Detection of endotoxin in human blood and demonstration of an inhibitor

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°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.

https://rupress.org/jem/article-pdf/108/5/685/1391205/685.pdf

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

The incubation of endotoxin with Na2Cr51O4 yielded a product which was well labeled. That the label was fixed on the endotoxin itself was shown by autoradiography on specific lines of precipitation formed in agar. Ultracentrifugation at 40,000 RPM sedimented 80 per cent of the total weight of the starting Boivin preparation. Agar diffusion patterns with subsequent autoradiographs demonstrated that the chromium tag was associated only with the heavy fractions of the pellet. The supernatant contained precipitable, but unlabeled endotoxin. Toxicity measurements showed that more than 99 per cent of the total toxicity resided in the pellet fractions. The chromate-tagged endotoxin was specifically identified in plasma samples taken up to 6 hours after intravenous administration of LD50 or sublethal doses. The endotoxin was not totally detoxified in vivo since plasma collected 6 hours after the injection of even the sublethal dose was toxic when assayed in adrenalectomized mice. The endotoxin was specifically identified in urine specimens but it was no longer toxic or radioactive. Agar diffusion experiments indicated that only degraded material was present.

https://rupress.org/jem/article-pdf/117/4/561/1081005/561.pdf

Characterization of a cr51-labeled endotoxin and its identification in plasma and urine after parenteral administration

A technique is described for perfusing the isolated rat liver with viable bacteria and for comparing their phagocytosis by Kupffer cells when different suspending fluids are used successively.

Various general factors that modify uptake of bacteria have been studied, notably the nature of the bacteria and their concentration, the flow rate through the liver, the age of the liver preparation and the effect of repeated perfusion.

Normal human, rat and mouse sera were found to exert an opsonic effect on the phagocytosis of Escherichia coli. Thus the average uptake of these bacteria suspended in Ringer-Locke solution was 11 per cent, as compared with 41 per cent in serum. A reduction in opsonic activity of human serum was produced by heat at 56° for 30 min., absorption with the homologous strain or with an antigen-antibody system. Activity was completely abolished by homologous absorption followed by heat at 56° or absorption with an antigen-antibody system or with zymosan. Full opsonic activity was shown by a mixture of heated serum and E. coli-absorbed serum.

It is concluded that the serum factors that contribute to opsonic activity in this system are specific antibody, complement and another heat-labile factor. The possible identity of the latter with properdin is considered.

The opsonic effect of normal serum on the uptake of bacteria by the reticulo-endothelial system; perfusion studies with isolated rat liver.

Horseshoe crab (HSC) hemolymph is the source of Limulus amebocyte lysate (LAL), a critical component in sterility testing that ensures drug and medical device safety for millions of patients every year. Wild HSC populations have been declining as a result of use as whelk and eel bait, and largely due to capture and bleeding for hemolymph, primarily while spawning, thus posing significant biomedical supply and species viability risks. We investigated aquaculture as an alternative to current practices as a means to foster conservation by establishing a sustainable endotoxin testing resource. We found HSC aquaculture to be practicable based on routine hemolymph harvesting, batch uniformity, and LAL quality, while safeguarding animal wellbeing. Achieving sustainable LAL production could satisfy industry needs for several years with a fraction of one year’s current capture with low-impact, year-round harvesting of a finite cohort. Sustainable supplies of LAL could also be adapted to address daunting trends in septicemia and antimicrobial resistance. LAL is uniquely sensitive and specific for gram-negative bacteria, which represent 70-80% of pathogens typically attributed to sepsis. Early diagnosis of bacterial infection and timely antibiotic therapy can reduce patient mortality. However, erratic results associated with interfering substances plagued efforts to adapt LAL for clinical use in the past. Our efforts to develop new methods have yielded a promising LAL screening technique to detect a gram-negative bacteria and endotoxins in human blood.

Horseshoe Crab Aquaculture as a Sustainable Endotoxin Testing Source

A reaction between fresh serum and lipopolysaccharides of gram-negative bacteria.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

D. Rowley

Author Tools

Chat about Author

Papers

A reaction between fresh serum and lipopolysaccharides of gram-negative bacteria.