Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Limulus Test”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 469 records · Page 26Linked to original sources
PubMed1985

Bacterial antigen detection in cerebrospinal fluid of patients with meningitis.

This study compared the sensitivity and specificity of four test systems in detecting Haemophilus influenzae type b, Neisseria meningitidis, Streptococcus pneumoniae, and gram-negative organisms in cerebrospinal fluid (CSF), versus culture. The tests used on CSF from 155 patients with meningitis were the Phadebact coagglutination (CoA) test, the Directigen latex agglutination (LA) test, counterimmunoelectrophoresis (CIE), and the Limulus amebocyte lysate (LAL) test. The sensitivity for patients with bacterial meningitis was 78% (18/23) for LA, 78% (25/32) for CoA, and 67% (18/27) for CIE for detection of H. influenzae type b; 71% (10/14) for CoA, 100% (6/6) for LA, and 50% (6/13) for CIE in detecting S. pneumoniae; and 33% (1/3) for LA and 50% (2/4) for CIE in detecting N. meningitidis. LAL had a sensitivity of 77% (37/48) in detecting CSF gram-negative endotoxin. The specificities of those with bacterial meningitis for H. influenzae, S. pneumoniae, and N. meningitidis tested by LA were, respectively, 100% (35/35), 96% (50/52), and 100% (54/54); for H. influenzae and S. pneumoniae using CoA 97% (62/64) and 96% (80/83); for H. influenzae, S. pneumoniae, and N. meningitidis using CIE 67% (18/27), 50% (6/12), and 50% (2/4). The specificity of LAL was 86% (38/44). The detection of bacterial antigen from CSF in patients with meningitis by commercial agglutination tests is more sensitive than CIE and is highly specific.

Agglutination Tests↗
PubMed2004

Evaluation of the bacterial endotoxin test for quantification of endotoxin contamination of porcine vaccines.

We investigated the application of the bacterial endotoxin test for the quantification of the endotoxin contamination of various commercial porcine vaccines. In endotoxin-spiked samples, Freund's complete adjuvant and aluminum hydroxide gel adjuvant failed to interfere with the results of the endotoxin test, and both recovery ratios were within the permissible range mentioned in the Japanese Pharmacopoeia. At the various dilutions tested, none of the adjuvants in commercial porcine vaccines caused noteworthy interference in the test. In addition, none of the 39 samples of porcine vaccines approved in Japan induced an interfering effect in the endotoxin test. Our findings suggest that the bacterial endotoxin test using endotoxin-specific Limulus amoebocyte lysate (LAL) can detect endotoxin contamination in commercial porcine vaccines containing either oil or aluminum adjuvants.

Aluminum Hydroxide↗
PubMed1983

Physical and biological properties of U.S. standard endotoxin EC after exposure to ionizing radiation.

Techniques that reduce the toxicity of bacterial endotoxins are useful for studying the relationship between structure and biological activity. We used ionizing radiation to detoxify a highly refined endotoxin preparation. U.S. standard endotoxin EC. Dose-dependent changes occurred by exposure to 60Co-radiation in the physical properties and biological activities of the endotoxin. Sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis showed gradual loss of the polysaccharide components (O-side chain and R-core) from the endotoxin molecules. In contrast, although endotoxin revealed a complex absorption pattern in the UV range, radiation treatment failed to modify that pattern. Dose-related destruction of the primary toxic component, lipid A, was suggested by the results of activity tests: both the pyrogenicity and limulus reactivity of the endotoxin were destroyed by increasing doses of radiation. The results indicate that the detoxification is probably due to multiple effects of the ionizing radiation on bacterial lipopolysaccharides, and the action involves (i) the destruction of polysaccharide moieties and possibly (ii) the alteration of lipid A component of the endotoxin molecule.

Animals↗
PubMed2001

A model for predicting endotoxin concentrations in metalworking fluid sumps in small machine shops.

METHODS: In British Columbia, Canada, nineteen small machine shops which used water-based metalworking fluids (MWF) were examined. One bulk MWF sample was taken from each independent sump (N=140) and tested for endotoxin using the Limulus Amoebocyte Lysate assay. Factors that might influence the MWF sump endotoxin concentration were investigated using mixed effect multiple regression modelling to control for repeated measures within shops. RESULTS: The geometric mean (GM) endotoxin concentration was 6791 EU/ml. Contamination of MWF with tramp oil, MWF pH, MWF temperature, and MWF type were significant predictors of sump fluid endotoxin concentration (model P=0.0001, ordinary least squares R(2) =0.36). Concentrations of endotoxin in sump fluids were increased by MWF contamination with tramp oils such as hydraulic oils, preservative oils, spindle oils, slidway lubricants, gear lubricants, and greases (model predicted GM=17400 EU/ml vs. 1600 EU/ml without tramp oil). Concentrations were also elevated where pH was lower than 8.5 (predicted GM=10600, vs 3600 EU/ml for pH 8.5 to 9.5), where soluble fluids were used (predicted GM=11800 vs. 2800 EU/ml for synthetic fluids), and where sump fluid temperatures were higher (predicted GM=2600 EU/ml at 11 degrees C vs. 21500 EU/ml at 32 degrees C). The within-shop correlation of sump bulk fluid endotoxin concentrations was 38%. CONCLUSIONS: Minimizing tramp oil contamination, using synthetic fluids, and monitoring pH and temperature would be valuable tools for controlling endotoxin contamination in MWF sumps. In addition, since there was correlation within-shop, contamination of one sump in a shop may suggest changing the fluids in all.

