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F Galacteros

Publications and source records attributed to F Galacteros.

At least 127 records · Page 7Linked to original sources
PubMed1987

[Hemoglobin Boumerdès alpha 2(37) (C2) Pro----Arg beta 2: a new variant of the alpha chain associated with hemoglobin S in an Algerian family].

We report the first case of Hb Boumerdes, an alpha chain variant alpha 2(37) (C2) Pro----Arg beta 2, in an Algerian family. The propositus was also homozygous for the sickle cell gene. The abnormal hybrid Hb alpha 2Boum. beta 2S had an electrophoretic mobility on cellulose acetate pH 8.7 electrophoresis between those of Hb S and Hb A2. Its expression was about 16%. The alpha 2Boum. beta 2A fraction has a mobility between those of Hb F and Hb S. The effects of this mutation on Hb oxygen affinity and deoxy Hb S polymer formation were not studied. The propositus' sickle cell phenotype was benign.

Adolescent↗
PubMed1987

[Adhesion of diabetic or sickle cell erythrocyte populations to human endothelium in culture].

Erythrocyte adhesion to endothelium was measured using human endothelial cells in culture and a radiometric technique. Erythrocyte adhesion was found to be significantly increased in diabetes mellitus and sickle cell anemia. In both diseases the extent of adhesion was correlated with the clinical severity of the disease. Using 3H Leucine radio-labelled reticulocytes or red cells separated by density gradient according to their age it was possible to further investigate the red cell abnormality responsible for increased adhesion. A population of abnormal reticulocytes in sickle cell anemia exhibited a higher adhesion than the whole red cell population. Diabetic dense red cells (old red cells) appeared to be mostly responsible for the increase in erythrocyte adhesion to endothelium observed in diabetes mellitus.

Adult↗
PubMed1987

Ca2+ permeability and cytosolic Ca2+ concentration are not impaired in beta-thalassemic and hemoglobin C erythrocytes.

Total calcium content, determined by atomic absorption spectroscopy, Ca2+ influx, and cytosolic free Ca2+ concentration ( [Ca]i), estimated by a method involving the incorporation of a Ca2+ chelator (Quin 2), were measured in erythrocytes from beta-thalassemic (beta-thal) and hemoglobin C (CC) patients. Elevation of the total calcium content was observed in the cells from all patients, particularly in CC and splenectomized beta-thal. However, [Ca]i was within the normal range (approximately 25 nmol/L) in all the pathologic cells. Ca2+ influx in CC cells and in cells from nonsplenectomized beta-thal patients was also within the same range as that observed in control erythrocytes. In cells from splenectomized beta-thal patients, the kinetic of 45Ca influx was biphasic, indicating the existence of two pools of exchangeable Ca2+. Density fractionation of the cells from one splenectomized beta-thal patient showed that the rapid pool corresponded to the lightest cell fraction, which was also found to have the highest calcium content. The dense cells exhibited a normal Ca2+ influx as well as a smaller increase in total calcium content. It is suggested that, as in sickle cell anemia, the excess of Ca2+ in beta-thal cells is not free in the cytoplasm but trapped within endocytic vacuoles, especially in a population of abnormal cells that are normally removed by the spleen. In CC patients, who have a functional spleen, a different mechanism could be responsible for the calcium retention. In conclusion, the present results demonstrate that in these two cases of hemolytic anemia associated with high calcium content, Ca2+ permeability and the the level of cytosolic Ca2+ are normal.

Adenosine Triphosphate↗
PubMed1986

Covalent binding of glutathione to hemoglobin. I. Inhibition of hemoglobin S polymerization.

Thiol reagents react with cysteine beta 93 of hemoglobin and as a result increase the oxygen affinity of hemoglobin. In the present studies we have used a thiol-disulfide exchange between mixed disulfides of hemoglobin and reduced glutathione to attach intracellular glutathione to hemoglobin and to study its antisickling properties. The rates of production of glutathionyl hemoglobin (G-Hb) depend on the structure of the thiol reagent linked to cysteine beta 93. Up to 25% G-Hb can be produced in normal and sickle red cells because of the high intracellular concentration of reduced glutathione. This high level of G-Hb in normal cells increases the oxygen affinity by about 35% and reduces heme-heme interactions. In sickle cells the increased oxygen affinity is associated with an inhibition of sickling of about 70% at 21 mm Hg. Inhibition of polymerization of deoxy HbS is also due to a direct inhibition of intermolecular contacts in the fibers as demonstrated by the increased solubility and the increased delay time of G-HbS compared to deoxy HbS.

Binding Sites↗
PubMed1986

Hemoglobin abnormalities. An evaluation on new-born infants and their mothers in a maternity unit close to Brazzaville (P.R. Congo).

