Comparative evaluation of Comfilcon A and Senofilcon A bandage contact lenses after transepithelial photorefractive keratectomy.

Science.gov (United States)

Mukherjee, Achyut; Ioannides, Antonis; Aslanides, Ioannis

2015-01-01

To evaluate and compare Comfilcon A and Senofilcon A silicone hydrogel contact lenses used as a therapeutic bandage following transepithelial excimer laser photorefractive keratectomy (PRK). Patients undergoing transepithelial PRK for myopia were prospectively recruited. Included patients had a Comfilcon A silicone hydrogel lens inserted in one eye, with a Senofilcon A lens in the contralateral eye. Postoperative assessment of subjective pain, epithelial healing and visual recovery was at day 1, 3 and 7. Contact lens factors including centration, movement and deposits were assessed. 48 eyes of 24 patients were included in the study. Mean age was 31 years (SD 11) and mean refractive error -4.5 D (SD 1.8). Mean pain score at day 1 was significantly higher in the Comfilcon group at 4.6 (SD 2.7) vs. 1.5 (SD2.5) in the Senofilcon group (P<0.005). Mean time to healing was 3.17 days (SD 0.37) in the Comfilcon group, and 3.21 days (SD 0.4) in the Senofilcon group, with no difference in defect size. There was a pronounced central raphe in 1 eye in the Comfilcon group vs. 5 eyes in the Senofilcon group (P=0.19). Significantly more eyes demonstrated no lens movement in the Senofilcon group (18 vs. 4, P=0.0001). The variation in material characteristics and lens geometry of different silicone hydrogel lenses affects their clinical characteristics in therapeutic roles. Other factors than oxygen permeability may affect pain and epithelial healing, with superior pain relief from the less permeable Senofilcon lens in this study. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Synergism between endotoxin priming and exotoxin challenge in provoking severe vascular leakage in rabbit lungs.

Science.gov (United States)

Schütte, H; Rosseau, S; Czymek, R; Ermert, L; Walmrath, D; Krämer, H J; Seeger, W; Grimminger, F

1997-09-01

Lipopolysaccharides (LPS) of gram-negative bacteria prime rabbit lungs for enhanced thromboxane-mediated vasoconstriction upon subsequent challenge with the exotoxin Escherichia coli hemolysin (HlyA) (Walmrath et al. J. Exp. Med. 1994;180:1437-1443). We investigated the impact of endotoxin priming and subsequent HlyA challenge on lung vascular permeability while maintaining constancy of capillary pressure. Rabbit lungs were perfused in a pressure-controlled mode in the presence of the thromboxane receptor antagonist BM 13.505, with continuous monitoring of flow. Perfusion for 180 min with 10 ng/ml LPS did not provoke vasoconstriction or alteration of capillary filtration coefficient (Kfc) values. HlyA (0.021 hemolytic units/ml) induced thromboxane release and a transient decrease in perfusion flow in the absence of significant changes in Kfc. Similar results were obtained when LPS and HlyA were coapplied simultaneously. However, when the HlyA challenge was undertaken after 180 min of LPS priming, a manifold increase in Kfc values was noted, with concomitant severe lung edema formation, although capillary pressure remained unchanged. Thus, endotoxin primes the lung vasculature to respond with a severe increase in vascular permeability to a subsequent low-dose application of HlyA. Such synergism between endotoxin priming and exotoxin challenge in provoking lung vascular leakage may contribute to the pathogenesis of respiratory failure in sepsis and severe lung infection.

A Clinical and Confocal Microscopic Comparison of Transepithelial PRK and LASEK for Myopia

Directory of Open Access Journals (Sweden)

Safak Korkmaz

2014-01-01

Full Text Available Purpose. To compare the clinical and confocal microscopic results of transepithelial PRK versus LASEK for correction of myopia. Materials and Methods. Twelve patients with myopia received transepithelial PRK in one eye and LASEK in the other. In transepithelial PRK-treated eyes, the corneal epithelium was removed with 40 microns of excimer laser ablation and in LASEK-treated eyes with 25-second application of 18% ethanol. Time to epithelial healing, ocular discomfort, uncorrected and best corrected visual acuities, manifest refraction, haze, greyscale value, and keratocyte apoptosis in confocal microscopy were recorded. Results. The mean time to epithelial healing was significantly longer after LASEK (4.00 ± 0.43 versus 3.17 ± 0.6 days. On day 1, ocular discomfort was significantly higher after transepithelial PRK. The grade of haze, keratocyte apoptosis, and greyscale value in confocal microscopy were significantly higher in transepithelial PRK-treated eyes at 1 month. All transepithelial PRK- and LASEK-treated eyes achieved 20/25 or better UCVA and were within ±1.00 D of emmetropia at final visits. Conclusions. Both transepithelial PRK and LASEK offer effective correction of myopia at 1 year. However, LASEK appeared to induce less discomfort and less intense wound healing in the early postoperative period.

A Clinical and Confocal Microscopic Comparison of Transepithelial PRK and LASEK for Myopia.

Science.gov (United States)

Korkmaz, Safak; Bilgihan, Kamil; Sul, Sabahattin; Hondur, Ahmet

2014-01-01

Purpose. To compare the clinical and confocal microscopic results of transepithelial PRK versus LASEK for correction of myopia. Materials and Methods. Twelve patients with myopia received transepithelial PRK in one eye and LASEK in the other. In transepithelial PRK-treated eyes, the corneal epithelium was removed with 40 microns of excimer laser ablation and in LASEK-treated eyes with 25-second application of 18% ethanol. Time to epithelial healing, ocular discomfort, uncorrected and best corrected visual acuities, manifest refraction, haze, greyscale value, and keratocyte apoptosis in confocal microscopy were recorded. Results. The mean time to epithelial healing was significantly longer after LASEK (4.00 ± 0.43 versus 3.17 ± 0.6 days). On day 1, ocular discomfort was significantly higher after transepithelial PRK. The grade of haze, keratocyte apoptosis, and greyscale value in confocal microscopy were significantly higher in transepithelial PRK-treated eyes at 1 month. All transepithelial PRK- and LASEK-treated eyes achieved 20/25 or better UCVA and were within ±1.00 D of emmetropia at final visits. Conclusions. Both transepithelial PRK and LASEK offer effective correction of myopia at 1 year. However, LASEK appeared to induce less discomfort and less intense wound healing in the early postoperative period.

Experiments on prevention of the endotoxin-abortifacient effect by radiodetoxified endotoxin pretreatment in rats

Energy Technology Data Exchange (ETDEWEB)

Csordas, T; Bertok, L; Csapo, Z

1978-01-01

Endotoxemia has been induced in pregnant rats by intravenous injection of 1 mg Escherichia coli endotoxin which resulted in intrauterine death and abortion of fetuses in 24 h. The abortifacient effect of endotoxin, injected intravenously 24 h earlier. The authors suppose that the radiodetoxified endotoxin can be a good tool also in the prevention of human septic (endotoxin) shock in pregnancy.

Endotoxin levels and contribution factors of endotoxins in resident, school, and office environments - A review

OpenAIRE

Salonen, Heidi; Duchaine, Caroline; Letourneau, Valerie; Mazaheri, Mandana; Laitinen, Sirpa; Clifford, Sam; Mikkola, Raimo; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

2016-01-01

As endotoxin exposure has known effects on human health, it is important to know the generally existing levels of endotoxins as well as their contributing factors. This work reviews current knowledge on the endotoxin loads in settled floor dust, concentrations of endotoxins in indoor air, and different environmental factors potentially affecting endotoxin levels. The literature review consists of peer-reviewed manuscripts located using Google and PubMed, with search terms based on individual ...

Measurement of endotoxin. I. Fundamental studies on radioimmunoassay of endotoxin

Energy Technology Data Exchange (ETDEWEB)

Kimura, H [Okayama Univ. (Japan). School of Medicine

1976-08-01

A method for estimating endotoxin by radioimmunoassay was recently introduced. The present paper describes improvements in the speed and sensitivity on this endotoxin measurement. Antigen was purified from E. coli 0111: B4(B) lipopolysaccharide by centrifugation and dialysis. Purified anti-endotoxin antibody was prepared from immunized rabbit serum. A radioimmunoassay system was established with the antigen and antibody. Dextran-coated charcoal was used to separate the antibody-bound antigen from free antigen. Experimental studies were also performed on possible factors related to the antigen-antibody reaction. Accurate measurements on quantitites as low as 100 pg/ml (10 ng/ml in the plasma) were performed by the dextran-coated charcoal method, and the reaction time was reduced to 2 hr at 4/sup 0/C. This new method does not require strict sterilization or aseptic handling, and therefore is quite practical for quantitative measurements of endotoxin.

Pseudomonas aeruginosa ExoU augments neutrophil transepithelial migration.

Science.gov (United States)

Pazos, Michael A; Lanter, Bernard B; Yonker, Lael M; Eaton, Alex D; Pirzai, Waheed; Gronert, Karsten; Bonventre, Joseph V; Hurley, Bryan P

2017-08-01

Excessive neutrophil infiltration of the lungs is a common contributor to immune-related pathology in many pulmonary disease states. In response to pathogenic infection, airway epithelial cells produce hepoxilin A3 (HXA3), initiating neutrophil transepithelial migration. Migrated neutrophils amplify this recruitment by producing a secondary gradient of leukotriene B4 (LTB4). We sought to determine whether this two-step eicosanoid chemoattractant mechanism could be exploited by the pathogen Pseudomonas aeruginosa. ExoU, a P. aeruginosa cytotoxin, exhibits phospholipase A2 (PLA2) activity in eukaryotic hosts, an enzyme critical for generation of certain eicosanoids. Using in vitro and in vivo models of neutrophil transepithelial migration, we evaluated the impact of ExoU expression on eicosanoid generation and function. We conclude that ExoU, by virtue of its PLA2 activity, augments and compensates for endogenous host neutrophil cPLA2α function, leading to enhanced transepithelial migration. This suggests that ExoU expression in P. aeruginosa can circumvent immune regulation at key signaling checkpoints in the neutrophil, resulting in exacerbated neutrophil recruitment.

Pseudomonas aeruginosa ExoU augments neutrophil transepithelial migration.

Directory of Open Access Journals (Sweden)

Michael A Pazos

2017-08-01

Full Text Available Excessive neutrophil infiltration of the lungs is a common contributor to immune-related pathology in many pulmonary disease states. In response to pathogenic infection, airway epithelial cells produce hepoxilin A3 (HXA3, initiating neutrophil transepithelial migration. Migrated neutrophils amplify this recruitment by producing a secondary gradient of leukotriene B4 (LTB4. We sought to determine whether this two-step eicosanoid chemoattractant mechanism could be exploited by the pathogen Pseudomonas aeruginosa. ExoU, a P. aeruginosa cytotoxin, exhibits phospholipase A2 (PLA2 activity in eukaryotic hosts, an enzyme critical for generation of certain eicosanoids. Using in vitro and in vivo models of neutrophil transepithelial migration, we evaluated the impact of ExoU expression on eicosanoid generation and function. We conclude that ExoU, by virtue of its PLA2 activity, augments and compensates for endogenous host neutrophil cPLA2α function, leading to enhanced transepithelial migration. This suggests that ExoU expression in P. aeruginosa can circumvent immune regulation at key signaling checkpoints in the neutrophil, resulting in exacerbated neutrophil recruitment.

Endotoxin levels and contribution factors of endotoxins in resident, school, and office environments - A review

Science.gov (United States)

Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Laitinen, Sirpa; Clifford, Sam; Mikkola, Raimo; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

2016-10-01

As endotoxin exposure has known effects on human health, it is important to know the generally existing levels of endotoxins as well as their contributing factors. This work reviews current knowledge on the endotoxin loads in settled floor dust, concentrations of endotoxins in indoor air, and different environmental factors potentially affecting endotoxin levels. The literature review consists of peer-reviewed manuscripts located using Google and PubMed, with search terms based on individual words and combinations. References from relevant articles have also been searched. Analysis of the data showed that in residential, school, and office environments, the mean endotoxin loads in settled floor dust varied between 660 and 107,000 EU/m2, 2180 and 48,000 EU/m2, and 2700 and 12,890 EU/m2, respectively. Correspondingly, the mean endotoxin concentrations in indoor air varied between 0.04 and 1610 EU/m3 in residences, and 0.07 and 9.30 EU/m3 in schools and offices. There is strong scientific evidence indicating that age of houses (or housing unit year category), cleaning, farm or rural living, flooring materials (the presence of carpets), number of occupants, the presence of dogs or cats indoors, and relative humidity affect endotoxin loads in settled floor dust. The presence of pets (especially dogs) was extremely strongly associated with endotoxin concentrations in indoor air. However, as reviewed articles show inconsistency, additional studies on these and other possible predicting factors are needed.

Eicosanoids, endotoxins and liver disease

NARCIS (Netherlands)

R.J.T. Ouwendijk (Rob)

1985-01-01

textabstractEndotoxins are cell wall lipopolysacharides of gram negative bacteria. The gut contains large numbers of bacteria and is generally accepted to be a large reservoir of endotoxins. In the normal state absorbed endotoxins are rapidly removed from the portal blood by especially the

Membrane adsorber for endotoxin removal

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Karina Moita de Almeida

Full Text Available ABSTRACT The surface of flat-sheet nylon membranes was modified using bisoxirane as the spacer and polyvinyl alcohol as the coating polymer. The amino acid histidine was explored as a ligand for endotoxins, aiming at its application for endotoxin removal from aqueous solutions. Characterization of the membrane adsorber, analysis of the depyrogenation procedures and the evaluation of endotoxin removal efficiency in static mode are discussed. Ligand density of the membranes was around 7 mg/g dry membrane, allowing removal of up to 65% of the endotoxins. The performance of the membrane adsorber prepared using nylon coated with polyvinyl alcohol and containing histidine as the ligand proved superior to other membrane adsorbers reported in the literature. The lack of endotoxin adsorption on nylon membranes without histidine confirmed that endotoxin removal was due to the presence of the ligand at the membrane surface. Modified membranes were highly stable, exhibiting a lifespan of approximately thirty months.

Increased intestinal permeability to macromolecules and endotoxemia in patients with chronic alcohol abuse in different stages of alcohol-induced liver disease

DEFF Research Database (Denmark)

Parlesak, Alexandr; Schäfer, C.; Schütz, Tanja

2000-01-01

BACKGROUND/AIMS: No information is yet available about the influence of alcohol abuse on the translocation of larger molecules (Mr>1200) through the intestinal mucosa in man. The present study aimed to determine the intestinal permeability to macromolecules in patients with chronic alcohol abuse...... and mild to more advanced stages of liver disease, and to measure the concentration of endotoxins in the plasma, as these compounds derive from the intestinal flora and are suspected to contribute to the development of alcoholic liver disease (ALD). METHODS: The permeability to polyethylene glycol Mr 400......, Mr 1500, Mr 4000, and Mr 10,000 and endotoxin plasma concentrations were measured in 54 patients with alcoholic liver disease, 19 of them with cirrhosis, and in 30 non-alcoholic healthy controls. RESULTS: Permeability to polyethylene glycol Mr 400 was found to be unchanged in patients with ALD...

Endotoxins in portal blood

NARCIS (Netherlands)

van Deventer, S. J.; Knepper, A.; Landsman, J.; Lawson, J.; ten Cate, J. W.; Buller, H. R.; Sturk, A.; Pauw, W.

1988-01-01

Endotoxemia may complicate diseases of the bowel and liver, and is associated with the occurrence of renal failure, coagulation disorders and death. The bowel contains a large quantity of endotoxins. According to the classical hypothesis, endotoxins continuously transmigrate through the bowel

Unsaturated fatty acids lactose esters: cytotoxicity, permeability enhancement and antimicrobial activity.

Science.gov (United States)

Lucarini, Simone; Fagioli, Laura; Campana, Raffaella; Cole, Hannah; Duranti, Andrea; Baffone, Wally; Vllasaliu, Driton; Casettari, Luca

2016-10-01

Sugar based surfactants conjugated with fatty acid chains are an emerging broad group of highly biocompatible and biodegradable compounds with established and potential future applications in the pharmaceutical, cosmetic and food industries. In this work, we investigated absorption enhancing and antimicrobial properties of disaccharide lactose, monoesterified with unsaturated fatty acids through an enzymatic synthetic approach. After chemical and cytotoxicity characterizations, their permeability enhancing activity was demonstrated using intestinal Caco-2 monolayers through transepithelial electrical resistance (TEER) and permeability studies. The synthesized compounds, namely lactose palmitoleate (URB1076) and lactose nervonate (URB1077), were shown to exhibit antimicrobial activity versus eight pathogenic species belonging to Gram-positive, Gram-negative microorganisms and fungi. Copyright © 2016 Elsevier B.V. All rights reserved.

Binding of 125I-labeled endotoxin to bovine, canine, and equine platelets and endotoxin-induced agglutination of canine platelets

International Nuclear Information System (INIS)

Meyers, K.M.; Boehme, M.; Inbar, O.

1982-01-01

Endotoxin from Escherichia coli O127:B8, Salmonella abortus-equi and S minnesota induced clumping of some canine platelets (PLT) at a final endotoxin concentration of 1 microgram/ml. Endotoxin-induced clumping of canine PLT was independent of PLT energy-requiring processes, because clumping was observed with canine PLT incubated with 2-deoxy-D-glucose and antimycin A. The PLT responded to adenosine diphosphate before, but not after, incubation with the metabolic inhibitors. Endotoxin induced a slight and inconsistant clumping of bovine and equine PLT at high (mg/ml) endotoxin concentration. High-affinity binding sites could not be demonstrated on canine, bovine, and equine PLT, using 125 I-labeled E coli O127:B8 endotoxin. Nonspecific binding was observed and appeared to be due primarily to an extraneous coat on the PLT surface that was removed by gel filtration. The endotoxin that was bound to PLT did not appear to modify PLT function. An attempt to identify plasma proteins that bound physiologically relevant amounts of endotoxin was not successful. The significance of the endotoxin-induced clumping or lack of it on the pathophysiology of endotoxemia is discussed

An Exploratory Investigation of Endotoxin Levels in Novice Long Distance Triathletes, and the Effects of a Multi-Strain Probiotic/Prebiotic, Antioxidant Intervention

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Justin D. Roberts

2016-11-01

Full Text Available Gastrointestinal (GI ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS. This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 females were randomly assigned either a multistrain pro/prebiotic/antioxidant (LAB4ANTI; 30 billion CFU·day−1 containing 10 billion CFU·day−1 Lactobacillus acidophilus CUL-60 (NCIMB 30157, 10 billion CFU·day−1 Lactobacillus acidophillus CUL-21 (NCIMB 30156, 9.5 billion CFU·day−1 Bifidobacterium bifidum CUL-20 (NCIMB 30172 and 0.5 billion CFU·day−1 Bifidobacterium animalis subspecies lactis CUL-34 (NCIMB 30153/55.8 mg·day−1 fructooligosaccharides/ 400 mg·day−1 α-lipoic acid, 600 mg·day−1 N-acetyl-carnitine; matched pro/prebiotic (LAB4 or placebo (PL for 12 weeks preceding a long-distance triathlon. Plasma endotoxin units (via Limulus amebocyte lysate chromogenic quantification and GI permeability (via 5 h urinary lactulose (L: mannitol (M recovery were assessed at baseline, pre-race and six days post-race. Endotoxin unit levels were not significantly different between groups at baseline (LAB4ANTI: 8.20 ± 1.60 pg·mL−1; LAB4: 8.92 ± 1.20 pg·mL−1; PL: 9.72 ± 2.42 pg·mL−1. The use of a 12-week LAB4ANTI intervention significantly reduced endotoxin units both pre-race (4.37 ± 0.51 pg·mL−1 and six days post-race (5.18 ± 0.57 pg·mL−1; p = 0.03, ηp2 = 0.35, but only six days post-race with LAB4 (5.01 ± 0.28 pg·mL−1; p = 0.01, ηp2 = 0.43. In contrast, endotoxin units remained unchanged with PL. L:M significantly increased from 0.01 ± 0.01 at baseline to 0.06 ± 0.01 with PL only (p = 0.004, ηp2 = 0.51. Mean race times (h:min:s were not statistically different between groups despite faster times with both pro/prebiotoic groups (LAB4ANTI: 13:17:07 ± 0:34:48; LAB4: 12

An Exploratory Investigation of Endotoxin Levels in Novice Long Distance Triathletes, and the Effects of a Multi-Strain Probiotic/Prebiotic, Antioxidant Intervention.

Science.gov (United States)

Roberts, Justin D; Suckling, Craig A; Peedle, Georgia Y; Murphy, Joseph A; Dawkins, Tony G; Roberts, Michael G

2016-11-17

Gastrointestinal (GI) ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS). This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 females) were randomly assigned either a multistrain pro/prebiotic/antioxidant (LAB⁴ ANTI ; 30 billion CFU·day -1 containing 10 billion CFU·day -1 Lactobacillus acidophilus CUL-60 (NCIMB 30157), 10 billion CFU·day -1 Lactobacillus acidophillus CUL-21 (NCIMB 30156), 9.5 billion CFU·day -1 Bifidobacterium bifidum CUL-20 (NCIMB 30172) and 0.5 billion CFU·day -1 Bifidobacterium animalis subspecies lactis CUL-34 (NCIMB 30153)/55.8 mg·day -1 fructooligosaccharides/ 400 mg·day -1 α-lipoic acid, 600 mg·day -1 N -acetyl-carnitine); matched pro/prebiotic (LAB⁴) or placebo (PL) for 12 weeks preceding a long-distance triathlon. Plasma endotoxin units (via Limulus amebocyte lysate chromogenic quantification) and GI permeability (via 5 h urinary lactulose (L): mannitol (M) recovery) were assessed at baseline, pre-race and six days post-race. Endotoxin unit levels were not significantly different between groups at baseline (LAB⁴ ANTI : 8.20 ± 1.60 pg·mL -1 ; LAB⁴: 8.92 ± 1.20 pg·mL -1 ; PL: 9.72 ± 2.42 pg·mL -1 ). The use of a 12-week LAB⁴ ANTI intervention significantly reduced endotoxin units both pre-race (4.37 ± 0.51 pg·mL -1 ) and six days post-race (5.18 ± 0.57 pg·mL -1 ; p = 0.03, ηp² = 0.35), but only six days post-race with LAB⁴ (5.01 ± 0.28 pg·mL -1 ; p = 0.01, ηp² = 0.43). In contrast, endotoxin units remained unchanged with PL. L:M significantly increased from 0.01 ± 0.01 at baseline to 0.06 ± 0.01 with PL only ( p = 0.004, ηp² = 0.51). Mean race times (h:min:s) were not statistically different between groups despite faster times with both pro/prebiotoic groups (LAB⁴ ANTI : 13:17:07 ± 0

Concentrations of lipopolysaccharide-binding protein, bactericidal/permeability-increasing protein, soluble CD14 and plasma lipids in relation to endotoxaemia in patients with alcoholic liver disease

DEFF Research Database (Denmark)

Schäfer, C.; Parlesak, Alexandr; Schütt, C.

2002-01-01

of endotoxin on its target cells (LPS-binding protein and sCD14) were increased. Endotoxin antagonists, such as bactericidal/permeability-increasing protein and high-density lipoprotein, were increased in the pre-cirrhotic stages, whereas a significant reduction of the latter was observed in cirrhosis. Low......-density lipoprotein remained unchanged. The elevation of binding factors in the pre-cirrhotic stages of alcoholic liver disease might attenuate the effects of endotoxaemia, whereas in cirrhosis the reduction of high density lipoprotein, to which large quantities of endotoxin bind, may contribute to its pro...

Haematologic effect and Shwartzman reactivity of radiodetoxified endotoxin

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, T; Csernyanszky, H; Gazdy, E [Debreceni Orvostudomanyi Egyetem (Hungary); Bertok, L [Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszsegugyi Kutato Intezet, Budapest (Hungary)

1978-01-01

Comparative experiments were made in rabbits with Escherichia coli 089 endotoxin and endotoxin detoxified by ionizing radiation (/sup 60/Co-gamma, 5 Mrad). Radiation significantly weakened the leukopenia and thrombocytopenia provoking effect of endotoxin. Radiodetoxified endotoxin decreased the fibrinogen level only slightly and caused insignificant changes in reptilase time. The complement level was decreased less by the detoxified than by the parent endotoxin. Even the local Shwartzman phenomenon inducing capacity of radiodetoxified endotoxin significantly, particularly when it was used for preparation and provocation, too.

Haematologic effect and Shwartzman reactivity of radiodetoxified endotoxin

International Nuclear Information System (INIS)

Szilagyi, T.; Csernyanszky, H.; Gazdy, E.; Bertok, L.

1978-01-01

Comparative experiments were made in rabbits with Escherichia coli 089 endotoxin and endotoxin detoxified by ionizing radiation ( 60 Co-gamma, 5 Mrad). Radiation significantly weakened the leukopenia and thrombocytopenia provoking effect of endotoxin. Radiodetoxified endotoxin decreased the fibrinogen level only slightly and caused insignificant changes in reptilase time. The complement level was decreased less by the detoxified than by the parent endotoxin. Even the local Shwartzman phenomenon inducing capacity of radiodetoxified endotoxin significantly, particularly when it was used for preparation and provocation, too. (author)

Transepithelial Riboflavin Absorption in an Ex Vivo Rabbit Corneal Model.

