Stepwise iodination. A general procedure for detoxification of proteins suitable for vaccine development and antiserum production.

By gradual incorporation of stable iodine into toxins and whole venoms it is possible to abolish completely the lesion and lethal properties of the native components. Allergen extracts can be turned anallergic. Physiological proteins with strong biological activity can also be rendered innocuous.

Theoretical considerations concerning the effect of relativistic velocities on the rate of biological processes.

Theoretical considerations were advanced on the reaction rate of biological systems in a rocket accelerated at fractional levels of the velocity of light. The values of mass increase in reacting molecules and length contraction of space under these relativistic velocities attained by the hypothetical rocket were inserted in equations of the absolute reaction rate theory. The equations employed were for the frequency of collisions, and for the internal kinetic energy of molecular reactions.

Detoxified venom from Crotalus durissus terrificus is devoid of cytotoxic activity and induces mitogenesis.

The venom from the snake Crotalus durissus terrificus was detoxified by stepwise incorporation of stable cationic iodine. The venoid, in a dosage equivalent to 100 LD50 of the lethal venom, was injected in mice without lethal exits. The native venom (NAT), or its toxoided (TXD) derivative were incubated in presence or absence of mitogens, with human mononuclear (MN), B and T cells, with a pulse of [3H]Thymidine.

Reversion by polyclonal antibodies of alpha effects of Tityus serrulatus venom on frog sciatic nerve.

Fraction T2 from Tityus serrulatus venom produced a marked lengthening of action potentials recorded with the single sucrose-gap technique, a characteristic effect of alpha scorpion toxins. This effect was not reversed by thorough washing of the nerve. On the other hand, T2 fraction deactivated by complete iodination did not cause any alteration of the compound action potential, even if applied in concentration as high as 4000 times the half saturation dose of the unmodified T2 fraction.

The effect of dithiothreitol on the activity of tityustoxin from the scorpion Tityus serrulatus venom.

The acetylcholine (ACh) liberating effect on rat brain slices of tityustoxin, an alpha toxin from the scorpion Tityus serrulatus venom, was measured in the absence and presence of dithiothreitol (DTT). The rate of net ACh liberation by toxin concentrations of 2 nmol in 5 ml of organ bath, was 7.5 +/- 0.