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F S ROSEN

Publications and source records attributed to F S ROSEN.

29 records · Page 2Linked to original sources
PubMed1958

Inactivation of endotoxin by a humoral component. II. Interaction of endotoxin with serum and plasma.

A humoral substance which inactivates endotoxin in vitro has been shown to be clearly distinguishable from complement, properdin, and specific antibody. For the present, it is designated "endotoxin-detoxifying component" or EDC. Animal species could be grouped in three categories with regard to the EDC activity of their sera; rat serum was highly potent; chimpanzee, dog, horse, and guinea pig sera were much less active; mouse, rabbit, and sheep sera exhibited no activity. The EDC potency of human sera varied widely, ranging from high to barely discernible activity. In contrast to the variations of EDC potency in serum, citrated plasma from all species manifested high potency of about the same magnitude. The influence of time, temperature, pH, and concentration of reactants on the inactivation of endotoxin by EDC was examined. EDC activity in plasma and serum was found to be labile to beating at 56 degrees C. for 1 hour. Bacterial endotoxins, derived by different isolation procedures from smooth and rough Gram-negative species, varied considerably in susceptibility to EDC action.

Animals↗
PubMed1958

Inactivation of endotoxin by a humoral component. III. Role of divalent cation and a dialyzable component.

The uniformly high potency of citrated plasma as compared with the limited capacity of serum to inactivate endotoxin in vitro was found to be a consequence of the anticoagulant employed in collecting the plasma. Addition of calcium to plasma suppressed the activity of its endotoxm detoxifying component (EDC) whereas the addition of calcium-binding anticoagulants rendered serum comparable to plasma. Dialysis of plasma resulted in a marked reduction of its EDC activity despite the concommittant elimination of calcium. EDC activity could then be fully restored upon the addition of calcium-binding anticoagulants. Resin-treated plasma, without added anticoagulant, had EDC activity equal to plasma obtained with calcium-binding anticoagulants. Following dialysis, resin-treated plasma also sustained a marked reduction in EDC activity which could be fully restored by calcium-binding anticoagulants. Restoration was also obtained with the dialysate even after ashing. These findings indicated that the suppression of EDC activity by calcium is not direct but is mediated through its effects on an anionic component of plasma which is required for inactivation of endotoxin by EDC.

Bacteria↗