Science.gov (United States)

Gore, Daniel M; O'Brart, David; French, Paul; Dunsby, Chris; Allan, Bruce D

2015-07-01

To measure depth-specific riboflavin concentrations in corneal stroma using two-photon fluorescence microscopy and compare commercially available transepithelial corneal collagen cross-linking (CXL) protocols. Transepithelial CXL riboflavin preparations--MedioCross TE, Ribocross TE, Paracel plus VibeX Xtra, and iontophoresis with Ricrolin+--were applied to the corneal surface of fresh postmortem rabbit eyes in accordance with manufacturers' recommendations for clinical use. Riboflavin 0.1% (VibeX Rapid) was applied after corneal epithelial debridement as a positive control. After riboflavin application, eyes were snap frozen in liquid nitrogen. Corneal cross sections 35-μm thick were cut on a cryostat, mounted on a slide, and imaged by two-photon fluorescence microscopy. Mean (SD) concentrations were calculated from five globes tested for each protocol. Peak riboflavin concentration of 0.09% (± 0.01) was observed within the most superficial stroma (stromal depth 0-10 μm) in positive controls (epithelium-off). At the same depth, peak stromal riboflavin concentrations for MedioCross TE, Ricrolin+, Paracel/Xtra, and Ribocross TE were 0.054% (± 0.01), 0.031% (0.003), 0.021% (± 0.001), and 0.015% (± 0.004), respectively. At a depth of 300 μm (within the demarcation zone commonly seen after corneal cross-linking), the stromal concentration in epithelium-off positive controls was 0.075% (± 0.006), while at the same depth MedioCross TE and Ricrolin+ achieved 0.018% (± 0.006) and 0.016% (0.002), respectively. None of the remaining transepithelial protocols achieved concentrations above 0.005% at this same 300-μm depth. Overall, MedioCross TE was the best-performing transepithelial formulation. Corneal epithelium is a significant barrier to riboflavin absorption into the stroma. Existing commercial transepithelial CXL protocols achieve relatively low riboflavin concentrations in the anterior corneal stroma when compared to gold standard epithelium-off absorption

Binding of /sup 125/I-labeled endotoxin to bovine, canine, and equine platelets and endotoxin-induced agglutination of canine platelets

Energy Technology Data Exchange (ETDEWEB)

Meyers, K.M.; Boehme, M.; Inbar, O.

1982-10-01

Endotoxin from Escherichia coli O127:B8, Salmonella abortus-equi and S minnesota induced clumping of some canine platelets (PLT) at a final endotoxin concentration of 1 microgram/ml. Endotoxin-induced clumping of canine PLT was independent of PLT energy-requiring processes, because clumping was observed with canine PLT incubated with 2-deoxy-D-glucose and antimycin A. The PLT responded to adenosine diphosphate before, but not after, incubation with the metabolic inhibitors. Endotoxin induced a slight and inconsistant clumping of bovine and equine PLT at high (mg/ml) endotoxin concentration. High-affinity binding sites could not be demonstrated on canine, bovine, and equine PLT, using /sup 125/I-labeled E coli O127:B8 endotoxin. Nonspecific binding was observed and appeared to be due primarily to an extraneous coat on the PLT surface that was removed by gel filtration. The endotoxin that was bound to PLT did not appear to modify PLT function. An attempt to identify plasma proteins that bound physiologically relevant amounts of endotoxin was not successful. The significance of the endotoxin-induced clumping or lack of it on the pathophysiology of endotoxemia is discussed.

Endotoxin dosage in sepsis

Directory of Open Access Journals (Sweden)

Vincenzo Rondinelli

2012-03-01

Full Text Available Introduction. Endotoxin, a component of the cell wall of Gram-negative bacteria is a major contributor to the pathogenesis of septic shock and multiple organ failure (MOF. Its entry into the bloodstream stimulates monocytes/macrophages which once activated produce and release cytokines, nitric oxide and other mediators that induce systemic inflammation, endothelial damage, organ dysfunction, hypotension (shock and MOF.The aim of this study is to evaluate the usefulness of a quantitative test for the dosage of endotoxin to determine the risk of severe Gram-negative sepsis. Materials and methods. In the period January 2009 - June 2011 we performed 897 tests for 765 patients, mostly coming from the emergency room and intensive care, of which 328 (43% women (mean age 53 and 437 (57% male (mean age 49. Fifty-nine patients, no statistically significant difference in sex, were monitored by an average of two determinations of EA.All patients had procalcitonin values significantly altered.The kit used was EAA (Endotoxin Activity Assay Estor Company, Milan, which has three ranges of endotoxin activity (EA: low risk of sepsis if <0.40 units, medium if between 0.40 and 0.59; high if 0.60. Results. 78 out of 765 patients (10% had a low risk, 447 (58% a medium risk and 240 (32% a high risk.The dosage of EA, combined with that of procalcitonin, has allowed a more targeted antibiotic therapy. Six patients in serious clinical conditions were treated by direct hemoperfusion with Toraymyxin, a device comprising a housing containing a fiber polypropylene and polystyrene with surface-bound polymyxin B, an antibiotic that removes bacterial endotoxins from the blood. Conclusions.The test is useful in risk stratification as well as Gram negative sepsis, to set and monitor targeted therapies, also based on the neutralization of endotoxin.

Endotoxin content in endodontically involved teeth. 1975.

Science.gov (United States)

Schein, Benjamin; Schilder, Herbert

2006-04-01

Fluid was aspirated from the root canals of 40 endodontically involved teeth. This fluid was assayed for endotoxin with the limulus lysate test. Pulpless teeth contained greater concentrations of endotoxin than those with vital pulps. Symptomatic teeth also contained more endotoxin than asymptomatic teeth.

Tre1, a G protein-coupled receptor, directs transepithelial migration of Drosophila germ cells.

Directory of Open Access Journals (Sweden)

Prabhat S Kunwar

2003-12-01

Full Text Available In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR, Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target.

Airborne endotoxin in woodworking (joinery) shops.

Science.gov (United States)

Harper, Martin; Andrew, Michael E

2006-01-01

Symptoms such as shortness of breath and cough have been noted in woodworking facilities even where wood dust itself is well-controlled. Suspicion has fallen on other possible contaminants in the workplace atmosphere, including bacterial endotoxin. A few studies have indicated potentially high endotoxin exposure with exposure to fresh wood in sawmills and in the production of fiberboard and chipboard, but fewer studies have been carried out on exposure to endotoxin in dry wood work, for example in joineries. A study of the endotoxin content of airborne wood dust samples from US woodworking facilities is presented, from the re-analysis of samples which previously had been taken to establish mass collection relationships between the IOM sampler, the closed-face 37 mm plastic cassette (CFC) sampler and the Button sampler. Endotoxin was strongly correlated with total dust, but the endotoxin content of a few fresh wood samples was found to be up to ten times higher per unit of wood dust than for dried-wood samples, and this difference was significant. No long-term time-weighted average sample exceeded the recommended limit value of 50 EU m(-3) (EU, endotoxin units)used in the Netherlands, although a number of the IOM samples came close (seven samples or 44% exceeded 20 EU m(-3)) and one short-term (48 minute) sample registered a high value of 73 EU m(-3). The geometric mean concentration from the IOM samples (11 EU m(-3)) is within the range of geometric means found from Australian joineries (3.7-60, combined: 24 EU m(-3)). In contrast, the corresponding values from the CFC (3.6 EU m(-3)), and the Button sampler (2.1 EU m(-3)) were much lower and no samples exceeded 20 EU m(-3). Endotoxin is likely only to be a significant problem in working with dried woods when associated with very high dust levels, where the wood dust itself is likely to be a cause for concern. The results from the few samples in this study where fresh wood was being worked were similar to results

Effect of endotoxin on radiation syndrome - a review

Energy Technology Data Exchange (ETDEWEB)

Hlouskova, D; Zak, M

1979-01-01

A review is given of studies on the effect of endotoxin on postirradiation syndrome. Recent knowledge is summed up on the compositions of endotoxins and on their general biological effects. Endotoxins of different bacteria are discussed such as are utilized for favourably affecting the postirradiation syndrome. For each bacterium the classification is shown in the microbe system. This, however, is not standard in the literature. General assessment is made of studies published so far on radiation protection of organisms with endotoxins.

Quality-control analytical methods: endotoxins: essential testing for pyrogens in the compounding laboratory, part 3: a simplified endotoxin test method for compounded sterile preparations.

Science.gov (United States)

Cooper, James F

2011-01-01

The first two parts of the IJPC series on endotoxin testing explained the nature of pyrogenic contamination and described various Limulus amebocyte lysate methods for detecting and measuring endotoxin levels with the bacterial endotoxin test described in the United States Pharmacopeia. This third article in that series describes the endotoxin test that is simplest to permorm for pharmacists who prefer to conduct an endotoxin assa at the time of compounding in the pharmacy setting.

Detection of endotoxins in radiopharmaceutical preparations--I. Comparison of rabbit hyperthermia after intravenous or intrathecal administration of reference endotoxin preparations

Energy Technology Data Exchange (ETDEWEB)

Merlin, L; Bruneau, J; Cohen, Y; Michaud, T

1986-01-01

The rise of the rabbit internal temperature after endotoxin injection is related to the route of administration. A rise of 1.71 +/- 0.411/sup 0/C is obtained after i.v. injection of 1 ng/kg Escherichia coli 0111.B.4 endotoxin. An increase of 1.93 +/- 0.236/sup 0/C is obtained after suboccipital intrathecal injection of 0.1 ng/kg of the same endotoxin; with the intrathecal route, the hyperthermia is induced by E. coli endotoxin after a dose ten times lower than with i.v. injection as shown by statistical analysis.

Duration of in vivo endotoxin tolerance in horses.

Science.gov (United States)

Holcombe, Susan J; Jacobs, Carrie C; Cook, Vanessa L; Gandy, Jeffery C; Hauptman, Joseph G; Sordillo, Lorraine M

2016-05-01

Endotoxemia models are used to study mechanisms and treatments of early sepsis. Repeated endotoxin exposures induce periods of endotoxin tolerance, characterized by diminished proinflammatory responses to lipopolysaccharide (LPS) and modulated production of proinflammatory cytokines. Repeated measure designs using equine endotoxemia models are rarely performed, despite the advantages associated with reduced variability, because the altered responsiveness would confound study results and because the duration of equine endotoxin tolerance is unknown. We determined the interval of endotoxin tolerance, in vivo, in horses based on physical, clinicopathologic, and proinflammatory gene expression responses to repeated endotoxin exposures. Six horses received 30 ng/kg LPS in saline infused over 30 min. Behavior pain scores, physical examination parameters, and blood for complete blood count and proinflammatory gene expression were obtained at predetermined intervals for 24h. Horses received a total of 3 endotoxin exposures. The first exposure was LPS 1, followed 7 days later by LPS 7 or 14-21 days later by LPS 14-21. Lipopolysaccharide exposures were allocated in a randomized, crossover design. Lipopolysaccharide produced clinical and clinicopathologic signs of endotoxemia and increased expression of tumor necrosis factor alpha (TNFα), interleukin (IL)-6 and IL-8, PHorses exhibited evidence of endotoxin tolerance following LPS 7 but not following LPS 14-21. Horses had significantly lower pain scores, heart rates, respiratory rates and duration of fever, after LPS 7 compared to LPS 1 and LPS 14-21, Phorses after LPS 7, P=0.05. Clinical parameters and TNFα gene expression were similar or slightly increased in horses following LPS 14-21 compared to measurements made in horses following LPS 1, suggesting that endotoxin tolerance had subsided. A minimum of 3 weeks between experiments is warranted if repeated measures designs are used to assess in vivo response to endotoxin in

Risks associated with endotoxins in feed additives produced by fermentation.

Science.gov (United States)

Wallace, R John; Gropp, Jürgen; Dierick, Noël; Costa, Lucio G; Martelli, Giovanna; Brantom, Paul G; Bampidis, Vasileios; Renshaw, Derek W; Leng, Lubomir

2016-01-15

Increasingly, feed additives for livestock, such as amino acids and vitamins, are being produced by Gram-negative bacteria, particularly Escherichia coli. The potential therefore exists for animals, consumers and workers to be exposed to possibly harmful amounts of endotoxin from these products. The aim of this review was to assess the extent of the risk from endotoxins in feed additives and to calculate how such risk can be assessed from the properties of the additive. Livestock are frequently exposed to a relatively high content of endotoxin in the diet: no additional hazard to livestock would be anticipated if the endotoxin concentration of the feed additive falls in the same range as feedstuffs. Consumer exposure will be unaffected by the consumption of food derived from animals receiving endotoxin-containing feed, because the small concentrations of endotoxin absorbed do not accumulate in edible tissues. In contrast, workers processing a dusty additive may be exposed to hazardous amounts of endotoxin even if the endotoxin concentration of the product is low. A calculation method is proposed to compare the potential risk to the worker, based on the dusting potential, the endotoxin concentration and technical guidance of the European Food Safety Authority, with national exposure limits.

Procoagulant activity of leukocytes pretreated with radiodetoxified endotoxin

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, T; Csernyanszky, H; Gazdy, E [Debreceni Orvostudomanyi Egyetem (Hungary); Bertok, L [Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszseguegyi Kutato Intezet, Budapest (Hungary)

1980-09-30

Rabbits were treated with Escherichia coli 089 endotoxin detoxified by ionizing irradiation (/sup 60/Co-gamma). The leukocytes (PMNs in 90%) obtained from rabbits treated with the mother endotoxin elicited a well defined activity; those obtained from rabbits pretreated with detoxified endotoxin elicited a less pronounced, procoagulant activity. It is suggested that the procoagulant effect may play a part in the mechanism of the local Shwartzman phenomenon.

Clinical Outcomes of SMILE With a Triple Centration Technique and Corneal Wavefront-Guided Transepithelial PRK in High Astigmatism.

Science.gov (United States)

Jun, Ikhyun; Kang, David Sung Yong; Reinstein, Dan Z; Arba-Mosquera, Samuel; Archer, Timothy J; Seo, Kyoung Yul; Kim, Tae-Im

2018-03-01

To comparatively investigate the clinical outcomes, vector parameters, and corneal aberrations of small incision lenticule extraction (SMILE) with a triple centration technique and corneal wavefront-guided transepithelial photorefractive keratectomy (PRK) for the correction of high astigmatism. This retrospective, comparative case series study included 89 eyes (89 patients) that received treatment for myopia with high astigmatism (≥ 2.50 diopters) using SMILE with a triple centration technique (SMILE group; 45 eyes) and corneal wavefront-guided transepithelial PRK (transepithelial PRK group; 44 eyes). Visual acuity measurement, manifest refraction, slit-lamp examination, autokeratometry, corneal topography, and evaluation of corneal wavefront aberration were performed preoperatively and at 1, 3, and 6 months after surgery. The safety, efficacy, vector parameters, and corneal aberrations at 6 months after surgery were compared between the two groups. At 6 months after surgery, the transepithelial PRK and SMILE groups exhibited comparable mean uncorrected distance visual acuities (-0.06 ± 0.07 and -0.05 ± 0.07 logMAR, respectively), safety, efficacy, and predictability of refractive and visual outcomes. There was a slight but statistically significant difference in the correction index between the transepithelial PRK and SMILE groups (0.96 ± 0.11 and 0.91 ± 0.10, respectively). Whereas the transepithelial PRK group exhibited increased corneal spherical aberration and significantly reduced corneal coma and trefoil, no changes in aberrometric values were noted in the SMILE group. Both SMILE with a triple centration technique and corneal wavefront-guided transepithelial PRK are effective and provide predictable outcomes for the correction of high myopic astigmatism, although slight undercorrection was observed in the SMILE group. The triple centration technique was helpful in astigmatism correction by SMILE. [J Refract Surg. 2018;34(3):156-163.]. Copyright 2018

Inactivation of Escherichia coli Endotoxin by Soft Hydrothermal Processing▿

Science.gov (United States)

Miyamoto, Toru; Okano, Shinya; Kasai, Noriyuki

2009-01-01

Bacterial endotoxins, also known as lipopolysaccharides, are a fever-producing by-product of gram-negative bacteria commonly known as pyrogens. It is essential to remove endotoxins from parenteral preparations since they have multiple injurious biological activities. Because of their strong heat resistance (e.g., requiring dry-heat sterilization at 250°C for 30 min) and the formation of various supramolecular aggregates, depyrogenation is more difficult than sterilization. We report here that soft hydrothermal processing, which has many advantages in safety and cost efficiency, is sufficient to assure complete depyrogenation by the inactivation of endotoxins. The endotoxin concentration in a sample was measured by using a chromogenic limulus method with an endotoxin-specific limulus reagent. The endotoxin concentration was calculated from a standard curve obtained using a serial dilution of a standard solution. We show that endotoxins were completely inactivated by soft hydrothermal processing at 130°C for 60 min or at 140°C for 30 min in the presence of a high steam saturation ratio or with a flow system. Moreover, it is easy to remove endotoxins from water by soft hydrothermal processing similarly at 130°C for 60 min or at 140°C for 30 min, without any requirement for ultrafiltration, nonselective adsorption with a hydrophobic adsorbent, or an anion exchanger. These findings indicate that soft hydrothermal processing, applied in the presence of a high steam saturation ratio or with a flow system, can inactivate endotoxins and may be useful for the depyrogenation of parenterals, including end products and medical devices that cannot be exposed to the high temperatures of dry heat treatments. PMID:19502435

Complications in obstructive jaundice: role of endotoxins

NARCIS (Netherlands)

Greve, J. W.; Gouma, D. J.; Buurman, W. A.

1992-01-01

Surgical treatment of patients with obstructive jaundice is associated with a high postoperative morbidity and mortality. A correlation was suggested between endotoxins and the observed complications. The mechanism by which endotoxins affect the negative outcome in operated jaundiced patients was,

Effects of endotoxin on mammary secretion of lactating cows

International Nuclear Information System (INIS)

Lengemann, F.W.; Pitzrick, M.

1986-01-01

The objectives were to describe the magnitude and time course of changes in milk pH, Na, K, lactose, and somatic cells and to determine if paracellular pathways were altered after infusion of Escherichia coli endotoxin (serotype 0128:AB12) to produce inflammation in one-half of the udder of the goat. Intramammary infusion of endotoxin increased pH, number of somatic cells, and Na and decreased K and lactose in milk. Sodium and number of somatic cells were increased by as little as .1μg of endotoxin; .25 μg produced changes in most of the other parameters; maximal effect was elicited by 1μg of endotoxin. The gland response peaked from 5 to 7 h after infusion of endotoxin with an increase in milk cellularity as the only significant effect noted in the control gland. Infusion of [ 14 C]lactose into the gland and [/sup 99m/Tc]albumin into the blood demonstrated that large molecules were more able to cross into and out of udder halves after endotoxin treatment. It is suggested that ion interchange rather than bulk flow across paracellular paths is responsible for changes. In addition, endotoxin appeared to reduce lactose secretion and synthesis

Personal endotoxin exposure in a panel study of school children with asthma

Directory of Open Access Journals (Sweden)

Tjoa Thomas

2011-08-01

Full Text Available Abstract Background Endotoxin exposure has been associated with asthma exacerbations and increased asthma prevalence. However, there is little data regarding personal exposure to endotoxin in children at risk, or the relation of personal endotoxin exposure to residential or ambient airborne endotoxin. The relation between personal endotoxin and personal air pollution exposures is also unknown. Methods We characterized personal endotoxin exposures in 45 school children with asthma ages 9-18 years using 376 repeated measurements from a PM2.5 active personal exposure monitor. We also assayed endotoxin in PM2.5 samples collected from ambient regional sites (N = 97 days and from a subset of 12 indoor and outdoor subject home sites (N = 109 and 111 days, respectively in Riverside and Whittier, California. Endotoxin was measured using the Limulus Amoebocyte Lysate kinetic chromogenic assay. At the same time, we measured personal, home and ambient exposure to PM2.5 mass, elemental carbon (EC, and organic carbon (OC. To assess exposure relations we used both rank correlations and mixed linear regression models, adjusted for personal temperature and relative humidity. Results We found small positive correlations of personal endotoxin with personal PM2.5 EC and OC, but not personal PM2.5 mass or stationary site air pollutant measurements. Outdoor home, indoor home and ambient endotoxin were moderately to strongly correlated with each other. However, in mixed models, personal endotoxin was not associated with indoor home or outdoor home endotoxin, but was associated with ambient endotoxin. Dog and cat ownership were significantly associated with increased personal but not indoor endotoxin. Conclusions Daily fixed site measurements of endotoxin in the home environment may not predict daily personal exposure, although a larger sample size may be needed to assess this. This conclusion is relevant to short-term exposures involved in the acute exacerbation of

Calcium reduces the sodium permeability of luminal membrane vesicles from toad bladder. Studies using a fast-reaction apparatus

International Nuclear Information System (INIS)

Chase, H.S. Jr.; Al-Awqati, Q.

1983-01-01

Regulation of the sodium permeability of the luminal membrane is the major mechanism by which the net rate of sodium transport across tight epithelia is varied. Previous evidence has suggested that the permeability of the luminal membrane might be regulated by changes in intracellular sodium or calcium activities. To test this directly, we isolated a fraction of the plasma membrane from the toad urinary bladder, which contains a fast, amiloride-sensitive sodium flux with characteristics similar to those of the native luminal membrane. Using a flow-quench apparatus to measure the initial rate of sodium efflux from these vesicles in the millisecond time range, we have demonstrated that the isotope exchange permeability of these vesicles is very sensitive to calcium. Calcium reduces the sodium permeability, and the half-maximal inhibitory concentration is 0.5 microM, well within the range of calcium activity found in cells. Also, the permeability of the luminal membrane vesicles is little affected by the ambient sodium concentration. These results, when taken together with studies on whole tissue, suggest that cell calcium may be an important regulator of transepithelial sodium transport by its effect on luminal sodium permeability. The effect of cell sodium on permeability may be mediated by calcium rather than by sodium itself

Comparison of Three Epithelial Removal Techniques in PRK: Mechanical, Alcohol-assisted, and Transepithelial Laser.

Science.gov (United States)

Shapira, Yinon; Mimouni, Michael; Levartovsky, Shmuel; Varssano, David; Sela, Tzahi; Munzer, Gur; Kaiserman, Igor

2015-11-01

To compare the visual and refractive results obtained after photorefractive keratectomy (PRK) in patients who underwent one of three different epithelial removal techniques. The authors reviewed the medical files of consecutive eyes with myopia and myopic astigmatism that were treated during a 10-year period by mechanical PRK, alcohol-assisted PRK, or transepithelial PRK (in the phototherapeutic keratectomy mode), and observed for more than 1 year. A total of 3,417 patients (3,417 eyes) were included in this study. At 3 and 6 months postoperatively, the outcome of alcohol-assisted PRK was superior both in efficacy (P PRK and transepithelial PRK, which were similar. At more than 1 year postoperatively, the mean efficacy index was still high for alcohol-assisted PRK, but low for the transepithelial PRK, corresponding to a mean uncorrected visual acuity of more than one Snellen line lower than those of the other two techniques (P PRK (P PRK. Copyright 2015, SLACK Incorporated.

Detoxifying Escherichia coli for endotoxin-free production of recombinant proteins.

Science.gov (United States)

Mamat, Uwe; Wilke, Kathleen; Bramhill, David; Schromm, Andra Beate; Lindner, Buko; Kohl, Thomas Andreas; Corchero, José Luis; Villaverde, Antonio; Schaffer, Lana; Head, Steven Robert; Souvignier, Chad; Meredith, Timothy Charles; Woodard, Ronald Wesley

2015-04-16

Lipopolysaccharide (LPS), also referred to as endotoxin, is the major constituent of the outer leaflet of the outer membrane of virtually all Gram-negative bacteria. The lipid A moiety, which anchors the LPS molecule to the outer membrane, acts as a potent agonist for Toll-like receptor 4/myeloid differentiation factor 2-mediated pro-inflammatory activity in mammals and, thus, represents the endotoxic principle of LPS. Recombinant proteins, commonly manufactured in Escherichia coli, are generally contaminated with endotoxin. Removal of bacterial endotoxin from recombinant therapeutic proteins is a challenging and expensive process that has been necessary to ensure the safety of the final product. As an alternative strategy for common endotoxin removal methods, we have developed a series of E. coli strains that are able to grow and express recombinant proteins with the endotoxin precursor lipid IVA as the only LPS-related molecule in their outer membranes. Lipid IVA does not trigger an endotoxic response in humans typical of bacterial LPS chemotypes. Hence the engineered cells themselves, and the purified proteins expressed within these cells display extremely low endotoxin levels. This paper describes the preparation and characterization of endotoxin-free E. coli strains, and demonstrates the direct production of recombinant proteins with negligible endotoxin contamination.

General effect of endotoxin on glucocorticoid receptors in mammalian tissues

International Nuclear Information System (INIS)

Stith, R.D.; McCallum, R.E.

