摘要:

A family has been observed in which aβthalassemia determinant is inherited over three generations together with high Hb F level (8–12 %) and increased number of fetal-hemoglobin-containing-cells (F-cells). The values of red cell indices and globin chain synthesis ratios, yet typical ofβthalassemia, were significantly shifted to the normal values when compared with those of typicalβthalassemia heterozygotes belonging to the same family group. The occurrence in these individuals of a heterocellular hereditary persistence of fetal hemoglobin (HPFH) determinant and its linkage relationship with theβthalassemia is discussed. In the third generation two adult individuals wereβthalassemia homozygotes having inherited aβthalassemia determinant from one parent and aβthalassemia together with the HPFH determinant from the other. They showed an extremely mild clinical condition, and 11–12 g/dl of mainly Hb F without having ever required blood transfusions. Virtually all the red cells were F-cells in both subjects. The importance of the coexistence of HPFH determinants capable of increasing the size of the F-cell population in patients affected by homozygous thalassemia is discussed, considering the sensible benefit which derives from enhanced Hb F production in this syndrome.

ISSN:0363-0269    

DOI:10.3109/03630268108996907

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

Hemoglobin Hotel-Dieu was detected by isoelectric focusing during investigation of a patient who had erythrocytosis. This variant migrates on cellulose acetate electrophoresis to a cathodic position relative to Hb F. In hemoglobin Hotel-Dieu, aspartic acid is substituted by glycine in position 99 of theβchain. As in other abnormal hemoglobins in which substitution of this residue has occured, Hb Hotel-Dieu exhibits a high oxygen affinity and is associated with familial erythrocytosis.

ISSN:0363-0269    

DOI:10.3109/03630268108996908

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

A patient with a“silent”mutant hemoglobin characterized by high oxygen affinity and erythrocytosis is described. A novel approach was used to identify the mutant chain. Functionally activeαandβchains were prepared from hemolysates of the patient and a normal control. Hybrid tetramers of patient'sαchain with normalβchain and normalαchain with patient'sβchain were prepared. Functional studies revealed that the patient'sβchains had a higher oxygen affinity (P50. 1.1 torr) than normalβchains (P50, 1.7 torr) and the hybrid containing the patient'sβchains had a P50similar to the patient's“stripped”hemolysate. It was assumed Therefore that the mutation was in theβchain; structural studies using cyanogen bromide cleavage revealed that the patient had Hb San Diego,β109 Val⇒Met, and that the patient's cells contained approximately 50 percent mutant hemoglobin.Functional studies were performed on a. series of mixtures of patient's hemolysate diluted with varying amounts of normal hemo-lysate. Regression analysis of the data extrapolated to an assumed 100% Hb San Diego gave values for P50and Hill's constant of 4.8 torr and 1.0. It is proposed that this method, not previously reported, may be useful in evaluating the functional properties of“silent”mutant hemoglobins that cannot be studied in the purified state.

ISSN:0363-0269    

DOI:10.3109/03630268108996909

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

The contribution of the high molecular weight hemoglobin (HMW Hb) to the antisickling effect produced by treatment of sickle cell erythrocytes with methyl acetimidate (MAI) was investigated. Erythrocytes obtained from sickle cell anemia and normal individuals were incubated with varying concentrations of MAI. The presence of intermolecularly crosslinked HMW Hb was detected by gel filtration of dialyzed hemolysates obtained from the incubated cells. HMW Hb has an increased oxygen affinity and a decreased Hill constant. Intermolecular crosslinking per se was shown to have no additional effect on Hb oxygen affinity other than that due to Hb amino group modification. Modified deoxy Hb S of normal molecular weight has a higher minimum gel concentration (MGC) than control deoxy Hb S. Deoxy HMW Hb did not gel at intra-cellular Hb concentrations. Therefore, the incracellular concentration of deoxy Hb S that gels necessarily decreases as the HMW Hb concentration increases. This“excluded volume effect”of the non-gelling Hb would be expected to increase The MGC of completely deoxygenated hemolysate obtained from the treated cells. The HMW Hb contributes to the inhibition of sickling resulting from treatment of sickle erythrocytes with MAI by increasing both MGC and oxygen affinity of the modified Hb.

ISSN:0363-0269    

DOI:10.3109/03630268108996910

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

An antioxidant commonly present in black rubber, N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD) caused very rapid oxidation and denaturation of purified hemoglobin. In the red cells, the reaction resulted in the formation of Heinz bodies, a decrease in reduced glutathione concentration, and stimulation of the hexose monophosphate shunt. IPPD appears therefore to have the potential to induce hemolysis in glucose-6-phosphate dehydrogenase deficiency. It would be expected to be more potent than most redox reagents of this type. It does not require further metabolism to be reactive, and its reactivity is similar to that of phenylhydrazine. But in particular since both IPPD and its oxidized form can oxidize hemoglobin it can act catalytically, and at low concentrations is much more effective than phenylhydrazine. Oxidation of blood stored in contact with rubber seals containing IPPD has been observed. It is also possible that prolonged contact of susceptible individuals either with rubber containing IPPD or to IPPD itself during rubber manufacture could result in hemolysis.

ISSN:0363-0269    

DOI:10.3109/03630268108996911

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268108996912

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268108996913

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

Hemoglobin Hammersmith was detected in a five year old white female suffering from severe anemia first noted at 18 months of age. She has been splenectomized and her peripheral blood red cells were found to contain inclusion bodies.

ISSN:0363-0269    

DOI:10.3109/03630268108996914

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268108996915

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630268108996916

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor