Mammalian sperm hyperactivation (HA) is a change in motility that accompanies capacitation (CAP) and is dependent on calcium (Ca) (Yanagimachi and Usui, Exp Cell Res 89:161, 1974). HA may be important for transport through the female tract and/or for fertilization. To develop an objective and quantitative assay for HA in individual mouse sperm, a computer-assisted motion-analysis system was used to describe sperm translational movements. To determine which movements were characteristic of HA, Ca-dependent motility was identified. This was done by incubating sperm with or without calcium (Ca+ or Ca- sperm, respectively), and determining the range of values for each motility parameter that was present only among Ca+ sperm. To do this, we compared frequency distributions of motility parameter values at the time of maximal CAP (90 min). CAP was monitored by measuring the level of in vitro fertilization and by evaluating the pattern of chlortetracycline binding to individual sperm heads [Ward and Storey, Dev Biol 104:287, 1984]. Two Ca-dependent motility subgroups were apparent: 1) a "slow-speed" subgroup with a curvilinear velocity (Vc) less than 169 microns/sec that had none of the characteristics expected of HA sperm; and 2) a subgroup with higher speeds (Vc greater than 169 microns/sec) and wider-amplitude head movements as measured by curvilinear progressiveness ratio (PRc less than 0.56). The latter subgroup was selected as HA, since the frequencies and time course were similar to those for CAP in the same population. Two media components known to be important for CAP, bicarbonate and bovine serum albumin (BSA) were then tested to determine whether they were necessary for HA. Incubation of sperm without bicarbonate prevented HA, but omitting BSA did not affect HA during the first 3 hrs. These data suggest that HA is not tightly coupled with CAP.

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This paper deals with the formation of serologically reactive dextrans from sucrose by certain streptococci from the blood of patients with subacute bacterial endocarditis, and with the distinction between the formation of dextran by those streptococci and the formation of levan from the same substrate (sucrose) by certain other streptococci.Dextrans and levans (which are respectively polymers of glucose anhydride and of fructose anhydride units) have long been recognized as products synthesized through action upon sucrose by a variety of bacteria from plant and soil sources. The literature on the general subject begins with the studies on "viscous fermentation" by early chemists (1) at a time when no one realized microorganisms were connected with fermentative processes, and, after passing through the period in which the dextrans (2) and levans (3) were identified chemically and in which the microbial agency was established (4), extends to the modern period in which the detailed chemical (5, 6) and serological (7-9) properties of both classes of the polysaccharides have been investigated and the enzymatic syntheses of both dextran (10) and of levan (11) have been experimentally accomplished in the absence of cells. Although the literature is abundant and is from a variety of fields, little of it deals with streptococci of human source. I-llava (12) in 1902, Oerskov and Poulsen (13) in 1931, and Koch (14) in 1933, reported the production by streptococci from throats of gum which, from the substrate spedfidty involved in its formation, can be assumed to have been either levan or dextran, although the product was not differentiated chemically. More definite evidence was presented in 1941 by the report of Niven, Smiley, and Sherman (15, 16) on the production of a chemically identified levan by strains of S. salivarius and by our (17, 18) report of the production of a dextro-rotatory polysaccharide (later chemically identified as dextran) by some strains of group H (19) streptococci. The sucrose-derived products of the group H streptococci (17, 18) and of the S. salivarius (9) were shown by us to have serological properties, which introduced the possibility of applying serological methods for the study of dextran and levan formation by streptococci. Method for the Recognition of Dextrans and LevansSince it was desired to recognize and distinguish the dextrans and levans without isolation of the polysaccharides, it was essential that the method be adequate not only with respect to capacity to detect small concentrations of the polysaccharides but also with respect to ca-

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775rises with anaphylaxis and uniform falls with cluded that the leukocyte changes after the pyrogenic reaction. (3) The mechanism anaphylaxis are not due to pyrogen contamof these hematologic changes is not touched ination. upon in the present study. (4) It is con-