1986-01-01

Considering the ubiquitous nature of glucocorticoid actions and the fact that endotoxin inhibits glucocorticoid action in the liver, we proposed to examine whether endotoxin affected extrahepatic actions of glucocorticoids. Fasted C57BL/6J mice were injected intraperitoneally with endotoxin (LD50) at 0800 and were killed 6 h later. Control mice were injected with an equal volume of saline. 3 H-dexamethasone binding, measured by a new cytosol exchange assay utilizing molybdate plus dithiothreitol, in liver, kidney, skeletal muscle, spleen, lung, and heart tissue was significantly lower in treated than in control mice. The equilibrium dissociation constants were not significantly different, but the number of available binding sites in each tissue was reduced by endotoxin treatment. Phosphoenolpyruvate carboxykinase activity was significantly reduced in liver but not in kidney. Endotoxin treatment lowered glycogen content in liver but not in skeletal muscle. The reduction observed in the a form of liver glycogen synthase due to endotoxin was not seen in skeletal muscle glycogen synthase a. These data support the proposal that endotoxin or a mediator of its action inhibits systemic glucocorticoid action. The results also emphasize the central role of the liver in the metabolic disturbances of the endotoxin-treated mouse

Clinical research on high myopia treatments using AMARIS trans-epithelial PRK

Directory of Open Access Journals (Sweden)

Wu-Qiang Shan

2015-12-01

Full Text Available AIM:To evaluate the efficiency and safety of high myopia treatments using AMARIS trans-epithelial photorefractive keratectomy(PRK.METHODS:One hundred and thirty six eyes in 68 patients with high myopic were treated using Amaris trans-epithelial PRK during December 2012～December 2013. Post-operative pain, haze, visual acuity, refraction and intraocular pressure(IOPwere analyzed during 12mo follow-up post-operatively.RESULTS:One hundred and eight eyes in 54 patients felt no discomfort at all, while 28 eyes in 14 patients reported dry eye, slight pain and foreign body sensation. UCVA between the two groups showed statistically different at 3, 6mo and 1a(t=2.04, P=0.047. UCVA at 3mo was the best compared with those at other time pionts, and became stable at 6mo. UCVA of all patients were above 0.8 at 12mo,and had no difference with that before operations(t=1.508, P=0.1670. Haze were hardly seen, and most of them were between grade 0～1. The patients' satisfaction was over 85% according to the survey about night vision, dry eye and asthenopia.CONCLUSION:Because of the great advantages of no-touch, fast recovery and less side effects, trans-epithelial PRK has great efficiency, safety and satisfaction. It now is the most ideal method of surface ablation for high myopia treatments.

Endotoxin Removal from Water Using Heterogenus Catalytic Ozonation by Bone Char

Directory of Open Access Journals (Sweden)

Abas Rezaee

2011-10-01

Full Text Available The endotoxin is one of pollutants with lipopolysaccharide structure which release from gram negative bacteria and cyanobacters. The aim of this study was removal of endotoxin from water using catalytic ozonation by bone char. The endotoxin for experiments have extracted from Escherichia coli bacterium cell wall by Stefan and Jan method. Chromogenic limulus ambusite lysate method in 405-410 nm wave length was used for analysing of endotoxin. The ozone have analysed by potassium iodine method. Results: Results of the research shown endotoxin removal rates using heterogenous catalytic ozonation were 6.0 Eu/ml.min and 0.5 Eu/ml.min for grey bone char and white bone char, respectively. The efficency of the process was found eighty percent. Primary concentration of basic compounds had no effect on endotoxin removal rate. Therefore, endotoxin removal kinetic of reaction is a zero order reaction. This study revealed that ozonation process using bone char is more efficient than other proposed methods such as ozonation or chlorination and can be used successfully for endotoxin removal from water as a efficient method.

Usefulness of vitamin A binding protein as a marker for capillary endothelial permeability

Energy Technology Data Exchange (ETDEWEB)

Ishizaka, Akitoshi; Suzuki, Yukio; Kanazawa, Minoru; Kubo, Atsushi; Kawashiro, Takeo [Keio Univ., Tokyo (Japan). School of Medicine

1992-06-01

We performed a preliminary study to assess the usefulness of Vitamin A binding protein (VABP) as a gamma-camera marker for capillary endothelial permeability. We used a guinea pig model of endotoxin (LPS) induced acute lung injury. We calculated the concentration ratio of either {sup 125}I-albumin or {sup 125}I-VABP in lung tissue to that in plasma (tissue plasma ratio; T/P) as a parameter of capillary endothelial permeability. {sup 99m}Tc-diethylene triamine pentaacetic acid (DTPA) was used as marker for pulmonary interstitial volume. We estimated wet to dry lung weight ratio as a parameter of lung water accumulation (W/D). LPS increased the T/P of {sup 125}I-albumin and W/D, suggesting the development of permeability edema. The T/P for {sup 125}I-VABP was also increased, indicating that {sup 125}I-VABP can be used to detect elevated capillary endothelial permeability. In both groups, LPS and saline, the T/P was higher for {sup 125}I-VABP than for {sup 125}I-albumin. These data suggest that the pulmonary capillary endothelium is more permeable to VABP than albumin. (author).

Comparison of transepithelial corneal crosslinking with epithelium-off crosslinking (epithelium-off CXL in adult Pakistani population with progressive keratoconus

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Bushra Akbar

2017-01-01

CONCLUSION: Transepithelial CXL is not recommended to be replaced completely by standard epithelium-off CXL due to continued ectatic progression in 25% of cases. However, thin corneas, unfit for standard epithelium-off CXL, can benefit from transepithelial CXL.

Ascorbic acid levels in human tears after photorefractive keratectomy, transepithelial photorefractive keratectomy, and laser in situ keratomileusis.

Science.gov (United States)

Bilgihan, A; Bilgihan, K; Toklu, Y; Konuk, O; Yis, O; Hasanreisoğlu, B

2001-04-01

To investigate the level of ascorbic acid in human tear fluid after photorefractive keratectomy (PRK), transepithelial PRK, and laser in situ keratomileusis (LASIK). Departments of Ophthalmology and Biochemistry, School of Medicine, Gazi University, Ankara, Turkey. Twenty patients (7 women and 13 men) were included in this study. Traditional PRK with epithelial scraping by a blunt spatula followed by surface ablation (7 eyes), transepithelial PRK (7 eyes), or LASIK (6 eyes) was performed. Tears were collected preoperatively and 1 and 5 days postoperatively. Ascorbic acid levels were measured using 2-4 dinitrophenylhydrazine. Ascorbic acid levels in the tear fluid were decreased significantly 1 day after PRK, transepithelial PRK, and LASIK (P <.05). On the fifth day, the ascorbic acid levels were significantly lower than preoperatively in all groups. After PRK, transepithelial PRK, and LASIK, the ascorbic acid levels of the tear fluid decreased significantly. Because ascorbic acid is the major scavenger of superoxide radicals in tears, topical ascorbic acid therapy may help eliminate the harmful effect of free radicals from excimer laser surgery.

Endotoxin and CD14 in the progression of biliary atresia

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Chen Ching-Mei

2010-12-01

Full Text Available Abstract Background Biliary atresia (BA is a typical cholestatic neonatal disease, characterized by obliteration of intra- and/or extra-hepatic bile ducts. However, the mechanisms contributing to the pathogenesis of BA remain uncertain. Because of decreased bile flow, infectious complications and damaging endotoxemia occur frequently in patients with BA. The aim of this study was to investigate endotoxin levels in patients with BA and the relation of these levels with the expression of the endotoxin receptor, CD14. Methods The plasma levels of endotoxin and soluble CD14 were measured with a pyrochrome Limulus amebocyte lysate assay and enzyme-linked immunosorbent assay in patients with early-stage BA when they received the Kasai procedure (KP, in patients who were jaundice-free post-KP and followed-up at the outpatient department, in patients with late-stage BA when they received liver transplantation, and in patients with choledochal cysts. The correlation of CD14 expression with endotoxin levels in rats following common bile duct ligation was investigated. Results The results demonstrated a significantly higher hepatic CD14 mRNA and soluble CD14 plasma levels in patients with early-stage BA relative to those with late-stage BA. However, plasma endotoxin levels were significantly higher in both the early and late stages of BA relative to controls. In rat model, the results demonstrated that both endotoxin and CD14 levels were significantly increased in liver tissues of rats following bile duct ligation. Conclusions The significant increase in plasma endotoxin and soluble CD14 levels during BA implies a possible involvement of endotoxin stimulated CD14 production by hepatocytes in the early stage of BA for removal of endotoxin; whereas, endotoxin signaling likely induced liver injury and impaired soluble CD14 synthesis in the late stages of BA.

The solubility-permeability interplay in using cyclodextrins as pharmaceutical solubilizers: mechanistic modeling and application to progesterone.

Science.gov (United States)

Dahan, Arik; Miller, Jonathan M; Hoffman, Amnon; Amidon, Gregory E; Amidon, Gordon L

2010-06-01

A quasi-equilibrium mass transport analysis has been developed to quantitatively explain the solubility-permeability interplay that exists when using cyclodextrins as pharmaceutical solubilizers. The model considers the effects of cyclodextrins on the membrane permeability (P(m)) as well as the unstirred water layer (UWL) permeability (P(aq)), to predict the overall effective permeability (P(eff)) dependence on cyclodextrin concentration (C(CD)). The analysis reveals that: (1) UWL permeability markedly increases with increasing C(CD) since the effective UWL thickness quickly decreases with increasing C(CD); (2) membrane permeability decreases with increasing C(CD), as a result of the decrease in the free fraction of drug; and (3) since P(aq) increases and P(m) decreases with increasing C(CD), the UWL is effectively eliminated and the overall P(eff) tends toward membrane control, that is, P(eff) approximately P(m) above a critical C(CD). Application of this transport model enabled excellent quantitative prediction of progesterone P(eff) as a function of HP beta CD concentrations in PAMPA assay, Caco-2 transepithelial studies, and in situ rat jejunal-perfusion model. This work demonstrates that when using cyclodextrins as pharmaceutical solubilizers, a trade-off exists between solubility increase and permeability decrease that must not be overlooked; the transport model presented here can aid in striking the appropriate solubility-permeability balance in order to achieve optimal overall absorption. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

Evaluation of different toxicity assays applied to proliferating cells and to stratified epithelium in relation to permeability enhancement with glycocholate

DEFF Research Database (Denmark)

Eirheim, Heidi Ugelstad; Bundgaard, Christoffer; Nielsen, Hanne Mørck

2004-01-01

The purpose of the present study was to evaluate different toxicity assays for use on proliferating buccal TR146 cells and on stratified TR146 epithelium and to compare these results to the permeability enhancing effect of glycocholate (GC). Both the proliferating cells and the epithelium were...... across the epithelium concurrent with a decrease in the transepithelial electrical resistance (TEER) was also determined. The robustness of the epithelium was significantly higher than that of the proliferating cells (P...

The effect of endotoxin on preirradiated mice

Energy Technology Data Exchange (ETDEWEB)

Oehlert, W.; Oehlert, M. (Freiburg Univ. (Germany). Inst. fuer Pathologie); Moenig, H.; Konermann, G. (Freiburg Univ. (Germany). Inst. fuer Biophysik und Strahlenbiologie)

1992-12-01

Adult male mice were given a whole body irradiation with non-lethal doses of 2.5 or 5 Gy. Unirradiated animals served as controls. The animals (including controls) received a single injection of endotoxin (LPS from Salmonella abortus equi) with doses of 100, 200 or 400 [mu]g one day up to one year after irradiation. Twelve, 24 or 48 hours after lipopolysaccharide (LPS) application the animals were killed and dissected. Animals which died spontaneously were also examined. Liver, lung, kidney, small intestine, and stomach were histologically investigated. The histological findings showed, that differences exist between irradiated and unirradiated mice and that the cause of death is also different for animals dying spontaneously. The investigations have shown that after irradiation phases of different degrees of sensitivity with regard to the endotoxin response exist. This behaviour can be observed by different lethality rates or in the light of the histological results. Moreover, the histological findings have shown, that distinct regenerative changes occur first of all in the liver, in the mucosa of small intestine, and the gastric mucosa, in which the number of differntiated cells compared with the mitotic active cells is reduced. It can be ascertained, that a whole body irradiation with 2.5 to 5 Gy enhances an additional injury by endotoxin weeks to months later. Contrary to this a preirradiation a few days before endotoxin application leads to a 'protection' against the efficacy of endotoxin. These findings can be explained by modes of action described in literature, according to which endotoxins induce the formation of highly active mediators especially the tumor necrosis factor. (orig.).

The effect of endotoxin on preirradiated mice

Energy Technology Data Exchange (ETDEWEB)

Oehlert, W; Oehlert, M [Freiburg Univ. (Germany). Inst. fuer Pathologie; Moenig, H; Konermann, G [Freiburg Univ. (Germany). Inst. fuer Biophysik und Strahlenbiologie

1992-12-01

Adult male mice were given a whole body irradiation with non-lethal doses of 2.5 or 5 Gy. Unirradiated animals served as controls. The animals (including controls) received a single injection of endotoxin (LPS from Salmonella abortus equi) with doses of 100, 200 or 400 [mu]g one day up to one year after irradiation. Twelve, 24 or 48 hours after lipopolysaccharide (LPS) application the animals were killed and dissected. Animals which died spontaneously were also examined. Liver, lung, kidney, small intestine, and stomach were histologically investigated. The histological findings showed, that differences exist between irradiated and unirradiated mice and that the cause of death is also different for animals dying spontaneously. The investigations have shown that after irradiation phases of different degrees of sensitivity with regard to the endotoxin response exist. This behaviour can be observed by different lethality rates or in the light of the histological results. Moreover, the histological findings have shown, that distinct regenerative changes occur first of all in the liver, in the mucosa of small intestine, and the gastric mucosa, in which the number of differntiated cells compared with the mitotic active cells is reduced. It can be ascertained, that a whole body irradiation with 2.5 to 5 Gy enhances an additional injury by endotoxin weeks to months later. Contrary to this a preirradiation a few days before endotoxin application leads to a 'protection' against the efficacy of endotoxin. These findings can be explained by modes of action described in literature, according to which endotoxins induce the formation of highly active mediators especially the tumor necrosis factor. (orig.).

Bacterial endotoxin in the endometrium and its clinical significance in reproduction.

Science.gov (United States)

Kamiyama, Shigeru; Teruya, Yoko; Nohara, Makoto; Kanazawa, Koji

2004-10-01

Bacterial endotoxin was detected in menstrual effluent from infertile women. Endometrial endotoxin appears to influence reproductive process because the pregnancy rate after IVF-ET was significantly associated with an endotoxin level.

Gel-chromatographic and light scattering study of the salmonella typhi endotoxin

Energy Technology Data Exchange (ETDEWEB)

Dezhelici, G; Dezhelici, N; Jusici, D [Zagreb Univ. (Yugoslavia)

1977-01-01

The endotoxin of Salmonella typhi, strain 0-901 extracted with 1 M sodium chloride was studied by gel-chromatography and light scattering. The extracted material consisted of two components: a high molecular weight endotoxin (5.6 milion dalton) and a lower molecular weight protein-polysaccharide complex (less than 66,000 dalton). The endotoxin component proved to be a highly polydispersed material. Estimation of various averages of gyration radii suggested a more compact structure of endotoxin particles than those obtained by the Boivin extraction method, possibly due to the tertiary structuring of polypeptide chains in the protein-lipopolysaccharide complex of the endotoxin particle.

Inhibition of radiation-induced transformation in vitro by bacterial endotoxins

International Nuclear Information System (INIS)

Carew, J.A.; Collins, M.F.; Kennedy, A.R.

1988-01-01

Bacterial endotoxins (lipopolysaccharides) were found to suppress X-ray-induced malignant transformation of C3H/10T1/2 cells. Endotoxins were effective if present either throughout the 6-week transformation assay period, or for the final 4-week phase, but not when present only for the initial 2-week phase. Neither growth nor survival of C3H/10T1/2 cells, or a radiation-transformed cell line derived from them, were affected by endotoxins. Also, the endotoxins did not affect the formation of foci by the radiation transformed cells when these cells were co-cultured with untransformed cells. These results suggest that endotoxins exert their effect directly upon the transformation process itself, perhaps at a 'late' step in the conversion of an untransformed to a transformed cell. (author)

Inhibition of radiation-induced transformation in vitro by bacterial endotoxins

Energy Technology Data Exchange (ETDEWEB)

Carew, J A; Collins, M F; Kennedy, A R

1988-05-01

Bacterial endotoxins (lipopolysaccharides) were found to suppress X-ray-induced malignant transformation of C3H/10T1/2 cells. Endotoxins were effective if present either throughout the 6-week transformation assay period, or for the final 4-week phase, but not when present only for the initial 2-week phase. Neither growth nor survival of C3H/10T1/2 cells, or a radiation-transformed cell line derived from them, were affected by endotoxins. Also, the endotoxins did not affect the formation of foci by the radiation transformed cells when these cells were co-cultured with untransformed cells. These results suggest that endotoxins exert their effect directly upon the transformation process itself, perhaps at a 'late' step in the conversion of an untransformed to a transformed cell.

Detection of Endotoxin Contamination of Graphene Based Materials Using the TNF-α Expression Test and Guidelines for Endotoxin-Free Graphene Oxide Production.

Directory of Open Access Journals (Sweden)

Sourav P Mukherjee

Full Text Available Nanomaterials may be contaminated with bacterial endotoxin during production and handling, which may confound toxicological testing of these materials, not least when assessing for immunotoxicity. In the present study, we evaluated the conventional Limulus amebocyte lysate (LAL assay for endotoxin detection in graphene based material (GBM samples, including graphene oxide (GO and few-layered graphene (FLG. Our results showed that some GO samples interfered with various formats of the LAL assay. To overcome this problem, we developed a TNF-α expression test (TET using primary human monocyte-derived macrophages incubated in the presence or absence of the endotoxin inhibitor, polymyxin B sulfate, and found that this assay, performed with non-cytotoxic doses of the GBM samples, enabled unequivocal detection of endotoxin with a sensitivity that is comparable to the LAL assay. FLG also triggered TNF-α production in the presence of the LPS inhibitor, pointing to an intrinsic pro-inflammatory effect. Finally, we present guidelines for the preparation of endotoxin-free GO, validated by using the TET.

Endotoxin, Coliform, and Dust Levels in Various Types of Rodent Bedding

OpenAIRE

Whiteside, Tanya E; Thigpen, Julius E; Kissling, Grace E; Grant, Mary G; Forsythe, Diane B

2010-01-01

Endotoxins in grain dust, household dust, and animal bedding may induce respiratory symptoms in rodents and humans. We assayed the endotoxin, coliform, and dust levels in 20 types of rodent bedding. Endotoxin concentrations were measured by using a commercial test kit, coliform counts were determined by using conventional microbiologic procedures, and dust content was evaluated by using a rotating–tapping shaker. Paper bedding types contained significantly less endotoxin than did other beddin...

Labelling of endotoxins with Na/sup 51/CrO/sub 4/

Energy Technology Data Exchange (ETDEWEB)

Oginski, M; Lipinska-Piotrowska, I [Akademia Medyczna, Lodz (Poland)

1974-01-01

The authors modified the method of Braude of labelling of endotoxins with /sup 51/Cr. A higher uptake of the isotope by endotoxin was obtained (98.4%) which has a favourable effect on the accuracy of measurements with labelled endotoxins.

Masking of endotoxin in surfactant samples: Effects on Limulus-based detection systems.

Science.gov (United States)

Reich, Johannes; Lang, Pierre; Grallert, Holger; Motschmann, Hubert

2016-09-01

Over the last few decades Limulus Amebocyte Lysate (LAL) has been the most sensitive method for the detection of endotoxins (Lipopolysaccharides) and is well accepted in a broad field of applications. Recently, Low Endotoxin Recovery (LER) in biopharmaceutical drug products has been noticed, whereby the detection of potential endotoxin contaminations is not ensured. Notably, most of these drug products contain surfactants, which can have crucial effects on the detectability of endotoxin. In order to analyze the driving forces of LER, endotoxin detection in samples containing nonionic surfactants in various buffer systems was investigated. The results show that the process of LER is kinetically controlled and temperature-dependent. Furthermore, only the simultaneous presence of nonionic surfactants and components capable of forming metal complexes resulted in LER. In addition, capacity experiments show that even hazardous amounts of endotoxin can remain undetectable within such formulation compositions. In conclusion, the LER phenomenon is caused by endotoxin masking and not by test interference. In this process, the supramolecular structure of endotoxin is altered and exhibits only a limited susceptibility in binding to the Factor C of Limulus-based detection systems. We propose a two-step mechanism of endotoxin masking by complex forming agents and nonionic surfactants. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Fluorometric sensing of endotoxin based on aggregation of CTAB capped gold nanospheres

Energy Technology Data Exchange (ETDEWEB)

Paul, Ida Evangeline [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Raichur, Ashok M. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Nanotechnology and Water Sustainability Unit, University of South Africa, Florida Park 1709 Johannesburg (South Africa); Chandrasekaran, N. [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India)

2016-10-15

Gold nanoparticles (GNPs) of different sizes were used to carry out comparative fluorometric detection study on endotoxin. At excitation wavelength, 308 nm the GNPs exhibited strong emission intensity at wavelength 421 nm with varying intensities at 215.122, 234.965 and 262.551 for 15 nm (GNPs-I), 30 nm (GNPs-II) and 40 nm (GNPs-III), respectively. The different sizes of GNPs were interacted with endotoxin to study the effect of GNPs size on endotoxin detection. The electrostatic interaction between GNPs (GNPs-I, II, and III) and endotoxin led to the enhancement of the fluorescence intensities. The sensitivity of endotoxin detection was improved significantly by decreasing the size of the GNPs to 15 nm (GNPs-I). The endotoxin detection limit using GNPs-I was theoretically calculated to be 0.56×10{sup −9} M using the formula 3SD/slope, and it was able to detect lower levels of endotoxin when compared to GNPs-II or GNPs-III. The GNPs-I showed excellent selectivity for endotoxin detection with the optimized pH and volumetric ratio. Most importantly the optimized size was successfully used to detect endotoxin in real samples (milk samples and fruit juices) with a recovery rate of 98–105%.

Transepithelial photorefractive keratectomy with crosslinking for keratoconus.

Science.gov (United States)

Mukherjee, Achyut N; Selimis, Vasilis; Aslanides, Ioannis

2013-01-01

To analyse visual, refractive and topographic outcomes of combining transepithelial photorefractive keratectomy (tPRK) with simultaneous corneal crosslinking for the visual rehabilitation of contact lens intolerant keratoconus patients. Patients with topographically significant keratoconus, limited corrected vision and intolerant of contact lenses were prospectively recruited, subject to ethical approval and consent. All patients underwent single step aspheric tPRK and sequential crosslinking. Preoperative vision, refraction, corneal topography and wavefront were assessed, with postoperative assessment at 1, 3, 6, and 12 months. 22 eyes of 14 patients were included in the pilot study. Mean age was 32 years (SD 6.8, range 24 to 43). Mean preoperative unaided vision was 1.39 LogMAR (SD 0.5) best corrected 0.31 LogMAR (SD 0.2). Mean preoperative spherical equivalent was -2.74 Diopters (D) (SD 4.1 range -12.25 to +7.75), and mean cylinder -2.9 D (SD 1.2, range 0 to -5.5). Mean central corneal thickness was 461um (SD 29, range 411 to 516). Vision improved postoperatively; unaided 0.32 LogMAR (SD 0.4), best corrected 0.11 (SD 0.13) (P=<0.005). Mean postoperative cylinder was -1.4D (SD1.2), significantly reduced (p<0.005). Maximum keratometry (Kmax) was stable throughout postoperative follow up. (p<0.05). Non topographic transepithelial PRK with simultaneous crosslinking improves vision, and may offer an alternative to keratoplasty in contact lens intolerant keratoconus. Further comparative studies to topographic PRK techniques are indicated.

The redistribution of granulocytes following E. coli endotoxin induced sepsis

DEFF Research Database (Denmark)

Toft, P; Lillevang, S T; Tønnesen, Else Kirstine

1994-01-01

Infusion of endotoxin elicits granulocytopenia followed by increased numbers of granulocytes in peripheral blood. The purpose of this study was to investigate the redistribution and sequestration of granulocytes in the tissues following E. coli endotoxin induced sepsis. From 16 rabbits granulocytes...... were isolated, labelled with Indium and reinjected intravenously. Eight rabbits received an infusion of E. coli endotoxin 2 micrograms kg-1 while eight received isotonic saline. The redistribution of granulocytes was imaged with a gamma camera and calculated with a connected computer before and 2 and 6...... hours after infusion of endotoxin or saline. Serum cortisol and interleukin-1 beta were measured. In another seven rabbits, respiratory burst activity and degranulation of granulocytes were measured prior to and from 5 min to 6 hours after infusion of E. coli endotoxin 2 micrograms kg-1 BW. Following...

Predictors of Airborne Endotoxin Concentrations in Inner City Homes

Science.gov (United States)

Mazique, D; Diette, GB; Breysse, PN; Matsui, EC; McCormack, MC; Curtin-Brosnan, J; Williams, D; Peng, RD; Hansel, NN

2011-01-01

Few studies have assessed in-home factors which contribute to airborne endotoxin concentrations. In 85 inner-city Baltimore homes, we found no significant correlation between settled dust and airborne endotoxin concentrations. Certain household activities and characteristics, including frequency of dusting, air conditioner use and type of flooring, explained 36–42% of the variability of airborne concentrations. Measurements of both airborne and settled dust endotoxin concentrations may be needed to fully characterize domestic exposure in epidemiologic investigations. PMID:21429483

Effects of endotoxin on monoamine metabolism in the rat.

