Hemoglobins fetal

Fetal Hemoglobin Has a Higher Affinity for O9 Because It Has a Lower Affinity for BPG... 

Residue H21 of the y subunit of fetal hemoglobin (HbF) is Ser rather than His. Since Ser cannot form a salt bridge, BPG binds more weakly to HbF than to HbA. The lower stabilization afforded to the T state by BPG accounts for HbF having a higher affinity for Oj than HbA. 

Fetal hemoglobin Is the major hemoglobin of the red cells of the fetus and the newborn. It has the characteristic property of being resistant to denaturatlon by alkali Hb-F Is composed of two a-chalns (the same as In Hbs A and A2) and two... 

Some of the abnormal fetal hemoglobin variants are the product of an allele of the structural locus and others of an allele of the % structural locus The structural abnormality In all eight variants of Hb-A2 has been determined ... 

Hematological Methods. Hematological analyses can Include the determination of the total hemoglobin concentration (In g%), the packed cell volume (PCV In %), the red blood cell count (In 10 /mm ) and reticulocytes count (In %), calculation of the red cell Indices, examination of a blood film, tests to demonstrate the presence of Inclusion bodies and of sickle cells, tests to evaluate the distribution of fetal hemoglobin (Hb-F) Inside the red cells, the red cell osmotic fragility, the concentration of serum Iron (SI), total Iron binding capacity (TIBC), and the survival time of the red cells. Details of all... 

The Determination of Fetal Hemoglobin (Hb-F). Specific properties of Hb-F have given rise to various methods for Its detection and quantitation which are based on electrophoretic and chromatographic mobilities of Hb-F, on Its slow rate of... 

Klelhauer, E. "Fetales Hemoglobin und fetale Erythrocyten . Archiv. Kinderhellk. Belh., 53, F. Enke-Verlag, Stuttgart, Germany, 1966. 

Klelhauer, E. "Determination of Fetal Hemoglobin Elution Technique", In "The Detection of Hemoglobinopathies", p. 

Fetal hemoglobin binds oxygen more tightly than HbA, and it has a decreased propensity to sickling. HbA2 also possesses this characteristic but to a lesser extent. RBCs that contain HbF sickle less readily than cells without. ISCs are found to have low HbF concentrations. In some patients, higher HbF may ameliorate the disease. 

HbF, fetal hemoglobin HbSC, sickle-hemoglobin C HbSS, homozygous sickle hemoglobin Hgb, hemoglobin WBC, white blood cell. 

Fetal hemoglobin (HbF) induction in patients with SCD, especially those with frequent crises, has been shown to decrease RBC sickling and RBC adhesion. A direct relationship between HbF concentrations and the severity of disease have been demonstrated in studies.3... 

Raghavan and Gonick 1977). Fetal hemoglobin appears to have a higher affinity for lead than adult hemoglobin (Ong and Lee 1980c). 

Restriction analysis can be used to detect sickle cell disease prenatally, since the DNA of all cells, including amniotic cells, carries the mutant DNA. It is much more difficult to obtain fetal blood for the analysis of the mutant hemoglobin A P-chain. Furthermore, fetal blood is composed mostly of fetal hemoglobin, sinee-hemoglobin A is made later in development. 

Feature presentations of SCD are hemolytic anemia and vasoocclusion. Symptoms are delayed until 4 to 6 months of age when HbS replaces fetal hemoglobin (HbF). Common findings include pain with fever, pneumonia, splenomegaly and, in infants, pain and swelling of the hands and feet (e.g., hand-and-foot syndrome or dactylitis). 

S. H., Increasing fetal hemoglobin in sickle cell disease comparisons of 5-azacytidine (subcutaneous or oral) with hydroxyurea, Trans. Assoc. Am. Physicians 97 (1984), p. 140-145... 

M. A., Moore, J. W., Hydroxyurea-induced augmentation of fetal hemoglobin production in patients with sickle cell anemia, Blood 69 (1987), p. 109-116... 

Class II devices are those for which general controls alone are insufficient to provide reasonable assurance of safety and effectiveness and for which sufficient information is available to establish special controls to provide this assurance. Special controls may include performance standards, postmarket surveillance, and guidance for analytical/clinical data. Examples of class II IVDs are automated differential cell counters, fetal hemoglobin test systems, sickle-cell tests, and Toxoplasma gondii serological reagents. 

Dover GJ, Brusilow S, Charache S (1994) Induction of fetal hemoglobin production in subjects with sickle cell anemia by oral sodium phenylbutyrate. Blood 84 339-343 El Kharroubi A, Martin MA (1996) cis-acting sequences located downstream of the human immunodeficiency virus type 1 promoter affect its chromatin structure and transcriptional activity. Mol Cell Biol 16 2958-2966... 

A similar adaptive mutation is found in human fetal hemoglobin. This has a lower oxygen affinity than the adult in the absence of phosphate, but it also has a lower affinity for DPG, due mainly to the replacement His H21(143)/3 — Ser. As a result, the oxygen affinity of fetal blood exceeds that of the adult, which helps the transfer of oxygen from the maternal to the fetal circulation across the placenta (5). 

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