Virulence of Entamoeba histolytica in rat and its comparison with the serological responses of the amoebic patients.

The virulence of 70 isolates of Entamoeba histolytica was studied in the Wistar strain of albino rat by intracaecal inoculation of amoebae. The results were evaluated by the Neal scoring system, histopathological grading of ulcers and virulence indices. It was found that isolates from acute amoebic cases could infect and produce ulcers in significantly more animals than could the isolates from asymptomatic cyst passers.

Photo-induced changes in proteins associated with floral induction in Amaranthus.

A. caudatus f. albiflorus, A.

Cellular and humoral responses in amoebic patients.

Cell-mediated immune response (CMIR) and humoral antibody response was studied in fifteen patients with amoebic liver abscess, five patients with amoebic colitis and fifteen patients with non-amoebic diseases which served as unexposed controls. CMIR as judged by macrophage migration inhibition factor (MIF) test was altered in amoebic patients and more so in amoebic liver abscess patients; it was normal in unexposed controls. This altered CMIR reverted back to normal levels within five to seven days after the initiation of drug therapy.

Protective effects of crude and chromatographic fractions of axenic Entamoeba histolytica in guinea-pigs.

Axenic amoebic antigen was chromatographed on Sephadex G-200. Two peaks divided into three fractions were obtained which were concentrated by lyophilization. Guinea-pigs were given a series of subcutaneous injections of crude Entamoeba histolytica antigen and its chromatographic fractions mixed with Freund's complete adjuvant.

Experimental amoebic infection in guinea-pigs immunized with low grade amoebic infection.

Guinea-pigs were immunzied with a low grade amoebic infection, either intracaecally or intramesenterically. The immunized animals were challenged with a virulent strain of Entamoeba histolytica. Some of the animals, immunized via the intracaecal route were challenged repeatedly.

Immunogenicity of axenic Entamoeba histolytica antigen and its fractions.

Amoebic antigen prepared from axenic Entamoeba histolytica (NIH:200 strain) grown at 37 degrees C in TPS I medium was chromatographed on a Sephadex G-200 column. Three fractions (F-I, F-II, F-II) were obtained, the molecular weights of which ranged from 650,000 to 1,450. Fractions were concentrated by lyophilization and antisera against each fraction and whole antigen were raised in rabbits.

Phenazines with two cationic side chains as potential antimalarials.

1,9-Phenazine-bis(dialkylaminocarboxamides) were prepared for screening as potential antimalarials. No significant activity against Plasmodium berghei was observed. The phenazine targets were prepared from 1,9-phenazinedicarboxylic acid by standard methods.

Effects of amino acids, adenine nucleotides and inorganic pyrophosphate on glutamine synthetase from Anabaena cylindrica.

Glutamine synthetase (L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.

Some properties of glutamine synthetase from Anabaena cylindrica.

Some properties of the biosynthetic and γ-glutamyltransferase activities of glutamine synthetase (EC 6.3.1.

Effects of adenine nucleotides and phosphate on adenosine triphosphate sulphurylase from Anabaena cylindrica.

Production of adenosine 5'-[35S]sulphatophosphate by a partially purified ATP sulphurylase from Anabaena cylindrica was inhibited by AMP, ADP and P1. Decreases in enzyme activity in the presence of these inhibitors were reversed by increasing the concentrations of ATP. The adenine nucleotides inhibited the enzyme competitively with respect to ATP.

Activation of sulphate in Anabaena cylindrica.

Crude cell-free extracts of Anabaena cylindrica synthesized adenosine-5'-phosphosulphate (AP(35)S) and 3'-phosphoadenosine-5'-phosphosulphate (PAP(35)S) from (35)SO4 (2-) in the presence of Mg(2+), ATP and inorganic pyrophosphatase. Maximum AP(35)S and PAP(35)S were produced at pH 7.15 and 8.

Floral induction by gibberellic acid in Zinnia elegans jacq. under non-inductive long days.

Flowering was induced in Zinnia elegans under non-inductive 24-h photoperiods by the application of gibberellic acid, although later than under inductive 8-h photoperiods. Gibberellic acid also enhanced extension growth and leaf differentiation under both photoperiods.

Role of light in the synthesis of nitrate reductase and nitrite reductase in rice seedlings.

1. In rice seedlings synthesis of methyl viologen-nitrite reductase was stimulated by light, as was that of NADH-nitrate oxidoreductase (EC 1.6.