Science.gov (United States)

Pohorecky, L. A.; Wurtman, R. J.; Taam, D.; Fine, J.

1972-01-01

Examination of effects of administered endotoxin on catecholamine metabolism in the rat brain, sympathetic neurons, and adrenal medulla. It is found that endotoxin, administered intraperitoneally, lowers the norepinephrine content in peripheral sympathetic neurons and the brain, and the catecholamine content in the adrenal medulla. It also accelerates the disappearance of H3-norepinephrine from all these tissues. It is therefore suggested that the effects of endotoxin on body temperature may be mediated in part by central non-adrenergic neurons.

Endotoxin, coliform, and dust levels in various types of rodent bedding.

Science.gov (United States)

Whiteside, Tanya E; Thigpen, Julius E; Kissling, Grace E; Grant, Mary G; Forsythe, Diane

2010-03-01

Endotoxins in grain dust, household dust, and animal bedding may induce respiratory symptoms in rodents and humans. We assayed the endotoxin, coliform, and dust levels in 20 types of rodent bedding. Endotoxin concentrations were measured by using a commercial test kit, coliform counts were determined by using conventional microbiologic procedures, and dust content was evaluated by using a rotating-tapping shaker. Paper bedding types contained significantly less endotoxin than did other bedding types; the highest levels of endotoxin were detected in hardwood and corncob beddings. The range of endotoxin content for each bedding type was: corncob bedding, 1913 to 4504 endotoxin units per gram (EU/g); hardwood bedding, 3121 to 5401 EU/g; corncob-paper mixed bedding, 1586 to 2416 EU/g; and paper bedding, less than 5 to 105 EU/g. Coliform counts varied from less than 10 to 7591 cfu/g in corncob beddings, 90 to 4010 cfu/g in corncob-paper mixed beddings, less than 10 to 137 cfu/g in hardwood beddings, and less than 10 cfu/g in paper beddings. Average dust content was less than 0.15% in all commercial bedding types. We conclude that paper bedding is the optimal bedding type for conducting LPS inhalation studies and that rodent bedding containing high levels of endotoxin may alter the results of respiratory and immunologic studies in rodents.

Dopamine enhances duodenal epithelial permeability via the dopamine D5 receptor in rodent.

Science.gov (United States)

Feng, X-Y; Zhang, D-N; Wang, Y-A; Fan, R-F; Hong, F; Zhang, Y; Li, Y; Zhu, J-X

2017-05-01

The intestinal barrier is made up of epithelial cells and intercellular junctional complexes to regulate epithelial ion transport and permeability. Dopamine (DA) is able to promote duodenal epithelial ion transport through D1-like receptors, which includes subtypes of D 1 (D 1 R) and D 5 (D 5 R), but whether D1-like receptors influence the duodenal permeability is unclear. FITC-dextran permeability, short-circuit current (I SC ), Western blot, immunohistochemistry and ELISA were used in human D 5 R transgenic mice and hyperendogenous enteric DA (HEnD) rats in this study. Dopamine induced a downward deflection in I SC and an increase in FITC-dextran permeability of control rat duodenum, which were inhibited by the D1-like receptor antagonist, SCH-23390. However, DA decreased duodenal transepithelial resistance (TER), an effect also reversed by SCH-23390. A strong immunofluorescence signal for D 5 R, but not D 1 R, was observed in the duodenum of control rat. In human D 5 R knock-in transgenic mice, duodenal mucosa displayed an increased basal I SC with high FITC-dextran permeability and decreased TER with a lowered expression of tight junction proteins, suggesting attenuated duodenal barrier function in these transgenic mice. D 5 R knock-down transgenic mice manifested a decreased basal I SC with lowered FITC-dextran permeability. Moreover, an increased FITC-dextran permeability combined with decreased TER and tight junction protein expression in duodenal mucosa were also observed in HEnD rats. This study demonstrates, for the first time, that DA enhances duodenal permeability of control rat via D 5 R, which provides new experimental and theoretical evidence for the influence of DA on duodenal epithelial barrier function. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Acamprosate has no impact on the permeability of paracellular markers across Caco-2 cells

DEFF Research Database (Denmark)

Antonescu, Irina; Steffansen, Bente; Neuhoff, Sibylle

of the paracellular markers, mannitol and Lucifer Yellow (LY), was investigated. Methods: Ppara of LY and [14C]-mannitol was investigated across filter grown human epithelial colorectal adenocarcinoma (Caco-2) cell monolayers. Changes in the transepithelial electrical resistance (TEER) across the monolayers were...... the [14C]-mannitol, Papp values of 0.71±0.2x10-6 and 0.51±0.17x10-6 cm/s were obtained. TEER values at the end of all experiments were in the range of 426-444 ohm*cm2. Summary/Conclusion: Acamprosate has no impact on the paracellular pathway across Caco-2 cell monolayers of LY and mannitol, or on the TEER......Backgrounds: The oral bioavailability of poorly permeable and non-metabolised acamprosate (BCS III) is 11%. It is controversial whether the intestinal effective permeability of the fully an-ionized acamprosate (pKa 1.83; MW 181.2 g/mol) is predominantly paracellular (Ppara) or transcellular...

Guiding flying-spot laser transepithelial phototherapeutic keratectomy with optical coherence tomography.

Science.gov (United States)

Li, Yan; Yokogawa, Hideaki; Tang, Maolong; Chamberlain, Winston; Zhang, Xinbo; Huang, David

2017-04-01

To analyze transepithelial phototherapeutic keratectomy (PTK) results using optical coherence tomography (OCT) and develop a model to guide the laser dioptric and depth settings. Casey Eye Institute, Portland, Oregon, USA. Prospective nonrandomized case series. Patients with superficial corneal opacities and irregularities had transepithelial PTK with a flying-spot excimer laser by combining wide-zone myopic and hyperopic astigmatic ablations. Optical coherence tomography was used to calculate corneal epithelial lenticular masking effects, guide refractive laser settings, and measure opacity removal. The laser ablation efficiency and the refractive outcome were investigated using multivariate linear regression models. Twenty-six eyes of 20 patients received PTK to remove opacities and irregular astigmatism due to scar, dystrophy, radial keratotomy, or previous corneal surgeries. The uncorrected distance visual acuity and corrected distance visual acuity were significantly improved (P laser ablation depths were 31.3% (myopic ablation) and 63.0% (hyperopic ablation) deeper than the manufacturer's nomogram. The spherical equivalent of the corneal epithelial lenticular masking effect was 0.73 diopter ± 0.61 (SD). The refractive outcome highly correlated to the laser settings and epithelial lenticular masking effect (Pearson R = 0.96, P < .01). The ablation rate of granular dystrophy opacities appeared to be slower. Smoothing ablation under masking fluid was needed to prevent focal steep islands in these cases. The OCT-measured ablation depth efficiency could guide opacity removal. The corneal epithelial lenticular masking effect could refine the spherical refractive nomogram to achieve a better refractive outcome after transepithelial ablation. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Measurement of operative plasma endotoxin levels in jaundiced and non-jaundiced patients.

Science.gov (United States)

Pain, J A; Bailey, M E

1987-01-01

A study of portal plasma endotoxin levels was performed using a chromogenic limulus amoebocyte lysate (LAL) assay. The assay proved sensitive and reproducible. In only 1 of 25 healthy subjects was the systemic plasma endotoxin level above 100 pg/ml (equivalent Escherichia coli 0111B4). In 30 non-jaundiced patients undergoing surgery the mean (+SEM) portal plasma endotoxin level (60 + 9 pg/ml) was significantly higher (p less than 0.05) than the mean level in the systemic blood (46 + 6 pg/ml), supporting the concept of endotoxin absorption from the intestine into the portal blood. In 20 patients with obstructive jaundice undergoing surgery 42% of portal, 45% of inferior mesenteric and 35% of systemic venous plasma endotoxin levels were above 100 pg/ml. There were significantly higher levels in the portal (p less than 0.05) and inferior mesenteric (p less than 0.05) compared with the systemic blood. Neither the presence of malignancy nor the duration of surgery appeared to influence endotoxin absorption. The significance of raised plasma endotoxin levels in obstructive jaundice is discussed.

Endotoxins in indoor air and settled dust in primary schools in a subtropical climate.

Science.gov (United States)

Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Clifford, Sam; Morawska, Lidia

2013-09-03

Endotoxins can significantly affect the air quality in school environments. However, there is currently no reliable method for the measurement of endotoxins, and there is a lack of reference values for endotoxin concentrations to aid in the interpretation of measurement results in school settings. We benchmarked the "baseline" range of endotoxin concentration in indoor air, together with endotoxin load in floor dust, and evaluated the correlation between endotoxin levels in indoor air and settled dust, as well as the effects of temperature and humidity on these levels in subtropical school settings. Bayesian hierarchical modeling indicated that the concentration in indoor air and the load in floor dust were generally (EU/m(3) and EU/m(2), respectively. Exceeding these levels would indicate abnormal sources of endotoxins in the school environment and the need for further investigation. Metaregression indicated no relationship between endotoxin concentration and load, which points to the necessity for measuring endotoxin levels in both the air and settled dust. Temperature increases were associated with lower concentrations in indoor air and higher loads in floor dust. Higher levels of humidity may be associated with lower airborne endotoxin concentrations.

Effect of Tris-acetate buffer on endotoxin removal from human-like collagen used biomaterials

International Nuclear Information System (INIS)

Zhang, Huizhi; Fan, Daidi; Deng, Jianjun; Zhu, Chenghui; Hui, Junfeng; Ma, Xiaoxuan

2014-01-01

Protein preparation, which has active ingredients designated for the use of biomaterials and therapeutical protein, is obtained by genetic engineering, but products of genetic engineering are often contaminated by endotoxins. Because endotoxin is a ubiquitous and potent proinflammatory agent, endotoxin removal or depletion from protein is essential for researching any biomaterials. In this study, we have used Tris-acetate (TA) buffer of neutral pH value to evaluate endotoxins absorbed on the Pierce high-capacity endotoxin removal resin. The effects of TA buffer on pH, ionic strength, incubation time as well as human-like collagen (HLC) concentration on eliminating endotoxins are investigated. In the present experiments, we design an optimal method for TA buffer to remove endotoxin from recombinant collagen and use a chromogenic tachypleus amebocyte lysate (TAL) test kit to measure the endotoxin level of HLC. The present results show that, the endotoxins of HLC is dropped to 8.3 EU/ml at 25 mM TA buffer (pH 7.8) with 150 mM NaCl when setting incubation time at 6 h, and HLC recovery is about 96%. Under this experimental condition, it is proved to exhibit high efficiencies of both endotoxin removal and collagen recovery. The structure of treated HLC was explored by Transmission Electron Microscopy (TEM), demonstrating that the property and structure of HLC treated by TA buffer are maintained. Compared to the most widely used endotoxin removal method, Triton X-114 extraction, using TA buffer can obtain the non-toxic HLC without extra treatment for removing the toxic substances in Triton X-114. In addition, the present study aims at establishing a foundation for further work in laboratory animal science and providing a foundation for medical grade biomaterials. - Graphical abstract: The processes of endotoxins adsorbed from HLC. - Highlights: • TA buffer is a mild buffer system for endotoxins removal of HLC. • TA buffer may facilitate endotoxins adsorbed on the

Endotoxin inactivation via steam-heat treatment in dilute simethicone emulsions used in biopharmaceutical processes.

Science.gov (United States)

Britt, Keith A; Galvin, Jeffrey; Gammell, Patrick; Nti-Gyabaah, Joseph; Boras, George; Kolwyck, David; Ramirez, José G; Presente, Esther; Naugle, Gregory

2014-01-01

Simethicone emulsion is used to regulate foaming in cell culture operations in biopharmaceutical processes. It is also a potential source of endotoxin contamination. The inactivation of endotoxins in dilute simethicone emulsions was assessed as a function of time at different steam temperatures using a Limulus amebocyte lysate kinetic chromogenic technique. Endotoxin inactivation from steam-heat treatment was fit to a four-parameter double exponential decay model, which indicated that endotoxin inactivation was biphasic, consisting of fast and slow regimes. In the fast regime, temperature-related effects were dominant. Transitioning into the slow regime, the observed temperature dependence diminished, and concentration-related effects became increasingly significant. The change in the Gibbs free energy moving through the transition state indicated that a large energy barrier must be overcome for endotoxin inactivation to occur. The corresponding Arrhenius pre-exponential factor was >10(12) s(-1) suggesting that endotoxins in aqueous solution exist as aggregates. The disorder associated with the endotoxin inactivation reaction pathway was assessed via the change in entropy moving through the transition state. This quantity was positive indicating that endotoxin inactivation may result from hydrolysis of individual endotoxin molecules, which perturbs the conformation of endotoxin aggregates, thereby modulating the biological activity observed. Steam-heat treatment decreased endotoxin levels by 1-2 logarithm (log) reduction (LRV), which may be practically relevant depending on incoming raw material endotoxin levels. Antifoam efficiency and cell culture performance were negligibly impacted following steam-heat treatment. The results from this study show that steam-heat treatment is a viable endotoxin control strategy that can be implemented to support large-scale biopharmaceutical manufacturing. © 2014 American Institute of Chemical Engineers.

Experiments in radioactive marking of lipopoly saccharides in the framework of endotoxin research

International Nuclear Information System (INIS)

Steinmueller, B.

1985-01-01

The endotoxin from E. coli was marked using Na-125-iodine, in order to eventually through animal experiments obtain more information about the biological attack site of the endotoxin in the organism. The endotoxin from S. equi served thereby as a reference substance, since more exact information about the structure and degree of purity of this endotoxin is present. (orig.) [de

Endotoxins in surgical instruments of hip arthroplasty

Directory of Open Access Journals (Sweden)

Vania Regina Goveia

2016-06-01

Full Text Available Abstract OBJECTIVE To investigate endotoxins in sterilized surgical instruments used in hip arthroplasties. METHOD A descriptive exploratory study conducted in a public teaching hospital. Six types of surgical instruments were selected, namely: acetabulum rasp, femoral rasp, femoral head remover, chisel box, flexible bone reamer and femoral head test. The selection was based on the analysis of the difficulty in removing bone and blood residues during cleaning. The sample was made up of 60 surgical instruments, which were tested for endotoxins in three different stages. The EndosafeTM Gel-Clot LAL (Limulus Amebocyte Lysate method was used. RESULT There was consistent gel formation with positive analysis in eight instruments, corresponding to 13.3%, being four femoral rasps and four bone reamers. CONCLUSION Endotoxins in quantity ≥0.125 UE/mL were detected in 13.3% of the instruments tested.

Importance of the personal endotoxin cloud in school-age children with asthma.

Science.gov (United States)

Rabinovitch, Nathan; Liu, Andrew H; Zhang, Lening; Rodes, Charles E; Foarde, Karin; Dutton, Steven J; Murphy, James R; Gelfand, Erwin W

2005-11-01

A number of studies have observed associations between the amount of endotoxin in urban dust and chronic asthma severity, but a direct relationship between personal exposure to household endotoxin and acute asthma worsening has not yet been defined. We sought to investigate the relationship between day-to-day changes in personal endotoxin exposure and asthma severity. In the winter and spring of 1999 through 2000, endotoxin exposures were monitored in asthmatic schoolchildren by using portable, as opposed to stationary, monitors designed to measure inhalable and respirable particulate matter less than or equal to 2.5 and 10 microm in diameter. Children were followed with daily measurements of FEV(1) and asthma symptoms. Over a 24-hour period, median daily personal endotoxin exposures ranged from 0.08 EU/m(3) (measured at a particulate matter size range Personal exposures were significantly (P personal activities might be better correlated with disease severity. Increases in personal endotoxin exposures were associated with decreased FEV(1) values and increased symptoms. These findings demonstrate the importance of using personal monitoring to both measure and correlate endotoxin exposure with asthma severity.

Distribution of /sup 51/Cr labelled endotoxin on tissue and intracellular organella in mice

Energy Technology Data Exchange (ETDEWEB)

Saito, K; Suzuki, M; Okuaki, A; Saito, M [Fukushima Medical Coll. (Japan)

1976-10-01

The distribution of /sup 51/Cr labelled endotoxin was investigated in mice. The degree of toxicity between non-labelled endotoxin and /sup 51/Cr labelled endotoxin did not change. /sup 51/Cr-endotoxin was distributed in the highest levels in the liver, and to a lesser degree in the intestine, lungs, spleen and kidneys. The affinity of the tissue to /sup 51/Cr-endotoxin was strongest in the liver followed by the spleen, lungs, kidneys and intestine. /sup 51/Cr-endotoxin was distributed mainly in the mitochondrial fraction and the nuclear fraction in the intracellular species. /sup 51/Cr-endotoxin was distributed only in the liver and the intestine when a small dose was administered. It was also distributed in the lungs, spleen and kidneys when a large dose was given, but the uptake in the liver was somewhat limited. /sup 51/Cr-endotoxin was distributed mainly in the liver and the spleen in the mice that survived one week.

Endotoxin predictors and associated respiratory outcomes differ with climate regions in the U.S.

Science.gov (United States)

Mendy, Angelico; Wilkerson, Jesse; Salo, Pӓivi M; Cohn, Richard D; Zeldin, Darryl C; Thorne, Peter S

2018-03-01

Although endotoxin is a recognized cause of environmental lung disease, how its relationship with respiratory outcomes varies with climate is unknown. To examine the endotoxin predictors as well as endotoxin association with asthma, wheeze, and sensitization to inhalant allergens in various US climate regions. We analyzed data on 6963 participants in the National Health and Nutrition Examination Survey. Endotoxin measurements of house dust from bedroom floor and bedding were performed at the University of Iowa. Linear and logistic regression analyses were used to identify endotoxin predictors and assess endotoxin association with health outcomes. The overall median house dust endotoxin was 16.2 EU/mg; it was higher in mixed-dry/hot-dry regions (19.7 EU/mg) and lower in mixed-humid/marine areas (14.8 EU/mg). Endotoxin predictors and endotoxin association with health outcomes significantly differed across climate regions. In subarctic/very cold/cold regions, log 10 -endotoxin was significantly associated with higher prevalence of wheeze outcomes (OR:1.48, 95% CI:1.19-1.85 for any wheeze, OR:1.48, 95% CI:1.22-1.80 for exercise-induced wheeze, OR:1.50, 95% CI:1.13-1.98 for prescription medication for wheeze, and OR:1.95, 95% CI:1.50-2.54 for doctor/ER visit for wheeze). In hot-humid regions, log 10 -endotoxin was positively associated with any wheeze (OR:1.66, 95% CI:1.04-2.65) and current asthma (OR:1.56, 95% CI:1.11-2.18), but negatively with sensitization to any inhalant allergens (OR:0.83, 95% CI:0.74-0.92). Endotoxin predictors and endotoxin association with asthma and wheeze differ across U.S. climate regions. Endotoxin is associated positively with wheeze or asthma in cold and hot-humid regions, but negatively with sensitization to inhalant allergens in hot-humid climates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bacterial endotoxin adhesion to different types of orthodontic adhesives

Directory of Open Access Journals (Sweden)

Priscilla Coutinho ROMUALDO

Full Text Available Abstract Bacterial endotoxin (LPS adhesion to orthodontic brackets is a known contributing factor to inflammation of the adjacent gingival tissues. Objective The aim of this study was to assess whether LPS adheres to orthodontic adhesive systems, comparing two commercial brands. Material and Methods Forty specimens were fabricated from Transbond XT and Light Bond composite and bonding agent components (n=10/component, then contaminated by immersion in a bacterial endotoxin solution. Contaminated and non-contaminated acrylic resin samples were used as positive and negative control groups, respectively. LPS quantification was performed by the Limulus Amebocyte Lysate QCL-1000™ test. Data obtained were scored and subjected to the Chi-square test using a significance level of 5%. Results There was endotoxin adhesion to all materials (p0.05. There was no significant difference (p>0.05 among commercial brands. Affinity of endotoxin was significantly greater for the bonding agents (p=0.0025. Conclusions LPS adhered to both orthodontic adhesive systems. Regardless of the brand, the endotoxin had higher affinity for the bonding agents than for the composites. There is no previous study assessing the affinity of LPS for orthodontic adhesive systems. This study revealed that LPS adheres to orthodontic adhesive systems. Therefore, additional care is recommended to orthodontic applications of these materials.

Removal of endotoxin from deionized water using micromachined silicon nanopore membranes

International Nuclear Information System (INIS)

Smith, Ross A; Fissell, William H; Fleischman, Aaron J; Roy, Shuvo; Goldman, Ken; Zorman, Christian A

2011-01-01

Endotoxins are lipopolysaccharide components of the cell membrane of Gram-negative bacteria that trigger the body's innate immune system and can cause shock and death. Water for medical therapy, including parenteral and dialysate solutions, must be free of endotoxin. This purity is challenging to achieve as many Gram-negative bacteria are endemic in the environment, and can thrive in harsh, nutrient-poor conditions. Current methods for removing endotoxin include distillation and reverse osmosis, both of which are resource intensive processes. Membranes that present an absolute barrier to macromolecular passage may be capable of delivering pure water for biomedical applications. In this work, endotoxin has been filtered from aqueous solutions using silicon nanopore membranes (SNMs) with monodisperse pore size distributions. SNMs with critical pore sizes between 26 and 49 nm were challenged with solutions of deionized water spiked with endotoxin and with Pseudomonas cepacia. The filtrate produced by the SNM from Pseudomonas-contaminated water had <1.0 endotoxin unit (EU) ml −1 , which meets standards for dialysate purity. This approach suggests a technique for single-step cleanup of heavily contaminated water that may be suitable for field or clinical use

Corneal-Wavefront guided transepithelial photorefractive keratectomy after corneal collagen cross linking in keratoconus

Directory of Open Access Journals (Sweden)

Massimo Camellin

2017-01-01

Conclusions: Corneal-Wavefront guided transepithelial PRK ablation profiles after conventional CXL yields to good visual, optical, and refractive results. These treatments are safe and efficacious for the correction of refracto-therapeutic problems in keratoconic patients.

Respiratory health effects of exposure to low levels of airborne endotoxin - a systematic review.

Science.gov (United States)

Farokhi, Azadèh; Heederik, Dick; Smit, Lidwien A M

2018-02-08

Elevated endotoxin levels have been measured in ambient air around livestock farms, which is a cause of concern for neighbouring residents. There is clear evidence that occupational exposure to high concentrations of airborne endotoxin causes respiratory inflammation, respiratory symptoms and lung function decline. However, health effects of exposure to low levels of endotoxin are less well described. The aim of this systematic review is to summarize published associations between exposure to relatively low levels of airborne endotoxin and respiratory health endpoints. Studies investigating respiratory effects of measured or modelled exposure to low levels of airborne endotoxin (average effects of exposure to low levels of endotoxin on respiratory symptoms and lung function. However, considerable heterogeneity existed in the outcomes of the included studies and no overall estimate could be provided by meta-analysis to quantify the possible relationship. Instead, a best evidence synthesis was performed among studies examining the exposure-response relationship between endotoxin and respiratory outcomes. Significant exposure-response relationships between endotoxin and symptoms and FEV 1 were shown in several studies, with no conflicting findings in the studies included in the best evidence synthesis. Significantly different effects of endotoxin exposure were also seen in vulnerable subgroups (atopics and patients with broncho-obstructive disease) and smokers. Respiratory health effects of exposure to low levels of airborne endotoxin (health effects, especially in vulnerable subgroups of the population.

Heat stress and reduced plane of nutrition decreases intestinal integrity and function in pigs.

Science.gov (United States)

Pearce, S C; Mani, V; Weber, T E; Rhoads, R P; Patience, J F; Baumgard, L H; Gabler, N K

2013-11-01

Heat stress can compromise intestinal integrity and induce leaky gut in a variety of species. Therefore, the objectives of this study were to determine if heat stress (HS) directly or indirectly (via reduced feed intake) increases intestinal permeability in growing pigs. We hypothesized that an increased heat-load causes physiological alterations to the intestinal epithelium, resulting in compromised barrier integrity and altered intestinal function that contributes to the overall severity of HS-related illness. Crossbred gilts (n=48, 43±4 kg BW) were housed in constant climate controlled rooms in individual pens and exposed to 1) thermal neutral (TN) conditions (20°C, 35-50% humidity) with ad libitum intake, 2) HS conditions (35°C, 20-35% humidity) with ad libitum feed intake, or 3) pair-fed in TN conditions (PFTN) to eliminate confounding effects of dissimilar feed intake. Pigs were sacrificed at 1, 3, or 7 d of environmental exposure and jejunum samples were mounted into modified Ussing chambers for assessment of transepithelial electrical resistance (TER) and intestinal fluorescein isothiocyanate (FITC)-labeled lipopolysaccharide (LPS) permeability (expressed as apparent permeability coefficient, APP). Further, gene and protein markers of intestinal integrity and stress were assessed. Irrespective of d of HS exposure, plasma endotoxin levels increased 45% (Pwarm summer months.

