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PubMed1992

The effect of chronic immunostimulation of the nonlactating bovine mammary gland with interleukin-2, pokeweed mitogen, and lipopolysaccharide.

Interleukin-2, pokeweed mitogen, and lipopolysaccharide were evaluated for their ability to accelerate involution and to stimulate local cellular defenses in the nonlactating bovine mammary gland. Twelve cows were divided into three treatment groups of 4 cows each to receive interleukin-2, pokeweed mitogen, or lipopolysaccharide. One day after drying off, 3 mammary quarters of each cow were infused with 100 micrograms of immunostimulant daily for 21 d; the remaining control quarter received PBS. Secretion samples were collected weekly to determine bacteriologic status, total SCC, and differential cell counts. On d 21, cows were killed, and tissues were collected for microscopy. Overall, SCC were higher in immunostimulated quarters, but only those infused with interleukin-2 were significantly elevated over controls. By wk 3, the percentage of neutrophils decreased in interleukin-2 and pokeweed mitogen quarters over pretreatment values, percentage of macrophages increased in interleukin-2 quarters, and percentage of lymphocytes increased in pokeweed mitogen and lipopolysaccharide quarters. Percentage of alveolar lumina was reduced, and connective tissue stroma increased, in all immunostimulated quarters compared with those of controls, suggesting accelerated involution. Involution was greatest in quarters treated with interleukin-2. Leukocyte infiltration was greater in immunostimulated quarters than in control quarters. Similarly, concentrations of Ig-producing plasma cells were greater in immunostimulated quarters than in control quarters. Quarters infused with interleukin-2 exhibited the greatest concentration of plasma cells, followed by quarters treated with pokeweed mitogen and lipopolysaccharide; IgG1 plasma cells predominated, followed by IgG2, IgA, and IgM. Interleukin-2 accelerated involution and stimulated local antibody production more than did the two mitogens, suggesting a potential role for this cytokine as a general immunostimulant at drying off.

Animals↗

PubMed2005

Erythropoietin attenuates lipopolysaccharide-induced splenic and thymic apoptosis in rats.

Apoptosis of lymphoid tissues during sepsis is well documented and linked to the pathobiology of organ failure and death. In this study, we evaluated the effect of a single dose of recombinant erythropoietin (EPO) on thymic and splenic apoptosis in an endotoxic sepsis model. Young male Wistar rats were divided into 3 groups and administered intraperitoneally (IP) either normal saline; lipopolysaccharide (LPS) 10 mg/kg; or EPO (5000 U/kg) 30 min before lipopolysaccharide. Six hours following LPS administration animals were sacrificed. Apoptosis was assessed by hematoxylin-eosin staining, terminal deoxynucleotide transferase-mediated fluorescein-dUTP nick end labeling (TUNEL), and caspase-3 immunostaining. When compared with animals given LPS, animals pretreated with EPO displayed reduced splenic and thymic TUNEL positivity of 44+/-3 (p<0.05) and 143+/-4 (p<0.05) nuclei per high power field (hpf), respectively. Caspase-3 positivity was also significantly reduced in the spleen and thymus, with 31+/-4 (p<0.05) and 93+/-3 (p<0.05) positive stained nuclei per hpf, respectively. Serum nitrite levels were elevated in animals given lipopolysaccharide. Pretreatment with EPO attenuated the increase in nitrite levels; however, this did not reach statistical significance. We conclude that a single dose of recombinant erythropoietin can reduce thymic and splenic apoptosis associated with lipopolysaccharide administration.

Animals↗

PubMed1998

[Estimation of mean molecular weight of Enterobacteriaceae lipopolysaccharides using gas chromatography for determination of fatty acids].

In the paper, we propose a method for estimation of the mean molecular weight of lipopolysaccharide, which is important for accuracy of endotoxin activity investigation. In our study, it was assumed that lipid A portion in Enterobacterial lipopolysaccharide is substituted by four 3-hydroxytetradecanoic acid residues. Lipopolysaccharides of S, Ra, Rc and Re chemotypes being laboratory preparations as well as purchased from Sigma were investigated. Fatty acids were determined by of gas chromatography as methyl esters according to the procedure described by Wollenweber and Rietschel. Mean molecular weight was calculated by the formula: MMW = [formula: see text]. A high agreement between the estimated and the theoretical molecular weight values was demonstrated in the case of Salmonella minnesota R595 (Re) LPS preparation. As expected, LPS heterogeneity increase together with enlargement of polysaccharide chain length which is visible in electrophoregrams also. Except for LPS mean molecular weight estimation, the method allows its detection in various preparations and samples, distinguishing of R and S LPS forms as well as the determination of mean length of O-specific chain in lipopolysaccharides which structures are known.

