Induction of proliferation and Ig production in human B leukemic cells by anti-immunoglobulins and T cell factors

The proliferation and differentiation of human leukemic B cells (B-CLL cells) with anti-Ig and T cell-derived helper factors are described. Stimulation of B-CLL cells with anti-Ig and T helper factors could induce proliferation as well as differentiation into IgM- and IgG-producing cells. Neither anti-Ig nor T helper factors alone could induce any proliferation and/or differentiation of B-CLL cells. Not only whole molecules of anti-Ig but also F(ab')2 fragments could induce proliferation and differentiation of B-CLL cells in the presence of T helper factors, but monovalent Fab' fragments were not effective. Induction of both IgM and IgG with the same idiotype was confirmed by immunofluorescent and SDS-PAGE analysis. By employing an IL 2-dependent cytotoxic T cell line and a TRF-responsive B cell line, T cell factors were separated into a fraction with IL2 activity but no TRF activity and a fraction with TRF activity but no IL 2 activity by chromatofocusing. Anti-Ig and IL 2 fraction could induce proliferation of B-CLL cells, but TRF fraction was not effective for the induction of proliferation in anti-IG-stimulated cells. For IgM and IgG production, anti-Ig and both IL 2 and TRF fractions were required. Depletion of IL 2 fraction in the first 2 days' culture inhibited Ig production, whereas the absence of TRF fraction in the first 2 days did not show any inhibitory effect on Ig production.     

Block of acid secretion by amytal and its partial reversal by menadione with ascorbate in the gastric mucosa of the guinea-pig

The effect of amytal on energy metabolism and acid secretion in an isolated gastric mucosa of the guinea-pig were studied. Determination of adenine nucleotides, creatine phosphate, pyruvate and lactate in the gastric mucosa showed that amytal depressed the levels of ATP, creatine phosphate and energy charge with elevation of the AMP and pyruvate levels. This treatment inhibited concomitantly acid secretion and active chloride transport detected by short circuit current. The addition of menadione with ascorbate to the medium in the presence of amytal partially restored ATP and energy charge levels and also induced a partial recovery of acid secretion and active chloride transport. These results suggest that ATP is a direct energy donor for acid secretion in the gastric mucosa of the guinea-pig.     

Purification and properties of ATPase from an alkalophilic Bacillus

ATPase was purified from an alkalophilic Bacillus. The enzyme has a molecular weight of 410,000 and consists of five types of subunits of molecular weights of 60,000 (α), 58,000 (β), 34,000 (γ), 14,000 (δ), and 11,000 (?). The subunit structure is suggested to be α₃β₃γδ?. The enzyme is activated by Mg²⁺ and Ca²⁺. The pH optima of the enzyme with 0.1 and 2.0 mm Mg²⁺ are 9 and 6, and those with 1 and 10 mm Ca²⁺ are 8–9 and 7, respectively. Ca²⁺-ATPase hydrolyzes only ATP, whereas Mg²⁺-ATPase hydrolyzes GTP and, to a lesser extent, ATP. The values of V and K_m of the enzyme with ATP in the presence of 10 mm Ca²⁺ or 0.6 mm Mg²⁺ at pH 7.2 are 17 or 0.5 units/mg protein and 1.2 or 0.3 mm, respectively. The enzyme with Mg²⁺ is appreciably activated by HCO^?₃. Relationship of the ATPase to the active transport system in the bacterium is suggested.     

Regulation of the production of the agglutination substances responsible for sexual agglutination in Saccharomyces cerevisiae: Changes associated with conjugation and temperature shift

Summary Isolated zygotes showed self-agglutination caused by the sex-specific glycoproteins, the agglutination substances responsible for sexual agglutination. The agglutination substances of both a and mating types were detected in the extracts obtained by the autoclave method from zygotes. Although the first diploid daughter cells from zygotes showed self-agglutinability, the self-agglutinability decreased gradually in the successive diploid daughter cells. The self-agglutination in diploid cells was also brought about by the complementary binding of the sex-specific agglutination substances of opposite mating types.The constitutive sexual agglutinability in a and cells was lost with concomitant loss of the agglutination substances in both cell wall and cytoplasmic fractions when cultured at a temperature higher than 35°C.The repression of the production of the agglutination substances was reversed by the opposite mating type pheromones even at the repressive temperature, 36°C, associated with the appearance of sexual agglutinability. The sex pheromones, a substance-I and substance-I, and the binding substance for substance-I were produced even at 36°C, repressive for the production of the agglutination substances.     

Subcellular localization of glycolytic key enzymes in germinating castor bean endosperm

Phosphofructokinase and pyruvate kinase activities in castorbean endosperm increased during germination. Subcellular localizationof pyruvate kinase and phosphofructokinase in germinating endospermtissues was studied by differential and sucrose density gradientcentrifugation techniques. Eighty five percent or more of thepyruvate kinase and phosphofructokinase activities were locatedin cytosol. The remaining activities were mainly detected inproplastids. (Received June 30, 1977; )     

Flash reactivation of Tris-inactivated chloroplasts

The light conditions required for reactivation of the oxygen-evolvingsystem in Tris-treated chloroplasts were studied by means ofrepetitive flashes. Inactive Tristreated chloroplasts were washedwith reduced 2,6-dichlorophenolindophenol, suspended in a reactivationmedium containing Mn²⁺⁺ and Ca²⁺⁺ ions, then illuminated withflashes. Flashes at dark intervals of 2 sec were most effectivefor reactivation, while those at shorter or longer intervalswere less effective. It was deduced that more than two sequentiallight reactions with dark reactions in between were involvedin the reactivation. (Received December 28, 1977; )     

Characterization of the intracellularly recorded response of identified flight motor neurons inDrosophila

Journal of Comparative Physiology A - Intracellular recordings were made from the motor neurons which innervate the dorsal longitudinal flight muscle (DLM) inDrosophila, while a normal-appearing...