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PubMed2000

Development of streptococcal pyrogenic exotoxin C vaccine toxoids that are protective in the rabbit model of toxic shock syndrome.

Streptococcal pyrogenic exotoxin C (SPE C) is a superantigen produced by many strains of Streptococcus pyogenes that (along with streptococcal pyrogenic exotoxin A) is highly associated with streptococcal toxic shock syndrome (STSS) and other invasive streptococcal diseases. Based on the three-dimensional structure of SPE C, solvent-exposed residues predicted to be important for binding to the TCR or the MHC class II molecule, or important for dimerization, were generated. Based on decreased mitogenic activity of various single-site mutants, the double-site mutant Y15A/N38D and the triple-site mutant Y15A/H35A/N38D were constructed and analyzed for superantigenicity, toxicity (lethality), immunogenicity, and the ability to protect against wild-type SPE C-induced STSS. The Y15A/N38D and Y15A/H35A/N38D mutants were nonmitogenic for rabbit splenocytes and human PBMCs and nonlethal in two rabbit models of STSS, yet both mutants were highly immunogenic. Animals vaccinated with the Y15A/N38D or Y15A/H35A/N38D toxoids were protected from challenge with wild-type SPE C. Collectively, these data indicate that the Y15A/N38D and Y15A/H35A/N38D mutants may be useful as toxoid vaccine candidates.

Animals↗
PubMed2000

[Detection of pyrogenic exotoxin SpeA, SpeB and SpeC genes in Chilean streptococci isolates and their association with clinical manifestations].

BACKGROUND: The virulence of Streptococcus pyogenes is determined by a variety of structural molecules, toxins and complex enzymes. Pyrogenic exotoxins cause fever, erythematous reactions, cytotoxic and immunological effects. AIM: To assess the frequency of speA, SpeB and SpeC genes in Chilean Streptococcus pyogenes strains and their association with the invasiveness of infections. MATERIAL AND METHODS: The genes for pyrogenic exotoxins SpeA, SpeB and SpeC were determined by polymerase chain reactions in 114 strains of group A Streptococcus pyogenes isolated from Chilean patients with invasive or non invasive infections. RESULTS: The gene for SpeA was present in 30.7% of isolates, the gene for SpeB was present in 69.3% and the gen for SpeC in 44.7% of isolates. The gene for SpeA was present in 20 of 33 invasive infections and in 15 of 81 non invasive infections (p < 0.0001). On the contrary, the gene for SpeC was present in 11 of 33 invasive infections and in 41 of 81 non invasive infections (p < 0.05). The frequency of speB was similar in invasive and non invasive infections. CONCLUSIONS: There is a clear relationship between the presence of SpeA genes and the severity of infections caused by Streptococcus pyogenes.

Bacterial Proteins↗
PubMed1975

[The endotoxin from S-, R- and M-forms of enteropathogenic E. coli O 149: pyrogenicity, Shwartzman-phenomenon and hypersensitivity (author's transl)].

The authors are interested in elucidation of the role of endotoxin from S, R- and M-forms of E. coli O 149, and of the role of hypersensitivity in pathogenesis of Colibacillosis. It was shown in this experiment that all S, R- and M-form of E. coli O149 possess endotoxin with almost the same pyrogenicity in normal rabbits. The pyrogenicity increases enormously in the hypersensitized rabbit. There were also not observed differences between endotoxins extracted from S, R, M-mutnants. All 3 endotoxins evoke in normal rabbits the skin Shwartzman-Phenomenon, the S-endotoxin was there much stronger. This phenomenon increases in capacity in hypersensitized rabbits. Thus again, the role of hypersensitivity in Colibacillosis was proved to be important.

Animals↗
PubMed2002

Comparative study of rabbit pyrogen test and human whole blood assay on human serum albumin.

