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Biomedical subjects

C Altay

Publications and source records attributed to C Altay.

At least 91 records · Page 5Linked to original sources
PubMed1981

In vitro synthesis of hemoglobin and hemoglobin chains in the BFUe-derived colonies form person with alpha- or beta-thalassemia.

The synthesis of alpha and non-alpha chains of human hemoglobin (Hb) was studied in reticulocytes and in BFUe-derived cell colonies from patients with alpha chain or beta chain deficiencies. The subjects included normal adults (alpha alpha/alpha alpha) with or without a beta chain variant (Hb S, Hb Leslie) or an alpha chain variant (Hb G-Georgia); alpha-thalassemia-2 heterozygotes (alpha 0 alpha/alpha alpha) with an alpha chain variant (G-Georgia or G-Philadelphia); an alpha-thalassemia-1 heterozygote (alpha 0 alpha 0/alpha alpha); alpha-thalassemia-2 homozygotes (alpha 0 alpha 0/alpha 0 alpha) with a beta chain variant (Hb S), an alpha chain variant (G-Philadelphia), a Hb S homozygosity with Hb G-Philadelphia, or a Hb G-Philadelphia homozygosity; and three black beta +-thalassemia homozygotes. Data from reticulocyte in vitro synthesis analysis showed the expected deficiencies. However, similar analyses of the Hb synthesized in cell colonies (even from the black beta-thalassemia homozygotes) gave (nearly) balanced sigma alpha/sigma non-alpha ratios. It is speculated that this balanced synthesis is due to a most effective proteolysis in the immature erythroblast which rapidly removes free alpha or beta chains. The levels of Hb F and Hb A2 were considerably increased in these proerythroblasts; a two- to threefold increase in the synthesis of Hb A2 was observed over that seen in the reticulocytes.

Adolescent↗
PubMed1981

alpha-thalassemia-2 and the variability of hematological values in children with sickle cell anemia.

Seventy children homozygous for Hb S (SS) and their 111 heterozygous (AS) parents were evaluated through their erythrocytic indices, hemoglobin composition, and occasionally through in vitro Hb chain synthesis values. Three groups of SS patients and of AS parents were identified based on differences in degree of microcytosis (MCV) and (degree of hypochromia (MCH) values. The level of Hb S in the Hb S heterozygotes showed a trimodal distribution. Five SS patients had an alpha-thalassemia homozygosity (alpha(0) alpha/alpha(0) alpha; beta(s)/beta(s) which was characterized by a distinct microcytosis and hypochromia (MCV), less than or equal to 70 fl; MCH, less than or equal to 22 pp). Nine SS patients had an alpha-thalassemia heterozygosity (alpha(0)/alpha/alpha alpha; beta(s)/beta(s)) with an MCV value of 71 to 78 fl, and an MCH value of 21.3 to 26.5 pg. Four AS parents had an alpha-thalassemia-2 homozygosity with values of MCV less than or equal to 71 fl and MCH less than or equal to 23.5. The level of Hb S was less than 31%. Thirty-nine AS parents had an alpha-thalassemia-2 heterozygosity characterized by an MCV value of 72 to 79 fl, an MCH value of 23.6 to 26.5, and a level of Hb S ranging between 31.0 and 36.8%. The Hb A2 level in SS patients was significantly correlated with the RBC counts and the MCV and MCH (r = 0.38, -0.52, and -0.47, respectively). Significant correlations in AS parents were also noted between the MCV, MCH, RBC, and Hb S percentages (r = 0.62, 0.68, and -0.49, respectively). Although the data are limited, the simultaneous occurrence of an alpha-thal-2 homozygosity seems to decrease the level of Hb F in sickle cell anemia. The presence of an alpha-thal-2 heterozygosity or homozygosity together with an SS or AS condition resulted in identifiable hematologic phenotypes.

Adolescent↗
PubMed1981

Clinical and hematological evaluation of two delta 0 beta 0-thalassemia homozygotes.

