Existence of 28R-antigen in a certain strain of group F streptococcus

An inter-Group common antigen was detected between Group A type 28 (Small)- and Group F (21/58/O'Mahoney, Colindale)-streptococcal cells by the T-typing agglutination reaction. The characteristics of this antigen coincide with those of the 28R-antigen, which was first detected in the Group A type 28 (Small) cells by Lancefield in 1943, in the following points: 1) It can be extracted from the cells with HC1 at pH 2.0 at 100 C in a stable state; 2) It can be kept in a stable state by heating in an alkaline solution at pH 7.8; 3) The antigen on the heat-killed cells was not affected by trypsin digestion at pH 7.8 but was destroyed by pepsin digestion at pH 2.0.

Characterization and in vitro polymerization of Tetrahymena tubulin

Tetrahymena tubulin was purified from the cell extract using DEAE-Sephadex A-50 ion-exchanger and ammonium sulfate precipitation. About 2.2% of the total protein in the 20,000 X g supernatant was recovered as DEAE-Sephadex-purified tubulin fraction. Applying the temperature-dependent polymerization-depolymerization method to this fraction in the presence of Tetrahymena outer fibers as a seed, almost pure tubulin was obtained. Tetrahymena tubulin dimer showed different behavior on SDS-polyacrylamide gels from porcine brain tubulin, and showed very low affinity for colchicine, amounting to about one-twentieth of the binding to porcine brain tubulin. The tubulin fraction failed to polymerize into microtubules by itself. Addition of a small amount of the ciliary outer fiber fragment induced polymerization as demonstrated by viscometric measurements, but the reconstituted microtubules were very unstable in the absence of glycerol. Microtubule-depolymerizing agents such as Ca2+ ions, low temperature, or colchicine all inhibited in vitro polymerization. Although Tetrahymena tubulin purified by the polymerization-depolymerization method could copolymerize with porcine brain microtubules, the DEAE-Sephadex-purified tubulin fraction suppressed the initial rate of porcine brain microtubule assembly in vitro. There seemed to be no differences between cytoplasmic tubulin and outer fiber tubulin in colchicine binding activity or SDS-gel electrophoretic behavior, or between the fine structure of both reconstituted microtubules observed by electron microscopy.

Effect of pyratrione (a tyrosine hydroxylase inhibitor) in essential hypertension

1. A clinical study of pyratrione, a tyrosine hydroxylase inhibitor, has been carried out in essential hypertension. 2. Out of thirty-nine patients who received pyratrione, twenty-eight showed a significant decrease in blood pressure.