A comparative study of rabbit pyrogen test and human whole blood assay was performed on released preparations of human serum albumin. In addition, the samples were spiked with 5 IU/ml (in whole blood 0.5 IU/ml too) and 10 IU endotoxin/ml. The unspiked samples were negative in both assays. The human whole blood test resulted in the same level of security for the products as the rabbit pyrogen test did. Both, the borderline 5 IU/kg and the 10 IU/kg-Spike partially lead to results of the rabbit test which would cause further testing with additional animals. In contrast, the human whole blood assay resulted in a 100% detection for the 5 IU/ml and 10 IU/ml-Spike. We designed a study protocol for a minimised number of test animals and were able to show the general usefulness of the human whole blood assay.

Animal Testing Alternatives↗
PubMedDate not supplied

[The prodigiozan and pyrogenal stimulation of the humoral response to influenza virus antigens in mice].

The adjuvant properties of prodigiosan and pyrogenal, lipopolysaccharides of medical importance, were studied. Prodigiosan inoculated to mice together with influenza virus was found, on the one hand, to increase 10-fold the titer of specific antibodies and, on the other, to allow to reduce the antigen dose 50-fold or more. No adjuvant properties of pyrogenal were observed under the experimental conditions.

Animals↗
PubMedDate not supplied

Current practices in endotoxin and pyrogen testing in biotechnology. The Quality Assurance/Quality Control Task Group. Parenteral Drug Association.

This article presents the results of a nationwide survey of the biotechnology industry regarding endotoxin and pyrogen testing and control. It identifies procedures and methods being used by biotechnology companies, and firms working with biotechnology products, in the testing for and detection of endotoxin and other pyrogenic substances. The review attempts to identify areas of commonality and standardization within the industry and includes topics for discussion at the end of the survey results.

Biotechnology↗
PubMed1989

A monoclonal antibody to the IL-1 beta peptide 163-171 blocks adjuvanticity but not pyrogenicity of IL-1 beta in vivo.

The synthetic fragment VQGEESNDK, corresponding to the amino acid sequence in position 163-171 of human IL-1 beta, possesses the immunostimulatory but not the pyrogenic activity of the mature IL-1 beta polypeptide in vivo. To assess the relevance of this domain of IL-1 beta for its biologic activities, a mAb was raised against the synthetic peptide 163-171. The mAb Vhp20 could effectively recognize human rIL-1 beta in RIA and immunoblotting. In vivo, the mAb Vhp20 was able to selectively inhibit the immunostimulatory activity of IL-1 beta, but it could not affect the fever-inducing capacity of IL-1 beta. It is proposed that functional domains could be identified in the human IL-1 beta protein and that the fragment in position 163-171 is of major importance for the adjuvant capacity of the entire molecule, but irrelevant to its pyrogenic activity.

Adjuvants, Immunologic↗
PubMedDate not supplied

Pyrogens in small-volume parenterals prepared in hospital pharmacy.

Three pyrogen assay methods [the rabbit method, Limulus Amebocyte Lysate (LAL) gelation and chromogenic substrate, and bioburden prior to sterilization] were evaluated in three standard batches of small-volume parenteral preparations; i.e., water for injection, sodium chloride 0.9% injection, and sodium bicarbonate 8.4% injection. The same preparations were also assayed after contamination with Escherichia coli followed by sterilization. All methods gave the same results with the water for injection and the sodium chloride 0.9%. With sodium bicarbonate 8.4%, only the rabbit method was valid. For sodium chloride 0.9%, the chromogenic substrate method was valid; the gelation method was not valid. Endotoxins from the manufacturing plant were less pyrogenic in rabbits than were standard endotoxins or those from hospital E. coli.

Drug Contamination↗
PubMed1978

Endogenous mediators of the acute-phase reaction. I. Rabbit granulocytic pyrogen and its chromatographic subfractions.