Endotoxins↗
PubMed1984

The Limulus Amoebocyte Lysate (LAL) assay for the detection of endotoxin in fat emulsions for total parenteral nutrition (TPN).

Fat emulsions spiked with Escherichia coli endotoxin were tested with Limulus Amoebocyte Lysate (LAL) reagent, using both the micro method and the tube method. The effect of vortexing, ultrasonication and addition of Pyrosperse on the dispersion of endotoxin in these emulsions was compared. The advantage of using the tube method, rather than the micro method, is shown. Ultrasonication may substitute vortex mixing. Pyrosperse had no convincing effect.

Endotoxins↗
PubMed1982

The inhibitory effect of polymyxin B on endotoxin-induced endogenous pyrogen production.

The effect of polymyxin B (PMB) on the endogenous pyrogen (EP)-induced property of lipopolysaccharide (LPS) in vitro was examined. PMB inhibited LPS when added to leukocyte suspension 5 min before or up to 30 min after the addition of LPS. The inhibitory effect was dose-related and appeared to be specific for LPS (including naturally occurring endotoxin). EP production in response to a different stimulus (staphylococci) was not prevented even when LPS-PMB complexes were presumably present. These data suggest that when experimental agents are found to stimulate the production of EP or lymphocyte activating factors (LAF, interleukin-1) in vitro, or when apparently spontaneous production of EP or LAF is seen, incubation with PMB may be a useful technique to exclude th effects of endotoxin contamination - especially when negative results have been obtained in the limulus gelation test.

Animals↗
PubMed1991

Assay of pyrogens by interleukin-6 release from monocytic cell lines.

A novel in-vitro system has been developed for the detection and quantification of pyrogen in pharmaceutical products. The measured variable was evoked secretion of the pyrogenic cytokine interleukin-6 from MONO MAC 6 monocytic cells incubated with the product. The interleukin-6 was detected using a specific and sensitive ELISA developed for this purpose. The test system detected pyrogenic contamination in 3 batches of therapeutic human serum albumin which had caused adverse reactions in recipients. The contamination was not detected in conventional tests: the rabbit pyrogen test and the limulus amoebocyte lysate test.

Animals↗
PubMed1984

Monoclonal antibody against a genus-specific antigen of Chlamydia species: location of the epitope on chlamydial lipopolysaccharide.

Monoclonal antibodies were prepared by the fusion of murine myeloma NS1 cells with spleen cells of BALB/c mice immunized with Formalin-killed elementary bodies of the Chlamydia trachomatis L2 serovar. The specificity of these monoclonal antibodies was determined with a solid-phase immunoassay in which HeLa 229 cells infected with C. trachomatis serovars D, G, H, I, L2 and the Chlamydia psittaci meningopneumonitis strain Cal-10 were used. An immunoglobulin G3 monoclonal antibody (L2I-6) was identified that reacted with both C. trachomatis- and C. psittaci-infected HeLa cells. The immunoreactivity of the genus-specific epitope was heat resistant (100 degrees C, 10 min) but was destroyed by sodium metaperiodate treatment. Further characterization of the chlamydial specificity of monoclonal antibody L2I-6 by microimmunofluorescence showed that it was reactive with all 15 C. trachomatis serovars and seven C. psittaci strains isolated from five different animal species. We undertook studies to identify the biochemical nature of the chlamydial component on which the genus-specific epitope was located. The immunoreactive component was isolated by hot phenol-water extraction of dithiothreitol-reduced chlamydial elementary bodies. The component was positive in the Limulus amoebocyte lysate test (results of Limulus amoebocyte lysate assay were identical with those of Salmonella typhimurium LT2 SAI 377 Re lipopolysaccharide [LPS]), contained 8.8% 2-keto-3-deoxyoctulosonic acid, was resistant to proteinase K, and possessed electrophoretic mobility and silver-staining characteristics in sodium dodecyl sulfate-polyacrylamide gel electrophoresis consistent with a rough LPS or glycolipid. On the basis of these findings, we conclude that the genus-specific epitope recognized by monoclonal L2I-6 is located on chlamydial LPS. We further characterized the antigenic properties of the chlamydial LPS epitope by examining the immunoreactivity of monoclonal antibody L2I-6 by immunoblotting analyses against isolated LPSs extracted from Neisseria gonorrhoeae, S. typhimurium, and Escherichia coli. Monoclonal antibody L2I-6 did not bind LPS of these organisms, demonstrating that the chlamydial genus-specific LPS epitope is apparently not shared by these gram-negative bacteria. We were able, however, to show that the chlamydial LPS does share antigenic determinants with LPS of gram-negative organisms. Polyclonal rabbit antisera raised against S. typhimurium Re LPS or lipid A showed intense immunological cross-reactivity with chlamydial LPS by immunoblotting.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Partial purification of a bacterial lectinlike substance from Eikenella corrodens.

