A simple method for the quantitative determination of sperm aggregation

Described in this paper are 2 methodological variants for photometric recording of sperm aggregation. Heparin was used to induce aggregation. One of the working principles was related to aggregation-associated alteration of turbidity in an agitated cell suspension, measured by the KZM-1 coagulation-time meter, in analogy to measurement of thrombocyte aggregation. The 2nd variant was based on variation of cloudiness due to sedimentation of aggregates in a non-agitated suspension. Both methods provided equally valid information. They characterised both intensity of aggregation as a combined effect of the number and size of aggregates as well as the rate of aggregation. Photometric recording has proved to be an objectivated method for quantitative assessment of aggregation. Its use is proposed for studies into capacitation or immunological response of spermatozoa.     

Determination of the protease activity in a Cuban strain of Babesia bovis]

The attenuation of a Babesia bovis strain depends on its protease content. The present work evaluates this parameter on a virulent strain, before and after attenuation by quick passages on splenectomized calves. The protease activity at different pH values was determined in protein fractions from the blood of calves. The enzymatic test showed marked differences between the protease content of both substrains.