Automation of cell-based drug absorption assays in 96-well format using permeable support systems.

Science.gov (United States)

Larson, Brad; Banks, Peter; Sherman, Hilary; Rothenberg, Mark

2012-06-01

Cell-based drug absorption assays, such as Caco-2 and MDCK-MDR1, are an essential component of lead compound ADME/Tox testing. The permeability and transport data they provide can determine whether a compound continues in the drug discovery process. Current methods typically incorporate 24-well microplates and are performed manually. Yet the need to generate absorption data earlier in the drug discovery process, on an increasing number of compounds, is driving the use of higher density plates. A simple, more efficient process that incorporates 96-well permeable supports and proper instrumentation in an automated process provides more reproducible data compared to manual methods. Here we demonstrate the ability to perform drug permeability and transport assays using Caco-2 or MDCKII-MDR1 cells. The assay procedure was automated in a 96-well format, including cell seeding, media and buffer exchanges, compound dispense, and sample removal using simple robotic instrumentation. Cell monolayer integrity was confirmed via transepithelial electrical resistance and Lucifer yellow measurements. Proper cell function was validated by analyzing apical-to-basolateral and basolateral-to-apical movement of rhodamine 123, a known P-glycoprotein substrate. Apparent permeability and efflux data demonstrate how the automated procedure provides a less variable method than manual processing, and delivers a more accurate assessment of a compound's absorption characteristics.

Exposure to household endotoxin and total and allergen-specific IgE in the US population

International Nuclear Information System (INIS)

Min, Kyoung-Bok; Min, Jin-Young

2015-01-01

Background: Although endotoxin has strong pro-inflammatory properties, endotoxin-allergy relationship in adults and children have been inconsistent. Objectives: We investigated the association between household endotoxin levels and total immunoglobulin E (IgE) or specific IgE in the US general population, classified into three age ranges: children/adolescent, adults, and older adults. Methods: We analyzed the 2005–2006 National Health and Nutrition Examination Surveys. A total of 5220 participants for whom serum IgE and household endotoxin data were available was included in the analyses. Results: Exposure to endotoxin reduced the risk for allergic sensitization, especially in specific IgE to plants (OR in Quartile 3 = 0.58; 95% CI = 0.44–0.76) and pets (OR in Quartile 3 = 0.62; 95% CI = 0.41–0.92), for children/adolescents. In contrast, the risk among adults and older adults increased with increasing endotoxin levels. Conclusions: Our findings suggest that the effect of endotoxin on allergic reaction is likely to depend on age. - Highlights: • Findings regarding the endotoxin-allergy relationship in adults and children are inconsistent. • We investigated the association of endotoxin with total and specific IgE in US population. • The association between endotoxin levels and allergic markers is likely to depend on age. • Exposure to endotoxin reduced the risk for allergic sensitization for children/adolescents. • The risk among adults and older adults increased with increasing endotoxin levels. - Exposure to endotoxin reduced the risk for allergic sensitization for children/adolescents, but decreased the risk among adults and older

Endotoxin-induced monocytic microparticles have contrasting effects on endothelial inflammatory responses.

Directory of Open Access Journals (Sweden)

Beryl Wen

Full Text Available Septic shock is a severe disease state characterised by the body's life threatening response to infection. Complex interactions between endothelial cells and circulating monocytes are responsible for microvasculature dysfunction contributing to the pathogenesis of this syndrome. Here, we intended to determine whether microparticles derived from activated monocytes contribute towards inflammatory processes and notably vascular permeability. We found that endotoxin stimulation of human monocytes enhances the release of microparticles of varying phenotypes and mRNA contents. Elevated numbers of LPS-induced monocytic microparticles (mMP expressed CD54 and contained higher levels of transcripts for pro-inflammatory cytokines such as TNF, IL-6 and IL-8. Using a prothrombin time assay, a greater reduction in plasma coagulation time was observed with LPS-induced mMP than with non-stimulated mMP. Co-incubation of mMP with the human brain endothelial cell line hCMEC/D3 triggered their time-dependent uptake and significantly enhanced endothelial microparticle release. Unexpectedly, mMP also modified signalling pathways by diminishing pSrc (tyr416 expression and promoted endothelial monolayer tightness, as demonstrated by endothelial impedance and permeability assays. Altogether, these data strongly suggest that LPS-induced mMP have contrasting effects on the intercellular communication network and display a dual potential: enhanced pro-inflammatory and procoagulant properties, together with protective function of the endothelium.

BAY K 8644-induced oscillations in rabbit gall-bladder transepithelial potential difference

DEFF Research Database (Denmark)

Hansen, C P; Holstein-Rathlou, N H; Frederiksen, O

1986-01-01

The effects of the Ca2+-channel activator BAY K 8644 (a novel dihydropyridine) on transepithelial potential difference (Pd), electrical resistance (Rt), and unidirectional Na+-fluxes were studied in the rabbit gall-bladder. It was observed that BAY K 8644 at concentrations between 10(-7) and 10...

Removal of endotoxins from bacteriophage preparations by extraction with organic solvents.

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Bożena Szermer-Olearnik

Full Text Available Lipopolysaccharide (LPS, endotoxin, pyrogen constitutes a very troubling contaminant of crude phage lysates produced in Gram-negative bacteria. Toxicity of LPS depends on the strong innate immunity response including the cytokines. Therefore, its removal is important for bacteriophage applications. In this paper, we present a procedure for extractive removal of endotoxin from bacteriophage preparations with water immiscible solvents (1-octanol or 1-butanol. During extraction most of the phage lytic activity is retained in the aqueous phase, while endotoxin accumulates in the organic solvent. The levels of endotoxin (expressed as endotoxin units, EU in the aqueous bacteriophage-containing fraction determined by limulus amebocyte lysate or EndoLISA assay were exceptionally low. While the initial endotoxin levels in the crude phage lysates ranged between 10(3 and 10(5 EU/ml the average level after organic extraction remaining in the aqueous fraction was 5.3 EU/ml. These values when related to phage titers decreased from 10(3-10(5 EU/10(9 PFU (plaque forming units down to an average of 2.8 EU/10(9 PFU. The purification procedure is scalable, efficient and applicable to all the bacteriophages tested: T4, HAP1 (E. coli and F8 (P. aeruginosa.

Changes in endotoxin levels in T2DM subjects on anti-diabetic therapies

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Kumar Sudhesh

2009-04-01

Full Text Available Abstract Introduction Chronic low-grade inflammation is a significant factor in the development of obesity associated diabetes. This is supported by recent studies suggesting endotoxin, derived from gut flora, may be key to the development of inflammation by stimulating the secretion of an adverse cytokine profile from adipose tissue. Aims The study investigated the relationship between endotoxin and various metabolic parameters of diabetic patients to determine if anti-diabetic therapies exerted a significant effect on endotoxin levels and adipocytokine profiles. Methods Fasting blood samples were collected from consenting Saudi Arabian patients (BMI: 30.2 ± (SD5.6 kg/m2, n = 413, consisting of non-diabetics (ND: n = 67 and T2DM subjects (n = 346. The diabetics were divided into 5 subgroups based on their 1 year treatment regimes: diet-controlled (n = 36, metformin (n = 141, rosiglitazone (RSG: n = 22, a combined fixed dose of metformin/rosiglitazone (met/RSG n = 100 and insulin (n = 47. Lipid profiles, fasting plasma glucose, insulin, adiponectin, resistin, TNF-α, leptin, C-reactive protein (CRP and endotoxin concentrations were determined. Results Regression analyses revealed significant correlations between endotoxin levels and triglycerides (R2 = 0.42; p 2 = 0.10; p 2 = 0.076; p 2 = 0.032; p 2 = 0.055; p Conclusion We conclude that sub-clinical inflammation in T2DM may, in part, be mediated by circulating endotoxin. Furthermore, that whilst the endotoxin and adipocytokine profiles of diabetic patients treated with different therapies were comparable, the RSG group demonstrated significant differences in both adiponectin and endotoxin levels. We confirm an association between endotoxin and serum insulin and triglycerides and an inverse relationship with HDL. Lower endotoxin and higher adiponectin in the groups treated with RSG may be related and indicate another mechanism for the effect of RSG on insulin sensitivity.

The redistribution of granulocytes following E. coli endotoxin induced sepsis

DEFF Research Database (Denmark)

Toft, P; Lillevang, S T; Tønnesen, Else Kirstine

1994-01-01

Infusion of endotoxin elicits granulocytopenia followed by increased numbers of granulocytes in peripheral blood. The purpose of this study was to investigate the redistribution and sequestration of granulocytes in the tissues following E. coli endotoxin induced sepsis. From 16 rabbits granulocytes...

Endotoxin and cancer chemo-prevention.

Science.gov (United States)

Mastrangelo, Giuseppe; Fadda, Emanuela; Cegolon, Luca

2013-10-01

Reduced rates of lung cancer have been observed in several occupational groups exposed to high levels of organic dusts contaminated by endotoxin. The underlying anti-neoplastic mechanism of endotoxin may be an increased secretion of endogenous anti-neoplastic mediators and activation of the toll-like receptors (TLR). A detoxified endotoxin derivative, Monophosphoryl Lipid A (MPL(®)) is marketed in Europe since 1999 as part of the adjuvant systems in allergy vaccines for treatment of allergic rhino-conjunctivitis and allergic asthma. Over 200,000 patients have used them to date (nearly 70% in Germany). Since detailed exposure (MPL(®) dose and timing of administration) and individual data are potentially available, an observational follow-up study could be conducted in Germany to investigate the protective effect of MPL(®) against cancer, comparing cancer incidence in two groups of patients with allergic rhinitis: those treated with allergoids plus MPL(®) and those treated with a vaccine including the same allergoids but not MPL(®). The protective effect of MPL(®) could be quantified in ever and never smokers. If this proposed observational study provides evidence of protective effects, MPL(®) could be immediately used as a chemo-preventive agent since it is already in use as adjuvant in human vaccines against cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of Tris-acetate buffer on endotoxin removal from human-like collagen used biomaterials.

Science.gov (United States)

Zhang, Huizhi; Fan, Daidi; Deng, Jianjun; Zhu, Chenghui; Hui, Junfeng; Ma, Xiaoxuan

2014-09-01

Protein preparation, which has active ingredients designated for the use of biomaterials and therapeutical protein, is obtained by genetic engineering, but products of genetic engineering are often contaminated by endotoxins. Because endotoxin is a ubiquitous and potent proinflammatory agent, endotoxin removal or depletion from protein is essential for researching any biomaterials. In this study, we have used Tris-acetate (TA) buffer of neutral pH value to evaluate endotoxins absorbed on the Pierce high-capacity endotoxin removal resin. The effects of TA buffer on pH, ionic strength, incubation time as well as human-like collagen (HLC) concentration on eliminating endotoxins are investigated. In the present experiments, we design an optimal method for TA buffer to remove endotoxin from recombinant collagen and use a chromogenic tachypleus amebocyte lysate (TAL) test kit to measure the endotoxin level of HLC. The present results show that, the endotoxins of HLC is dropped to 8.3EU/ml at 25 mM TA buffer (pH7.8) with 150 mM NaCl when setting incubation time at 6h, and HLC recovery is about 96%. Under this experimental condition, it is proved to exhibit high efficiencies of both endotoxin removal and collagen recovery. The structure of treated HLC was explored by Transmission Electron Microscopy (TEM), demonstrating that the property and structure of HLC treated by TA buffer are maintained. Compared to the most widely used endotoxin removal method, Triton X-114 extraction, using TA buffer can obtain the non-toxic HLC without extra treatment for removing the toxic substances in Triton X-114. In addition, the present study aims at establishing a foundation for further work in laboratory animal science and providing a foundation for medical grade biomaterials. Copyright © 2014 Elsevier B.V. All rights reserved.

The emerging role of microRNA in regulation of endotoxin tolerance.

LENUS (Irish Health Repository)

Quinn, Edel M

2012-05-01

Endotoxin tolerance is a phenomenon where cells show reduced responsiveness toward repeated endotoxin stimulation. Regulation of tolerance occurs at multiple levels of the cell signaling cascade, and many of these levels are potentially regulated by miRNA, which are a class of small RNA that bind to mRNA to down-regulate gene expression at the post-transcriptional level. Roles have been identified for miR-146a, miR-221, miR-579, miR-125b, miR-155, let-7e, and miR-98 in regulating the TLR4 signaling pathway during the development of endotoxin tolerance at receptor, signaling pathway, and gene transcription and translational levels. miRNA represent exciting, new potential targets in attempts to exogenously modulate development of endotoxin tolerance.

EFFECTS OF LIME (CAO) ON THE ENDOTOXIN LEVELS OF BIOSOLIDS

Science.gov (United States)

Lime addition is a common practice for treating biosolids in order to meet EPA 503 requirements for land application. Since this treatment kills the majority of microorganisms, will it increase the level of endotoxins present in biosolids? And, if endotoxin levels are increased, ...

Comparison of Endotoxin Exposure Assessment by Bioaerosol Impinger and Filter-Sampling Methods

OpenAIRE

Duchaine, Caroline; Thorne, Peter S.; Mériaux, Anne; Grimard, Yan; Whitten, Paul; Cormier, Yvon

2001-01-01

Environmental assessment data collected in two prior occupational hygiene studies of swine barns and sawmills allowed the comparison of concurrent, triplicate, side-by-side endotoxin measurements using air sampling filters and bioaerosol impingers. Endotoxin concentrations in impinger solutions and filter eluates were assayed using the Limulus amebocyte lysate assay. In sawmills, impinger sampling yielded significantly higher endotoxin concentration measurements and lower variances than filte...

High exposure to endotoxin in farming is associated with less new-onset pollen sensitisation

DEFF Research Database (Denmark)

Elholm, Grethe; Schlünssen, Vivi; Doekes, Gert

2017-01-01

OBJECTIVES: Little is known about risk factors for new onset and loss of atopic sensitisation in adulthood. The aim is to examine the longitudinal effect of quantitatively assessed endotoxin exposures on changes in specific allergen sensitisation in young adults. METHODS: The cohort consisted...... in relation to cumulative endotoxin exposure during follow-up, considering early life farm exposure. RESULTS: Endotoxin exposure during follow-up was significantly associated with less new onset of specifically grass and birch pollen sensitisation. For the highest versus lowest quartile of cumulative...... endotoxin exposure, the OR for new-onset IgE sensitisation was 0.35 (0.13-0.91) for birch and 0.14 (0.05-0.50) for grass. On the other hand, loss of pollen sensitisation showed a positive, although mostly non-significant, association with increased levels of endotoxin exposure. Endotoxin exposure...

Sensitisation to common allergens and respiratory symptoms in endotoxin exposed workers

DEFF Research Database (Denmark)

Basinas, Ioannis; Schlünssen, Vivi; Heederik, Dick

2012-01-01

Objective To test the hypotheses that current endotoxin exposure is inversely associated with allergic sensitisation and positively associated with non-allergic respiratory diseases in four occupationally exposed populations using a standardised analytical approach. Methods Data were pooled from...... four epidemiological studies including 3883 Dutch and Danish employees in veterinary medicine, agriculture and power plants using biofuel. Endotoxin exposure was estimated by quantitative job-exposure matrices specific for the study populations. Dose–response relationships between exposure, Ig...... Current endotoxin exposure was dose-dependently associated with a reduced prevalence of allergic sensitisation (ORs of 0.92, 0.81 and 0.66 for low mediate, high mediate and high exposure) and hay fever (ORs of 1.16, 0.81 and 0.58). Endotoxin exposure was a risk factor for organic dust toxic syndrome...

Effect of plasmapheresis on the immune system in endotoxin-induced sepsis

DEFF Research Database (Denmark)

Toft, P; Schmidt, R; Broechner, A C

2008-01-01

BACKGROUND: It has been proposed that plasmapheresis is most effective when applied early in Gram-negative sepsis. We therefore studied the effect of early plasmapheresis on immunity in experimental Escherichia coli endotoxin-induced sepsis. METHODS: 20 pigs received 30 microg/kg of E. coli...... endotoxin. 40 min later, half of the pigs were treated with plasmapheresis which lasted 4 h. The adhesion molecules, the oxidative burst, the number of neutrophils in blood and lungs, and cytokines were measured. RESULTS: Infusion of endotoxin was associated with activation of adhesion molecules increased...... oxidative burst, increased concentration of cytokine, and accumulation of granulocytes in lung tissue. Plasmapheresis reduced the oxidative burst, and there was a tendency towards a reduced accumulation of granulocytes in the lung. CONCLUSION: Though plasmapheresis was initiated early after the endotoxin...

Geographical variation and the determinants of domestic endotoxin levels in mattress dust in Europe

NARCIS (Netherlands)

Chen, C.M.; Thiering, E.; Doekes, G.; Zock, J.P.; Bakolis, I.; Norbäck, D.; Sunyer, J.; Villani, S.; Verlato, G.; Täubel, M.; Jarvis, D.

2012-01-01

Endotoxin exposures have manifold effects on human health. The geographical variation and determinants of domestic endotoxin levels in Europe have not yet been extensively described. To investigate the geographical variation and determinants of domestic endotoxin concentrations in mattress dust in

Ambient endotoxin in PM10 and association with inflammatory activity, air pollutants, and meteorology, in Chitwan, Nepal.

Science.gov (United States)

Mahapatra, Parth Sarathi; Jain, Sumeet; Shrestha, Sujan; Senapati, Shantibhusan; Puppala, Siva Praveen

2018-03-15

Endotoxin associated with ambient PM (particulate matter) has been linked to adverse respiratory symptoms, but there have been few studies of ambient endotoxin and its association with co-pollutants and inflammation. Our aim was to measure endotoxin associated with ambient PM 10 (particulate matter with aerodynamic diametermeteorology, co-pollutants, and inflammatory activity. PM 10 concentrations were recorded and filter paper samples were collected using E-samplers; PM 1, PM 2.5 , black carbon (BC), methane (CH 4 ), and carbon monoxide (CO) were also measured. The Limulus amebocyte lysate (LAL) assay was used for endotoxin quantification and the nuclear factor kappa B (NFκB) activation assay to assess inflammatory activity. The mean concentration of PM 10 at the different locations ranged from 136 to 189μg/m 3 , and of endotoxin from 0.29 to 0.53EU/m 3 . Pollutant presence was positively correlated with endotoxin. Apart from relative humidity, meteorological variations had no significant impact on endotoxin concentration. NF-κB activity was negatively correlated with endotoxin concentration. To the best of our knowledge, this study provides the first measurements of ambient endotoxin associated with PM 10 in Nepal. Endotoxin and co-pollutants were positively associated indicating a similar source. Endotoxin was negatively correlated with inflammatory activity as a result of a time-limited forest fire event during the sampling period. Studies of co-pollutants suggested that the higher levels of endotoxin related to biomass burning were accompanied by increased levels of anti-inflammatory agents, which suppressed the endotoxin inflammatory effect. Copyright © 2017. Published by Elsevier B.V.

Single session of Nd:YAG laser intracanal irradiation neutralizes endotoxin in dental root dentin.

Science.gov (United States)

Archilla, José R F; Moreira, Maria S N A; Miyagi, Sueli P H; Bombana, Antônio C; Gutknecht, Norbert; Marques, Márcia M

2012-11-01

Endotoxins released in the dental root by Gram-negative microorganisms can be neutralized by calcium hydroxide, when this medication is applied inside the root canal for at least seven days. However, several clinical situations demand faster root canal decontamination. Thus, for faster endotoxin neutralization, endodontists are seeking additional treatments. The in vitro study tested whether or not intracanal Nd:YAG laser irradiation would be able to neutralize endotoxin within the human dental root canal in a single session. Twenty-four human teeth with one root were mounted between two chambers. After conventional endodontic treatment, root canals were contaminated with Escherichia coli endotoxin. Then they were irradiated or not (controls) in contact mode with an Nd:YAG laser (1.5 W, 15 Hz, 100 mJ and pulse fluency of 124  J/cm2). The endotoxin activity was measured using the limulus lysate technique and data were statistically compared (p≤0.05). The concentration of active endotoxin measured in the negative control group was significantly lower than that of the positive control group (p=0.04). The concentrations of endotoxin in both irradiated groups were significantly lower than that of the positive control group (p=0.027) and similar to that of negative control group (p=0.20). A single session of intracanal Nd:YAG laser irradiation is able to neutralize endotoxin in the dental root tissues.

Experimental design and Bayesian networks for enhancement of delta-endotoxin production by Bacillus thuringiensis.

Science.gov (United States)

Ennouri, Karim; Ayed, Rayda Ben; Hassen, Hanen Ben; Mazzarello, Maura; Ottaviani, Ennio

2015-12-01

Bacillus thuringiensis (Bt) is a Gram-positive bacterium. The entomopathogenic activity of Bt is related to the existence of the crystal consisting of protoxins, also called delta-endotoxins. In order to optimize and explain the production of delta-endotoxins of Bacillus thuringiensis kurstaki, we studied seven medium components: soybean meal, starch, KH₂PO₄, K₂HPO₄, FeSO₄, MnSO₄, and MgSO₄and their relationships with the concentration of delta-endotoxins using an experimental design (Plackett-Burman design) and Bayesian networks modelling. The effects of the ingredients of the culture medium on delta-endotoxins production were estimated. The developed model showed that different medium components are important for the Bacillus thuringiensis fermentation. The most important factors influenced the production of delta-endotoxins are FeSO₄, K2HPO₄, starch and soybean meal. Indeed, it was found that soybean meal, K₂HPO₄, KH₂PO₄and starch also showed positive effect on the delta-endotoxins production. However, FeSO4 and MnSO4 expressed opposite effect. The developed model, based on Bayesian techniques, can automatically learn emerging models in data to serve in the prediction of delta-endotoxins concentrations. The constructed model in the present study implies that experimental design (Plackett-Burman design) joined with Bayesian networks method could be used for identification of effect variables on delta-endotoxins variation.

Single session of Nd:YAG laser intracanal irradiation neutralizes endotoxin in dental root dentin

Science.gov (United States)

Archilla, José R. F.; Moreira, Maria S. N. A.; Miyagi, Sueli P. H.; Bombana, Antônio C.; Gutknecht, Norbert; Marques, Márcia M.

2012-11-01

Endotoxins released in the dental root by Gram-negative microorganisms can be neutralized by calcium hydroxide, when this medication is applied inside the root canal for at least seven days. However, several clinical situations demand faster root canal decontamination. Thus, for faster endotoxin neutralization, endodontists are seeking additional treatments. The in vitro study tested whether or not intracanal Nd:YAG laser irradiation would be able to neutralize endotoxin within the human dental root canal in a single session. Twenty-four human teeth with one root were mounted between two chambers. After conventional endodontic treatment, root canals were contaminated with Escherichia coli endotoxin. Then they were irradiated or not (controls) in contact mode with an Nd:YAG laser (1.5 W, 15 Hz, 100 mJ and pulse fluency of 124 J/cm2). The endotoxin activity was measured using the limulus lysate technique and data were statistically compared (p≤0.05). The concentration of active endotoxin measured in the negative control group was significantly lower than that of the positive control group (p=0.04). The concentrations of endotoxin in both irradiated groups were significantly lower than that of the positive control group (p=0.027) and similar to that of negative control group (p=0.20). A single session of intracanal Nd:YAG laser irradiation is able to neutralize endotoxin in the dental root tissues.

Panum's studies on "putrid poison" 1856. An early description of endotoxin

DEFF Research Database (Denmark)

Kolmos, Hans Jørn

2006-01-01

, but insoluble in alcohol, and with preserved activity after long-term boiling. "Putrid poison" has striking similarities with endotoxin, a cell wall product of Gram-negative bacteria and a powerful inducer of inflammation and septic shock. Thanks to Panum's carefully arranged experiments and meticulous...... recording of observations it is fair to conclude that "putrid poison" was endotoxin, and as such he deserves credit for being the first to have described endotoxin. Panum published his observations twice, in Danish in 1856, and in German in 1874. At first he rejected the possibility that bacteria could play...... a causative role in the development of symptoms and signs seen after infusion of "putrid poison". However, in his last publication he hypothesized that "putrid poison" could be a bacterial product, and he envisaged future antibacterial chemotherapy of sepsis and treatment with anti-endotoxin agents....

Dialysate bacterial endotoxin as a prognostic indicator of peritoneal dialysis related peritonitis.

