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C Galanos

Publications and source records attributed to C Galanos.

At least 109 records · Page 6Linked to original sources
PubMed1987

Lethal toxicity of lipopolysaccharide and tumor necrosis factor in normal and D-galactosamine-treated mice.

The toxic properties of human recombinant tumor necrosis factor (TNF) were investigated in mice made hypersensitive to endotoxin by treatment with D-galactosamine. C3H/TifF mice treated with D-galactosamine were rendered sensitive to the lethal effects of submicrogram amounts of TNF. In the absence of D-galactosamine, TNF caused approximately 80% lethality with 500 micrograms. The duration of sensitization to TNF lasted up to 8 h after D-galactosamine administration, that towards LPS, up to 4 h. As with LPS, with TNF sensitization could be inhibited by uridine administered up to 2 h after D-galactosamine/TNF, showing that the early biochemical alterations in the liver known to be necessary for sensitization to LPS are also necessary for sensitization to TNF. In contrast to LPS, the toxicity of TNF was expressed also in D-galactosamine-treated endotoxin-resistant C3H/HeJ mice. The susceptibility of these mice to TNF was identical to that of endotoxin sensitive mice. In the absence of D-galactosamine the toxicity of TNF in C3H/HeJ mice was comparable to that obtained in C3H/TifF mice, being lethal with amounts of the order of 500 micrograms. The present results support the hypothesis that TNF is a mediator of lethal toxicity of endotoxin.

Animals↗
PubMed1987

Characterisation of protein co-extracted together with LPS in Escherichia coli, Salmonella minnesota and Yersinia enterocolitica.

The porin proteins of Escherichia coli, Yersinia enterocolitica, and Salmonella minnesota were found to co-extract by the phenol-chloroform-petroleum ether method together with the R lipopolysaccharide of these strains. Lipopolysaccharide free protein recovered from the phenolic residue of the phenol-chloroform-petroleum ether extract migrated as a Mr 36-37,000 protein. We could demonstrate that the protein was extracted from bacteria as a high molecular weight protein-lipopolysaccharide complex. Once exposed to phenolic conditions, the protein was no longer soluble in the phenol-chloroform-petroleum ether extraction mixture, indicating a highly specific lipopolysaccharide-protein association.

Amino Acids↗
PubMed1987

Enhancement of endotoxin lethality and generation of anaphylactoid reactions by lipopolysaccharides in muramyl-dipeptide-treated mice.

Intravenous injection of muramyl dipeptide (MDP) and Salmonella lipopolysaccharides (LPS) enhanced lethal toxicity of the LPS in C57BL/6 mice. This was true for S (smooth)- and R (rough)-form LPS and free lipid A. Enhancement of toxicity was maximum when the LPS was administered 4 h after MDP, at which time the lethal doses for 50% of mice of S- and R-form LPS and free lipid A were between 1 and 10 micrograms, compared with more than 100 micrograms in normal animals. This sensitization was absent in endotoxin-resistant C3H/HeJ mice. Lethality usually commenced 15 h after LPS injection and was complete after 72 h. Higher doses of some S-form LPS (100 micrograms or more) administered 4 h after MDP led to a strong anaphylactoid reaction within 10 to 20 min of injection, with lethal outcomes in less than 1 h after LPS administration. This early anaphylactoid reaction was observed for various mouse strains, including LPS-resistant C3H/HeJ mice, but it was very weak or completely absent with R-form LPS or free lipid A even in concentrations of up to 1,000 micrograms. A strong anaphylactoid reaction comparable to that seen with S-form LPS was also obtained, after MDP treatment, with an LPS of low toxicity prepared from Bacteroides gingivalis. It is noteworthy that oral administration of MDP also contributed to the anaphylactoid reaction and enhanced the late-phase lethality of LPS. The present findings strongly suggest that the early- and late-phase reactions induced by MDP and LPS are caused by different mechanisms.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Induction of human granulocyte chemiluminescence by bacterial lipopolysaccharides.

