ABSTRACT
Os espectros de absorçäo obtidos por ressonância eletrônica paramagnética (REP) após oxidaçäo, armazenamento e aqueciemnto de Hb Zurich revelaram numerosos sinais na regiäo de alto campo (g=-) que säo indicativos da formaçäo de hemicromos. Espectros de absorçäo ópticos na regiäo visível obtidos da Hb Zurich oxidada ou de seu precipitado formado espontaneamente mostram aspectos característico da formaçäo de hemicromos. Os sinais de REP aumentam em g =-2) proporcionalmente ao decréscimo em g =-6,37. Além do mais, a relaçäo entre os valores de absorbância em 540 nm (heme) e 280 nm (proteína) näo se alteram durante o aquecimento da Hb Zurich a 50-C e säo similares no precipitado espontâneo desta hemoglobina en na HbA. Estes achados indicam que näo há perda do heme durante os estágios iniciais da desnaturaçäo da Hb Zurich
Subject(s)
Humans , Male , Electron Spin Resonance Spectroscopy , Hemeproteins/biosynthesis , Hemoglobins, Abnormal/metabolism , Hemoglobins, Abnormal/analysis , Hot TemperatureABSTRACT
1. Clinical, hematological, genetic and peripheral blood globin synthesis studies were carried out on 17 symptomatic Brazilian thalassemics and ther parents who live in the northeast of Säo Paulo State. The group inclued 8 beta--thalassemia homozygotes, 7 carriers of at least one beta+ gene, one delta beta-/beta--thalassemia double heterozygote and one beta- homozygote also carrying the alfa-chain variant Hb Hasharon (alfa2 47 His beta2). 2. The mean non-alfa/alfa ratio for globin biosynthesis of the patients lacking HbA (beta- homozygotes and delta beta-/beta- double heterozygotes) was 0.26 ñ 0.11 ( mean ñSD), which is not statistically different from the value of 0.32 ñ 0.06 obtained for the carriers of at least one beta+ gene. In contrast, the mean non-alfa/alfa ratio for the thalassemia major patients (0.22 ñ 0.07) was significantly lower than that obtained for the milder cases (0.34 ñ 0.06) although the beta/alfa ratios for the parents of the two groups were similar. 3. The heterogeneity within this group of Brasilian patients having two thalassemic genes, i.e. 60% who are beta- homozygotes and 40% who are carriers of at least one beta+ gene, is consistent with the Italian origin of most of these patients