SUMMARYA long-chain fatty-acid fraction obtained from the marine alga, Ulva lactuca, as well as decanoic, dodecanoic and hexadecanoic acids at levels of 25opg/m1 induced lysis of various Trypanosomatidae. However, octanoic and cis-9-octadecenoic acids at higher concentrations had no effect. Decanoic, dodecanoic and hexadecanoic acids at levels below IOO ,ug/ml inhibited motility of the promastigotes of Leishmania donovani and L. tropica, and the epimastigotes and trypomastigotes of Trypanosoma cruzi. Crithidia fasciculata was relatively resistant to fatty acids and was not affected by decanoic acid at this level.The lysis induced by the marine algal fatty acids and by decanoic and dodecanoic acids was preceded by the formation of rounded forms of the haemoflagellates which indicated the loss of membrane structure.

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The introduction of polybrominated biphenyls (PBB) into the Michigan food chain resulted in the presence of low levels of PBB in plasma pools used for blood fractionation. Pooled plasma lots contained an average of 1.0 +/- 0.2 ng/ml of PBB, while antihemophilic factor, fibrinogen, and immune serum globulin did not contain detectable amounts of PBB. Albumin (25%) lots contained an average of 2.0 +/- 0.4 ng/ml of PBB. Analysis of old lots showed that PBB first appeared in an albumin lot filled in January, 1974. Plasma used in preparing this lot was drawn during the period when PBB was entering the food chain. The results indicated that the behavior of chemical pollutants is an important consideration when fractionating blood or plasma collected in areas where industrial or environmental pollution have occurred.

Hydrolysis of ristocetin A in 0.1 N HCl at 37 degrees C for 2 h resulted in the loss of its ability to induce platelet aggregation in platelet-rich plasma derived from guinea-pigs and humans. However its antibiotic activity against Staph. aureus was not lost.

To demonstrate the importance of the carbohydrate portions of bovine factor VIII and ristocetin for the induction of platelet aggregation, guinea pig platelets were treated with either borate or glycerol before and after addition of ristocetin or bovine factor VIII. Both borate and glycerol were capable of inhibiting the aggregation of blood platelets induced by adding bovine factor VIII or ristocetin to platelet-rich plasma. Furthermore, aggregates formed after treatment with either agent could be dispersed by high concentrations of either borate or glycerol. These effects did not appear to be solely the result of high ionic strength or of irreversible damage to the platelets. The results obtained support the hypothesis that the binding of the carbohydrate groups of factor VIII plays an important role in the induction of platelet aggregation and in the maintenance of aggregates formed in response to the treatment of platelet-rich plasma with bovine factor VIII or ristocetin.