Bacterial lipopolysaccharides (LPS) have been reported to influence the oxidative response of human polymorphonuclear leukocytes (PMN). However, results sometimes conflict. In the present study, we demonstrated that activation of human PMN by LPS depends on the class (smooth [S] or rough [R]) to which the LPS belongs. Lucigenin-dependent chemiluminescence was used to assay oxygen radical production. Twenty different S- and R-form LPS and free lipid A were tested in concentrations of 0.01 to 100 micrograms/ml. S-form LPS activated PMN only at maximal concentrations and to a low extent. R-form LPS and free lipid A were potent inducers of granulocyte chemiluminescence even at a concentration of 0.1 microgram/ml. The results indicated that R-form LPS are very effective in inducing granulocyte chemiluminescence, whereas true S-form preparations are inactive. It is not known at present whether this higher activity is due to a more lipophilic character of R-form LPS or whether the presence of the O polysaccharide in S-form LPS exerts an inhibitory effect on their action on granulocytes.

Humans↗
PubMed1987

Growing tumors induce hypersensitivity to endotoxin and tumor necrosis factor.

Lewis lung carcinoma and EMT6 sarcoma growing as solid tumors in mice caused a gradual increase in the susceptibility of the animals to lethal toxicity of endotoxins (lipopolysaccharides [LPS]). By day 15 following inoculation of the tumors, the 50% lethal dose of LPS, which in normal mice was approximately 400 micrograms, decreased to 2 micrograms for the sarcoma-bearing mice and 0.1 microgram for the carcinoma-bearing mice. This sensitization to endotoxin was paralleled by a high sensitization to tumor necrosis factor (TNF). Human recombinant TNF given to normal mice was lethal at about 500 micrograms. It was lethal for 50% of the animals bearing EMT6 or Lewis lung carcinoma tumors in amounts of 4 and 0.01 micrograms, respectively, on day 15 following tumor inoculation. The sensitization of tumor-bearing animals to LPS and TNF was paralleled by marked granulocytosis.

Animals↗
PubMed1987

Absence of complement fixing antibodies against lipopolysaccharides from Escherichia coli in a subgroup of patients with Crohn's disease.

Complement fixing antibodies against different Escherichia coli lipopolysaccharides were determined in patients with Crohn's disease and in healthy individuals and compared with antitetanus toxoid antibodies. All healthy individuals had antilipopolysaccharide antibodies, 10 of 27 patients with Crohn's disease had no antibodies and six had rapidly changing antibody titres. These abnormalities were found in patients with disease in the colon, with arthropathy and fistula. Antilipid A was found at lower titres in Crohn's disease. Neither antitetanus toxoid antibodies, nor immunoglobulin concentrations were different in patients with or without antilipopolysaccharide antibodies. There was no evidence for circulating immune complexes in patients lacking antilipopolysaccharide antibodies. Certain subgroups of patients with Crohn's disease have altered antibody levels to typical enteral antigens which most likely can be explained by local antibody binding to lipopolysaccharides at inflammatory sites, or by changes in immunoregulation in this disease.

Adolescent↗
PubMed1987

Endotoxin alters arachidonate metabolism in pulmonary endothelial cells.

Endotoxin and lipid A dose dependently (1 ng/ml to 10 micrograms/ml) and time dependently (6-24 h) stimulated the generation of large amounts of prostacyclin in cultured pig pulmonary artery endothelial cells. This effect occurred in the absence of cell detachment and overt cell damage. The presence of at least 1% serum was required but the activation of the complement cascade was not. Endotoxin-treated endothelial cells generated increased amounts of prostacyclin upon stimulation with A23187 and arachidonic acid. Endotoxin-induced activation of arachidonate metabolism could be reduced by 10(-10) M glucocorticoids but not by progesterone. It was further affected by inhibitors of protein and RNA synthesis and calmodulin function. In addition, exposure of endothelial cells to endotoxin resulted in an enhanced synthesis of cyclooxygenase and in a higher enzymatic capacity of prostacyclin synthase. The data indicate that endotoxin in concentrations occurring in the plasma of patients profoundly alters arachidonic acid metabolism in endothelial cells.

Animals↗
PubMed1986

Biological activity of synthetic heptaacyl lipid A representing a component of Salmonella minnesota R595 lipid A.

A synthetic lipid A (preparation 516), containing seven acyl groups and representing one component of natural free lipid A of Salmonella minnesota R595, has been investigated for biological activity in a number of endotoxin test systems. It was found that the synthetic preparation was, in typical in vivo endotoxin tests (lethality, pyrogenicity, Shwartzman reactivity) as well as in its antigenicity and macrophage activation capacity, significantly less active than natural Salmonella lipid A. However, in other in vitro assay systems (B-cell mitogenicity, complement activation, Limulus amoebocyte lysate gelation) it expressed similar activity as Salmonella lipid A.

