Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Respirable cotton dust, implicated in the pathogenesis of byssinosis, contains a number of bioactive compounds. These include lipopolysaccharide (LPS), tannins, bacterial peptides, byssinosin, iacinilene C, and 1,3-beta-D-glucan. The exact aetiological agent of byssinosis in such dust has not been definitively identified nor has its mechanism of action on lower lung surfaces been determined. In the present study 1,3-beta-D-glucan, Enterobacter agglomerans LPS, and ovine pulmonary surfactant were mixed in varying combinations. After incubation, their characteristics were determined by sucrose density centrifugation, TLC, and carbohydrate analysis. Precipitates were found in mixtures containing surfactant-glucan and surfactant-glucan-LPS, but not in surfactant-LPS. Precipitates were not seen in the surfactant, LPS, and glucan controls. The formation of a precipitate did not increase the density of the surfactant glucan mixture when compared by density gradient centrifugation with the surfactant control. The interaction between surfactant and glucan was analysed by molecular modelling. The energy of a surfactant-glucan complex (60.07 kcal/mol) was calculated to be much lower than the sum of glucan (47.09 kcal/mol) and surfactant (30.98 kcal/mol) when added separately. The results indicate that 1,3-beta-D-glucan does interact with surfactant and this complex may play a part in the pathogenesis of byssinosis by altering lung physiology maintained by pulmonary surfactant.
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PMID:Agglutination of lung surfactant with glucan. 146 75

Exposure to endotoxin has been associated with systemic toxicity, including pulmonary disorders such as byssinosis, as well as with beneficial biologic activities such as adjuvanticity and mitogenicity. The purified lipopolysaccharide (LPS) from endotoxin has been employed to investigate structure-activity relationships for various biologic effects. The current study was undertaken to examine the relationship between LPS structure and its ability to cause respiratory toxicity in guinea pigs after inhalation exposure. Animals were exposed to atmospheres containing 0.076 to 2.1 micrograms/m3 Salmonella minnesota LPS (S. minn. LPS), LPS from the mutant S. minn. Re595, S. minn. Re595 lipid A, and monophosphoryl S. minn. Re595 lipid A (S. minn. Re595 MPL). Each of the LPS aerosols caused increased breathing frequency (f), decreased tidal volume (VT), and airflow disturbance when measured 18 h after the 6-h inhalation exposure. The LPS preparations had equivalent toxicity, whereas the lipid A aerosol had slightly reduced toxicity. The MPL preparation did not produce this respiratory toxicity response. The results indicated that absence of the terminal phosphate group from the reducing end of the lipid A disaccharide destroyed its ability to cause the respiratory effect. These results initiate structure-activity studies of defined LPS in the lung and indicate the possibility of chemically treating endotoxins to remove adverse pulmonary effects.
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PMID:Acute respiratory response of guinea pigs to lipopolysaccharide, lipid A, and monophosphoryl lipid A from Salmonella minnesota. 281 7

Our laboratory has been comparing the activity of a water extract of cotton bract (CBE) with the isolated trachealis smooth muscle of the dog, guinea pig, and cat. CBE induced contractions that were not mediated by 5-hydroxytryptamine (5-HT), histamine, or muscarinic receptors. The active agent(s) in CBE was dialyzable (less than 14,000 molecular weight), and substantial activity was retained after low-temperature ashing. CBE potentiated contractions of dog trachealis to histamine and 5-HT and relaxation responses to isoproterenol, whereas it had no effect on responses to methacholine and KCl. In the guinea pig trachealis, CBE reduced responsiveness to KCl, potentiated relaxations to adenosine and ATP, and did not alter the responses to the remaining agents. Responses of cat trachealis to KCl and isoproterenol were potentiated by CBE, while those to 5-HT were unaffected. Neurogenic cholinergic contractile responses were potentiated by CBE in the trachealis of the dog, but not of the guinea pig, while neurogenic relaxations were potentiated by CBE in guinea pig trachealis but not in the dog trachealis. There are thus marked species differences in the acute effects of CBE on airway smooth muscle. Due to recent interest in the possible involvement of bacterial endotoxins in the etiology of byssinosis, we examined the effects of E. coli lipopolysaccharide (LPS) in guinea pig trachealis. An initial examination revealed that LPS potentiated responses to histamine, but not those to methacholine and isoproterenol. This effect vanished upon a second appraisal with a different batch of LPS. The effect of LPS in airway smooth muscle is thus, at present, equivocal.
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PMID:An overview of species differences in the effects of a water extract of cotton bract on isolated airway smooth muscle, and effects of E. coli lipopolysaccharide. 301 94