In order to evaluate the polymorphism of hemoglobin in a population of Equatorial Africa, we undertook a prospective study of 146 births at a rural maternity hospital close to Brazzaville (P.R. Congo). This showed among the mothers 31 (22%) carriers of the sickle cell trait (AS), six with delta mutation, and two with beta-thalassemia trait. Among the children, 27 (18.5%) had sickle cell trait and one had sickle cell homozygosity. The frequency of the HbF Sardinia trait was 7.5%. This and other studies suggested a dilution gradient from Europe to Africa. Hemoglobin Bart's could be visually detected in 23.3% of the new-born babies. We attempted to distinguish between those infants with a high level of Hb Bart's (Bart's ++ group: 13.7%) and a group with a detectable Hb Bart's level that in our experimental conditions is between 1 and 2% (Bart's + group: 9.6%). Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were 88.6 +/- 5.7 fl and 29.0 +/- 2.1 pg in the Bart's ++ group; 94.5 +/- 10.9 fl and 30.6 +/- 4.1 pg in the Bart's + group; whereas they were 101.0 +/- 8.7 fl and 33.9 +/- 2.5 pg in the control group. Since iron deficiencies are very rare in new-borns and selecting according to published data on black people as homozygous alpha-thalassemia of the type I (-alpha/-alpha), individuals of the Bart's ++ group whose MCV was below 95 fl and MCV below 30 pg, the gene frequency is estimated to be 34% and that of heterozygotes (-alpha/alpha alpha) 45%. These high frequencies were confirmed in AS mothers: 45% showed a significant decrease of the S fraction.

Adult↗
PubMed1986

Hemoglobin S Antilles: a variant with lower solubility than hemoglobin S and producing sickle cell disease in heterozygotes.

We have found a sickling variant, Hb S Antilles, alpha 2 beta 2(6 Glu----Val, 23 Val----Ile), that has the same electrophoretic mobility as Hb S but a distinct isoelectric focus and produces sickling in the carriers of the Hb A/S Antilles trait. The carriers' erythrocytes tend to sickle at O2 partial pressures similar to those that induce sickling in Hb S/C disease. Pure deoxy-Hb S Antilles is 50% as soluble as deoxy-Hb S (saturating concentration = 11 g X dl-1 compared to 18.4 for Hb S). Dilute solutions of pure Hb S Antilles have a lower oxygen affinity than those of Hb A or Hb S (partial pressure for 50% binding is 9 mm Hg compared to 5.5 mm Hg for Hb A or S at pH 7.00). A/S Antilles erythrocytes have a much lower oxygen affinity than A/S cells; this is further decreased in dense cells fractionated on a Percoll density gradient. Their oxygen equilibrium curves had anomalous shapes like those of S/S cells. Fiber formation in the erythrocytes of Hb S Antilles carriers is clearly due to its low solubility and oxygen affinity, showing that heterozygosity for this hemoglobin presents another sickle cell syndrome and suggesting that Hb S heterozygotes who exhibit symptoms of sickle cell disease should be carefully screened for double mutations.

Amino Acid Sequence↗
PubMed1986

Hemoglobin D-Los Angeles [beta 121(GH4)Glu----Gln] in the Province of Liège, Belgium.

Since 1975, more than 19,000 persons have been tested for hemoglobin abnormalities in Liège. Nine unrelated carriers of Hb D-Los Angeles were discovered. They were of Belgian origin. The family of the ninth index case was studied thoroughly. In six generations, 372 descendants of a couple married in 1818 were recorded. Of the 93 tested, 31 were carriers of the Hb D variant. The complete pedigree indicates that Hb D-Los Angeles was already present in Liege province in the 18th century. A connection with India is unlikely.

Adult↗
PubMed1986

Interaction of hemoglobin Siriraj with hemoglobin S: a mild sickle cell syndrome.

Hb Siriraj is a beta chain variant in which beta 7 (A4) Glu is replaced by a lysine. It has been encountered in association with Hb S in a black man from Martinique. Some properties of Hb Siriraj are compared, particularly, with Hb C [alpha 2 beta 26(A3)Glu----Lys], and a study of its in vitro interaction with Hb S is discussed.

Amino Acid Sequence↗
PubMed1986

[Abnormal hemoglobins screened in Tunisia].

We report the complete data we have collected concerning abnormal Hb in Tunisia, and their local repartition. The highest frequencies are observed in the North-West countries.

Genetic Testing↗
PubMed1986

[Screening for hemoglobinopathies and G6PD deficiencies in Morocco].

Screening for abnormal hemoglobins and G6PD deficiency was conducted in adult and new born Maroccans from Casablanca. The results presented deal with HbS and HbC traits, alpha, gamma, and delta mutations, the presence of detectable amount of Hb Bart's and the G6PD deficiency frequency.

Adult↗
PubMed1986

[Epidemiologic study of hemoglobinopathies in the Congo in 2,257 newborn infants].