Two homozygous delta 0 beta 0-thalassemia patients, one with the G gamma A gamma type and the other with the G gamma type, and their heterozygous parents are described. Red cell indices among the heterozygotes with the G gamma A gamma type of delta 0 beta 0-thalassemia were markedly different from those in heterozygotes with the G gamma type. However, the imbalance in in vitro hemoglobin synthesis was quite similar in the two heterozygous conditions. The same was observed for the homozygous patients; the in vitro chain synthesis was severely imbalanced as seen in beta-thalassemia major. The clinical and some of the hematological findings were milder in the G gamma-delta 0 beta 0-thalassemia homozygote than in the G gamma A gamma-delta 0 beta 0-thalassemia homozygote. The death of a sibling of the G gamma-delta 0 beta 0-thalassemia homozygote with a diagnosis of thalassemia major suggests that both types of delta 0 beta 0-thalassemia could follow a severe clinical and hematological course. The discovery of the G gamma type of delta 0 beta 0-thalassemia in a Turkish child shows that two types of delta 0 beta 0-thalassemia can be found in that country. Differentiation between the two types can only be made through structural analyses of Hb F.

Child↗
PubMed1981

Quantitation of three types of gamma chain of HbF by high pressure liquid chromatography; application of this method to the HbF of patients with sickle cell anemia or the S-HPFH condition.

A modification of a high pressure liquid chromatographic (HPLC) procedure is described that enables the complete separation and quantitation of the A gamma T, A gamma I, and G gamma chains in human fetal hemoglobin. The method, which is fast and accurate, requires 5 to 2000 micrograms Hb F. The purity of the Hb F is not essential and admixture of up to 70% adult Hb does not interfere with the determination. The method has been applied to the Hb F of 64 Black SS patients and 7 persons with the Hb S-HPFH (G gamma A gamma type) conditions. (A) Both "adult" G gamma to A gamma (2:3) and "newborn" G gamma to A gamma (3:2) ratios were observed in adult SS patients, 8 yr and older. Only 12% of the SS patients had the "newborn" ratio. This high G gamma to A gamma ratio may be due to a modification of the genetic switch mechanism that regulates the change of this ratio after birth. (B) Intermediate G gamma to A gamma ratios were only found in young SS patients, 5 yr of age or less. The results suggest a delayed switch of the newborn leads to adult ratio in sickle cell anemia. (C) The A gamma T chain was present in only 6% of all SS patients. One patient is homozygous for this variant chain. (D) Three of the 7 subjects with Hb S-HPFH were positive for the A gamma T chain. Its percentage was low, which suggests that the A gamma T chain gene is in trans of the HPFH determinant. (E) Quantitation of the three gamma chain types is also possible in the Hb F from Hb S heterozygotes with (nearly) normal Hb F levels. Such an analysis is useful for an evaluation of genetic conditions involving variations in the production of (different types of) Hb F.

Adolescent↗
PubMed1980

Hematological evaluation of patients with various combinations of alpha-thalassemia.

Six patients and their parents from five different families with Hb H have been evaluated clinically and hematologically. Previous studies using restriction endonuclease mapping technique indicated that alpha-thalassemia determinants in these cases are heterogeneous. Only one of the five cases have the usual genotype for Hb H, which is characterized by an alpha-DNA-specific fragment of 20 kb long by Eco RI digestion. Three cases from two different families have Hb H disease with alpha-specific DNA fragments of 22.5 kg/2.6 kg long; and the other two have alpha-specific DNA fragments of 20 kb/2.6 kg long, in Eco RI digestion of the cellular DNA. The hematological examination of the parents suggests that the alpha-thalassemia condition associated with the Eco RI fragment of alpha-specific cellular DNA of approximately 22.5 kb long produces an alpha-thal-2-like clinical condition, while the other alpha-thalassemia determinant associated with a fragment 2.6 kg long results in an alpha-thal-1-like clinical condition. The clinical and hematological findings of the cases with 22.5 kb/2.6 kb fragment patterns were more severe than the case with the 20 kb/2.6 kb combination. This study suggests that variation in the clinical and hematological findings among patients with Hb H disease may well reflect a heterogeneity of the genotype combination.