A guinea pig animal model of byssinosis has been described that demonstrates both acute and chronic effects of cotton dust inhalation (Ellakkani et al., 1984, 1987). During the latter study in which guinea pigs were exposed to 21 mg/m3 cotton dust 5 d/wk, 6 h/d for 52 wk, blood samples were taken from animals (20 exposed, 20 sham-exposed) prior to exposure and monthly during the exposure period. Sera were evaluated for quantities of the major protein fractions, and for IgG antibodies to cotton dust components. At the completion of the study, blood was evaluated for total and differential leukocytes. At 6 mo of exposure, each of the five protein fractions was significantly different from the corresponding fraction in the control animals. Antibodies reactive with an aqueous cotton dust extract (ACDE) were prominent by 2 mo of exposure and the titer was increased with continued exposure. The extract was composed of 2.6% protein, 12.8% reducing sugar, and 4.1% nucleic acid, with the remainder being largely simply sugars and inorganic material. A fraction of the antibodies showed reactivity with gram-negative bacteria and specifically with Enterobacter agglomerans, the most prevalent gram-negative microorganism in the dust. Minimal antibody response was detected using lipopolysaccharide from this microorganism or gram-positive bacteria. These results indicate that exposure of guinea pigs to cotton dust resulted in hematologic changes and in specific antibody formation. The presence of antibodies in each of the animals suggests their possible use as an indicator of cotton dust exposure.
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PMID:Serologic study of guinea pigs exposed for 12 months to cotton dust. 317 72

Due to the ubiquitous nature of airborne endotoxin, an understanding of pulmonary alterations which follow inhalation of environmentally realistic concentrations of purified bacteria derived lipopolysaccharide (LPS) is important. Using LPS derived from Enterobacter agglomerans, a bacterium found in cotton and cotton mill dust, aqueous aerosols (effective LPS concentration 4 micrograms/m3) were generated and used to expose either normal hamsters (N = 6) or those rendered endotoxin tolerant by pre-ip injection of 0.1 LD50 LPS. Control groups (normal--N = 6; tolerant--N = 6) received saline aerosol only. At 6 hr after 5-hr aerosol exposure, lungs of all animals were fixed, processed for light and transmission electron microscopy, and subject to qualitative and to multitiered morphometric analysis using standard point counting techniques. Qualitative evaluation of TEM micrographs from LPS aerosolized-nontolerant hamsters showed endothelial alteration (focal disruption, subendothelial space formation, and cytoplasmic blebbing) but volume and number of endothelial cells were not changed indicating only slight, focal endothelial damage. Quantitatively, septal capillary blood space in nontolerant, LPS aerosolized hamsters showed increased Vv of PMNs and platelets. These changes were not seen in tolerant induced-LPS aerosolized hamsters. Independent of tolerization treatment, LPS inhalation led to a decrease in fixed lung volume and an increase in numerical density of endothelial pinocytotic vesicles. It is concluded that the inhalation of realistic, environmental levels of bacterial endotoxin may induce significant changes in distal lung and may be important in the pathogenesis of byssinosis and adult respiratory distress syndrome.
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PMID:Morphometric changes of the lung induced by inhaled bacterial endotoxin. 406 10

Comparative in vivo and in vitro studies were made on bacterial lipopolysaccharide (LPS) and the chemotactic peptide NF-Met-Leu-Phe with a view toward studying their possible role in the pathophysiology of byssinosis. In contrast to LPS, chemotactic peptides did not cause Limulus amebocyte lysate gelation, nor did they induce the release of endogenous pyrogen. Inhalation of LPS caused a peripheral leukocytosis in rabbits 30 min after aerosol administration, whereas peptide inhalation caused a significant leukopenia in the same period. Cellular analysis of guinea pig bronchial lavages after LPS aerosol challenge revealed immediate decreases in all cell types, with subsequent, large increases of macrophages and granulocytes 4-24 h after aerosolization. Inhalation challenge with NF-Met-Leu-Phe induced no significant cellular changes. It was concluded that it is unlikely that these microbial products could be confused with each other when administered in pure form by the inhalation route.
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PMID:Comparative toxicity studies between bacterial lipopolysaccharide (endotoxin) and N-formyl methionyl peptide as factors in the pathogenesis of byssinosis. 408 22

