Word: toxin
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...chronicle with great anger and great love-anger for the stupidity and venality of the powerful, love for the weakness of the weak. In their testimony, the town fathers incriminate themselves: the rich doctor objects that Marcy is taking money from the purses of honest physicians with her free toxin-antitoxin shots; the minister pompously complains of Marcy's interfering when she tells of tubercular prisoners in the penitentiary. The voices of the poor exalt Marcy: it is recalled that she went more than 20 miles through waist-deep snow to tend the dying child of a miner when...
Pappenheimer has endeavored to analyze the action of the toxin right down to the molecular level, in order to determine the ultimate biochemical reasons for its destructive potency. This problem has taken him into many fields. From a commercial laboratory he learned that traces of iron reduce the yield of toxin. He was able to determine that the production of a pink pigment called coproporphyrin was similarly diminished by iron. This discovery in turn led him back to work he had done as a graduate student...
...addition, he had conducted research on cytochromes, iron-containing enzymes which are closely related to hemoglobin. Cytochromes fulfill an important function in the oxidative processes of metabolism in many organisms. Since diphtherial cytochrome is probably a derivative of coproporphyrin, the dual inhibiting effect of iron suggested that the toxin operates by "impersonating" cytochrome...
...synthesis would produce readily detectable effects. The Cecropia silk worm satisfied the requirement. During both the caterpillar phase and the period of adult development Cecropia produces substantial quantities of cytochromes. In the dormant pupa stage, though, the enzymes occur in only trace amounts. By showing that resistance to diphtheria toxin in the pupa stage is much greater than during other phases, Pappenheimer furnished compelling evidence for his theory...
...study the broad topic of oxidative phosphorylation. Of particular interest to him is ATP, the major energy-storing compound of the living cell. ATP is involved in the cytochrome oxidizing processes mentioned above. Thus, Pappenheimer's work at Amsterdam will probably yield additional information concerning his old friend, diphtheria toxin...