LP, a saline extract of exudate-derived rabbit granulocytes, shown to be free of endotoxin contamination by sensitive LAL assay, can elicit brisk acute-phase responses in the rabbit. Following a single large intravenous dose of LP (875 mce) there is a brisk fall in serum iron at 8 hr and marked elevations in concentrations of CxRP, haptoglobin, fibrinogen, and ceruloplasmin and a lesser rise in sialic acid in the blood at 24 hr, which return toward baseline to varying degrees by 48 hr. When the crude LP solution is fractionated by column chromatography on Sephadex G75, all detectable acute-phase mediating activity elutes in a fraction (pool C) which contains all the pyrogenic activity and about 15% of the total eluted protein. Within the limitations of the methods employed, the acute phase stimulating activity and the pyrogenic activity of LP preparations appear to be closely linked.

Animals↗
PubMed1977

Biological activities of tritiated endotoxins: correlation of the Limulus lysate assay with rabbit pyrogen and complement-activation assays for endotoxin.

Tritiated endotoxins were prepared by three different methods. The biological activities of the tritiated endotoxins were determined by the Limulus amebocyte lysate assay, a rabbit pyrogen assay, and a complement-activation assay and were compared to native, unlabeled endotoxin. All three tritiated endotoxin preparations manifested adequate biological activity in each of the three assay systems, and all three assays ranked the biological activity of the different endotoxin preparations in the same order. Endotoxin tritiated by the Wilzbach procedure retained most of its biological activity and also had the highest specific radioactivity. The good correlation between the Limulus lysate, rabbit pyrogen, and complement-activation assays suggests that the same active site of the endotoxin molecule is identified by the three different assays.

Animals↗
PubMed1988

Pyrogenic reactions associated with the reuse of disposable hollow-fiber hemodialyzers.

We investigated 18 pyrogenic reactions (PRs) that occurred between July 1 and 13, 1987, in 16 patients receiving long-term hemodialysis at one dialysis center in Illinois. We defined a case of PR as the onset of chills or fever (oral temperature, greater than or equal to 37.8 degrees C) in a patient who was afebrile and had no signs or symptoms of infection before a dialysis treatment. Pyrogenic reactions to dialysis sessions during the epidemic period (July 1 through 14) were associated with the use of a reused dialyzer (risk ratio, 6.2; 95% confidence interval, 0.8 to 45). The water used to rinse the dialyzers after use and to dilute the germicide for disinfecting the dialyzers contained high concentrations of endotoxins (greater than 6 ng/mL) and bacteria (greater than 10(4) colony forming units/mL). After reuse of dialyzers was discontinued at the center, the PR rate fell to pre-epidemic levels. We concluded that PRs were associated with reuse of dialyzers, probably contaminated with endotoxins. Active surveillance for PRs among patients undergoing long-term hemodialysis should be routine at all dialysis centers; an increase in PRs should prompt timely review of water treatment and dialyzer reprocessing systems.

Bacteria↗
PubMed1987

[Effects and properties of sodium nucleinate used as a pyrogen working standard. 4. Acquired tolerance in rabbits following repeated intravenous injections of sodium nucleinate].

In rabbits, the repeated i. v. injection of bacterial lipopolysaccharide very quickly induces partial pyrogen tolerance if the injections are made at intervals of 1d. Evidently, this tolerance is without effect on the temperature increases due to subsequent sodium nucleinate injections, i. e. there is no cross tolerance between the bacterial lipopolysaccharide used for comparison and sodium nucleinate. A repeated sodium nucleinate injection, if made at intervals of 1d, does not induce pyrogen tolerance either under the experimental conditions chosen. Evidently, the temperature increases due to subsequent injections of the bacterial lipopolysaccharide used for comparison are not affected by preceding sodium nucleinate injections.

Animals↗
PubMedDate not supplied

[Effect of the bacterial polysaccharide pyrogenal on embryogenesis in noninbred white rats].

Pyrogenal was administered intramuscularly to albino rats in different terms of pregnancy in a single dose of 1000-1250 MTD/kg, twice with a 24-hour interval in a dose of 500-625 MTD/kg and repeatedly on 3rd-18th days of pregnancy in doses of 1.0-1.2, 5.0-6.3, 50.0-63.0 MTD/kg. Fetuses were studied on 20th day of pregnancy. Pyrogenal produced in embryos depending on the time of administration and dose congenital developmental defects, a decrease of body weight, thrombohemorrhagic syndrome, and erythrocytic hemolysis.