Chromatography, Gas↗

PubMed2000

Omeprazole fails to suppress up-regulation of gastric mucosal endothelin-converting enzyme-1 by Helicobacter pylori lipopolysaccharide.

BACKGROUND: Endothelin-1, a key mediator of inflammatory processes, is produced from its biologically inactive precursor, big ET- by the action of endothelin converting enzyme-1(ECE-1). In this study, we applied the animal model of H. pylori lipopolysaccharide-induced gastritis to assess the effect of three different types of antiulcer agents on the gastric mucosal expression of ECE-1 activity. METHODS: Rats, pretreated twice daily for 3 days with proton pump inhibitor, omeprazole at 40 mg/kg, gastroprotective agent, sulglycotide at 200 mg/kg, H2-receptor antagonist, ebrotidine at 100 mg/kg or the vehicle, were subjected to intragastric application of H. pylori lipopolysaccharide at 50 microg/animal, and after 2, and 4 additional days on the drug or vehicle regimen their mucosal tissue used for histologic and biochemical assessment. RESULTS: In the absence of antiulcer agents, H. pylori lipopolysaccharide elicited a pattern of mucosal inflammatory responses resembling that of acute gastritis which reached a maximum by the 4th day and were accompanied by a 4.1-fold increase in the mucosal expression of ECE-1 activity and an 8.8-fold enhancement in TNF-alpha. Treatment with sulglycotide led to a 56.7% reduction in the extent of mucosal inflammatory involvement, the mucosal expression of ECE-1 activity fell by a 40.5% and the level of TNF-alpha declined by a 69%. Ebrotidine produced a 50.9% decrease in the extent of mucosal inflammatory involvement, a 33.6% decrease in the expression of ECE-1 activity and a 64.1% decline in TNF-alpha, whereas omeprazole elicited a 37.6% reduction in the extent of mucosal inflammatory involvement and a 29.5% decrease in TNF-alpha, but had no effect on the lipoploysaccharide-induced increase in the mucosal expression of ECE-1 activity. CONCLUSIONS: The findings implicate up-regulation of ECE-1 in triggering the induction of TNF-alpha and propagation of gastric mucosal inflammatory responses to H. pylori. We also show that omeprazole, in contrast to sulglycotide and ebrotidine, fails to counter the enhancement in the mucosal expression of ECE-1 caused by H. pylori- lipopolysaccharide.

Animals↗

PubMed1975

Effect of core lipopolysaccharides from Salmonella minnesota R mutants on the survival times of mice bearing Ehrlich tumor.

Injection of a homologous series of bacterial core lipopolysaccharides obtained from Salmonella minnesota R mutants to Ehrlich solid tumor-beating mice results in an increase of survival times of treated animals. Lower chain length favors greater antitumor activity. Oligosaccharides and polysaccharides derived from lipopolysaccharides were found to be ineffective in increasing survial time of tumore-bearing mice. Smaller-sugar-chain-length core lipopolysaccharides were found to be better adjuvant than were those with longer sugar chains. Implication of adjuvant action of lipopolysaccharides in the elicitation of antitumor activity is suggested.

Adjuvants, Immunologic↗

PubMed2001

Structure and serological characterization of an Nepsilon-[(R)-1-carboxyethyl]-L-lysine-containing O-chain of the lipopolysaccharide of Proteus mirabilis O13.

