Do the results of semen analysis predict future fertility? A survival analysis study.

The authors examined the results of the initial semen analysis from 1089 couples in an infertility clinic. The distributions of the values for various semen variables among couples who remained infertile were very similar to those among couples who later conceived. A cutoff point was selected in each pair of distributions to compare the cumulative probability of conception for couples with higher and lower results.

The stabilizing effect of gelatin on dilutions of various tuberculins.

Adsorption of highly diluted tuberculin to the inner surface of containers is particularly pronounced for acid-precipitated PPD, and certain such preparations are routinely issued with the non-ionic detergent Tween 80 as a stabilizing agent. It has been shown, however, that Tween 80, besides its anti-adsorptive effect, also has a depressive in vivo effect, especially on tuberculin reactions that would have been weak even for a test without Tween. The authors have shown in a previous report that gelatin (0.