Inactivation of Biologically Active ("Endotoxic") Polysaccharides by Fresh Human Serum

Landy, Maurice; Skarnes, Robert C.; Rosen, Fred S.; Trapani, Robert-John; Shear, M. J.

doi:10.3181/00379727-96-23596

Cited by 48 publications

(20 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, investigators who employed reaction mixtures which contained high concentrations of endotoxin, or mixtures that were incubated for prolonged periods at 370 C, usually observed a reduction in the pyrogenic and other toxic properties of endotoxin (8,10,(14)(15)(16)(17)(18). In much of the earlier work, however, insufficient attention was given to the critical importance of the relative concentrations of the reactants.…”

Section: Discussionmentioning

confidence: 98%

“…Other investigators working on different facets of the problem have made it evident that reaction of serum and endotoxin under appropriate conditions results in the inactivation of every hostreactive property of endotoxin thus far examined (13)(14)(15)(16)(17)(18)(19)(20) as well as in striking alterations in the immunochemical properties of the lipopolysaccharide complex (7,19). However, the mechanism by which endotoxin is inactivated by plasma has remained uncertain.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Inactivation of Endotoxin by a Humoral Component. Vii. Enzymatic Degradation of Endotoxin by Blood Plasma*

Keene¹,

Landy²,

Shear³

1961

J. Clin. Invest.

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 98%

mentioning

confidence: 99%

Inactivation of Endotoxin by a Humoral Component. Vii. Enzymatic Degradation of Endotoxin by Blood Plasma*

Keene¹,

Landy²,

Shear³

1961

J. Clin. Invest.

View full text Add to dashboard Cite

“…The Serratia marcescens endotoxin supplied by Dr. Landy is highly purified, as judged by its low nitrogen content, but is no more toxic than the acetone-ether-dried S. typhimurium, as indicated by the data of Table V. This same material, according to Landy et al (13)(14)(15)(16), is a potent pyrogen, however, and is effective in tumor necrosis. The Upjohn preparation of E. coli lipopolysaccharide stands out, on the other hand, as the most active material so far tested by the urinary nitrogen assay and is unusually lethal for mice.…”

Section: Effect Of E Coli Lipopolysaccharide O~ Nitrogen Excretion Fmentioning

confidence: 86%

“…Influence of Serum "Endotoxin-Detoxifying Component" (EDC) and DCI on the Assay for E. coli Endotoxin.--As Landy and collaborators have reported in a series of publications (13)(14)(15)(16), calcium-free serum from a number of animal sources is capable of detoxifying endotoxin as judged by its loss of (a) tumornecrotizing action, (b) toxicity for experimental animals, and (c) antigenicity. With this work as a background, the effect of calcium-free mouse serum on Table IV were obtained.…”

Section: Effect Of E Coli Lipopolysaccharide O~ Nitrogen Excretion Fmentioning

confidence: 99%

Effects of Bacterial Endotoxins on Metabolism

Berry

Smythe

1961

The Journal of Experimental Medicine

View full text Add to dashboard Cite

Endotoxins can be assayed on the basis of their toxicity for experimental animals, their pyrogenicity, their ability to necrotize tumors, and their antigenicity. Another property, observed in the course of recent experiments, makes possible a new assay. The initial observation on which the assay is based was obtained when an intraperitoneal injection of appropriate numbers of heatkilled cells of Salmonella typhimurium was found to prevent completely the elevation in urinary nitrogen excreted by mice given adrenocorticotropic hormone (ACTH) subcutaneously (1). The same number of heat-killed cells had no apparent effect on the total protein catabolized in response to concurrently injected cortisone as judged by the increase in urinary nitrogen eliminated under these conditions. From these observations, endotoxins seem to prevent certain physiological manifestations normally elicited by ACTH but do not influence the metabolic activity of exogenous glycocorticoid. Since there is an inverse proportionality between the quantity of endotoxin injected and the quantity of urinary nitrogen excreted following ACTH administration (2), this relationship has been used to develop the assay. In order to establish the validity of such an assay, endotoxin alone must be shown to produce the effect on which the assay is based. The extent to which such proof is possible is, of course, limited but within these limits the evidence to be presented is convincing. It is also necessary to determine the sensitivity of the assay before its usefulness can be related to other methods. This report is concerned with results obtained with these aims in mind. Method•ndotoadn.--Seven different preparations were used. A saline suspension of a known number of Salmonella typhimur~um, strain SR-11, were killed by pasteurization at 60°C.for 30 minutes. Lack of growth on subculture in brain-heart infusion broth (Difco) was taken as proof of steAlization. Usually the suspension had to be heated a second or third time before no growth was observed. The final material was stored at 5°C. in sealed vials. The dry weight of three different preparations was found to be about 8/~ mg. per 109 heat-killed cells. Comparatively crude endotoxin was derived as acetone and ether-extracted cells of

