Dietary protein and chronic toxicity of 1,2-dimethylhydrazine fed to mice.

1,2-Dimethylhydrazine-HCl (DMH-2HCl) is derived from the natural toxin cycasin, and is extensively used to induce cancers in experiments with rodents. We examined the toxicity of DMH-2HCl, incorporated into purified diets varying in protein, to determine concentrations compatible with long-term survival in B6C3H1 mice. Initial studies showed single-dose oral LD50 values (95% confidence intervals) of 26 (18-32) mg DMH-2HCl/kg body weight for males, and 60 (53-65) for females.

Computers and videodiscs in pathology education: ECLIPS as an example of one approach.

We have enumerated ways in which the evolving computer and videodisc technologies are being used in pathology education and discussed in some detail the particular use with which we are most familiar, text management. While it is probably premature to speculate as to how these technologies will ultimately affect pathology education, one recent trend--the convergence that seems to be developing between those working on expert consulting systems and those working primarily on educational applications--will probably influence this impact substantially. We believe that we are moving, from opposite directions, toward the same end result, namely, the use of machine intelligence to facilitate and augment human learning.