A systematic examination of 2,257 Congolese newborns from Brazzaville for abnormal hemoglobins has been conducted. Gene frequency for HbS was 0.117; no HbC was found. Of the sample 14.4% had detectable amounts of Hb Bart's. Beta-thalassemia trait frequency was approximately estimated to 0.3%, 5 mutations of gamma chain, and 1 mutation for alpha chain were detected.

Anemia, Sickle Cell↗
PubMed1986

Hémoglobinopathies in France.

A first approximation of the incidences of abnormal hemoglobin traits in France is given. The data include all the large ethnic minorities living in France, and also take into account the second and third generations. We estimate 1.3 X 10(5) and 1.8 X 10(5) individuals with HbS trait and beta-thalassemia trait respectively.

Anemia, Sickle Cell↗
PubMed1986

[Discovery of hemoglobin J Baltimore in an episode of methemoglobinemia in an infant].

A case of a heterozygote for Hb J Baltimore is reported in a French family. This variant hemoglobin was coincidentally discovered during an episode of methemoglobinemia in a 6-week-old baby. The father and one of the brothers were also carriers of the trait. Hematological findings for all of them were normal. As Hb J Baltimore is a frequently occurring hemoglobin variant, we discuss: its possible role in the appearance of methemoglobin, and whether this mutation in different racial groups (Caucasians of West Europe, Canadians, and American blacks) has a common origin or more probably arises from a number of independent mutations.

Electrophoresis↗
PubMed1986

Hb Kokura alpha 2 47 (CE5) Asp----Gly beta 2 in a French Jewish family.

An abnormal hemoglobin was found in a young polycythemic man. Case study showed that the polycythemia was not due to hemoglobinopathy as the blood oxygen affinity was normal. Structural study of this variant permitted the characterization of a Hb Kokura alpha 2 47 (CE5) Asp----Gly beta 2 for the first time in France.

Adult↗
PubMed1985

Kinetics of polymerization of hemoglobin S modified by thiol reagents and by oxidation.

The effects of four thiol reagents on the kinetics of polymerization of hemoglobin S have been studied in high phosphate buffer (1.8 M), in the presence (3 mM) or absence of sodium dithionite, depending on the reduction of mixed disulfides of Hb in the presence of this reducing agent. The effect of oxidized forms (methemoglobin) of HbS on the kinetics of aggregation of deoxyHbS was also studied because of the presence of 33% metHbS when HbS was modified by 4-aminophenyl disulfide. In the presence of sodium dithionite, the delay times prior to polymerization of deoxyHbS modified by N-ethylmaleimide, iodoacetamide and 4-aminophenyl disulfide were, respectively, 1.5-, 1.35- and 1.15-times longer than that of native deoxyHbS. The results indicate that the radicals bound to the cysteine beta 93 residue inhibit the contacts in the polymer formation to various extents but do not modify the size of the nuclei.

Aniline Compounds↗
PubMed1985

Kinetics of water transport in sickle cells.

This paper reports the results of stopped-flow studies on differences in the kinetics of osmotic water transport of sickle and normal erythrocytes. The kinetics of inward osmotic water permeability are similar in sickle and normal red blood cells. In contrast, the kinetics of outward water flux are significantly (approx. 38%) decreased in sickle cells. Deoxygenation does not modify the water influx kinetics in either type of cells, but accelerates considerably the rate of water efflux in sickle cells. No significant variation of water transport kinetics was observed in density-separated cell fractions of either type. The results suggest that membrane-associated hemoglobin may decrease the outward water permeability and that in deoxygenated sickle cells the fraction of hemoglobin S near the lipid bilayer is lower than in oxygenated conditions.

Anemia, Sickle Cell↗
PubMed1985

Clinical manifestations and erythrocyte adhesion to endothelium in sickle cell syndrome.

Painful vasocclusive episodes are one of the most prominent pathological features of sickle cell disease. In addition to abnormal shape and poor deformability, increased adhesion of red cells to endothelium has been reported. On several occasions, we have studied the adhesion of erythrocytes from 30 patients with mixed sickle cell syndromes to evaluate the influence of clinical conditions. The percentage of erythrocytes adhering was significantly higher when erythrocytes from sickle patients were compared with controls (p less than 0.01). Furthermore, adhesion was significantly higher when the patients were in crises (p less than 0.01), and the highest values of all were observed in patients with inflammatory conditions. To investigate the possibility that a limited population of red cells could be responsible for the increase in red cell adhesion, we have measured the HbS concentration in the different washes and found that the HbS concentration was higher in the last washes compared to the first washes. Sickle red cells capable of protein synthesis (young red cells) were labelled with [3H] leucine. The adhesion to endothelial cells of [3H] leucine-labelled red cells was higher than that of the 51Cr-labelled red cells from the same patient. On the other hand, the most dense sickle red cells separated by density gradient adhered to a greater extent than the light red cells. This apparent discrepancy could be partly explained by the presence of [3H] leucine-labelled red cells in the dense fractions of sickle red cells separated by stractan gradient.

Adolescent↗