show abstract

“…(Submitted for publication August 18, 1959; accepted October 2, 1959) The blood of mammalian species contains a component which inactivates endotoxins in vitro (1). This endotoxin-detoxifying component (EDC) is identified by attributes which distinguish it from other substances in blood of known biologic activity (2,3).…”

mentioning

confidence: 99%

Inactivation of Endotoxin by a Humoral Component. Vi. Two Separate Systems Required for Viable and Killed Salmonella Typhosa

Landy¹,

Trapani²,

Rosen³

1960

J. Clin. Invest.

View full text Add to dashboard Cite

The blood of mammalian species contains a component which inactivates endotoxins in vitro (1). This endotoxin-detoxifying component (EDC) is identified by attributes which distinguish it from other substances in blood of known biologic activity (2, 3). Following appropriate interaction in vitro with this component, endotoxins from gram-negative bacteria are so altered that they no longer elicit such characteristic host reactions as the production of antibody (4), tumor damage, local skin reactivity and fatal shock. Bacterial endotoxins elicit the same host reactions which are evoked by the intact gram-negative bacilli from which they are isolated (5). It was therefore expected that the endotoxin in its native state on the bacterial surface would also be susceptible to inactivation by an agent with the distinctive properties of EDC.This communication records the results of experiments which show that, by appropriate interaction in vitro with serum, it is possible to eliminate characteristic host-reactive properties of a typical gram-negative species. In the course of these studies with Salmonella typhosa, EDC was found to inactivate the endotoxin of bacilli which had been killed by heat or by chemical means, but not that in viable organisms; however, in the latter the endotoxin was inactivated by the serum bactericidal system consisting of antibody and complement. It is thus evident that two humoral mechanisms can function to inactivate the endotoxic properties of intact gram-negative bacilli. MATERIALS AND METHODSCollection of serum. Pooled serum specimens were prepared from the blood (10 or more individual donors) of mice, guinea pigs and rats. In some experiments human serum, pooled from 100 or more individuals, was employed. In other instances, animal and human serum samples were individual specimens. All serum samples * Present address: Children's Hospital, Boston, Mass.were stored at -20°C in sealed glass ampoules. Plasma was obtained from blood collected in heparin, sodium citrate or ACD solution,' and by passage of blood through a Fenwal ion exchange pack; the latter is referred to as "resin-treated" plasma.Preparation of complemnent reagentts. The reagents were prepared by standard methods (6) and each was checked for absence of hemolytic and/or bactericidal activity. Human serum was made deficient in the first component of complement (C'1) by dialysis against acetate buffer (pH 5.5, u = 0.02) for 48 hours at 40 C. The serum was then centrifuged, and the supernatant fluid was adjusted to the desired pH and ionic strength with NaOH and NaCl. This reagent, deficient in C'1, is referred to as RI.The precipitate obtained in this way (by dialysis and centrifugation) was washed twice with the dialyzing buffer and taken up in saline to original volume. This reagent is deficient in the second component of complement (C'2) and is referred to as R2.Human serum was made deficient in the third component of complement (C'3) by incubation for 1 hour at 370 C with zymosan (Fleischmann; 2 mg per ml serum).This reagent ...

show abstract

Inactivation of Biologically Active ("Endotoxic") Polysaccharides by Fresh Human Serum

Cited by 48 publications

References 0 publications

Inactivation of Endotoxin by a Humoral Component. Vii. Enzymatic Degradation of Endotoxin by Blood Plasma*

Inactivation of Endotoxin by a Humoral Component. Vii. Enzymatic Degradation of Endotoxin by Blood Plasma*

Effects of Bacterial Endotoxins on Metabolism

Inactivation of Endotoxin by a Humoral Component. Vi. Two Separate Systems Required for Viable and Killed Salmonella Typhosa

Contact Info

Product

Resources

About