Science.gov (United States)

Szeto, Cheuk-Chun; Lai, Ka-Bik; Chow, Kai-Ming; Kwan, Bonnie Ching-Ha; Law, Man-Ching; Pang, Wing-Fai; Ma, Terry King-Wing; Leung, Chi-Bon; Li, Philip Kam-Tao

2016-12-01

Peritonitis is the major complication of peritoneal dialysis (PD). The aim of our present study is to explore the prognostic value of endotoxin level in PD effluent for the prediction of treatment failure in PD-related peritonitis. We studied 325 peritonitis episodes in 223 patients. PD effluent (PDE) was collected every 5 days for endotoxin level and leukocyte count. Patients were followed for relapsing or recurrent peritonitis. We found 20 episodes (6.2%) had primary treatment failure; 41 (12.6%) developed relapsing, 19 (5.8%) had recurrent, and 22 (6.8%) had repeat episodes. Endotoxin was detectable in the PDE of 19 episodes (24.4%) caused by Gram negative organisms, 4 episodes (6.8%) of mixed bacterial growth, and none of the culture negative episodes or those by Gram positive organisms. For episodes caused by Gram negative bacteria, a detectable endotoxin level in PDE on day 5 had a sensitivity and specificity of 66.7% and 83.3%, respectively, for predicting primary treatment failure. In contrast, PDE leukocyte count > 1000 per mm3 on day 5 had a sensitivity and specificity of 88.9% and 89.1%, respectively; the addition of PDE endotoxin assay did not improve the sensitivity or specificity. We conclude that detectable endotoxin in PDE 5 days after antibiotic therapy might predict primary treatment failure in peritonitis episodes caused by Gram negative organisms. However, the sensitivity and specificity of PDE endotoxin assay was inferior to PDE leukocyte count. © 2016 Asian Pacific Society of Nephrology.

Transepithelial SCFA fluxes link intracellular and extracellular pH regulation of mouse colonocytes.

Science.gov (United States)

Chu, S; Montrose, M H

1997-10-01

We have studied pH regulation in both intracellular and extracellular compartments of mouse colonic crypts, using distal colonic mucosa with intact epithelial architecture. In this work, we question how transepithelial SCFA gradients affect intracellular pH (pHi) and examine interactions between extracellular pH (pHo) and pHi regulation in crypts of distal colonic epithelium from mouse. We studied pH regulation in three adjacent compartments of distal colonic epithelium (crypt lumen, crypt epithelial cell cytosol, and lamina propria) with SNARF-1 (a pH sensitive fluorescent dye), digital imaging microscopy (for pHi), and confocal microscopy (for pHo). Combining results from the three compartments allows us to find how pHi and pHo are regulated and related under the influence of physiological transepithelial SCFA gradients, and develop a better understanding of pH regulation mechanisms in colonic crypts. Results suggest a complex interdependency between SCFA fluxes and pHo values, which can directly affect how strongly SCFAs acidify colonocytes.

Identification of Sources of Endotoxin Exposure as Input for Effective Exposure Control Strategies.

Science.gov (United States)

van Duuren-Stuurman, Birgit; Gröllers-Mulderij, Mariska; van de Runstraat, Annemieke; Duisterwinkel, Anton; Terwoert, Jeroen; Spaan, Suzanne

2018-02-13

Aim of the present study is to investigate the levels of endotoxins on product samples from potatoes, onions, and seeds, representing a relevant part of the agro-food industry in the Netherlands, to gather valuable insights in possibilities for exposure control measures early in the process of industrial processing of these products. Endotoxin levels on 330 products samples from companies representing the potato, onion, and seed (processing) industry (four potato-packaging companies, five potato-processing companies, five onion-packaging companies, and four seed-processing companies) were assessed using the Limulus Amboecyte Lysate (LAL) assay. As variation in growth conditions (type of soil, growth type) and product characteristics (surface roughness, dustiness, size, species) are assumed to influence the level of endotoxin on products, different types, and growth conditions were considered when collecting the samples. Additionally, waste material, rotten products, felt material (used for drying), and process water were collected. A large variation in the endotoxin levels was found on samples of potatoes, onions, and seeds (overall geometric standard deviation 17), in the range between 0.7 EU g-1 to 16400000 EU g-1. The highest geometric mean endotoxin levels were found in plant material (319600 EU g-1), followed by soil material (49100 EU g-1) and the outer side of products (9300 EU g-1), indicating that removal of plant and soil material early in the process would be an effective exposure control strategy. The high levels of endotoxins found in the limited number of samples from rotten onions indicate that these rotten onions should also be removed early in the process. Mean endotoxin levels found in waste material (only available for seed processing) is similar to the level found in soil material, although the range is much larger. On uncleaned seeds, higher endotoxin levels were found than on cleaned seeds, indicating that cleaning processes are important

On the effects of endotoxin in previously irradiated mice and their time relationships. Ueber die Wirkung von Endotoxin auf vorbestrahlte Maeuse in Abhaeengigkeit von der Zeit

Energy Technology Data Exchange (ETDEWEB)

Moenig, H; Oehlert, W [Institut fuer Pathologie, Histologie und Zytologie, Freiburg im Breisgau (Germany); Oehlert, M [Institut fuer Pathologie, Histologie und Zytologie, Freiburg im Breisgau (Germany); Konermann, G [Freiburg Univ. (Germany). Inst. fuer Biophysik und Strahlenbiologie

1993-01-01

Adult mice were subjected to non-lethal wholebody irradiation with doses of 2.5 and 5.0 Gy. Non-irradiated animals served as controls. Following periods varying from one day to one year after irradiation, the animals were once administered endotoxin (LPS from S. abortus equi) using doses of 100, 200 or 400 [mu]g. Twelve to 48 hours following the single administration of endotoxin the animals were sacrificed and examined for changes to the liver, lungs, kidneys, small intestine and stomach. It was confirmed on a histological basis that the causes of death differed between irradiated and non-irradiated animals. The studies have shown that the responsiveness to endotoxin subsequent to irradiation was characterized by considerable fluctuations over time. Histology further provided evidence to prove that regenerative processes were in progress in the liver as well as the intestinal and gastric mucosae, with the number of differentiated cells determined here being lower than that of mitotic cells. To summarize it can be stated that wholebody irradiation with 2.5 Gy to 5 Gy in the course of weeks or months clearly adds to the damage already done by endotoxin. Conversely, irradiation a few days prior to administration of endotoxin provides protection against those damaging influences. (orig./MG)

Immunomodulatory effects of honey cannot be distinguished from endotoxin

DEFF Research Database (Denmark)

Timm, Michael; Bartelt, Stine; Hansen, Erik Wind

2008-01-01

in vitro effects of honey. Our results show that natural honeys induce interleukin-6 release from Mono Mac 6 cells as well as release of reactive oxygen species from all-trans retinoic acid (ATRA) differentiated HL-60 cells. The natural honeys contained substantial amounts of endotoxin, and the responses...... observed in the cell based assays were similar to the responses induced by endotoxin alone. In addition, we determined that the immunomodulatory component present in the natural honeys was retained in the ultra filtrated fraction with a molecular weight greater than 20 kDa. The component was resistant...... to boiling and its immunomodulatory activity could be abrogated by the addition of polymyxin B. We speculate that the observed in vitro immunomodulatory effects of honey might solely be explained by the endotoxin content in the natural honeys....

21 CFR 866.3210 - Endotoxin assay.

Science.gov (United States)

2010-04-01

... DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay. (a... intended for use in conjunction with other laboratory findings and clinical assessment of the patient to...

Gut Endotoxin Leading to a Decline IN Gonadal function (GELDING) - a novel theory for the development of late onset hypogonadism in obese men.

Science.gov (United States)

Tremellen, Kelton

2016-01-01

Obesity is an increasing public health problem, with two-thirds of the adult population in many Western countries now being either overweight or obese. Male obesity is associated with late onset hypogonadism, a condition characterised by decreased serum testosterone, sperm quality plus diminished fertility and quality of life. In this paper we propose a novel theory underlying the development of obesity related hypogonadism- the GELDING theory (Gut Endotoxin Leading to a Decline IN Gonadal function). Several observational studies have previously reported an association between obesity related hypogonadism (low testosterone) and systemic inflammation. However, for the first time we postulate that the trans-mucosal passage of bacterial lipopolysaccharide (LPS) from the gut lumen into the circulation is a key inflammatory trigger underlying male hypogonadism. Obesity and a high fat/high calorie diet are both reported to result in changes to gut bacteria and intestinal wall permeability, leading to the passage of bacterial endotoxin (lipopolysaccharide- LPS) from within the gut lumen into the circulation (metabolic endotoxaemia), where it initiates systemic inflammation. Endotoxin is known to reduce testosterone production by the testis, both by direct inhibition of Leydig cell steroidogenic pathways and indirectly by reducing pituitary LH drive, thereby also leading to a decline in sperm production. In this paper we also highlight the novel evolutionary benefits of the GELDING theory. Testosterone is known to be a powerful immune-suppressive, decreasing a man's ability to fight infection. Therefore we postulate that the male reproductive axis has evolved the capacity to lower testosterone production during times of infection and resulting endotoxin exposure, decreasing the immunosuppressive influence of testosterone, in turn enhancing the ability to fight infection. While this response is adaptive in times of sepsis, it becomes maladaptive in the setting of "non

Origin of endotoxemia influences the metabolic response to endotoxin in dogs

NARCIS (Netherlands)

Moeniralam, H. S.; Bemelman, W. A.; Romijn, J. A.; Endert, E.; Ackermans, M. T.; van Lanschot, J. J.; Hermsen, R. C.; Sauerwein, H. P.

1997-01-01

Different routes of endotoxin administration have been used to mimic inflammatory and metabolic responses observed during sepsis. Because the origin of endotoxemia may affect the reactions to endotoxin, we compared the induction of tumor necrosis factor (TNF), interleukin-6 (IL-6), hormones, and

The role of amoebocytes in endotoxin-mediated coagulation in the innate immunity of Achatina fulica snails.

Science.gov (United States)

Biswas, C; Mandal, C

1999-02-01

Achatina amoebocyte lysate (AAL) derived from amoebocytes of Achatina fulica was activated by Gram-negative bacterial endotoxins in a time-dependent manner resulting in gel formation/coagulation. The activation and maximum proliferation of amoebocytes was observed 40 min after intramuscular injection (20 microg/snail) of endotoxin. Endotoxin-mediated proteolytic activity of AAL towards a serine-protease-specific chromogenic substrate was maximum at pH 8.0, 37 degrees C and within 15 min in a divalent-cation-dependent manner. The AAL activity induced by the endotoxin was directly dependent on the endotoxin concentration, showed a high specificity and saturated at higher endotoxin concentrations. An endotoxin-sensitive factor (ESF) was purified from AAL to apparent homogeneity by single-step affinity chromatography on a heparin-Sepharose 4B column. Native ESF of molecular weight 140 000 was composed of two identical subunits of molecular weight 70 000 attached through non-covalent association. A strong binding to endotoxin (Escherichia coli 055:B5) was exhibited by ESF with a 40-fold higher biological activity than AAL. The ESF was shown to have a unique Phe-Ile active site with regard to its alternate activation by alpha-chymotrypsin instead of endotoxin. The ESF was characterized as a serine protease type as evidenced by potent inhibition with specific inhibitors.

Immunoradiometric assay of lipid A: a test for detecting and quantitating endotoxins of various origins

Energy Technology Data Exchange (ETDEWEB)

Nolan, J P; Vladutiu, A O; Moreno, D M; Cohen, S A; Camara, D S [State University of New York, Buffalo (USA). School of Medicine

1982-11-26

The ability to measure circulating endotoxin in various disease states has been hampered by the lack of a specific and quantitative assay. The test most commonly used has been the Limulus gelation assay, which measures an enzymatic effect of endotoxin rather than the substance itself. Based on a solid-phase immunoradiometric assay previously developed to detect the specific lipopolysaccharide from Escherichia coli 026, a similar assay has been developed for the lipid A moiety of endotoxins. The assay uses rabbit antibodies to lipid A which do not react with ketodeoxyoctonate, myristic or beta-hydroxymyristic acids, and detects lipid A obtained from endotoxins of various origins after acid hydrolysis of lipopolysaccharide. Experiments in rats given exogenous endotoxin suggest that this assay can be useful for quantitation of bacterial endotoxins in serum and for studying the pathophysiology of experimental endotoxemia.

Effects of hepatocyte CD14 upregulation during cholestasis on endotoxin sensitivity.

Directory of Open Access Journals (Sweden)

Ming-Huei Chou

Full Text Available Cholestasis is frequently related to endotoxemia and inflammatory response. Our previous investigation revealed a significant increase in plasma endotoxin and CD14 levels during biliary atresia. We therefore propose that lipopolysacharides (LPS may stimulate CD14 production in liver cells and promote the removal of endotoxins. The aims of this study are to test the hypothesis that CD14 is upregulated by LPS and investigate the pathophysiological role of CD14 production during cholestasis. Using Western blotting, qRT-PCR, and promoter activity assay, we demonstrated that LPS was associated with a significant increase in CD14 and MD2 protein and mRNA expression and CD14 promoter activity in C9 rat hepatocytes but not in the HSC-T6 hepatic stellate cell line in vitro. To correlate CD14 expression and endotoxin sensitivity, in vivo biliary LPS administration was performed on rats two weeks after they were subjected to bile duct ligation (BDL or a sham operation. CD14 expression and endotoxin levels were found to significantly increase after LPS administration in BDL rats. These returned to basal levels after 24 h. In contrast, although endotoxin levels were increased in sham-operated rats given LPS, no increase in CD14 expression was observed. However, mortality within 24 h was more frequent in the BDL animals than in the sham-operated group. In conclusion, cholestasis and LPS stimulation were here found to upregulate hepatic CD14 expression, which may have led to increased endotoxin sensitivity and host proinflammatory reactions, causing organ failure and death in BDL rats.

Pyometra in Bitches Induces Elevated Plasma Endotoxin and Prostaglandin F2α Metabolite Levels

Directory of Open Access Journals (Sweden)

Hagman R

2006-03-01

Full Text Available Endotoxemia in bitches with pyometra can cause severe systemic effects directly or via the release of inflammatory mediators. Plasma endotoxin concentrations were measured in ten bitches suffering from pyometra with moderately to severely deteriorated general condition, and in nine bitches admitted to surgery for non-infectious reasons. Endotoxin samples were taken on five occasions before, during and after surgery. In addition, urine and uterine bacteriology was performed and hematological, blood biochemical parameters, prostaglandin F2α metabolite 15-ketodihydro-PGF2α (PG-metabolite, progesterone and oestradiol (E2-17β levels were analysed. The results confirm significantly increased plasma levels of endotoxin in bitches with pyometra and support previous reports of endotoxin involvement in the pathogenesis of the disease. Plasma concentrations of PG-metabolite were elevated in pyometra bitches and provide a good indicator of endotoxin release since the concentrations were significantly correlated to the endotoxin levels and many other hematological and chemistry parameters. The γ-globulin serum protein electrophoresis fraction and analysis of PG-metabolite can be valuable in the diagnosis of endotoxin involvement if a reliable, rapid and cost-effective test for PG-metabolite analysis becomes readily available in the future. Treatment inhibiting prostaglandin biosynthesis and related compounds could be beneficial for bitches suffering from pyometra.

Inhibiting TNF-α signaling does not attenuate induction of endotoxin tolerance

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Loosbroock C

2014-12-01

Full Text Available Christopher Loosbroock, Kenneth W Hunter Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, NV, USA Abstract: Tumor necrosis factor-alpha (TNF-α is a central mediator of inflammatory responses elicited by Toll-like receptor agonists, such as the Gram-negative bacterial outer membrane antigen lipopolysaccharide (LPS. TNF-α is responsible for altering vascular permeability and activating infiltrating inflammatory cells, such as monocytes and neutrophils. Interestingly, TNF-α has also demonstrated the ability to induce tolerance to subsequent challenges with TNF-α or LPS in monocyte and macrophage cell populations. Tolerance is characterized by the inability to mount a typical inflammatory response during subsequent challenges following the initial exposure to an inflammatory mediator such as LPS. The ability of TNF-α to induce a tolerant-like state with regard to LPS is most likely a regulatory mechanism to prevent excessive inflammation. We hypothesized that the induction of tolerance or the degree of tolerance is dependent upon the production of TNF-α during the primary response to LPS. To investigate TNF-α-dependent tolerance, human monocytic THP-1 cells were treated with TNF-α-neutralizing antibodies or antagonistic TNF-α receptor antibodies before primary LPS stimulation and then monitored for the production of TNF-α during the primary and challenge stimulation. During the primary stimulation, anti-TNF-α treatment effectively attenuated the production of TNF-α and interleukin-1β; however, this reduced production did not impact the induction of endotoxin tolerance. These results demonstrate that interfering with TNF-α signaling attenuates production of inflammatory cytokines without affecting the induction of tolerance. Keywords: endotoxin tolerance, lipopolysaccharide, tumor necrosis factor-alpha, anti-tumor necrosis factor-alpha, THP-1 cells

Endotoxin induction of an inhibitor of plasminogen activator in bovine pulmonary artery endothelial cells

Energy Technology Data Exchange (ETDEWEB)

1986-01-05

The effects of bacterial lipopolysaccharide (endotoxin) on the fibrinolytic activity of bovine pulmonary artery endothelial cells were examined. Endotoxin suppressed the net fibrinolytic activity of cell extracts and conditioned media in a dose-dependent manner. The effects of endotoxin required at least 6 h for expression. Cell extracts and conditioned media contained a 44-kDa urokinase-like plasminogen activator. Media also contained multiple plasminogen activators with molecular masses of 65-75 and 80-100 kDa. Plasminogen activators in extracts and media were unchanged by treatment of cells with endotoxin. Diisopropyl fluorophosphate (DFP)-abolished fibrinolytic activity of extracts and conditioned media. DFP-treated samples from endotoxin-treated but not untreated cells inhibited urokinase and tissue plasminogen activator, but not plasmin. Inhibitory activity was lost by incubation at pH 3 or heating to 56/sup 0/C for 10 min. These treatments did not affect inhibitory activity of fetal bovine serum. Incubation of /sup 125/I-urokinase with DFP-treated medium from endotoxin-treated cells produced an inactive complex with an apparent molecular mass of 80-85 kDa.

The role of endotoxin in the pathogenesis of acute bovine laminitis.

Science.gov (United States)

Boosman, R; Mutsaers, C W; Klarenbeek, A

1991-07-01

To study the possible role of endotoxin in the pathogenesis of bovine laminitis, local and systemic injections of endotoxin (E. coli 0111 B4) with different doses were given to three groups of four cows each. Clinical and haematologic parameters indicated an acute-phase response, including positive plasma ethanol gelation (soluble fibrin), the occurrence of fibrin degradation products and decreased thrombocyte counts. Local Shwartzman reactions were not evoked. Clinical examination of the claws and the gait of the animals revealed no signs of laminitis. However, on histopathological examination of the claw corium signs of laminitis such as vacuolisation of the Stratum basale, lymphocyte and leucocyte infiltration and thrombosis were found. These results indicate that endotoxin indeed may be involved in the pathogenesis of laminitis. For the development of a clinical acute laminitis model in cattle either another dosage, other toxins or factors in addition to the endotoxin used in this experiment are needed.

Endotoxin induced chorioamnionitis prevents intestinal development during gestation in fetal sheep.

Directory of Open Access Journals (Sweden)

Tim G A M Wolfs

Full Text Available Chorioamnionitis is the most significant source of prenatal inflammation and preterm delivery. Prematurity and prenatal inflammation are associated with compromised postnatal developmental outcomes, of the intestinal immune defence, gut barrier function and the vascular system. We developed a sheep model to study how the antenatal development of the gut was affected by gestation and/or by endotoxin induced chorioamnionitis.Chorioamnionitis was induced at different gestational ages (GA. Animals were sacrificed at low GA after 2d or 14d exposure to chorioamnionitis. Long term effects of 30d exposure to chorioamnionitis were studied in near term animals after induction of chorioamnionitis. The cellular distribution of tight junction protein ZO-1 was shown to be underdeveloped at low GA whereas endotoxin induced chorioamnionitis prevented the maturation of tight junctions during later gestation. Endotoxin induced chorioamnionitis did not induce an early (2d inflammatory response in the gut in preterm animals. However, 14d after endotoxin administration preterm animals had increased numbers of T-lymphocytes, myeloperoxidase-positive cells and gammadelta T-cells which lasted till 30d after induction of chorioamnionitis in then near term animals. At early GA, low intestinal TLR-4 and MD-2 mRNA levels were detected which were further down regulated during endotoxin-induced chorioamnionitis. Predisposition to organ injury by ischemia was assessed by the vascular function of third-generation mesenteric arteries. Endotoxin-exposed animals of low GA had increased contractile response to the thromboxane A2 mimetic U46619 and reduced endothelium-dependent relaxation in responses to acetylcholine. The administration of a nitric oxide (NO donor completely restored endothelial dysfunction suggesting reduced NO bioavailability which was not due to low expression of endothelial nitric oxide synthase.Our results indicate that the distribution of the tight

Effects of Puerariae Radix Extract on Endotoxin Receptors and TNF-α Expression Induced by Gut-Derived Endotoxin in Chronic Alcoholic Liver Injury

Directory of Open Access Journals (Sweden)

Jing-Hua Peng

2012-01-01

Full Text Available Kudzu (Pueraria lobata is one of the earliest medicinal plants used to treat alcohol abuse in traditional Chinese medicine for more than a millennium. However, little is known about its effects on chronic alcoholic liver injury. Therefore, the present study observed the effects of puerariae radix extract (RPE on chronic alcoholic liver injury as well as Kupffer cells (KCs activation to release tumor necrosis factor alpha (TNF-α induced by gut-derived endotoxin in rats and macrophage cell line. RPE was observed to alleviate the pathological changes and lipids deposition in liver tissues as well as the serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, and hepatic gamma-glutamyl transpeptidase (GGT activity. Meanwhile, RPE inhibited KCs activation and subsequent hepatic TNF-α expression and downregulated the protein expression of endotoxin receptors, lipopolysaccharide binding protein (LBP, CD14, Toll-like receptor (TLR 2, and TLR4 in chronic alcohol intake rats. Furthermore, an in vitro study showed that RPE inhibited the expression of TNF-α and endotoxin receptors, CD14 and TLR4, induced by LPS in RAW264.7 cells. In summary, this study demonstrated that RPE mitigated liver damage and lipid deposition induced by chronic alcohol intake in rats, as well as TNF-α release, protein expression of endotoxin receptors in vivo or in vitro.

Detection of bacterial endotoxin in food: New planar interdigital sensors based approach

KAUST Repository

Abdul Rahman, Mohd Syaifudin; Mukhopadhyay, Subhas Chandra; Yu, Paklam; Goicoechea, J.; Matias, Ignacio R.; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

2013-01-01

coating thickness on sensor sensitivity, selectivity and stability. Different food samples contaminated with endotoxin were also tested to verify that the interdigital sensing approach is able to be used for endotoxin detection. © 2012 Elsevier Ltd. All

The food contaminant deoxynivalenol, decreases intestinal barrier permeability and reduces claudin expression

International Nuclear Information System (INIS)

Pinton, Philippe; Nougayrede, Jean-Philippe; Del Rio, Juan-Carlos; Moreno, Carolina; Marin, Daniela E.; Ferrier, Laurent; Bracarense, Ana-Paula; Kolf-Clauw, Martine; Oswald, Isabelle P.

2009-01-01

'The gastrointestinal tract represents the first barrier against food contaminants as well as the first target for these toxicants. Deoxynivalenol (DON) is a mycotoxin that commonly contaminates cereals and causes various toxicological effects. Through consumption of contaminated cereals and cereal products, human and pigs are exposed to this mycotoxin. Using in vitro, ex vivo and in vivo approaches, we investigated the effects of DON on the intestinal epithelium. We demonstrated that, in intestinal epithelial cell lines from porcine (IPEC-1) or human (Caco-2) origin, DON decreases trans-epithelial electrical resistance (TEER) and increases in a time and dose-dependent manner the paracellular permeability to 4 kDa dextran and to pathogenic Escherichia coli across intestinal cell monolayers. In pig explants treated with DON, we also observed an increased permeability of intestinal tissue. These alterations of barrier function were associated with a specific reduction in the expression of claudins, which was also seen in vivo in the jejunum of piglets exposed to DON-contaminated feed. In conclusion, DON alters claudin expression and decreases the barrier function of the intestinal epithelium. Considering that high levels of DON may be present in food or feed, consumption of DON-contaminated food/feed may induce intestinal damage and has consequences for human and animal health.

Single-step transepithelial photorefractive keratectomy in myopia and astigmatism: 18-month follow-up.

Science.gov (United States)

Adib-Moghaddam, Soheil; Soleyman-Jahi, Saeed; Salmanian, Bahram; Omidvari, Amir-Houshang; Adili-Aghdam, Fatemeh; Noorizadeh, Farsad; Eslani, Medi

2016-11-01

To evaluate the long-term quantitative and qualitative optical outcomes of 1-step transepithelial photorefractive keratectomy (PRK) to correct myopia and astigmatism. Bina Eye Hospital, Tehran, Iran. Prospective interventional case series. Eyes with myopia with or without astigmatism were evaluated. One-step transepithelial PRK was performed with an aberration-free aspheric optimized profile and the Amaris 500 laser. Eighteen-month follow-up results for refraction, visual acuities, vector analysis, higher-order aberrations, contrast sensitivity, postoperative pain, and haze grade were assessed. The study enrolled 146 eyes (74 patients). At the end of follow-up, 93.84% of eyes had an uncorrected distance visual acuity of 20/20 or better and 97.94% of eyes were within ±0.5 diopter of the targeted spherical refraction. On vector analysis, the mean correction index value was close to 1 and the mean index of success and magnitude of error values were close to 0. The achieved correction vector was on an axis counterclockwise to the axis of the intended correction. Photopic and mesopic contrast sensitivities and ocular and corneal spherical, cylindrical, and corneal coma aberrations significantly improved (all P < .001). A slight amount of trefoil aberration was induced (P < .001, ocular aberration; P < .01, corneal aberration). No eye lost more than 1 line of corrected distance visual acuity. No eye had a haze grade of 2+ degrees or higher throughout the follow-up. Eighteen-month results indicate the efficacy and safety of transepithelial PRK to correct myopia and astigmatism. It improved refraction and quality of vision. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Predictors and respiratory depositions of airborne endotoxin in homes using biomass fuels and LPG gas for cooking.

