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Biomedical subjects

E C Herrmann

Publications and source records attributed to E C Herrmann.

At least 19 recordsLinked to original sources
PubMed1991

Choline inhibition of prothrombin activation.

A computer-interfaced spectrophotometric kinetic assay for prothrombin activation was developed, coupling the production of thrombin to a thrombin-specific amidolytic chromogenic reaction. As thrombin accumulated initially at constant velocity, the simultaneous release from S-2238 of pNA conformed to an acceleration function. Adherence to the acceleration function of the temporally increasing A400 of pNA was evaluated after transforming the data into linear format which permitted linear regression analysis. High correlation coefficients, routinely greater than 0.99, verified linearity of thrombin production in individual assay mixtures. As prothrombin concentrations were varied, factor Xa exhibited Michaelis-Menten kinetics. Added choline produced a pattern of mixed-type inhibition. Replots of LB slopes and intercepts versus choline concentration gave apparent Ki and Ki' values (mM): 22 +/- 3 and 48 +/- 7 without factor Va, 25 +/- 4 and 41 +/- 4 with factor Va.

Aspirin↗
PubMed1982

Prevention of death in mice infected with coxsackievirus A16 using guanidine HCl mixed with substituted benzimidazoles.

A significant reduction in the death rate of infant mice infected with ten 50% lethal doses (LD50) of coxsackievirus A16 was observed when they were treated 58 h after infection with two injections of guanidine at 145 mg/kg per injection. Tremors occurred at this level but disappeared after treatment was discontinued. Tremors were apparent, but less severe at 97 mg/kg per injection and did not occur at 48 mg/kg per injection. No antiviral effect could be detected at either of these levels of guanidine. When an inactive level of guanidine (97 mg/kg per injection) was combined with 1.7 mg/kg per injection of LY122771-72, LY127123, or 2-(alpha-hydroxybenzyl)benzimidazole (HBB) and 17 mg/kg per injection of 2-guanidino-benzimidazole (GB), significant activity resulted with 2-8 treatments begun 58 h after infection. The same treatment schedule using 136 mg/kg per injection of LY122771-72, 90 mg/kg per injection of LY127123, 136 mg/kg per injection of HBB and 68 mg/kg per injection of GB produced no effect. Guanidine-associated tremors were also enhanced by the addition of the substituted benzimidazoles. When guanidine was reduced to 48 mg/kg per injection, 34 mg/kg per injection of LY122771-72 was required to produce a significant reduction in the death rate and no tremors were observed.

Animals↗