Effects of tetracyclines on membranous bone growth and dentin apposition in young rhesus monkeys

Various tetracyclines were administered by different routes to young monkeys that received multiple injections of lead acetate as an intravital stain of calcification sites. Microscopically, the tetracyclines inhibited membranous bone growth, but they did not affect dentin apposition.

Effects of systemic demethylchlortetracycline on human cutaneous microflora

The aerobic flora of the axilla and forehead of 20 normal human subjects was studied through a 3-week course of 600 mg of demethylchlortetracycline daily and a 3-week follow-up. In general in the axilla, an initial fall in bacterial density was followed by recovery in numbers due to the proliferation of resistant coagulase-negative cocci and diminution of the lipophilic diphtheroid group of bacteria within 1 week of treatment. During the remainder of the treatment period, the flora was essentially stable in both density and composition. In the follow-up phase, the initial flora was slowly re-established but resistant cocci persisted for more than 3 weeks. On the forehead the fall in density was slower and recovery during treatment was incomplete. Resistant coagulase-negative cocci became dominant and persisted through the follow-up phase. In two individuals, temporary colonization of the axilla by Staphylococcus aureus was seen.