Science.gov (United States)

Padhi, Bijaya K; Adhikari, Atin; Satapathy, Prakasini; Patra, Alok K; Chandel, Dinesh; Panigrahi, Pinaki

2017-01-01

Recent studies have highlighted the presence of endotoxin in indoor air and its role in respiratory morbidities. Burning of household fuels including unprocessed wood and dried animal dung could be a major source of endotoxin in homes. We measured endotoxin levels in different size fractions of airborne particles (PM10, PM2.5, and PM1), and estimated the deposition of particle-bound endotoxin in the respiratory tract. The study was carried out in homes burning solid biomass fuel (n=35) and LPG (n=35). Sample filters were analyzed for endotoxin and organic carbon (OC) content. Household characteristics including temperature, relative humidity, and carbon dioxide levels were also recorded. Multivariate regression models were used to estimate the contributing factors for airborne endotoxin. Respiratory deposition doses were calculated using a computer-based model. We found a higher endotoxin concentration in PM2.5 fractions of the particle in both LPG (median: 110, interquartile range (IQR) 100-120 EU/m 3 ) and biomass (median: 350, IQR: 315-430 EU/m 3 ) burning homes. In the multivariate-adjusted model, burning of solid biomass fuel (β: 67; 95% CI: 10.5-124) emerged as the most significant predictor followed by OC (β: 4.7; 95% CI: 2.7-6.8), RH (β: 1.6; 95% CI: 0.76-2.4), and PM2.5 (β: 0.45; 95% CI: 0.11-0.78) for airborne endotoxin (P<0.05). We also observed an interaction between PM organic carbon content and household fuel in predicting the endotoxin levels. The model calculations showed that in biomass burning homes, total endotoxin deposition was higher among infants (59%) than in adult males (47%), of which at least 10% of inhaled endotoxin is deposited in the alveolar region of the lung. These results indicate that fine particles are significant contributors to the deposition of endotoxin in the alveolar region of the lung. Considering the paramount role of endotoxin exposure, and the source and timing of exposure on respiratory health, additional

Transepithelial transport of PEGylated anionic poly(amidoamine) dendrimers: implications for oral drug delivery.

Science.gov (United States)

Sweet, Deborah M; Kolhatkar, Rohit B; Ray, Abhijit; Swaan, Peter; Ghandehari, Hamidreza

2009-08-19

The purpose of this work was to assess the impact of PEGylation on transepithelial transport of anionic poly(amidoamine) dendrimers. Cytotoxicity, uptake and transport across Caco-2 cells of PEGylated G3.5 and G4.5 PAMAM dendrimers were studied. Methoxy polyethylene glycol (750 Da) was conjugated to carboxylic acid-terminated PAMAM dendrimers at feed ratios of 1, 2 and 4 PEG per dendrimer. Compared to the control, PEGylation of anionic dendrimers did not significantly alter cytotoxicity up to a concentration of 0.1 mM. PEGylation of G3.5 dendrimers significantly decreased cellular uptake and transepithelial transport while PEGylation of G4.5 dendrimers led to a significant increase in uptake, but also a significant decrease in transport. Dendrimer PEGylation reduced the opening of tight junctions as evidenced by confocal microscopy techniques. Modulation of the tight junctional complex correlated well with changes in PEGylated dendrimer transport and suggests that anionic dendrimers are transported primarily through the paracellular route. PEGylated dendrimers show promise in oral delivery applications where increased functionality for drug conjugation and release is desired.

Actions of four organic acids in radix isatidis on endotoxin-neutralization investigated by kinetic turbidimetric assay.

Science.gov (United States)

Ma, Li; He, Ying-jun; Li, You; Gong, Mu-xin

2012-06-01

To investigate anti-endotoxin action of four OAs reacted with endotoxin by the LAL assay with KTA. Using a incubating kinetic tube reader and kinetic turbidimetric assay (KTA), the concentration-response time curve of endotoxin reacted with limulus amebocyte lysate (LAL) at 37 degrees C were obtained and the action of four organic acids (OAs) on it were investigated. The four OAs were benzoic acid, salicylic acid, syringic acid and 2-amino-benzoic acid from Radix isatidis. Meanwhile, the temperature variation caused by endotoxin with the four OAs was studied by the rabbit pyrogen test (RPT). It was showed that a low concentration (1 mg/mL) of the four OAs had a little effect of anti-endotoxin, and when the concentrations of the four OAs were 30 mg/mL, the endotoxin was neutralized completely. The relationships between the concentrations of endotoxin and the OAs were all linear with correlation coefficients of greater than 0.9995, indicating that the four OAs all had strong anti-endotoxin action, while syringic acid had the strongest action among the four OAs with IC50 of 12.84 mg/mL. The investigations of KTA agreed well with the results obtained by means of RPT.

The role of endotoxin in grain dust-induced lung disease.

Science.gov (United States)

Schwartz, D A; Thorne, P S; Yagla, S J; Burmeister, L F; Olenchock, S A; Watt, J L; Quinn, T J

1995-08-01

To identify the role of endotoxin in grain dust-induced lung disease, we conducted a population-based, cross-sectional investigation among grain handlers and postal workers. The study subjects were selected by randomly sampling all grain facilities and post offices within 100 miles of Iowa City. Our study population consisted of 410 grain workers and 201 postal workers. Grain workers were found to be exposed to higher concentrations of airborne dust (p = 0.0001) and endotoxin (p = 0.0001) when compared with postal workers. Grain workers had a significantly higher prevalence of work-related (cough, phlegm, wheezing, chest tightness, and dyspnea) and chronic (usual cough or phlegm production) respiratory symptoms than postal workers. Moreover, after controlling for age, gender, and cigarette smoking status, work-related respiratory symptoms were strongly associated with the concentration of endotoxin in the bioaerosol in the work setting. The concentration of total dust in the bioaerosol was marginally related to these respiratory problems. After controlling for age, gender, and cigarette smoking status, grain workers were found to have reduced spirometric measures of airflow (FEV1, FEV1/FVC, and FEF25-75) and enhanced airway reactivity to inhaled histamine when compared with postal workers. Although the total dust concentration in the work environment appeared to have little effect on these measures of airflow obstruction, higher concentrations of endotoxin in the bioaerosol were associated with diminished measures of airflow and enhanced bronchial reactivity. Our results indicate that the concentration of endotoxin in the bioaerosol may be particularly important in the development of grain dust-induced lung disease.

Personal exposure to dust and endotoxin in Robusta and Arabica coffee processing factories in Tanzania.

Science.gov (United States)

Sakwari, Gloria; Mamuya, Simon H D; Bråtveit, Magne; Larsson, Lennart; Pehrson, Christina; Moen, Bente E

2013-03-01

Endotoxin exposure associated with organic dust exposure has been studied in several industries. Coffee cherries that are dried directly after harvest may differ in dust and endotoxin emissions to those that are peeled and washed before drying. The aim of this study was to measure personal total dust and endotoxin levels and to evaluate their determinants of exposure in coffee processing factories. Using Sidekick Casella pumps at a flow rate of 2l/min, total dust levels were measured in the workers' breathing zone throughout the shift. Endotoxin was analyzed using the kinetic chromogenic Limulus amebocyte lysate assay. Separate linear mixed-effects models were used to evaluate exposure determinants for dust and endotoxin. Total dust and endotoxin exposure were significantly higher in Robusta than in Arabica coffee factories (geometric mean 3.41 mg/m(3) and 10 800 EU/m(3) versus 2.10 mg/m(3) and 1400 EU/m(3), respectively). Dry pre-processed coffee and differences in work tasks explained 30% of the total variance for total dust and 71% of the variance for endotoxin exposure. High exposure in Robusta processing is associated with the dry pre-processing method used after harvest. Dust and endotoxin exposure is high, in particular when processing dry pre-processed coffee. Minimization of dust emissions and use of efficient dust exhaust systems are important to prevent the development of respiratory system impairment in workers.

A pharmacological modification of pain and epithelial healing in contemporary transepithelial all-surface laser ablation (ASLA

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Aslanides IM

2015-04-01

Full Text Available Ioannis M Aslanides, Vasilis D Selimis, Nikolaos V Bessis, Panagiotis N Georgoudis Emmetropia Mediterranean Eye Institute, Heraklion, Crete, Greece Purpose: We report our experience with the use of the matrix regenerating agent (RGTA Cacicol® after reverse transepithelial all-surface laser ablation (ASLA-SCHWIND to assess the safety, efficacy, pain, and epithelial healing.Methods: Forty eyes of 20 myopic patients were prospectively recruited to a randomized fellow eye study. Patients underwent transepithelial ASLA in both eyes, with one of the eyes randomly assigned to the use of the RGTA Cacicol. Postoperative pain and vision were subjectively assessed with the use of a questionnaire on the operative day, at 24 hours, 48 hours and 72 hours. Epithelial defect area size was measured at 24 hours, 48 hours, and 72 hours. Uncorrected distance visual acuity (UDVA and corrected distance visual acuity (CDVA were assessed at 1 month.Results: Mean UDVA at 1 month was LogMAR 0.028. The epithelial defect area was 10.91 mm2 and 13.28 mm2 at 24 hours and 1.39 mm2 and 1.24 mm2 at 48 hours for treated and nontreated eyes, respectively. Overall, 50% and 65% of treated and nontreated eyes healed by 48 hours. There was no statistically significant difference in the subjective vision between the groups, although vision of patients in the RGTA group was reported to be better. Pain scores were better at 24 hours and 48 hours in the RGTA group but with no statistically significant difference.Conclusion: The use of RGTA Cacicol shows faster epithelial recovery after transepithelial ASLA for myopia. Subjectively reported scores of pain and subjective vision were better in the RGTA group, although the difference was not statistically significant. There seems to be a consensual acceleration of epithelial healing even in eyes that did not receive treatment. There were no adverse events and no incidents of inflammation, delayed healing, or haze. Keywords: matrix

Insoluble glycogen, a metabolizable internal adsorbent, decreases the lethality of endotoxin shock in rats

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S. Sipka

1997-01-01

Full Text Available Insoluble glycogen is an enzymatically modified form of naturally occurring soluble glycogen with a great adsorbing capacity. It can be metabolized by phagocytes to glucose. In this study we used insoluble glycogen intravenously in the experimental endotoxin shock of rats. Wistar male rats were sensitized to endotoxin by Pb acetate. The survival of rats were compared in groups of animals endotoxin shock treated and non-treated with insoluble glycogen. Furthermore, we have determined in vitro the binding capacity of insoluble glycogen for endotoxin, tumour necrosis factor alpha, interleukin-1 and secretable phospholipase A2. Use of 10 mg/kg dose of insoluble glycogen could completely prevent the lethality of shock induced by LD50 quantity of endotoxin in rats. All animals treated survived. Insoluble glycogen is a form of ‘metabolizable internal adsorbents’. It can potentially be used for treatment of septic shock.

Effect of Gliadin on Permeability of Intestinal Biopsy Explants from Celiac Disease Patients and Patients with Non-Celiac Gluten Sensitivity

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Hollon, Justin; Leonard Puppa, Elaine; Greenwald, Bruce; Goldberg, Eric; Guerrerio, Anthony; Fasano, Alessio

2015-01-01

Background: Intestinal exposure to gliadin leads to zonulin upregulation and consequent disassembly of intercellular tight junctions and increased intestinal permeability. We aimed to study response to gliadin exposure, in terms of barrier function and cytokine secretion, using intestinal biopsies obtained from four groups: celiac patients with active disease (ACD), celiac patients in remission (RCD), non-celiac patients with gluten sensitivity (GS) and non-celiac controls (NC). Methods: Ex-vivo human duodenal biopsies were mounted in microsnapwells and luminally incubated with either gliadin or media alone. Changes in transepithelial electrical resistance were monitored over 120 min. Media was subsequently collected and cytokines quantified. Results: Intestinal explants from all groups (ACD (n = 6), RCD (n = 6), GS (n = 6), and NC (n = 5)) demonstrated a greater increase in permeability when exposed to gliadin vs. media alone. The increase in permeability in the ACD group was greater than in the RCD and NC groups. There was a greater increase in permeability in the GS group compared to the RCD group. There was no difference in permeability between the ACD and GS groups, between the RCD and NC groups, or between the NC and GS groups. IL-10 was significantly greater in the media of the NC group compared to the RCD and GS groups. Conclusions: Increased intestinal permeability after gliadin exposure occurs in all individuals. Following gliadin exposure, both patients with gluten sensitivity and those with active celiac disease demonstrate a greater increase in intestinal permeability than celiacs in disease remission. A higher concentration of IL-10 was measured in the media exposed to control explants compared to celiac disease in remission or gluten sensitivity. PMID:25734566

Effect of Gliadin on Permeability of Intestinal Biopsy Explants from Celiac Disease Patients and Patients with Non-Celiac Gluten Sensitivity

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Justin Hollon

2015-02-01

Full Text Available Background: Intestinal exposure to gliadin leads to zonulin upregulation and consequent disassembly of intercellular tight junctions and increased intestinal permeability. We aimed to study response to gliadin exposure, in terms of barrier function and cytokine secretion, using intestinal biopsies obtained from four groups: celiac patients with active disease (ACD, celiac patients in remission (RCD, non-celiac patients with gluten sensitivity (GS and non-celiac controls (NC. Methods: Ex-vivo human duodenal biopsies were mounted in microsnapwells and luminally incubated with either gliadin or media alone. Changes in transepithelial electrical resistance were monitored over 120 min. Media was subsequently collected and cytokines quantified. Results: Intestinal explants from all groups (ACD (n = 6, RCD (n = 6, GS (n = 6, and NC (n = 5 demonstrated a greater increase in permeability when exposed to gliadin vs. media alone. The increase in permeability in the ACD group was greater than in the RCD and NC groups. There was a greater increase in permeability in the GS group compared to the RCD group. There was no difference in permeability between the ACD and GS groups, between the RCD and NC groups, or between the NC and GS groups. IL-10 was significantly greater in the media of the NC group compared to the RCD and GS groups. Conclusions: Increased intestinal permeability after gliadin exposure occurs in all individuals. Following gliadin exposure, both patients with gluten sensitivity and those with active celiac disease demonstrate a greater increase in intestinal permeability than celiacs in disease remission. A higher concentration of IL-10 was measured in the media exposed to control explants compared to celiac disease in remission or gluten sensitivity.

Erythropoietin augments the cytokine response to acute endotoxin-induced inflammation in humans

DEFF Research Database (Denmark)

Hojman, Pernille; Taudorf, Sarah; Lundby, Carsten

2009-01-01

in a human in vivo model of acute systemic low-grade inflammation, we measured circulating inflammatory mediators after intravenous administration of Escherichia coli endotoxin (LPS) bolus injection (0.1 ng/kg of body weight) in young healthy male subjects. The subjects were divided into three groups...... receiving either (1) LPS alone, (2) EPO alone (15,000 IE of rHuEPO) or (3) EPO and LPS. Endotoxin administration alone induced a 3-, 12- and 5-fold increase in plasma concentrations of TNF-alpha, IL-6 and IL-10, respectively, 3h after LPS challenge. When EPO was given prior to a bolus injection...... with endotoxin, the levels of TNF-alpha and IL-6 were enhanced by 5- and 40-fold, respectively, whereas the endotoxin-induced increase in IL-10 response was not influenced by EPO. In contrast to our hypothesis, we find that EPO augments the acute inflammatory effect....

Engineering of dendrimer surfaces to enhance transepithelial transport and reduce cytotoxicity.

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Jevprasesphant, Rachaneekorn; Penny, Jeffrey; Attwood, David; McKeown, Neil B; D'Emanuele, Antony

2003-10-01

To evaluate the cytotoxicity, permeation, and transport mechanisms of PAMAM dendrimers and surface-modified cationic PAMAM dendrimers using monolayers of the human colon adenocarcinoma cell line, Caco-2. Cytotoxicity was determined using the MTT assay. The effect of dendrimers on monolayer integrity was determined from measurements of transepithelial electrical resistance (TEER) and [14C]mannitol apparent permeability coefficient (Papp). The Papp of dendrimers through monolayers was measured in both the apical (A)-to-basolateral (B) and B --> A directions at 4 degrees C and 37 degrees C and also in the presence and absence of ethylenediamine tetraacetic acid (EDTA) and colchicine. The cytotoxicity and permeation of dendrimers increased with both concentration and generation. The cytotoxicity of cationic dendrimers (G2, G3, G4) was greater than that of anionic dendrimers (G2.5, G3.5) but was reduced by conjugation with lauroyl chloride: the least cytotoxic conjugates were those with six attached lauroyl chains. At 37 degrees C the Papp of cationic dendrimers was higher than that of anionic dendrimers and, in general, increased with the number of attached lipid chains. Cationic dendrimers decreased TEER and significantly increased the Papp of mannitol. Modified dendrimers also reduced TEER and caused a more marked increase in the Papp of mannitol. The Papp values of dendrimers and modified dendrimers were higher in the presence of EDTA, lower in the presence of colchicine, and lower at 4 degrees C than at 37 degrees C. The properties of dendrimers may be significantly modified by surface engineering. Conjugation of cationic PAMAM dendrimers with lauroyl chloride decreased their cytotoxicity and increased their permeation through Caco-2 cell monolayers. Both PAMAM dendrimers and lauroyl-PAMAM dendrimer conjugates can cross epithelial monolayers by paracellular and transcellular pathways.

Endotoxin levels correlate positively with a sedentary lifestyle and negatively with highly trained subjects.

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Lira, Fabio S; Rosa, Jose C; Pimentel, Gustavo D; Souza, Hélio A; Caperuto, Erico C; Carnevali, Luiz C; Seelaender, Marília; Damaso, Ana R; Oyama, Lila M; de Mello, Marco T; Santos, Ronaldo V

2010-08-04

A sedentary lifestyle increases the risk of developing cardiovascular disease, obesity, and diabetes. This phenomenon is supported by recent studies suggesting a chronic, low-grade inflammation status. Endotoxin derived from gut flora may be key to the development of inflammation by stimulating the secretion of inflammatory factors. This study aimed to examine plasma inflammatory markers and endotoxin levels in individuals with a sedentary lifestyle and/or in highly trained subjects at rest. Fourteen male subjects (sedentary lifestyle n = 7; highly trained subjects n = 7) were recruited. Blood samples were collected after an overnight fast (approximately 12 h). The plasmatic endotoxin, plasminogen activator inhibitor type-1 (PAI-1), monocyte chemotactic protein-1 (MCP1), ICAM/CD54, VCAM/CD106 and lipid profile levels were determined. Endotoxinemia was lower in the highly trained subject group relative to the sedentary subjects (p < 0.002). In addition, we observed a positive correlation between endotoxin and PAI-1 (r = 0.85, p < 0.0001), endotoxin and total cholesterol (r = 0.65; p < 0.01), endotoxin and LDL-c (r = 0.55; p < 0.049) and endotoxin and TG levels (r = 0.90; p < 0.0001). The plasma levels of MCP-1, ICAM/CD54 and VCAM/CD106 did not differ. These results indicate that a lifestyle associated with high-intensity and high-volume exercise induces favorable changes in chronic low-grade inflammation markers and may reduce the risk for diseases such as obesity, diabetes and cardiovascular diseases.

Long-term interdisciplinary therapy reduces endotoxin level and insulin resistance in obese adolescents.

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Lira, Fábio S; Rosa, Jose C; Pimentel, Gustavo D; Santos, Ronaldo V; Carnier, June; Sanches, Priscila L; de Piano, Aline; de Souza, Claudio T; Tock, Lian; Tufik, Sergio; de Mello, Marco T; Seelaender, Marília; Oller do Nascimento, Claudia M; Oyama, Lila M; Dâmaso, Ana R

2012-09-18

The purpose of the present study was to assess the dietary fat intake, glucose, insulin, Homeostasis model assessment for insulin resistance HOMA-IR, and endotoxin levels and correlate them with adipokine serum concentrations in obese adolescents who had been admitted to long-term interdisciplinary weight-loss therapy. The present study was a longitudinal clinical intervention of interdisciplinary therapy. Adolescents (n = 18, aged 15-19 y) with a body mass index > 95th percentile were admitted and evaluated at baseline and again after 1 year of interdisciplinary therapy. We collected blood samples, and IL-6, adiponectin, and endotoxin concentrations were measured by ELISA. Food intake was measured using 3-day diet records. In addition, we assessed glucose and insulin levels as well as the homeostasis model assessment for insulin resistance (HOMA-IR). The most important finding from the present investigation was that the long-term interdisciplinary lifestyle therapy decreased dietary fat intake and endotoxin levels and improved HOMA-IR. We observed positive correlations between dietary fat intake and endotoxin levels, insulin levels, and the HOMA-IR. In addition, endotoxin levels showed positive correlations with IL-6 levels, insulin levels and the HOMA-IR. Interestingly, we observed a negative correlation between serum adiponectin and both dietary fat intake and endotoxin levels. The present results indicate an association between dietary fat intake and endotoxin level, which was highly correlated with a decreased pro-inflammatory state and an improvement in HOMA-IR. In addition, this benefits effect may be associated with an increased adiponectin level, which suggests that the interdisciplinary therapy was effective in improving inflammatory pathways.

Long-term interdisciplinary therapy reduces endotoxin level and insulin resistance in obese adolescents

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Lira Fábio S

2012-09-01

Full Text Available Abstract Aim The purpose of the present study was to assess the dietary fat intake, glucose, insulin, Homeostasis model assessment for insulin resistance HOMA-IR, and endotoxin levels and correlate them with adipokine serum concentrations in obese adolescents who had been admitted to long-term interdisciplinary weight-loss therapy. Design The present study was a longitudinal clinical intervention of interdisciplinary therapy. Adolescents (n = 18, aged 15–19 y with a body mass index > 95th percentile were admitted and evaluated at baseline and again after 1 year of interdisciplinary therapy. We collected blood samples, and IL-6, adiponectin, and endotoxin concentrations were measured by ELISA. Food intake was measured using 3-day diet records. In addition, we assessed glucose and insulin levels as well as the homeostasis model assessment for insulin resistance (HOMA-IR. Results The most important finding from the present investigation was that the long-term interdisciplinary lifestyle therapy decreased dietary fat intake and endotoxin levels and improved HOMA-IR. We observed positive correlations between dietary fat intake and endotoxin levels, insulin levels, and the HOMA-IR. In addition, endotoxin levels showed positive correlations with IL-6 levels, insulin levels and the HOMA-IR. Interestingly, we observed a negative correlation between serum adiponectin and both dietary fat intake and endotoxin levels. Conclusions The present results indicate an association between dietary fat intake and endotoxin level, which was highly correlated with a decreased pro-inflammatory state and an improvement in HOMA-IR. In addition, this benefits effect may be associated with an increased adiponectin level, which suggests that the interdisciplinary therapy was effective in improving inflammatory pathways.

Growth inhibitory effects of endotoxins from Bacteroides gingivalis and intermedius on human gingival fibroblasts in vitro

International Nuclear Information System (INIS)

Layman, D.L.; Diedrich, D.L.

1987-01-01

Purified endotoxin or lipopolysaccharide from Bacteroides gingivalis and Bacteroides intermedius caused a similar dose-dependent inhibition of growth of cultured human gingival fibroblasts as determined by 3 H-thymidine incorporation and direct cell count. Approximately 200 micrograms/ml endotoxin caused a 50% reduction in 3 H-thymidine uptake of logarithmically growing cells. Inhibition of growth was similar in cultures of fibroblasts derived from either healthy or diseased human gingiva. When examining the change in cell number with time of exposure in culture, the rate of proliferation was significantly suppressed during the logarithmic phase of growth. However, the cells recovered so that the rate of proliferation, although reduced, was sufficient to produce a cell density similar to the control cells with prolonged culture. The endotoxins were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The profiles of the Bacteroides endotoxins were different. B. gingivalis endotoxin showed a wide range of distinct bands indicating a heterogeneous distribution of molecular species. Endotoxin from B. intermedius exhibited a few discrete low molecular weight bands, but the majority of the lipopolysaccharides electrophoresed as a diffuse band of high molecular weight material. The apparent heterogeneity of the two Bacteroides endotoxins and the similarity in growth inhibitory capacity suggest that growth inhibitory effects of these substances cannot be attributed to any polysaccharide species of endotoxin

Mapping the areas sensitive to long-term endotoxin tolerance in the rat brain: a c-fos mRNA study.