In this paper we present the structure and describe serological properties of the O-specific polysaccharide of Proteus mirabilis O13 lipopolysaccharide, which contains a unique component: an amide of D-galacturonic acid (D-GalA) with an unusual amino acid, Nepsilon-[(R)-1-carboxyethyl]-L-lysine (alaninolysine, AlaLys). Selective chemical degradations of either GalA or AlaLys resulted in the loss of the serological reactivity of the polysaccharide with anti-O serum against P. mirabilis O13. Neither synthetic stereoisomers of AlaLys nor the isolated amide of GalA with AlaLys inhibited the reaction of the O-antiserum with the homologous lipopolysaccharide. The O-antiserum did not cross-react with the lipopolysaccharide of Providencia alcalifaciens O23 containing an amide of D-glucuronic acid with AlaLys. These data showed that both uronic acid and amino acid components of the amide play an important role in manifesting the P. mirabilis O13-specificity, but the full specific epitope also includes another O-specific polysaccharide component(s). A cross-reactivity of anti-O13 serum with some other P. mirabilis strains was observed and attributed to a common heat-stable antigen(s) different from the lipopolysaccharide.

Antibodies, Bacterial↗

PubMed2001

[Analysis of fatty acids from lipopolysaccharides of Bacteroides thetaiotaomicron and Bacteroides fragilis].

The aim of this study was to determine and to compare fatty acids occurring in lipopolysaccharides (LPS) isolated from B. thetaiotaomicron and B. fragilis strains of different origin. Lipopolysaccharides of three B. thetaiotaomicron strains and four B. fragilis strains were isolated by phenol-water extraction according to the procedure of Westphal and Jann (1965). Water-phase LPS fractions were then treated with nucleases and purified by ultracentrifugation as described by Gmeiner (1975). Fatty acid methyl esters, obtained by methanolysis of LPS, were analysed in gas-liquid chromatography combined with mass spectrometry (GLC-MS). Trimethylsilylated hydroxyl groups of fatty acid methyl esters were identified with GLC-MS using a method of selective ion monitoring (SIM). Lipopolysaccharides of B. thetaiotaomicron and B. fragilis strains contained long-chain (15-18 carbon atoms) fatty acids. The broad spectrum of simple long-chain and branched-chain fatty acids as well as 3-hydroxy fatty acids were detected. The main fatty acid of analyzed bacterial species was 3-hydroxy-hexadecanoic acid (3OH C16:0). Several 3-hydroxy fatty acids were detected in LPS of examined strains. Fatty acids occurring in LPS of B. thetaiotaomicron and B. fragilis strains appeared to be qualitatively similar. Quantitative differences in fatty acids composition of lipopolysaccharides isolated from strains of different origin were observed.

Bacteroides↗

PubMed2002

Rat periodontal fibroblast responses to bacterial lipopolysaccharide in vitro.

Rat periodontal ligament fibroblasts and gingival fibroblasts were stimulated with lipopolysaccharide from Escherichia coli. Cell proliferation and both interleukin-1beta and nitric oxide production were determined by a colorimetric, enzyme-linked immunosorbent assay and the Griess reaction, respectively. The results showed that at lipopolysaccharide concentration up to 100 ng per well, the cell proliferation of periodontal ligament fibroblasts was higher than that of gingival fibroblasts. No significant difference between the levels of interleukin-1beta produced by periodontal ligament and gingival fibroblasts can be observed. At high concentration of lipopolysaccharide (1000 ng/well), the levels of nitric oxide in the periodontal ligament fibroblasts cultures were higher than those in the gingival fibroblasts cultures. These results suggest those rat periodontal ligament and gingival fibroblasts may respond differently to lipopolysaccharide and, thus, may be different periodontal fibroblast subpopulations.

Animals↗

PubMed2002

[Use of reactions with Limulus amoebocyte lysate (LAL) to determine biological activity of lipopolysaccharides from reference and clinical strains of the Bacteroides fragilis group].

The aim of this study was to determine and compare a biological activity of lipopolysaccharides (LPS) from reference and clinical strains of strictly anaerobic bacteria belonging to the Bacteroides fragilis group (BFG) by means of quantitative, photometric BET (LAL) method with Limulus polyphemus amoebocyte lysate and chromogenic substrate S-2423. Lipopolysaccharides of five BFG species were extracted by Westphal and Jann method (1965) from eight reference and two clinical strains of B. fragilis group. Crude LPS preparations were purified according to the procedure described by Gmeiner (1975) with ultracentrifugation and nuclease treatment. Biological activities of bacterial endotoxins were determined by quantitative BET method with chromogenic substrate S-2423 (ENDOCHROME kit, Charles River Endosafe Ltd., USA). Tests were performed according to the producer's recommendations. E. coli O55:B5 LPS was applied to compare its activity in reaction with LAL reagent with activities of LPS preparations from rods of the Bacteroides genus. Among examined bacterial compounds the most active in BET method was E. coli O55:B5 LPS. Activities of lipopolysaccharides from five species of BFG rods in reaction with Limulus amoebocyte lysate were differentiated. Greater ability to activate LAL proenzyme revealed lipopolysaccharides of these species of the Bacteroides genus, which are important from the clinical point of view--B. fragilis and B. thetaiotaomicron.