A bacterial lectinlike substance, which is considered to participate in the adherence of Eikenella corrodens to various host cells, was purified from E. corrodens cells. The substance was extracted in 1% Triton X-100 with sonication from the cell envelope of E. corrodens 1073 and partially purified by galactosamine affinity chromatography and gel filtration chromatography based on its hemagglutination (HA) activity. The lectinlike substance was purified about 256-fold as evaluated by its specific HA activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the partially purified lectinlike substance (PPL) produced a single protein band of large molecular weight when it was applied to the gel without the addition of beta-mercaptoethanol and heating. Chemical analysis showed that PPL contained 14.4 micrograms of hexose per 100 micrograms of protein and that it did not contain muramic acid, glucosamine, or 2,6-diaminopimelic acid, which are characteristic of peptidoglycans. The HA activity of PPL was inhibited by EDTA but restored by adding Ca2+. The HA activity was remarkably inhibited by sugars containing N-acetyl-D-galactosamine and D-galactose. These results indicate that the lectinlike substance on the E. corrodens cells is an essential factor for the adherence to host cells.

Bacterial Proteins↗
PubMed1994

[Investigation of the endotoxin content of veterinary vaccines]

Vaccines composed of gram-negative bacteria contain endotoxin in considerable amounts. This may result in adverse effects after vaccination of sensitive animals. For reasons of safety and animal welfare the endotoxin level of veterinary vaccines should be limited. The limulus amebocyte lysate test is suitable to check the endotoxin content in most vaccines. Safety tests in animals should only be performed if the results of the limulus test are satisfactory.

Journal Article↗
PubMed1986

Endotoxin detection and elimination in biotechnology.

Endotoxins liberated by gram-negative bacteria are frequent contaminants of aqueous and physiological solutions. Because of their potent biological effects in vivo and in vitro, their detection and removal are essential for the safe parenteral administration of products produced from natural sources, as well as those produced by recombinant DNA technology. Traditional methods of endotoxin detection include the U.S. Pharmacopeia rabbit test and the Limulus amebocyte lysate test. Elimination of endotoxins, however, continues to be a problem. Standard methods of sterilization, such as autoclaving or sterile filtration, have little effect on endotoxin levels. Various techniques for the prevention of endotoxin contamination and endotoxin removal have been discussed. The overall role of endotoxin prevention, detection, and elimination in biotechnology is emphasized.

Endotoxins↗
PubMed1999

Bacterial lipopolysaccharides in sterile corneal organ-culture media.

PURPOSE: Lipopolysaccharides (LPS) are known to stimulate various inflammatory reactions by interaction with cytokines and macrophages. As contamination of sterile organ culture media with nonviable bacterial substances may influence donor tissue prognosis, we investigated a series of culture media drawn from organ culture for the presence of LPS. METHODS: One hundred eighty-two samples of sterile organ-culture media were tested for LPS using the Limulus-amoebocyte-lysate assay (LALA). We then investigated the time course of LPS levels during organ culture, the influence of medium changes, the graft deswelling procedure and transportation as well as repeated freezing on the detection of lipopolysaccharides with the LALA. RESULTS: LPS above background threshold was found in 21.4% of the organ-culture media. The time course of LPS during organ culture and through the deswelling procedure was quite stable. Medium changes may wash out LPS, thus the highest LPS values were normally seen in the examination medium, which has the first contact with the corneal tissue. Repeated freezing did not influence the detectability of LPS with the LALA. CONCLUSION: LPS detected in sterile corneal organ cultures is probably derived from nonreplicating bacterial postmortem donor tissue contamination. It is a rather heat and cold stable product that may be washed out from the donor tissue by medium changes. As LPS may directly influence graft viability or trigger inflammatory host responses, further investigations of the clinical course of these grafts are required.

