythroid marrow activity. It is concluded that the measurement of ETU provides a more direct ferrokinetic evaluation of erythroid activity in anemic states.

Acute Kidney Injury↗
PubMed1987

Plasma iron and transferrin iron-binding capacity evaluated by colorimetric and immunoprecipitation methods.

We evaluated plasma iron (PI) and total iron-binding capacity (TIBC) or transferrin in normal individuals and in patients with iron imbalance. The standard colorimetric measurements of PI and TIBC and the standard isotope-dilution measurement of TIBC were compared with an immunoprecipitation method and also with immunoelectrophoresis of transferrin. PI concentrations as measured by the standard and immunoprecipitation methods agreed closely for all individuals except those with saturated transferrin, where nontransferrin iron increased the results in the standard assay. This excess iron in saturated plasma may be derived from either free iron or iron-bearing ferritin. There were also differences in TIBC between the two methods. Iron-deficient sera gave higher values for transferrin when measured by immunoelectrophoresis. Unsaturated iron-binding capacity was increased in the isotope-dilution method in some iron-saturated plasma, compounding errors when added to erroneously high PI values to compute TIBC. Perhaps some exchange of iron occurred between added iron and transferrin iron in the isotope-dilution method. These measurements confirm the accuracy of the standard colorimetric method of measuring PI and TIBC except in iron-saturated plasma. However, the greater specificity of a polyclonal immunoprecipitation method of measuring PI and TIBC makes it particularly useful in differentiating transferrin-bound iron from nontransferrin iron.

Colorimetry↗
PubMed1987

Adequacy of iron supply for erythropoiesis: in vivo observations in humans.

The adequacy of tissue iron supply was examined with ferrokinetic techniques in subjects with decreased plasma iron concentration and in subjects with a normal plasma iron concentration but with increased tissue iron requirements. The competition by transferrin receptors for diferric vs monoferric transferrin was measured in eight normal persons and eight with iron deficiency. There was a highly significant (P less than 0.001) decrease in receptor preference for diferric transferrin in subjects with iron deficiency, indicating an insufficient amount of iron-bearing transferrin to saturate tissue receptors. The adequacy of the plasma iron supply was also examined by determining the number of iron-bearing transferrin molecules with receptors at normal and elevated plasma iron concentrations. Significant increases were found at the higher plasma iron concentration, not only in patients with iron deficiency, but also in patients with sickle cell anemia and thalassemia. Furthermore, the increase in the latter two groups was shown to be proportional to the degree of erythroid hyperplasia. These data indicate that tissue iron supply must be evaluated in terms of both plasma iron supply and erythropoietic requirements and that a relative iron deficiency is frequent in patients with erythroid hyperplasia.

Anemia, Hypochromic↗