Bacteroides fragilis↗

PubMed1975

Chemical structure of lipopolysaccharides and endotoxin immunity.

Lipopolysaccharides (endotoxins) of gram-negative bacteria consist of 2 components with distinct physico-chemical character: a heteropolysaccharide and a covalently linked lipid, termed lipid A. The chemical structure of lipid A, which represents the toxic center of lipopolysaccharides, is discussed. Evidence is presented that lipid A antiserum suppresses the pyrogenic effect of lipid A and lipopolysaccharides in rabbits. The protective power of lipid A antiserum, however, is only expressed in animals which have been pretreated with lipid A or lipopolysaccharide indicating that other than humoral factors, perhaps cellular, also participate in endotoxin fever (cross) immunity. The fever resistance mediated by lipid A antiserum seems to be endotoxin-specific with regard to both the preparative and the challenging injection. Lipid A antiserum therefore may serve as a tool to discriminate between fever caused by endotoxins and that induced by other pyrogens.

Absorption↗

PubMed1992

Inhibition of gastric mucosal laminin receptor by Helicobacter pylori lipopolysaccharide: effect of ebrotidine.

The effect of lipopolysaccharide from H. pylori, a bacteria implicated in the etiology of gastric disease, on the gastric mucosal laminin-receptor interaction was investigated. The receptor protein, prepared from rat gastric epithelial cell membrane by affinity chromatography on laminin-coupled Sepharose, was radioiodinated, and incorporated into liposomes which exhibited specific affinity towards laminin-coated surface. The binding was inhibited by H. pylori lipopolysaccharide, which caused a maximum inhibition of 96% at 50 micrograms/ml. The inhibitory effect of the lipopolysaccharide was prevented by an antiulcer agent, ebrotidine that evoked essentially complete restoration in binding at 6-8 micrograms/ml. The results demonstrate that H. pylori through its lipopolysaccharide interferes with gastric epithelial cell-laminin binding, and that this disruptive effect could be successfully countered by ebrotidine.

Animals↗

PubMed2005

Phosphatidylinositol 3-kinase/Akt pathway mediates heme oxygenase-1 regulation by lipopolysaccharide.

The stress-inducible protein heme oxygenase-1 exerts potent antiinflammatory, antiapoptotic and cytoprotective effects in vitro and in vivo. Another important mediator of cytoprotection, the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway activates many proteins involved in the maintenance of cellular homeostasis. Since activation of heme oxygenase-1 and PI3K/Akt both protect the cellular environment, we postulated that PI3K/Akt can regulate the induction of heme oxygenase-1 by proinflammatory stress. The treatment of primary murine macrophage cells (RAW 264.7) with lipopolysaccharide induced heme oxygenase-1 protein and mRNA expression, and increased the phosphorylation of Akt and p38 mitogen activated protein kinase (p38 MAPK). These cellular effects of lipopolysaccharide were markedly diminished by pre-treatment with wortmannin, a specific inhibitor of PI3K. Furthermore, lipopolysaccharide-inducible heme oxygenase expression was blocked by SB203580, a specific inhibitor of p38 MAPK. Both wortmannin and SB203580 decreased lipopolysaccharide-inducible NF-E2-related factor (Nrf2) DNA binding activity. Transfection of macrophages with dominant negative mutants of PI3K, Akt and Nrf2, as well as wortmannin treatment, significantly reduced the transcriptional activity of a minimal heme oxygenase-1 promoter luciferase construct (D33HO-1luc). We demonstrate, to our knowledge for the first time, that upon proinflammatory stimulation heme oxygenase-1 gene expression in macrophages depends on PI3K/Akt and p38 MAPK acting upstream of Nrf2-dependent promoter activation.

Animals↗

PubMed1991

Inhibition of gastric mucosal laminin receptor by Helicobacter pylori lipopolysaccharide: effect of sucralfate.

