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1.
Rev. bras. hematol. hemoter ; 28(4): 301-302, out.-dez. 2006. ilus, tab
Artigo em Português | LILACS | ID: lil-456243

RESUMO

Oxygen-derived free radical damage is associated with the molecular toxicity of hemoglobin. Especially in thalassemia syndromes, this toxicity has a relationship with "free" alpha globin concentrations. This study of beta thalassemia trait blood samples from 39 individuals shows that the evaluation of methemoglobin is a sensitive method of indicating molecular toxicity and the superoxide dismutase concentration revealing the intensity of oxidative stress of this process.


Assuntos
Humanos , Talassemia beta , Técnicas de Laboratório Clínico , Eritrócitos/metabolismo , Talassemia/metabolismo
2.
Bol. Soc. Bras. Hematol. Hemoter ; 18(173): 75-81, set.-dez. 1996. ilus, tab
Artigo em Português | LILACS | ID: lil-186247

RESUMO

Radicais livres derivados de espécies ativadas de oxigênio estao associados a lesoes citológicas, que diminuem a sobrevida dos eritrócitos, especialmente quando contêm defeitos congênitos, como sao os casos da anemia falciforme e da talassemia maior. As atividades antioxidantes dos eritrócitos dependem de três tipos de enzimas: superóxido dismutase, catalase e glutatiao peroxidase. Entretanto, as atividades antioxidantes podem ser ineficazes em situaçoes em que ocorrem o comprometimento dos hidroxiperóxidos da membrana eritrocitária, devido às células falciformes irreversíveis e à ligaçao de hemicromos à membrana dos eritrócitos talassêmicos.


Assuntos
Humanos , Anemia Falciforme/metabolismo , Eritrócitos/metabolismo , Radicais Livres , Talassemia/metabolismo , Anemia Falciforme/enzimologia , Eritrócitos/enzimologia , Talassemia/enzimologia
3.
Blood ; 69(6): 1742-6, June 1987.
Artigo em Inglês | MedCarib | ID: med-15878

RESUMO

To further explore the cause for variation in hemoglobin F (HbF) levels in sickle cell disease, the á globin restriction-fragment length polymorphism haplotypes were determined in a total of 303 (126SS, 141AS, 17Sá§, 7Aá§, and 12AA) Indians from the state of Orissa. The ás globin gene was found to be linked almost exclusively to a ás haplotype (+++-++-), which is also common in Saudi Arabian patients from the Eastern province (referred to as the Asian ás haplotype). By contrast, the majority of áA and ᧠thalassemia globin genes are linked to hoplotypes common in all European and Asian populations (+-----[+/-];--++-++). Family studies showed that there is a genetic factor elevating HbF levels dominantly in homozygotes (SS). This factor appears to be related to the Asian ás globin haplotype, and a mechanism for its action is discussed. There is also a high prevalence of an independent Swiss type hereditary presistance of fetal hemoglobin (HPFH) determinant active in both the sickle cell trait and in sickle cell disease.(AU)


Assuntos
Humanos , Pré-Escolar , Criança , Adolescente , Adulto , Anemia Falciforme/metabolismo , Hemoglobina Fetal/análise , Globinas/genética , Anemia Falciforme , Haplótipos , Heterozigoto , Homozigoto , Índia , Jamaica , Talassemia/metabolismo
4.
Br J Haematol ; 28(4): 505-13, Dec. 1974.
Artigo em Inglês | MedCarib | ID: med-15892

RESUMO

Globin synthesis was studied in three Jamaican Negro families with 18 heterozygotes and 5 homozygotes for beta-thalassemia. Synthesis of the beta chain of Hb A in the peripheral blood of heterozygotes was equal to that of the alpha-chain in 10 patients and was decreased in the remainder. In one patient with Hb C beta-thalassemia the beta/alpha ratio was normal. These findings were similar to those in American Negroes, but differed from those in Caucasian with beta-thalassemia trait, in each of whom the beta/alpha ratio was decreased. Globin synthesis was balanced in the bone marrows of Negro and Caucasian heterozygotes. Despite the milder clinical disease in Negro homozygotes as compared to Caucasian patients, the beta/alpha ratios were similar in both groups. The presence of alpha-thalassemia combined with beta-thalassemia in Negro heterozygotes is not a likely explanation for the high incidence of balanced globin synthesis ratios. The expression of relative beta to alpha chain synthesis in Negro heterozygotes appears to be modified by a factor which is not linked to the delta-chain locus. The nature of this factor is not known at present.(Summary)


Assuntos
Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Masculino , Feminino , Globinas/biossíntese , Talassemia/metabolismo , Medula Óssea/metabolismo , Hemoglobina C/análise , Heterozigoto , Homozigoto , Talassemia/genética , Talassemia/fisiopatologia , Fragmentos de Imunoglobulinas/biossíntese , Jamaica , América do Norte/etnologia , Linhagem
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