[A new salt of dihydrostreptomycin: tri-2-(1-isonicotinoylhydrazono)-pyruvate of dihydrostreptomycin. II. Comparison of the toxicity of tri-2(1-isonicotinoylhydrazono)-pyruvate of dihydrostreptomycin with that of dihydrostreptomycin sulfate; effects of anion on dihydrostreptomycin toxicity].