The maintenance of gastric mucosal integrity depends upon the interaction involving specific cell surface receptors with distinct proteins of extracellular matrix, one of which is laminin. We present here evidence that lipopolysaccharide from Helicobacter pylori interferes with laminin binding on the receptor. The laminin receptor was isolated from gastric epithelial cell membrane by the procedure involving membrane solubilization with octylglucoside followed by affinity chromatography on laminin-coupled Sepharose. The receptor protein yielded on SDS-PAGE a single 67 kDa band. After radioiodination, the protein was incorporated into liposomes which displayed specific affinity toward laminin-coated surface. The binding of liposomal receptor to the laminin-coated surface was inhibited by lipopolysaccharide from H. pylori. The inhibitory effect was proportional to the concentration of lipopolysaccharide up to 50 micrograms/ml, at which a 96% decrease in binding occurred. Introduction of sucralfate to the assay system led to the prevention of the inhibitory effect of lipopolysaccharide on the receptor-laminin binding. The effect was dose dependent and, at sucralfate concentration of 45 micrograms/ml, nearly complete restoration in binding was achieved. The results suggest that H. pylori also may be capable of disrupting the gastric mucosal integrity through a similar mechanism in vivo, and that anti-ulcer drug sucralfate counteracts this effect.

Animals↗

PubMed1979

Structure of the lipopolysaccharide from an Escherichia coli heptose-less mutant. I. Chemical degradations and identification of products.

The structure of lipopolysaccharide from a heptose-less mutant of Escherichia coli K-12 has been investigated. Lipopolysaccharide isolated from 32P-labeled cells was treated with mild alkali to yield two separable components: [OH-LPS]-I (approximately 70%) and [OH-LPS]-II (approximately 30%). Mild acidic treatment of [OH-LPS]-I gave mainly a product which was identified as (4-O-phosphoryl-N-beta-hydroxymyristyl-D-glucosaminyl)-beta(1 leads to 6)-N-beta-hydroxymyristyl-D-glucosamine 1-phosphate (Compound I). Further acidic hydrolysis of both [OH-LPS]-I and [OH-LPS]-II yielded as the main product (4-O-phosphoryl-N-beta-hydroxymyristyl-D-glucosaminyl)-beta(1 leads to 6)-N-beta-hydroxymyristyl-D-glucosamine (Compound II). The structures of the above products were deduced by a combination of compositional analyses, sensitivity to phosphomonoesterase, rates of hydrolysis of the phosphate groups and alkali-catalyzed beta elimination of the phosphate residues following appropriate oxidation of hydroxyl groups. These studies together with work reported in the accompanying papers have led to the identification of two species of lipopolysaccharide in the E. coli strain both of which contain a single glucosamine dissacharide unit but differ in having monosubstituted phosphate or pyrophosphate groups at the glycosidic position. Each species of lipopolysaccharide also appeared to be heterogeneous with respect to the number of esterified fatty acyl groups.

Alkaline Phosphatase↗

PubMed1985

Comparison of lipopolysaccharides of Rhodomicrobium vannielii grown in photo- and chemotropic conditions.

Chemical composition of the lipopolysaccharides obtained from the strain Rhodomicrobium vannielii (ZoBell) grown in photo- and chemoheterotrophic conditions was compared. No significant differences in the constitution of both lipopolysaccharides were revealed, except for the presence of an additional 2-0-methyl-pentose and palmitic acid in the LPS isolated from the chemotrophically grown bacteria. The degraded polysaccharides from both lipopolysaccharide preparations, when fractionated in column chromatography, revealed the occurrence of two fractions only: the first one containing all the sugars present in the respective lipopolysaccharide and the second composed of KDO. Glucan was shown to be produced by the investigated strain in phototrophic conditions only.

Epitopes↗

PubMed1988

The heterogeneity of lipopolysaccharides from Citrobacter 023 serotype.