Cadaver↗
PubMed1983

Rapid and reliable techniques for the laboratory detection of bacterial meningitis.

Microorganisms encountered in cerebrospinal fluid require rapid and accurate means of detection and identification in the laboratory. Although restricted to morphologic study and Gram reaction, the Gram stain of cerebrospinal fluid has been the primary diagnostic tool for preliminary diagnosis of purulent meningitis, with identification of the etiologic agent often made within one to two hours by direct microscopic examination. Gram stain and appropriate culture procedures still provide the basis for comparing other diagnostic methods. Nonimmunologic methods that show promise in being both rapid and reliable include gas-liquid chromatography and the Limulus amebocyte lysate test. Fatty acid and carbohydrate profiles characteristic of Haemophilus influenzae, Streptococcus pneumoniae, Neisseria meningitidis, and Staphylococcus aureus in the cerebrospinal fluid of human subjects and animals have been obtained by gas-liquid chromatography. Also, a unique compound has been detected by gas-liquid chromatography in cerebrospinal fluid from patients with tuberculous meningitis. The Limulus test has been reliable in spinal fluid and almost always gives positive results in H. influenzae and other Gram-negative meningitides. Nonspecific test procedures of varying degrees of accuracy and promise include lactic acid, C-reactive protein, and lactate dehydrogenase determination. Direct microscopic examination of cerebrospinal fluid remains the most practical and accurate method for identifying the etiologic basis of bacterial (and fungal) meningitis.

Animals↗
PubMed1977

Comparison of the pyrogen tests in rabbits and with limulus lysate.

In the past years an assortment of samples of plasma proteins, enzymes, vaccines and blood substitutes were tested comparatively in rabbits (pyrogen test, European Pharmacopoeia) and with the LAL test (Pyrogent, Byk-Mallinckrodt, Inc.). Specificity and sensitivity were tested with endotoxins and lipid A of gram-negative bacteria. The limulus amebocyte lysate (LAL) test gave similar results or was tenfold more sensitive than the assay in rabbits. More than 300 samples of drugs were examined by both tests. All preparations positive in the rabbit test were positive in the LAL test too. In the testing of plasma proteins the LAL test was more sensitive. The examination of 45 samples of vaccines for pyrogens gave the same result in both assays. Streptokinase does not inhibit the LAL test unspecifically. The LAL test is not an alternative but an additional method in the detection of lipopolysaccharides in drugs.

Animals↗
PubMed1987

Endotoxemia in patients with alcoholic and non-alcoholic cirrhosis and in subjects with no evidence of chronic liver disease following acute alcohol excess.

The presence of endotoxemia in peripheral venous blood was evaluated in 88 patients with alcoholic cirrhosis (AC) and in 42 patients with non-alcoholic cirrhosis (NAC). The two groups did not differ significantly with respect to mean age, liver function tests, and incidence of esophageal varices or ascites. In addition, a group of 24 patients with no evidence of chronic liver disease but with acute exposure to large quantities of alcoholic beverages was investigated. Endotoxin was determined by using the Limulus lysate test. The assays were carried out in the plasma samples by both the dilution technique and the chloroform extraction method. Endotoxemia was found more frequently in patients with AC (67.3%) than in patients with NAC (45.5%, P less than 0.025). The prevalence of endotoxemia was not significantly higher in cirrhotics with ascites or esophageal varices when compared to the subgroup without ascites or esophageal varices. Of the 24 patients with no evidence of chronic liver disease investigated because of acute alcohol excess immediately before admission 11 (45.7%) were found to have endotoxin in the peripheral venous blood. In 7 of these patients a second blood sample was tested 5-8 days later and no endotoxin could be detected. The latter results suggest that heavy alcohol abuse leads to transient endotoxemia even in patients with no signs of chronic liver disease. The findings support the hypothesis that gut-derived endotoxins might play a role in the initiation and aggravation of alcohol-induced liver disease.

Adult↗
PubMed1983

Lack of endotoxin in Borrelia hispanica and Treponema pallidum.

Borrelia hispanica from infected guinea pigs and Treponema pallidum from testicular syphilomas of rabbits were assayed for the presence of endotoxin with the Limulus lysate test. A suspension of Borrelia, containing 1.3 X 10(8) spirochetes/ml, was nonreactive both when it was tested as intact organisms, and when tested after disruption of the spirochetes by sonication. Eight different suspensions of treponemes, ranging from 0.6 X 10(9) to 3 X 10(9) treponemes/ml, were negative at a 1:10 dilution and were no more active than control suspensions of normal rabbit testes. Therefore, it was concluded that T. pallidum, as well as the Borrelia, possessed no endotoxin.

Animals↗