摘要:

The major hemoglobin component Hb A of the tuatara, Sphenodon punctatus. a relict of the rhynchocephalian reptiles that lived 200 million years ago, was investigated in the light of the apparent contradiction inherent in an effect of organic phosphate cofactors on the oxygen affinity of hemoglobins exhibiting hyperbolic oxygen equilibrium curves. The heterotropic allosteric effect of ATP, the major erythrocytic cofactor in the tuatara, is shown to be correlated with distinct homotropic interactions (Hill's cooperativity coefficient at half-saturation, n50, attaining 1.3–1.5 above pH 7.9, and with free energies of heme-heme interaction (4.7 kJ.mole−1at pH 7.2) which resemble those in other vertebrate hemoglobins that exhibit higher n50values. Curiously, chloride ions increase hemoglobin-oxygen affinity below pH±7.2. The possible mechanisms underlying the effects of ATP and chloride are discussed.

ISSN:0363-0269    

DOI:10.3109/03630268908998840

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

An abnormal hemoglobin found in an erythremic blood donor was separable only by isoelectrofocusing, where it was located at the cathodic edge of Hb A. Cation exchange high performance liquid chromatography of a tryptic digest from the total a chain revealed splitting of theαT-6 peak, although our routine procedures failed to uncover the abnormality. This enabled the chemical characterization and quantitation of the abnormal hemoglobin asα41 (C6)Thr→Ser comprising about 30% of the total hemoglobin. The purified hemoglobin showed increased oxygen affinity, decreased subunit cooperativity and effect of organic phosphates, and normal Bohr effect.

ISSN:0363-0269    

DOI:10.3109/03630268908998841

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

The purpose of the present study was to investigate the effect ofα-thalassemia on the prevalence of avascular necrosis in 52 adult patients with sickle cell anemia.α-Globin genotypes were determined by restriction endonuclease mapping of genomic DNA extracted from peripheral blood leukocytes. Radiographs of humeral and femoral heads were interpreted by two radiologists who were not aware of the clinical picture and the genotype of the patients in the study. We present data showing that there is a significant positive correlation betweenα-gene deletion and the prevalence and extent of avascular necrosis in our patient population.

ISSN:0363-0269    

DOI:10.3109/03630268908998842

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Characterization ofβ-thalassemia mutations were attempted for 29 Japanese families clinically diagnosed as havingβ-thalassemia. Following the identification of a mutation by cloning and sequencing, all families were screened for this particular mutation, using biotinylated allele-specific oligonucleotide probes. Seven different mutations were detected in 17 families: Six families had the frameshift mutation at codons 41/42, resulting from a 4 nucleotide deletion (TTCTTT+- - - - TT); four had the deletion at codons 127/128 (CA66CT+CCT); and three had theTATAbox mutation at nucleotide -31 (A→6). Four additional families had mutations at codon 24 (GGT→GGA), codon 26 (GAG→AAG), IVS-11-654 (C→T) and codon 110 (GTG→CCG), respectively. The newly discovered deletion mutation at codons 127/128, and mutations at nucleotide -31, and at codon 110 are peculiar to Japanese, and have not been found in any other ethnic group. The haplotypes of theβ-globin gene cluster were also determined. Some of the haplotypes andβ-thalassemia mutations are identical to those reported in the Chinese population. However, it is noteworthy that nearly half of theβ-thalassemia mutations were unique to Japanese.

ISSN:0363-0269    

DOI:10.3109/03630268908998843

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Details are presented of analyses of hemoglobins in blood samples from four newborn babies with hydrops fetal is using reversed phase and anion exchange high performance liquid chromatographic methodology. Three were homozygous for the a-thalas-semia-1 (SEA) deletion, and one was a compound heterozygote for the same deletion and the largerα-thalassemia-1 (Fil) deletion. All four babies hadβ,Gγ,Aγ, and 5 chains; these chains were present in Hb Bart's orγ4, Hb Portland-I (ζ2γ2), and Hb Portland-II (ζ2β). Hb H (β) could not be detected. The level ofζwas directly related to the level of B and, thus, the fetal age. A lower level of 5 chain was present in the baby with the compound heterozygosity because the large deletion (Fil) on one chromosome included theζandψζgenes. Circulating red cells, i.e. reticulocytes and nucleated red cells, were unable to synthesizeζchains, indicating that this capability must have ceased a few months prior to birth. Quantitative data obtained by chromatographic procedures were greatly influenced by the condition of the blood sample and the way it was stored, Hb Portland-II (ζ2β2) and Hb Bart's (γ4)are rather unstable when a red cell lysate is stored at 4°C; this is in contrast to Hb Portland-I (ζ2γ2) which appears to be stable. Samples can best be stored as washed red cells or red cell lysates at−70°C.

ISSN:0363-0269    

DOI:10.3109/03630268908998844

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268908998845

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268908998846

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268908998847

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268908998848

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268908998849

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor