The nature of rice bodies was studied, utilizing histochemistry, immunofluorescence, and scanning and transmission electron microscopy. Rice bodies were found to consist primarily of fibrous material, most of which was fibrin with small amounts of collagen. Channels containing a variety of viable cells permeated the rice bodies. Blood vessels occurred in a few rice bodies indicating a former connection with the synovial membrane. Nonvascularized rice bodies might represent a further degeneration of the vascular type. Rice bodies seem to be a nonspecific response to inflammation.

Hyperimmune antisera to chromatographically purified hemoglobins F and A2 were produced in rabbits and made specific for the immunogen by adsorption with normal human hemoglobin A conjugated to cyanogen bromide-activated agarose. A radioimmunoassay was established that permitted identification and quantitation of each of these two minor hemoglobins in hemolysates containing other hemoglobin components. The quantities of hemoglobins A2 and/or F present in hemolysates of individuals with beta-thalassemia, sickle cell anemia, Hb-C disease, and other hematological disorders were determined immunochemically, and the results were commpared to values obtained by microcolumn chromatography for the measurement of Hb-A2 or with the alkali denaturation technique in quantitating Hb-F. The immunoassay procedure has a greater sensitivity than other commonly employed techniques and can detect as little as 0.05 mug of these hemoglobins.

Members of 7 large families, containing 20 patients with sickle cell anemia (SS) characterized by high levels of fetal hemoglobin (HbF), were studied using immunofluorescence to count F cells and a radioimmunoassay to measure small amounts of HbF. In five of these families, one of the sickle cell trait (AS) parents had a much higher HbF and F-cell count than the other; in one family, both parents had a marked increase in HbF and F cells; in the remaining family, HbF and F cells were at borderline values in both parents. Seven of 14 AS siblings, but only 1 of 8 normal hemoglobin (AA) siblings, also had HbF and F-cell counts above the “normal” range. It seems that a factor for increased F cells, linked to the beta S gene of one parent, is segregating in these families and is responsible for the greatly increased HbF and F cells in the SS subjects. HbF per F cell in AS parents and siblings was the same as that of normal AA subjects, whereas in the SS offspring it was greatly increased, suggesting that it was the result of marrow hyperplasia associated with their hemolytic anemia. The similarity of this “increased F-cell gene” to heterocellular hereditary persistence of fetal hemoglobin (HPFH). Swiss type, is discussed, and it is suggested that it may control the persistent synthesis of HbF in sickle cell anemia by its presence in early infancy.

No abstract

A new hernoglobin variant, designated hemoglobin-St Luke's, was detected by routine starch-gel electrophoresis in four members of a Maltese family. The carriers of this abnormality are clinically and hematologically normal. Structural analyses showed the replacement of prolyl residue in position 95 (G2) of the alpha chain by an arginyl residue. The relative amount of hemoglobin-St Luke's present in the red cell hemolysates of its carrier is approximately loo/,, compared to about 2301, for hemoglobin-G Georgia and 15Oj, for hemoglobin-Rampa (the other two variant,s in which prolyl residue a95 (G2) is replaced). Sedimentation velocity studies of hemoglobin-St Luke's in NaCl solutions of increasing concentration up to 2 M indicak &hat the oxy derivative is extensively dissociated into dimers in 0.1 M NaCl a t neutral pH; whereas under the same conditions, the deoxygenated molecule retains a tetrameric structure. In the deoxy state, appreciable tetramer formation occurs even in 2 M NaCI. In addition, association-dissociation in oxyor cyanferrihemoglobin St Luke's is both pH and temperature dependent.Hemoglobins G Georgia and Rainpa are variants in which the proIyl residue in position 95 of the cx chain is replaced by a leucyl and a seryl residue, respectively [I, 2 ) . The liganded derivatives of these abnormal hemoglobins are extensively dissociated into dimers in NaCl solutions of low molarity and a t neutral pH [3]. I n contrast, the deoxygenated derivatives of the two variants are tetramers under the same conditions. The substitution of the prolyl residue occurs a t a site which involves one of the critical contacts ; these contacts are broken when hemoglobin tetramers dissociate into dimers [41. The introduction of either a leucyl residue or a seryl residue in position a95 (G2) ruptures the contacts normally present between Pro-ag5 (G2) and Trp-/337 (C3) in oxygenated hemoglobin [4], and causes an extensive disruption of the al-& contact, probably because the contact becomes accessible to water 131. The greatly increased degree of dimer formation of the two variants is associated with an increased affinity for oxygen and a decrease in heme-heme interaction [3] ; carriers of these abnormalities appear normal.Abbreviation. Hb, hemoglobin.We recently observed an additional variant in which the prolyl residue in position a95 is substituted by an arginyl residue. The variant, t-ermed HbSt Luke's, was present in four members of a Maltese family. This paper describes results of structural analyses and data from sedimentation velocity analyses of the oxy (or cyanferri) and deoxy forms of Hb-St Luke's as a function of salt concentration, pH, and temperature. Results of a few oxygen equilibrium experiments are also included. MATERIALS AND METHODSBlood samples from members of family M were collected with EDTA as anticoagulant. Hematological studies were made by standard methods [5]. Parts of the samples were mailed by air from Malta to Augusta (Georgia, U.S.A.). Hemolysates were prepared by mixing 1 vol. washed packed cel...