Experiments were performed to evaluate the in vitro effects of Escherichia coli lipopolysaccharide on viability and function of human alveolar macrophages. Alveolar macrophages were obtained by fiberoptic bronchoscopy and saline bronchial lavage from 12 normal, nonsmoking volunteers. Cells were incubated with different concentrations of E. coli endotoxin for 1 and 24 h. Endotoxin (10 microgram/ml and more) was cytotoxic for alveolar macrophages after 24 h of incubation and induced significant inhibition of phagocytosis, adherence, and spreading. The effects of endotoxin on alveolar macrophage viability and function were dose and time dependent and were not influenced by indomethacin. Thus, human alveolar macrophages, like other mononuclear phagocytes, are extremely sensitive to endotoxin effects; these observations may be relevant in conditions in which endotoxin may be in contact with alveolar macrophages in vivo: endobronchial infections with gram-negative organisms, byssinosis, chronic bronchitis of grain handles, and humidifier fever.
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PMID:Human alveolar macrophages: effects of endotoxin in vitro. 701 47

Airborne lipopolysaccharide (LPS) levels were determined at various working sites in industries processing vegetable fibers. On several occasions the amounts assessed with the Limulus assay exceeded those presumed to cause human reactions i.e. about 0.5 microgram/m3. Low values were often found in areas for weaving. High levels of LPS were found in flax carding rooms but levels in jute mills did not exceed those considered to produce reactions in humans. Low values were also found in nontextile industries processing cotton fibers. By and large the variations in airborne LPS corresponded to previous experience on the extent of byssinosis seen in the different types of industries.
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PMID:Airborne endotoxin in industries processing vegetable fibers. 716 39

Endotoxin is thought to contribute to pulmonary hyperresponsiveness in byssinosis, asthma, and the acute respiratory distress syndrome (ARDS). The aim of this study was to elucidate the mechanism of this phenomenon in the isolated, blood-free perfused mouse lung. Perfusion with lipopolysaccharide (LPS) had no effect on pulmonary resistance or pulmonary artery pressure, but induced airway hyperreactivity (AHR) to methacholine (MCh) and pulmonary vascular hyperreactivity (VHR) to platelet-activating factor (PAF). Blockade of the thromboxane/endoperoxide (TP) receptor with SQ29.548 completely protected against LPS-induced AHR and VHR. Blockade of cyclooxygenase-2 (COX-2) abolished LPS-induced VHR but suppressed LPS-induced AHR only marginally. COX-2 messenger RNA was upregulated in LPS-treated lungs, and inhibition of transcription with actinomycin D or of protein biosynthesis with cycloheximide protected against LPS-induced VHR but not AHR. Pretreatment with the radical scavenger N-acetylcysteine partly protected against LPS-induced AHR. In addition, perfusion of mouse lungs with the isoprostane 8-epiprostaglandin F(2alpha) (8-epi-PGF(2alpha)), which may be formed as a consequence of oxidative stress in the lung, elicited AHR, which was completely blocked by SQ29.548. Enzyme immunoassay did not detect either 8-epi-PGF(2alpha )or thromboxane B(2) in perfusate samples. Our findings show that LPS induces AHR and VHR in mouse lungs via activation of the TP receptor. Although induction of VHR depends on COX-2 activity, AHR is largely mediated by a non-COX-derived TP agonist, which might be a product of radical-induced lipid peroxidation.
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PMID:Mechanisms of endotoxin-induced airway and pulmonary vascular hyperreactivity in mice. 1102 75

In early studies, research to control byssinosis focused on methods to reduce the trash in the textile mill environment. Dust control has been effective in reducing the prevalence of byssinosis, but simple reduction in dust levels does not always assure its prevention. Also, bacteria and fungi present in cotton do not in themselves cause byssinosis, but the endotoxins-heat-stable lipopolysaccharide-protein complexes contained in the cell wall of Gram-negative bacteria-are responsible for the development of this respiratory disease of workers on cotton, flax, and some other fibers. Experimental work was carried out in cotton fields in different cotton growing countries. Opened cotton capsules were treated by spraying them with bactericidal water solutions of benzododecinium bromide to avoid the growth of bacteria by bacteriostatic effect during transportation and storage and thus to prevent the formation of endotoxins. To simulate transport conditions, treated and nontreated cotton samples were incubated under high air humidity. The endotoxin contents were determined by Limulus amebocyte lysate assay depending on the duration of incubation. In nontreated samples the endotoxin content grew to over 5,000 ng/mg. In comparison, in treated samples the endotoxin content grew extremely slowly. Thus, the bactericidal treating of raw cotton showed high efficiency as a potential method of byssinosis prevention. The irradiation by gamma-rays is also efficient, but it is not realistic in cotton growing areas of developing countries at the present time.
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PMID:Bactericidal treatment of raw cotton as the method of byssinosis prevention. 1257 Apr


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