Adult↗
PubMed1980

Defective bactericidal function of polymorphonuclear neutrophils in children with measles.

Killing capacities of polymorphonuclear neutrophils (PMN) and the serum opsonic activity were investigated in 15 children with measles. Seven of them had bacterial infection secondary to the measles. The mean values for killing capacities of the patients were significantly impaired when they were compared with those of the control group which consisted of 15 healthy age-matched children (p less than 0.001). These defects were found to be present during the early stages of the measles. The serum opsonic activity was found to be normal.

Child, Preschool↗
PubMed1979

The molecular basis of alpha-thalassemias: frequent occurrence of dysfunctional alpha loci among non-Asians with Hb H disease.

Study of Asians has previously indicated that deletion of alpha-globin structural genes is the predominant lesion in alpha-thalassemias and that Hb H disease occurs when three of four normal alpha loci per cell are deleted. To test the generality of this model, Hb H disease DNAs of both Asian and non-Asian origin were analyzed by restriction endonuclease mapping using the technique of Southern (1975). Whereas in normal DNA, alpha sequences are present in a single Eco Rl fragment of cellular DNA approximately 22.5 kb long, fragments of 22.5, 20 and 2.6 kb were found in various Hb H disease DNAs. The 20 kb Eco Rl fragment alone, in which a single alpha-globin structural locus resides, was found in Asian Hb H disease DNA. This finding is consistent with the deletion model of alpha-thalassemia. In contrast, seven of eight non-Asian Hb H disease DNAs displayed a more complex molecular composition. The fragment patterns observed were 22.5 kb alone, 22.5 plus 2.6 kb, 20 plus 2.6 kb and 20 kb alone. Non-Asian Hb H disease DNAs contained one, two or three alpha loci per cell in contrast to the one locus predicted by the simple deletion model of alpha-thalassemia. The data are best explained by the existence of defective alpha loci in certain individuals with alpha-thalassemia, particularly outside the Asian population. Restriction mapping of the 20 kb Eco Rl fragment found in Asian and some non-Asian Hb H disease DNAs demonstrated a striking similarity in the placement of restriction sites about the single alpha gene compared with sites about the two genes in the 22.5 kb Eco Rl fragment seen in normal DNA. These data are consistent with origin of the 20 kb fragment from the 22.5 kb normal Eco Rl fragment by either unequal crossing-over or a deletion event. The molecular heterogeneity and frequent occurrence of defective alpha loci in non-Asian Hb H disease DNAs described here may explain, in part, the clinical heterogeneity of alpha-thalassemias and the absence of the homozygous deletion state (hydrops fetalis) in non-Asians. Further study of cellular DNA fragments containing the defective alpha loci identified in this work may indicate the types of specific mutations responsible for abnormal globin gene expression and complement similar studies on abnormal beta genes in beta-thalassemias.

Asia↗
PubMed1979

Myeloperoxidase activity and bactericidal function of PMN in iron deficiency.

In children with iron deficiency anemia, bactericidal capacity of polymorphonuclear leukocytes (PMN) and serum opsonic activity were studied. Nitroblue tetrazolium test (NBT), hexose monophosphate (HMP) shunt activation, and myeloperoxidase (MPO) activity of PMN of these cases were also examined. Bactericidal capacity and HMP shunt activation were found to be decreased in iron deficiency anemia ( p less than 0.001). MPO activity, NBT test, and serum opsonic activity were found to be within normal limits. After 1 1/2 months of iron therapy there was an improvement in bactericidal capacity and it returned to a normal level after 3 months of therapy.

Adolescent↗
PubMed1979

Deletion of the A gamma-globin gene in G gamma-delta beta-thalassemia.