Animals↗
PubMed1986

In vitro deacylation of lipopolysaccharide of Salmonella minnesota by Acanthamoeba castellanii enzymes.

Enzymatic deacylation of the lipopolysaccharide isolated from a Salmonella Rd mutant by a cell-free preparation from Acanthamoeba castellanii has been studied. The degradation was found to be dependent on the presence of a surface-active component (Triton X-100) in the reaction mixture. The lipid A part of the lipopolysaccharide was the primary target of the enzymes, which cleaved with high efficiency the ester-bound long-chain nonhydroxylated and 3-hydroxylated acyl residues, i.e. lauric, myristic, palmitic and 3-hydroxymyristic acid. The cell-free preparation also exhibited amidase activity cleaving about 50% of the amide-bound 3-hydroxymyristic acid residues. In addition the extract proved to possess phosphatase activity liberating ester-bound and glycosidically bound phosphate groups of lipid A. On the other hand, the glucosaminyl-beta 1,6-glucosamine disaccharide was not degraded and remained bound to the oligosaccharide part (heptose/3-deoxyoctulosonic acid) of the lipopolysaccharide.

Amidohydrolases↗
PubMed1986

Investigation into the origin of mouse liver sinusoidal cells.

The possibility that liver sinusoidal cells are derived from the bone-marrow was investigated in chimeric mice. H2k-positive bone-marrow cells from F1 (B10.BR X B10.D2) hybrid mice were transplanted into irradiated H2k-negative parental mice (B10.D2), and the liver examined immunohistochemically for the presence of H2k-positive cells, with the help of an anti-H2k monoclonal antibody. With the passage of time (from the fifth week onwards), increasing numbers of transplanted bone-marrow cells enter the liver sinusoids, undergo alteration in their shape, and remain there, probably replacing sinusoidal lining cells. DNA-synthesising cells in the sinusoids were observed, suggesting, in addition, local cell proliferation. The replacement of sinusoidal cells from bone-marrow was greatly accelerated after liver damage had been induced by sublethal doses of endotoxin (LPS), and proliferation was also enhanced after treatment with LPS. These results strongly suggest that the bone-marrow participates in the replacement of liver sinusoidal cells.

Animals↗
PubMed1986

Relationship between immune system and gram-negative bacteria. Acid-treated Salmonella minnesota R595 (Re) enhances immune responsiveness in patients with gynecologic malignancies.

Nine patients with gynecologic malignancies (six cervix, two endometrium and one ovary) were injected with acid-treated Salmonella minnesota R595 (Re). Patients received a total of four injections (at increasing doses from 0.5 to 3 micrograms) every 2 weeks. All patients, before treatment, had a severe impairment of their immune system either of cell-mediated immunity (leukocyte inhibiting factor activity) or non-specific immunity (polymorphonuclear cell and/or monocyte-mediated phagocytosis and killing). In contrast, the same patients displayed a normal Natural Killer cell frequency in their peripheral blood as evaluated in an agarose-single cell cytotoxic assay. At the end of the immunotherapeutic regimen, all the above immune functions significantly augmented likely via an immunomodulating effect exerted by the lipid A portion of Salmonella minnesota Re which represents the lipopolysaccharide molecule in these bacteria. This suggests a potential role for lipid A in the treatment of cancer-related immunodeficiency.

Cytotoxicity, Immunologic↗
PubMed1986

Requirement for lipopolysaccharide-responsive macrophages in galactosamine-induced sensitization to endotoxin.

Injection of D-galactosamine sensitizes mice many thousand-fold to the lethal action of endotoxin (lipopolysaccharide [LPS]). Comparable sensitization was practically absent in LPS-resistant C3H/HeJ mice, which after D-galactosamine treatment were about 500,000 times less sensitive to LPS lethality than histocompatible LPS-sensitive C3H/HeN mice. D-Galactosamine induces changes in the hepatocytes of treated animals, such as depletion of UTP and alterations in the pattern of UDP sugars. These early biochemical changes, which are necessary for development of sensitization, were similar in both mouse strains which we examined. High sensitivity to the lethal effects of LPS was achieved in C3H/HeJ mice after D-galactosamine treatment by transfer of C3H/HeN macrophages obtained in culture from bone marrow precursor cells.