Chemical studies on carbohydrate part of lipopolysaccharides isolated from Citrobacter 87/57 and Citrobacter 1556 strains (serotype 023) were carried out. Lipopolysaccharides (LPS) were hydrolyzed with 1% acetic acid and the carbohydrate material was fractionated on Sephadex G-50 and Bio-Gel P-4 columns. All fractions obtained were subjected to chemical analysis by colorimetric methods and by gas-liquid chromatography. It was found that O-specific polysaccharide from LPS 87/57 is composed of mannose and N-acetylgalactosamine in the molar ratio of 3:1. Both lipopolysaccharides contain unsubstituted core oligosaccharides (built of heptose, glucose and galactose in molar ratio of 3:3:1) as well as core oligosaccharides substituted with shorter (LPS 87/57 and LPS 1556) and longer (LPS 87/57) O-specific oligosaccharides. Strain 87/57 is of S (smooth) type and strain 1556 lacking O-specific polysaccharide is of SR (semi-rough) type. The data of Sephadex G-100 chromatography showed that O-antigen from Citrobacter 87/57 is heterogeneous; it contains polysaccharide chains of different length but the same composition. The heterogeneity of Citrobacter 023 lipopolysaccharides has been also detected by SDS-polyacrylamide gel electrophoresis.

Acetylgalactosamine↗

PubMed1989

Fatty acid composition of lipopolysaccharides of the strains of different species of Yersinia.

The fatty acid composition of lipopolysaccharides of the strains of Y. enterocolitica, Y. intermedia, Y. frederiksenii and Y. ruckeri studied during cultivation on meat-peptone agar is characterized by the predominance of 3-hydroxytetradecanoic and dodecanoic acids. Closely related to the mentioned bacteria is the strain of Y. kristensenii which is distinguished only by its higher level of hexadecanoic acid. The strains of Y. pseudotuberculosis and the vaccine strain of Y. pestis have a uniform fatty acid composition of lipopolysaccharides with predominance of 3-hydroxytetradecanoic acid. Their relatively low level of dodecanoic acid conditions the characteristic fatty acid spectrum of lipopolysaccharides which differs from that of the above mentioned group of Yersinia. The peculiarities of the fatty acid composition of lipopolysaccharides of both groups of Yersinia are preserved during growth on meat-peptone broth, but the increase in the level of hexadecanoic acid balances the differences between Y. kristensenii, the other Y. enterocolitica-like bacteria and Y. ruckeri. The obtained results confirm close relationship of Y. pseudotuberculosis and Y. pestis, and also of Y. enterocolitica and Y. enterocolitica-like bacteria, showing propinquity of Y. ruckeri to the latter.

Fatty Acids↗

PubMed1986

Isolation and biological characterization of two lipopolysaccharides and a capsular-enriched polysaccharide preparation from Haemophilus pleuropneumoniae.

A smooth-type lipopolysaccharide (HpS-LPS), a rough-type lipopolysaccharide (HpR-LPS), and a capsular-enriched polysaccharide preparation (HpC-PS) were extracted and purified from Haemophilus pleuropneumoniae serotype 5, strain J45, by the use of phenol-water (HpS-LPS) and phenol-chloroform-petroleum-ether (HpR-LPS) techniques. Chemical analysis of the HpS-LPS and HpR-LPS indicated that they contained 0.7% and 4.4% (w/w) 2-keto-3-deoxyoctonate, 11.8% and 10.4% phosphate, 0.8% and 0.8% nucleic acid, and 0.8% and 1.1% protein, respectively. The HpC-PS contained 0.3% 2-keto-3-deoxyoctonate, 1.4% phosphate, 0.2% nucleic acid, and 0.8% protein. With sodium dodecyl sulfate-polyacrylamide-gel electrophoresis, the HpS-LPS banded as a smooth-type LPS and the HpR-LPS banded as a rough-type LPS. Electrophoresis of HpC-PS indicated the presence of a broad high molecular weight band. Gelation of Limulus amoebocyte lysate developed at a minimum concentration of 8 ng/ml of HpS-LPS, 0.3 ng/ml of HpR-LPS, and 35 ng/ml of HpC-PS. The lipopolysaccharide preparations provoked a positive dermal Shwartzman reaction in rabbits and swine, a biphasic febrile response in rabbits, and a monophasic response in swine. Responses were typical of endotoxic activity with swine having greater sensitivity than rabbits. The chick embryo 50% lethal dose was calculated to be 7.3 ng for HpS-LPS, 1.6 ng for HpR-LPS, 5.1 ng for the lipopolysaccharide of Escherichia coli 0111:B4; and the HpC-PS was not toxic. In all assays, HpR-LPS was significantly more toxic than was HpS-LPS. The HpC-PS preparation was not toxic, even at high concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