Abnormalities, Drug-Induced↗
PubMed1986

The limulus amoebocyte lysate (LAL) assay--a replacement for the rabbit pyrogen test.

Pharmaceutical products which are to be given by injection are required by law to be sterile and pyrogen-free. This paper outlines some of the advantages and disadvantages of the rabbit pyrogen test. It then covers briefly the history of the development of the Limulus Amoebocyte Lysate assay, followed by the advantages and disadvantages this assay has for use in the pharmaceutical industry.

Endotoxins↗
PubMedDate not supplied

Absence of selective brain cooling in pyrogen-induced fever in rabbits.

In 9 rabbits the effect of intravenous administration of E. coli pyrogen 0.5 microgram/kg on the reaction of selective brain cooling was studied at ambient temperatures of 20, 30 and 40 degrees C. In the freely moving animals the temperatures of the brain, carotid artery and nuchal muscles were measured with an accuracy down to 0.05 degree C and the temperatures of the ear pinna and nasal mucosa were measured accurate to 0.5 degree C. The respiratory rate was measured as well. It was found that the spontaneous febrile reaction without the component of passive hyperthermia failed to cause selective brain cooling, even if its temperature reached higher values than in case of brain temperature rise caused only by high ambient temperature. On the other hand, when the high ambient temperature caused thermal panting, pyrogen administration at an ambient temperature of 30 degrees C could reduce panting, while at an ambient temperature of 40 degrees C intense panting initiated prior to the appearance of the febrile reaction and was associated with the fever and outlasted it.

Animals↗
PubMed1985

Assessment of the pyrogenic potency of the thromboxane A2-mimetics, SQ26655 and U46619, and thromboxane B2 by intrapreoptic injection in the cat.

Using bilateral injection into the anterior hypothalamic/preoptic region of the conscious, indomethacin pretreated cat as an assay system, the pyrogenic activity of two thromboxane A2-mimetics (SQ26655 and U46619) and thromboxane B2 was assessed. PGE2 was used as a reference pyrogenic agent. Thromboxane B2 and both of the thromboxane A2-mimetics were at least 5263 times less potent than PGE2. The results do not support the putative role of thromboxanes as mediators of fever.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMedDate not supplied

[Effect of prodigiozan and pyrogenal on the neural regulation of the frog heart].

The action of bacterial lipopolysaccharides (pyrogenal and prodigiosan) on nervous regulation of the frog heart was studied. Both the substances provoked a considerable increase in the arrest of spontaneous contractility of the atria during stimulation of the extracardial nerves. This effect did not occur after atropine administration, but became manifest during the benzohexonium-induced blockade of conduction in the intracardiac ganglia. The bacterial lipopolysaccharides did not alter acetylcholinesterase activity or myocardial sensitivity to acetylcholine. It is assumed that variation of the nervous regulation of the heart under the effect of prodigiosan and pyrogenal is determined by the effect of these substances on the transmitter release from the presynaptic endings of the extracardial ganglia.

Action Potentials↗
PubMed1985

Endotoxin in blood products: correlation between the Limulus assay and the rabbit pyrogen test.

The possibility of replacing the rabbit pyrogen test by the Limulus (LAL) test, as a final release test for plasma products, was investigated. The LAL test measured the endotoxin content quantitatively, using a chromogenic substrate. The samples were boiled and centrifuged to remove inhibiting substances, which represent a major problem when testing plasma protein samples. In order to correlate the LAL test to the rabbit test, parallel assays were performed on 85 batches of two different human albumin preparations. For both products, a positive correlation was observed between the two tests. However, the pass/fail limit of the rabbit test was found at different endotoxin levels, corresponding to about 2 and 20 ng/kg, respectively. This discrepancy could be removed by extracting the endotoxin before administration to rabbits. It is concluded that the endotoxin, detected in plasma products by the LAL test, may be present in a non-pyrogenic state.

Animals↗