Animals↗
PubMed1985

Alterations in rats in vivo of the chemical structure of lipopolysaccharide from Salmonella abortus equi.

A biosynthetically double-labelled lipopolysaccharide (LPS) from Salmonella abortus equi was used to study possible in vivo degradation of LPS in rats. The preparation designated rLPS-I was labelled with 3H in the fatty acids and 14C in the sugars. Three days after its intravenous injection the concentration of the two isotopes in the liver was analysed directly by combustion of liver tissue in a sample oxidizer. It was found that compared to the starting LPS, less 3H activity was present than 14C, indicating that partial deacylation had occurred. Reisolation and purification of radioactive material present in the liver revealed that all radioactivity was present in a macromolecular form. Analysis showed that the ratio of the two isotopes was identical to that determined in the starting liver tissue. To exclude the possibility that the loss of 3H might have been due to isotopic dilution the above experiments were repeated with a second LPS preparation (rLPS-II) labelled with 14C in the fatty acids and 3H in glucosamine. Isotopic analysis confirmed that here too a lower content of fatty acids in the LPS was present in the liver. A large-scale (20 rats) reisolation of non-radioactive LPS of S. abortus equi from rat livers three days after injection was carried out. Chemical analysis revealed the presence of 3-deoxy-D-manno-octulosonic acid, heptose, galactose, mannose and rhamnose in a molar ratio similar to that of the original LPS. However a significant reduction in the amount of abequose was found. Fatty acid analysis showed a significant reduction in the content of 3-hydroxytetradecanoic, dodecanoic and hexadecanoic acids, while 2-hydroxytetradecanoic acid was virtually absent. Only the relative amount of tetradecanoic acid was comparable to that of the starting LPS. Biological activity tests on the reisolated material showed a reduced antigenic activity. However, pyrogenicity, lethal toxicity, local Shwartzman-inducing properties and Limulus lysate gelating activity were comparable to the starting S. abortus equi LPS.

Animals↗
PubMed1985

Synthetic and natural Escherichia coli free lipid A express identical endotoxic activities.

The recently chemically synthesized Escherichia coli lipid A and the natural free lipid A of E. coli were compared with respect to their endotoxic activities in the following test systems: lethal toxicity, pyrogenicity, local Shwartzman reactivity, Limulus amoebocyte lysate gelation capacity, tumour necrotizing activity, B cell mitogenicity, induction of prostaglandin synthesis in macrophages, and antigenic specificity. It was found that synthetic and natural free lipid A exhibit identical activities and are indistinguishable in all tests.

Animals↗
PubMed1985

Serum anti-lipid A antibodies in multiple myeloma and Waldenström's macroglobulinaemia.

Anti-lipid A antibodies were determined in sera from 38 patients with IgG multiple myeloma, 33 patients with IgA multiple myeloma and 38 patients with Waldenström's macroglobulinaemia using an enzyme-linked immunosorbent assay (ELISA). Compared to 34 healthy adults, significantly (p less than 0.025, p less than 0.005, p less than 0.0025) lower serum anti-lipid A antibody levels were measured for the respective patient groups. Low anti-lipid A antibody levels correlated with a higher infection rate with gram-negative bacteria in patients with monoclonal B-cell malignancies. The highest infection rate was seen in patients with simultaneous low anti-lipid A levels and secondary antibody deficiency.

Antibodies, Bacterial↗
PubMed1985

Distribution and localization of endotoxin in the reticulo-endothelial system (RES) and in the main vessels of the rat during shock.

The fate of endotoxin was followed with immunohistochemistry and radio-labelled lipopolysaccharide (LPS) in organs of the reticulo-endothelial system (RES), in the great vessels and the thoracic duct of rats during a 14 day period after the injection of a shock-inducing amount of endotoxin. The immunohistochemical detectability of LPS in most tissues increased continuously during the first 48 hours, showing the strongest LPS staining in the liver and adrenal gland. Macrophages were found to be the most important cells of primary LPS uptake in all organs except the adrenal glands, where endotoxin was mainly present in phagocytic vacuoles of the cortical epithelium. The comparison of results obtained with the immunoperoxidase method and radioactivity measurements revealed that at a later stage of the experiment the persisting LPS in liver and spleen looses its antigenic activity. The correlation between the appearance of LPS positive macrophages and histological signs of tissue injury during endotoxin shock is striking.

Adrenal Glands↗