In an individual homozygous for G gamma-delta beta-thalassemia, a physical alteration in gamma-globin gene organization was detected by restriction enzyme mapping. The data indicated that the absence of A gamma-globin chains resulted from extension of the DNA deletion from the delta beta-globin gene region into the gamma-globin gene region rather than a functional disturbance of gamma-gene expression.

Child↗
PubMed1978

Application of endonuclease mapping to the analysis and prenatal diagnosis of thalassemias caused by globin-gene deletion.

We applied a recently developed and more direct technic to diagnose thalassemia syndromes associated with deletion of particular globin structural genes and to assess a fetus at risk for one of those conditions, deltabeta-thalassemia. The method allows assessment of the globin genes present in total cellular DNA and is applicable to amniotic-fluid cell DNA. Cellular DNA fragments produced by cleavage using two specific restriction endonucleases are separated on the basis of size by agarose-gel electrophoresis, and the distribution of specific sequences among the DNA fragments determined by molecular hybridization. We observed the total deletion of alpha-globin genes in homozygous alpha-thalassemia (hydrops fetalis with hemoglobin Bart's) and the deletion of particular beta and beta-like sequences in cases homozygous for hereditary persistence of fetal hemoglobin and deltabeta-thalassemia. Analysis of amniotic-fluid cell DNA from a fetus at risk for deltabeta-thalassemia demonstrated the feasibility of these improved methods for antenatal diagnosis. The molecular studies confirmed the diagnosis predicted by analysis of fetal blood and established at birth.

Adult↗
PubMed1978

Hemoglobin S and some other hemoglobinopathies in Eti-Turks.

Frequencies of various hemoglobinopathies were examined in a total of 1,922 individuals of Eti-Turk origin by electrophoretical techniques. Hemoglobin A2 (Hb A2) and hemoglobin F (Hb F) determinations were also performed in 651 and 1,642 cases, respectively. Mean hemoglobin S (Hb S) frequency was found to be 15.3%. Variations among the different age groups were insignificant. Hemoglobin E (Hb E) and beta-thalassemia frequencies wer 0.47 and 1.23%, respectively. Hemoglobin Hacettepe and hemoglobin D were found once. Red cell glucose-6-phosphate dehydrogenase (G6PD) deficiency was found in 6.5% of males.

Adolescent↗
PubMed1977

alpha-Thalassemia and beta-thalassemia in a Turkish family.

A Turkish family is described in which three children have a clinical picture similar to that of thalassemia major, with typical red cell morphology and indices, and with about 10% Hb Bart's but without measurable amounts of Hb H. Hematological evaluation of six members of this family that included in vitro hemoglobin synthesis suggests that beta-(or delta beta-) thalassemia, beta-silent thalassemia, and mild and severe alpha-thalassemia genes are present in different combinations. The data indicate that beta/alpha chain ratios in patients with more than one type of thalassemia should be evaluated in relationship to values obtained for several relatives even though some of the thalassemia determinants may be silent in the parents.

Adolescent↗
PubMed1977

Hemoglobin alpha chain deficiency in black children with variable quantities of hemoglobin Bart's at birth.

Hematologic and globin chain synthesis studies have been made in 21 children, aged 2 to 6 years, many of their parents, and several normal adults and alpha-thalassemia heterozygotes. At birth, 11 children had about 5% hemoglobin (Hb) Bart's, 5 had about 2% Hb Bart's, and 5 had no trace of Hb Bart's. A significant decrease in mean corpuscular volume. (MCV) and mean corpuscular hemoglobin (MCH) values and an increase in the beta/alpha ratio was observed in the first group; microcytosis and hypochromia were absent in the children of the second group although the beta/alpha ratio was significantly increased. The alpha chain deficiency is familial. Increased alpha/alpha ratios were present in many parents although only two parents of children with 5% Hb Bart's at birth had hematologic findings suggestive of the presence of the same type of defect as observed in the children with the larger amount of Hb Bart's at birth.

Adult↗