Amelioration by menadione of the experimental chronic immune arthritis in the rabbit.

The immunological induction of arthritis in the knee of the rabbit is well established as a model for human rheumatoid arthritis. It has the special advantage of allowing the development of the condition, and the effect of disease-modifying agents, to be followed. Attention has been focussed on the activity of glucose 6-phosphate dehydrogenase in the synovial lining cells since the fourfold elevation of this activity was shown to be fundamental in the human condition.

A quantitative cytochemical method for ornithine decarboxylase activity.

Although decarboxylases, particularly ornithine decarboxylase, are of considerable importance in cell metabolism, it has been impossible to demonstrate their activity histochemically, as this depends on trapping carbon dioxide at neutral pH values. A new reagent, lead hydroxyisobutyrate, has been shown capable of such trapping. It has been applied to the demonstration of ornithine decarboxylase activity in mouse kidney.