摘要:

We describe a rare set of monozygotic twins with coexistent sickle cell anemia andα-/ααthalassemia who have asynchronous painful crises of different frequency and severity. Studies include measurements of cell deformability and other hemorheologic tests, cell density distribution, the percentage of irreversibly sickled cells, adherence of red cells to endothelial cells, membrane he me and membrane free iron, calcium containing internal vesicles and serum antioxidants. Results of these studies, including estimates of organ damage (bone, spleen, retina), were similar except for an increase in red cell membrane free iron in the patient with more frequent and severe painful crises. The study supports the concept that non-inherited factors are important contributors to the frequcncy and severity of painful crises in sickle cell anemia.

ISSN:0363-0269    

DOI:10.3109/03630269109027877

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

The presence of point mutations at position -202 relative to the mRNA Cap site of both human fetalγ-globin genes is linked with elevated fetal globin levels in adults. The question addressed in this study is whether the -202 mutation affectsγ-globin gene expression in the same manner as the -117 hereditary persistence of fetal. hemoglobin (HPFH)Aγ-globin mutation. The -117 mutation was found to cause over-expression and confer inducibility of a retro-virally transferredγ-globin gene in cytosine arabinoside (araC)-treated KMOE cells in an earlier study. In this study, fetal globin genes driven by either the normalGγor -202 HPFHGγ-globin promoter were retrovirally transferred into human erythroid HOE cells. The -202 HPFH mutation did not cause over-expression or confer inducibility of the transferredγ-globin gene in araC-treated KMOE cells. Thus, the -202 HPFH mutation affectsγ-globin gene expression by a different mechanism than the -117 HPFH mutation. Furthermore, this study provides evidence against a general increasing ofγ-globin gene expression as might be expected from the -202 mutation altering binding of a ubiquitous factor such as Spl.

ISSN:0363-0269    

DOI:10.3109/03630269109027878

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

Hb Cleveland is characterized by two amino acid Substitutions, namelyβ121(GH4)Glu→Gln as in Hb D-Los Angeles andβ93(F9)Cys→Arg as in Hb Okazaki, and shares with Hb Okazaki a decreased stability, an increase in oxygen affinity, and decreases in Bohr effect and heme-heme interaction. It is the 13thβchain variant with two substitutions that has been described thus far.

ISSN:0363-0269    

DOI:10.3109/03630269109027879

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

A 50-year-old Japanese female patient was found to have hemolytic anemia. Isoelectrofocusing of her hemolysate revealed two abnormal hemoglobin bands, one of which wasveryclose to the Hb A2band, and the other between the Hb A2and Hb F bands. CM-cellulose column chromatography of the globin prepared from the abnormal hemoglobin showed that the abnormal chain eluted faster than the normalβandδchains; theβXchain, however, did not separate from the normalβchain in urea cellulose acetate electrophoresis. An instability test of the patient's hemolysate revealed the presence of an unstable component. Structural analysis of the abnormal B chain indicated that the histidine residue atβ92(F8) was replaced by an asparagine or aspartic acid residue. DNA amplified by poly-merase chain reaction was sequenced by the dideoxy method. The nucleotide sequence of theβ92 codon wasAAC instead ofCAC, suggesting that the amino acid substitution corresponded to His→tAsn, which is the same as is found in Hb Redondo or∼92(F8)His→Asn→Asp.

ISSN:0363-0269    

DOI:10.3109/03630269109027880

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

Hb Westmead orα2122(H5)His→Glnβ2 is one of the most common hemoglobin variants in Guangxi, a province in Southern China. Theα2-globin DNA sequence of a carrier for this variant was selectively amplified by the polymerase chain reaction and analyzed with the restriction enzyme Stu I. We found that this mutant globin was encoded at theα2 locus and that the CAG→CAG mutation at codon 122 created a new Stu I restriction site. It is easy to detect this mutation by these methods.

ISSN:0363-0269    

DOI:10.3109/03630269109027881

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269109027882

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269109027883

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269109027884

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269109027885

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269109027886

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor