iii hemoglobin forniatiomi am’e present siniult.aneoumsly. As a result of such studies, it has been shown that the genes m’esponsihle for hemogbobins C amid S are very proi)ably ableies,m amid that. the genetic locus involved iii the produmction of these two types of abnormual heniogbobin is imidependemit of the thalassemia locus,2’ although the latter conclusion is complicated by the growing r...

BACKGROUND Erythrocytes are transfused to treat or prevent imminent inadequate tissue oxygenation. 2,3-diphosphoglycerate concentration decreases and oxygen affinity of hemoglobin increases (P50 decreases) with blood storage, leading some to propose that erythrocytes stored for 14 or more days do not release sufficient oxygen to make their transfusion efficacious. The authors tested the hypothe...

The absorption spectrum of deoxygenated human hemoglobin differs from that of the isolated a! and /3 chains, and the difference has been ascribed to the conformational changes on which depends the cooperative ligand binding. Studies on hybrid-heme hemoglobins, in which one chain contains protoheme and the other chain mesoheme, showed that the prominent peak in the Soret region of the difference...

The etiologic agent of chancroid is Haemophilus ducreyi. To fulfill its obligate requirement for heme, H. ducreyi uses two TonB-dependent receptors: the hemoglobin receptor (HgbA) and a receptor for free heme (TdhA). Expression of HgbA is necessary for H. ducreyi to survive and initiate disease in a human model of chancroid. In this study, we used a swine model of H. ducreyi infection to demons...

By MORRIS GOODMAN, PH.D.* AND DAN H. CAMPBELL, Pn.D. T HE DEMONSTRATION by Pauling et al.’ that sickle cell anemia hemoglobin has a slightly higher isoelectric point (0.2 pH unit) than normal human adult hemoglobin and the reports of differences in ability to form nematic liquid crystals2 and solubility differences in strong salt solutions3 suggest that differences might also exist in immunoche...

We have measured plasma volume and cardiac index in rats after 50% isovolemic exchange transfusion with human hemoglobin cross-linked between the alpha-chains with bis(3,5-dibromosalicyl)fumarate (alpha alpha Hb) and with bovine hemoglobin modified with polyethylene glycol (PEGHb). alpha alpha Hb and PEGHb differ in colloid osmotic pressure (23.4 and 118.0 Torr, respectively), oxygen affinity (...

We investigated the suitability of a lyophilized bovine hemoglobin (LBH) preparation containing various fractions of oxyhemoglobin (O2Hb), carboxyhemoglobin (COHb), and methemoglobin (MetHb) for quality assessment in multicomponent analysis (MCA) of hemoglobin derivatives. It was demonstrated that a stable preparation of these components after reconstitution yields a hemoglobin solution that is...

Plasmodium falciparum infecting hemoglobin (Hb)H and/or Hb Constant Spring erythrocytes has higher resistance to artemisinin in vitro than when infecting normal erythrocytes. This is due to low drug accumulation of infected erythrocytes resulting from competition with uninfected variant erythrocytes, which have a higher accumulation capacity than genetically normal cells. Drug accumulation of t...

By MORRIS GOODMAN, PH.D.* AND DAN H. CAMPBELL, Pn.D. T HE DEMONSTRATION by Pauling et al.’ that sickle cell anemia hemoglobin has a slightly higher isoelectric point (0.2 pH unit) than normal human adult hemoglobin and the reports of differences in ability to form nematic liquid crystals2 and solubility differences in strong salt solutions3 suggest that differences might also exist in immunoche...

H UMAN and several other mammalian species sequentially express different globin genes during ontogeny, or during periods of “stress,” such as hypoxemia or anemia. Hemoglobin ontogeny in humans includes three distinct phases. The “embryonic” phase predominates from the 5th to the 16th week of gestation. In this period, embryonic hemoglobin chains are and . Throughout the remainder of gestation ...