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Endotoxin Activity Assay for the Detection of Whole Blood Endotoxemia in Critically Ill Patients
Published on: June 24, 2019
EFFECTS OF BACTERIAL ENDOTOXINS ON METABOLISM : III. NITROGEN EXCRETION AFTER ACTH AS AN ASSAY FOR ENDOTOXIN
1Department of Biology, Bryn Mawr College, Bryn Mawr.
The Journal of Experimental Medicine
|October 30, 2009
Summary
A new assay uses heat-killed Salmonella typhimurium cells to detect bacterial endotoxin. The assay measures urinary nitrogen excretion in mice following ACTH administration, with a minimum detectable endotoxin amount of 0.25 micrograms.
Area of Science:
- Immunology
- Microbiology
- Toxicology
Background:
- Bacterial endotoxins are potent immune stimulants.
- Accurate detection of endotoxins is crucial for public health.
- Existing endotoxin assays may have limitations in sensitivity or specificity.
Purpose of the Study:
- To develop a novel bioassay for quantifying bacterial endotoxin.
- To investigate the relationship between Salmonella typhimurium cell counts and urinary nitrogen excretion.
- To establish the sensitivity and specificity of the proposed endotoxin assay.
Main Methods:
- Administering heat-killed Salmonella typhimurium cells intraperitoneally to mice.
- Measuring urinary nitrogen excretion following subcutaneous ACTH administration.
- Utilizing techniques like immunization, saccharated iron oxide administration, and serum inactivation to assess assay parameters.
Main Results:
- An inverse relationship was found between heat-killed S. typhimurium cell number and urinary nitrogen excretion.
- The assay demonstrated sensitivity down to 0.25 micrograms of endotoxin.
- Immunity and reticuloendothelial system blockade significantly influenced assay sensitivity.
Conclusions:
- A sensitive and specific bioassay for bacterial endotoxin has been developed.
- The assay relies on the modulation of urinary nitrogen excretion in response to ACTH.
- This method offers a valuable tool for endotoxin detection in biological samples.
