Leukemic Reticuloendotheliosis

The anatomical and functional featuresof the hairy cells of leukemic reticuloendothelisis were investigated by timelapse cinematography; phytohemagglutinin stimulation; adherence to siliconizedsurfaces; a variety of cytochemicalmethods; and phase, transmission, andscanning electron microscopy. The scanning electron microscopic image supportsthe morphologic evidence for a relationship between the hairy and the reticularcells.

Submitted on February 24, 1971 Revised on April 1, 1971 Accepted on April 13, 1971     

Effects of calcium and pH on the mechanical performance of heart muscle in the frog,Rana temporaria,during anoxia and subsequent recovery

Heart ventricular muscle strips from Rana temporaria recover their isometric contractile tension completely within 20 min of reoxygenation following an anoxic period of 60 min in a physiological solution at pH 7.6. Corresponding recovery at pH 6.6 is only 43% of pretreatment values. High calcium concentration during the period of anoxia at pH 6.6 and subsequent recovery, returns contractile tension to almost pre-anoxic values within 1 h. If, however, the calcium concentration is increased at the moment of reoxygenation, contractile tension is restored even faster than if high calcium levels were present during anoxia. The loss of contractile tension caused by anoxia is the same at both pH 7.6 and 6.6 with the same calcium concentration. Comparison of the velocity parameters between high and low calcium experiments always shows a greater difference for the contraction velocities than for the corresponding relaxation velocities, independently of the pH. The quotient of these two velocities is used as an index of their relative rate of change. The results are interpreted in terms of calcium and hydrogen ion competition at various subcellular structures and the different influences these ions may have on contractile tension and both contraction and relaxation velocities.     

Multiple continuous-flow solid-phase peptide synthesis Synthesis of an HIV antigenic peptide and its omission analogues

Multiple continuous-flow solid-phase peptide synthesis was performed on a standard polystyrene-based resin under low-pressure conditions using a simple manually operated synthesizer. Stable-flow resin-packed columns were prepared in small polypropylene flow reactors, adjustable for volume. The concurrent synthesis of 10 peptides was carried out in flow reactors concatenated together; solvents and reactants were passed through this set of columns using moderate overpressure. One decapeptide, H-Val-Tyr-Tyr-Arg-Asp-Ser-Arg-Asn-Pro-Leu-NH₂, containing an antigenic determinant of the p31 protein product of the pol gene of the human immunodeficiency virus, and its nine omission analogues were synthesized.     

RAPID SEPARATION OF PROTEINS AND THEIR HIGHER-MOLECULAR FRAGMENTS BY MEANS OF SPHERON ION-EXCHANGES*

Ion-exchange derivatives are described, of a hydrophilic rigid macroporous glycolmethacrylate gel called Spheron, suitable for rapid high-performance liquid chromatography (HPLC) of proteins and their fragments. Their flow parameters are compared with those of ion exchange derivatives of cellulose and poly-dextran. The conditions for work with them are described (regeneration, cycling, equilibration, column packing) as well as the construction of a simple apparatus for medium-pressure ion exchange chromatography of proteins. The efficiency of these ion exchangers for the separation of proteins is illustrated with examples of chromatography of an artificial mixture of serum albumin, chymotrypsinogen and lysozyme. Chromatography of cyanogen bromide fragments of serum albumin and the A and B chains of oxidized insulin showed that the method can be applied in chromatography on higher molecular protein fragments. A review of all proteins, including technical enzymes, which have already been chromatographed on Spheron ion exchangers is also given. The prospects of Spheron ion exchangers for HPLC of proteins and their fragments are briefly discussed.