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Vallès, Astrid; Martí, Octavi; Armario, Antonio

2005-06-01

We have recently found that a single endotoxin administration to rats reduced the hypothalamic-pituitary-adrenal response to another endotoxin administration 4 weeks later, which may be an example of the well-known phenomenon of endotoxin tolerance. However, the time elapsed between the two doses of endotoxin was long enough to consider the above results as an example of late tolerance, whose mechanisms are poorly characterized. To know if the brain plays a role in this phenomenon and to characterize the putative areas involved, we compared the c-fos mRNA response after a final dose of endotoxin in animals given vehicle or endotoxin 4 weeks before. Endotoxin caused a widespread induction of c-fos mRNA in the brain, similar to that previously reported by other laboratories. Whereas most of the brain areas were not sensitive to the previous experience with endotoxin, a few showed a reduced response in endotoxin-pretreated rats: the parvocellular and magnocellular regions of the paraventricular hypothalamic nucleus, the central amygdala, the lateral division of the bed nucleus and the locus coeruleus. We hypothesize that late tolerance to endotoxin may involve plastic changes in the brain, likely to be located in the central amygdala. The reduced activation of the central amygdala in rats previously treated with endotoxin may, in turn, reduce the activation of other brain areas, including the hypothalamic paraventicular nucleus.

Research on securing no bacteria and nonfeverish property for disposable medical appliances. Inactivation of endotoxin by Co-60 γ ray

International Nuclear Information System (INIS)

Hosobuchi, Kazunari; Tanamoto, Kenichi; Haijima, Yuji.

1996-01-01

The contamination by fever-causing endotoxin has become a large problem in medical treatment field. In the industry manufacturing disposable medical appliances, the method of manufacturing endotoxin-free products is an important subject, and the development of the methods of inactivating and eliminating efficiently endotoxin is desired. As a part of this development, the possibility of inactivating endotoxin with Co-60 γ ray was examined. The sample was the endotoxin originated from E.Coli R3 F653 strain. For the irradiation, the Co-60 γ ray irradiation apparatus of 185 T-Bq in National Institute of Hygienic Sciences was used. The measurement of the activity of endotoxin was carried out by limulus test synthetic substrate method. The activity value of the endotoxin in aqueous solution decreased logarithmically with the increasing irradiation dose, and this decreasing tendency was not affected by the initial concentration of the endotoxin. The experiment of recovering freezing-dried endotoxin from a vial is described. The results of inactivating the endotoxin in dry system by γ ray are reported. (K.I.)

Endotoxin as a cause of aseptic meningitis after radionuclide cisternography

International Nuclear Information System (INIS)

Cooper, J.F.; Harbert, J.C.

1975-01-01

The role of pyrogens in aseptic meningitis after radionuclide cisternography was studied by means of the Limulus test, a sensitive detector of endotoxin. During a 15-month period, 39 reactions associated with cisternography were reported. Ten samples of specific lots of the radioactive drugs implicated in 20 of these reactions were tested and all reacted strongly positive to the Limulus test. The less sensitive rabbit pyrogen test was negative for these preparations when tested on a dose-per-weight basis. Our findings apparently provide clinical evidence for the observation made in animals that endotoxin is at least 1,000 times more toxic intrathecally than intravenously. The data implicate endotoxin contamination as a cause of adverse reactions to radionuclide cisternography. We conclude that the USP pyrogen test is insufficiently sensitive for intrathecal injectables and should be supplemented by the Limulus test. (auth)

Topography-guided transepithelial PRK after intracorneal ring segments implantation and corneal collagen CXL in a three-step procedure for keratoconus.

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Coskunseven, Efekan; Jankov, Mirko R; Grentzelos, Michael A; Plaka, Argyro D; Limnopoulou, Aliki N; Kymionis, George D

2013-01-01

To present the results of topography-guided transepithelial photorefractive keratectomy (PRK) after intracorneal ring segments implantation followed by corneal collagen cross-linking (CXL) for keratoconus. In this prospective case series, 10 patients (16 eyes) with progressive keratoconus were included. All patients underwent topography-guided transepithelial PRK after Keraring intracorneal ring segments (Mediphacos Ltda) implantation, followed by CXL treatment. The follow-up period was 6 months after the last procedure for all patients. Time interval between both intracorneal ring segments implantation and CXL and between CXL and topography-guided transepithelial PRK was 6 months. LogMAR mean uncorrected distance visual acuity and mean corrected distance visual acuity were significantly improved (PPRK with intracorneal ring segments implantation and CXL in a three-step procedure seems to be an effective, promising treatment sequence offering patients a functional visual acuity and ceasing progression of the ectatic disorder. A longer follow-up and larger case series are necessary to thoroughly evaluate safety, stability, and efficacy of this innovative procedure. Copyright 2013, SLACK Incorporated.

Transepithelial resistance and claudin expression in trout RTgill-W1 cell line

DEFF Research Database (Denmark)

T. Trubitt, Rebecca; Rabeneck, D. Brett; Bujak, Joanna

2015-01-01

In the present study, we examined the trout gill cell line RTgill-W1 as a possible tool for in vitro investigation of epithelial gill function in fish. After seeding in transwells, transepithelial resistance (TER) increased until reaching a plateau after 1–2 days (20–80 Ω⋅cm2), which was then mai......In the present study, we examined the trout gill cell line RTgill-W1 as a possible tool for in vitro investigation of epithelial gill function in fish. After seeding in transwells, transepithelial resistance (TER) increased until reaching a plateau after 1–2 days (20–80 Ω⋅cm2), which...... was then maintained for more than 6 days. Tetrabromocinnamic acid, a known stimulator of TER via casein kinase II inhibition, elevated TER in the cell line to 125% of control values after 2 and 6 h. Treatment with ethylenediaminetetraacetic acid induced a decrease in TER to b15% of pre-treatment level. Cortisol...... detected Cldn-10e and Cldn-30 immunoreactive proteins of expected molecular weight in samples from rainbow trout gills but not from RTgill-W1 cultures, possibly due to low expression levels. Collectively, these results show that the RTgill-W1 cell layers have tight junctions between cells, are sensitive...

G5 PAMAM dendrimer versus liposome: a comparison study on the in vitro transepithelial transport and in vivo oral absorption of simvastatin.

Science.gov (United States)

Qi, Rong; Zhang, Heran; Xu, Lu; Shen, Wenwen; Chen, Cong; Wang, Chao; Cao, Yini; Wang, Yunan; van Dongen, Mallory A; He, Bing; Wang, Siling; Liu, George; Banaszak Holl, Mark M; Zhang, Qiang

2015-07-01

This study compared formulation effects of a dendrimer and a liposome preparation on the water solubility, transepithelial transport, and oral bioavailability of simvastatin (SMV). Amine-terminated G5 PAMAM dendrimer (G5-NH2) was chosen to form SMV/G5-NH2 molecular complexes, and SMV-liposomes were prepared by using a thin film dispersion method. The effects of these preparations on the transepithelial transport were investigated in vitro using Caco-2 cell monolayers. Results indicated that the solubility and transepithelial transport of SMV were significantly improved by both formulations. Pharmacokinetic studies in rats also revealed that both the SMV/G5-NH2 molecular complexes and the SMV-liposomes significantly improved the oral bioavailability of SMV with the liposomes being more effective than the G5-NH2. The overall better oral absorption of SMV-liposomes as compared to SMV/G5-NH2 molecular complexes appeared to arise from better liposomal solubilization and encapsulation of SMV and more efficient intracellular SMV delivery. Various carrier systems have been designed to enhance drug delivery via the oral route. In this study, the authors compared G5 PAMAM dendrimers to liposome preparations in terms of solubility, transepithelial transport, and oral bioavailability of this poorly water-soluble drug. This understanding has improved our knowledge in the further development of drug carrier systems. Copyright © 2015 Elsevier Inc. All rights reserved.

Kinetics of the disappearance of Cr/sup 51/-labelled endotoxin from the circulation in domestic hens

Energy Technology Data Exchange (ETDEWEB)

Malwinska, K

1974-01-01

The clearance rate of Cr/sup 51/-labelled S. gallinarum endotoxin from the circulation of the hen was investigated. The relationship between the dose of endotoxin and the disappearance rate or radioactivity from the blood was observed. It was noted that radioactivity in the blood decreased faster after injection of 5 mg of endotoxin than after administration of 10 mg. These differences were most pronounced during the first hour of observation and diminished later. Blood radioactivity of Cr/sup 51/Cl/sub 3/ was disappearing slower than that of labelled endotoxin. 17 references, 1 figure.

Connexin 26-mediated gap junctional intercellular communication suppresses paracellular permeability of human intestinal epithelial cell monolayers

International Nuclear Information System (INIS)

Morita, Hidekazu; Katsuno, Tatsuro; Hoshimoto, Aihiro; Hirano, Noriaki; Saito, Yasushi; Suzuki, Yasuo

2004-01-01

In some cell types, gap junctional intercellular communication (GJIC) is associated with tight junctions. The present study was performed to determine the roles of GJIC in regulation of the barrier function of tight junctions. Caco-2 human colonic cells were used as a monolayer model, and barrier function was monitored by measuring mannitol permeability and transepithelial electrical resistance (TER). The monolayers were chemically disrupted by treatment with oleic acid and taurocholic acid. Western blotting analyses were performed to evaluate the protein levels of connexins, which are components of gap junctional intercellular channels. Cx26 expression was detected in preconfluent Caco-2 cells, and its level increased gradually after the monolayer reached confluency. These results prompted us to examine whether overexpression of Cx26 affects barrier function. Monolayers of Caco-2 cells stably expressing Cx26 showed significantly lower mannitol permeability and higher TER than mock transfectants when the monolayers were chemically disrupted. The levels of claudin-4, an important component of tight junctions, were significantly increased in the stable Cx26 transfectant. These results suggest that Cx26-mediated GJIC may play a crucial role in enhancing the barrier function of Caco-2 cell monolayers

Allergen specific responses in cord and adult blood are differentially modulated in the presence of endotoxins

DEFF Research Database (Denmark)

Eiwegger, T.; Mayer, E.; Pedersen, Susanne Brix

2008-01-01

Background Endotoxins are common contaminants in allergen preparations and affect antigen-specific cellular responses. Distinct effects of endotoxin on cells in human umbilical cord and adult blood are poorly defined. Objectives To examine the effect of endotoxins in allergen preparations...... on cellular responses in human cord and peripheral blood (PB). Methods The endotoxin content in beta lactoglobulin (BLG), the peanut allergen Ara h 1 and the major birch pollen allergen Bet v 1 was assessed. Proliferation and cytokine response of mononuclear cells towards contaminated and lipopolysaccharide....... Results The proliferative response of cord blood (CB)-derived mononuclear cells towards allergen-preparations at day 3 was related to the level of LPS contamination. At day 7, proliferation was also detected in the absence of endotoxin. Cytokine production in CB was strongly affected by the content...

Comparison of endotoxin levels found in primary and secondary endodontic infections.

Science.gov (United States)

Gomes, Brenda P F A; Endo, Marcos S; Martinho, Frederico C

2012-08-01

This clinical study was conducted to compare the levels of endotoxins (lipopolysaccharides [LPSs]) found in primary and secondary endodontic infections with apical periodontitis by correlating LPS contents with clinical/radiographic findings. In addition, the presence of target gram-negative anaerobic bacteria was also investigated. Samples were taken from 15 root canals with primary infections and 15 with secondary infections by using paper points. The limulus amebocyte lysate assay was used to quantify endotoxins, and the polymerase chain reaction technique (16S rDNA) was used for bacterial investigation. Endotoxins were detected in 100% of the root canal samples collected from primary (15/15) and secondary (15/15) infections with median values of 7.49 EU/mL and 3.96 EU/mL, respectively (P asymptomatic teeth with primary infections (P 3 mm) (P < .05). Prevotella nigrescens (10/15, 4/15), Fusobacterium nucleatum (5/15, 1/15), Treponema denticola (3/15, 1/15), and Treponema socranskii (5/15, 1/15) were detected in teeth with primary and secondary infections, respectively. P. endodontalis was present only in teeth with primary infections (5/15). Teeth with primary endodontic infections had higher contents of endotoxins and a more complex gram-negative bacterial community than teeth with secondary infections. Moreover, the levels of endotoxins were related to the severity of bone destruction in periapical tissues as well as the development of clinical features in teeth with primary infections. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Sensitisation to common allergens and respiratory symptoms in endotoxin exposed workers: a pooled analysis.

Science.gov (United States)

Basinas, Ioannis; Schlünssen, Vivi; Heederik, Dick; Sigsgaard, Torben; Smit, Lidwien A M; Samadi, Sadegh; Omland, Oyvind; Hjort, Charlotte; Madsen, Anne Mette; Skov, Simon; Wouters, Inge M

2012-02-01

To test the hypotheses that current endotoxin exposure is inversely associated with allergic sensitisation and positively associated with non-allergic respiratory diseases in four occupationally exposed populations using a standardised analytical approach. Data were pooled from four epidemiological studies including 3883 Dutch and Danish employees in veterinary medicine, agriculture and power plants using biofuel. Endotoxin exposure was estimated by quantitative job-exposure matrices specific for the study populations. Dose-response relationships between exposure, IgE-mediated sensitisation to common allergens and self-reported health symptoms were assessed using logistic regression and generalised additive modelling. Adjustments were made for study, age, sex, atopic predisposition, smoking habit and farm childhood. Heterogeneity was assessed by analysis stratified by study. Current endotoxin exposure was dose-dependently associated with a reduced prevalence of allergic sensitisation (ORs of 0.92, 0.81 and 0.66 for low mediate, high mediate and high exposure) and hay fever (ORs of 1.16, 0.81 and 0.58). Endotoxin exposure was a risk factor for organic dust toxic syndrome, and levels above 100 EU/m(3) significantly increased the risk of chronic bronchitis (pOccupational endotoxin exposure has a protective effect on allergic sensitisation and hay fever but increases the risk for organic dust toxic syndrome and chronic bronchitis. Endotoxin's protective effects are most clearly observed among agricultural workers.

Effects of endotoxin exposure on childhood asthma risk are modified by a genetic polymorphism in ACAA1

Directory of Open Access Journals (Sweden)

Sordillo Joanne E

2011-12-01

Full Text Available Abstract Background Polymorphisms in the endotoxin-mediated TLR4 pathway genes have been associated with asthma and atopy. We aimed to examine how genetic polymorphisms in innate immunity pathways interact with endotoxin to influence asthma risk in children. Methods In a previous analysis of 372 children from the Boston Home Allergens and the Connecticut Childhood Asthma studies, 7 SNPs in 6 genes (CARD15, TGFB1, LY96, ACAA1, DEFB1 and IFNG involved in innate immune pathways were associated with asthma, and 5 SNPs in 3 genes (CD80, STAT4, IRAK2 were associated with eczema. We tested these SNPs for interaction with early life endotoxin exposure (n = 291, in models for asthma and eczema by age 6. Results We found a significant interaction between endotoxin and a SNP (rs156265 in ACAA1 (p = 0.0013 for interaction. Increased endotoxin exposure (by quartile showed protective effects for asthma in individuals with at least one copy of the minor allele (OR = 0.39 per quartile increase in endotoxin, 95% CI 0.15 to 1.01. Endotoxin exposure did not reduce the risk of asthma in children homozygous for the major allele. Conclusion Our findings suggest that protective effects of endotoxin exposure on asthma may vary depending upon the presence or absence of a polymorphism in ACAA1.

Epithelial Permeability Alterations in an In Vitro Air-Liquid Interface Model of Allergic Fungal Rhinosinusitis

Science.gov (United States)

Den Beste, Kyle A.; Hoddeson, Elizabeth K.; Parkos, Charles A.; Nusrat, Asma; Wise, Sarah K.

2012-01-01

Background Chronic rhinosinusitis (CRS) is an inflammatory upper-airway disease with numerous etiologies. Patients with a characteristic subtype of CRS, allergic fungal rhinosinusitis (AFRS), display increased expression of Th2 cytokines and antigen-specific IgE. Various sinonasal inflammatory conditions are associated with alterations in epithelial barrier function. The aim of this study was to compare epithelial permeability and intercellular junctional protein expression amongst cultured primary sinonasal cells from AFRS patients versus non-inflammatory controls. Methods Epithelial cells isolated from paranasal sinus mucosa of AFRS and non-inflammatory control patients were grown to confluence on permeable supports and transitioned to air-liquid interface (ALI). Trans-epithelial resistance (TER) was measured with a horizontal Ussing chamber to characterize the functional permeability of each cell type. After TER recordings were complete, a panel of intercellular junctional proteins was assessed by Western blot and immunofluorescence labeling followed by confocal microscopy. Results After 12 samples were measured from each group, we observed a 41% mean decrease in TER in AFRS cells (296±89 ohms × cm2) compared to control (503±134 ohms × cm2, P=0.006). TER deficits observed in AFRS were associated with decreased expression of the tight junction proteins occludin and Junctional Adhesion Molecule-A (JAM-A), and increased expression of a leaky tight junction protein claudin-2. Conclusions Cultured sinonasal epithelium from AFRS patients displayed increased epithelial permeability and altered expression of intercellular junctional proteins. Given that these cells were not incubated with inflammatory cytokines in vitro, the cultured AFRS epithelial alterations may represent a retained modification in protein expression from the in vivo phenotype. PMID:22927233

Transepithelial Transport of Curcumin in Caco-2 Cells Is significantly Enhanced by Micellar Solubilisation.

Science.gov (United States)

Frank, Jan; Schiborr, Christina; Kocher, Alexa; Meins, Jürgen; Behnam, Dariush; Schubert-Zsilavecz, Manfred; Abdel-Tawab, Mona

2017-03-01

Curcumin, the active constituent of Curcuma longa L. (family Zingiberaceae), has gained increasing interest because of its anti-cancer, anti-inflammatory, anti-diabetic, and anti-rheumatic properties associated with good tolerability and safety up to very high doses of 12 g. Nanoscaled micellar formulations on the base of Tween 80 represent a promising strategy to overcome its low oral bioavailability. We therefore aimed to investigate the uptake and transepithelial transport of native curcumin (CUR) vs. a nanoscaled micellar formulation (Sol-CUR) in a Caco-2 cell model. Sol-CUR afforded a higher flux than CUR (39.23 vs. 4.98 μg min -1  cm -2 , respectively). This resulted in a higher P app value of 2.11 × 10 -6  cm/s for Sol-CUR compared to a P app value of 0.56 × 10 -6  cm/s for CUR. Accordingly a nearly 9.5 fold higher amount of curcumin was detected on the basolateral side at the end of the transport experiments after 180 min with Sol-CUR compared to CUR. The determined 3.8-fold improvement in the permeability of curcumin is in agreement with an up to 185-fold increase in the AUC of curcumin observed in humans following the oral administration of the nanoscaled micellar formulation compared to native curcumin. The present study demonstrates that the enhanced oral bioavailability of micellar curcumin formulations is likely a result of enhanced absorption into and increased transport through small intestinal epithelial cells.

Experimental study of 『PERSICAE SEMEN』 on the blood injected by Endotoxin in rats

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Chang-Keun

2005-06-01

Full Text Available This study was performed to investigate the effects of 「Persicae Semen」(PS on the blood injected by Endotoxin in rats. The blood was induced by Endotoxin injection into the caudal vein of rats and PS group taken a measurement of RBC, Hb, Hct, Platelet, WBC, ESR, CRP. The results were obtained as follows: 1. RBC, Hb, Hct, Platelet, WBC were increased with statistical significance at PS group as compared with those of the control group. 2. ESR, CRP were decreased with statistical significance at PS group as compared with those of the control group. It is concluded that PS group has significant effects on the blood injected by Endotoxin in rats. Therefore, PS group seems to be applicable to the diseases related to Endotoxin in clinics.

Endotoxin testing of proteins for parenteral administration using the Mono Mac 6 assay

DEFF Research Database (Denmark)

Moesby, Lise; Hansen, E W; Christensen, J D

2000-01-01

Pharmaceutical products containing proteins cause problems in testing for endotoxin and pyrogens. Many proteins interfere with the LAL test and the proteins are immunogenic in rabbits. The monocytic cell line Mono Mac 6 is an alternative assay for detection of endotoxin and other pyrogens....

Endotoxin and dust at respirable and nonrespirable particle sizes are not consistent between cage- and floor-housed poultry operations.

Science.gov (United States)

Kirychuk, Shelley P; Reynolds, Stephen J; Koehncke, Niels K; Lawson, Joshua; Willson, Philip; Senthilselvan, Ambikaipakan; Marciniuk, Darcy; Classen, Henry L; Crowe, Trever; Just, Natasha; Schneberger, David; Dosman, James A

2010-10-01

Individuals engaged in work in intensive animal houses experience some of the highest rates of occupationally related respiratory symptoms. Organic dust and in particular endotoxin has been most closely associated with respiratory symptoms and lung function changes in workers. It has previously been shown that for intensive poultry operations, type of poultry housing [cage-housed (CH) versus floor-housed (FH)] can influence the levels of environmental contaminants. The goal of the study was to determine the differences in endotoxin and dust levels at different size fractions between CH and FH poultry operations. Fifteen CH and 15 FH poultry operations were sampled for stationary measurements (area) of dust and associated endotoxin. Fractioned samples were collected utilizing Marple cascade impactors. Gravimetric and endotoxin analysis were conducted on each of the filters. When assessed by individual Marple stage, there was significantly greater airborne endotoxin concentration (endotoxin units per cubic meter) in the size fraction >9.8 μm for the FH operations whereas at the size fraction 1.6-3.5 μm, the CH operations had significantly greater airborne endotoxin concentration than the FH operations. Endotoxin concentration in the dust mass (endotoxin units per milligram) was significantly greater in the CH operations as compared to the FH operations for all size fractions >1.6 μm. As such, endotoxin in the respirable fraction accounted for 24% of the total endotoxin in the CH operations whereas it accounted for only 11% in the FH operations. There was significantly more dust in all size fractions in the FH operations as compared to the CH poultry operations. There is more endotoxin in the presence of significantly lower dust levels in the respirable particle size fractions in CH poultry operations as compared to the FH poultry operations. This difference in respirable endotoxin may be important in relation to the differential respiratory response experienced by

Determination of bacterial endotoxin (pyrogen) in radiopharmaceuticals by the gel clot method. Validation

International Nuclear Information System (INIS)

Fukumori, Neuza Taeko Okasaki

2008-01-01

Before the Limulus amebocyte lysate (LAL) test, the only available means of pirogenicity testing for parenteral drugs and medical devices was the United States Pharmacopoeia (USP) rabbit pyrogen test. Especially for radiopharmaceuticals, the LAL assay is the elective way to determine bacterial endotoxin. The aim of this work was to validate the gel clot method for some radiopharmaceuticals without measurable interference. The FDA's LALTest guideline defines interference as a condition that causes a significant difference between the endpoints of a positive water control and positive product control series using a standard endotoxin. Experiments were performed in accordance to the USP bacterial endotoxins test in the 131 I- m-iodobenzylguanidine; the radioisotopes Gallium-67 and Thallium-201; the lyophilized reagents DTPA, Phytate, GHA, HSA and Colloidal Tin. The Maximum Valid Dilution (MVD) was calculated for each product based upon the clinical dose of the material and a twofold serial dilution below the MVD was performed in duplicate to detect interferences. The labeled sensitivity of the used LAL reagent was 0.125 EU mL -1 (Endotoxin Units per milliliter). For validation, a dilution series was performed, a twofold dilution of control standard endotoxin (CSE) from 0.5 to 0.03 EU mL -1 , to confirm the labeled sensitivity of the LAL reagent being tested in sterile and non pyrogenic water, in quadruplicate. The same dilution series was performed with the CSE and the product in the 1:100 dilution factor, in three consecutive batches of each radiopharmaceutical. The products 131 I-m-iodobenzylguanidine, Gallium-67, Thallium-201, DTPA, HSA and Colloidal Tin were found compatible with the LAL test at a 1:100 dilution factor. Phytate and GHA showed some interference in the gel clot test. Other techniques to determine endotoxins as the chromogenic (color development) and the turbidimetric test (turbidity development), were also assessed to get valuable quantitative and

Intestinal Endotoxins as Co-Factors of Liver Injury in Obstructive Jaundice

OpenAIRE

Menteş, B. Bülent; Tatlicioğlu, Ertan; Akyol, Gülen; Uluoğlu, Ömer; Sultan, Nedim; Yilmaz, Erdal; Çelebi, Murat; Taneri, Ferit; Ferahköşe, Zafer

1996-01-01

The concept of endotoxin-mediated rather than direct liver injury in biliary obsruction was investigated using the experimental rat model of bile duct ligation (BDL) and small bowel bacterial overgrowth (SBBO). Small identical doses of intravenous endotoxin (bacterial LPS) caused a significantly more severe liver injury in rats with BDL, compared with sham-operated rats, suggesting the possible contribution of LPS in this type of liver damage. BDL was then combined with surgica...

Transepithelial transport and toxicity of PAMAM dendrimers: implications for oral drug delivery.

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Sadekar, S; Ghandehari, H

2012-05-01

This article summarizes efforts to evaluate poly(amido amine) (PAMAM) dendrimers as carriers for oral drug delivery. Specifically, the effect of PAMAM generation, surface charge and surface modification on toxicity, cellular uptake and transepithelial transport is discussed. Studies on Caco-2 monolayers, as models of intestinal epithelial barrier, show that by engineering surface chemistry of PAMAM dendrimers, it is possible to minimize toxicity while maximizing transepithelial transport. It has been demonstrated that PAMAM dendrimers are transported by a combination of paracellular and transcellular routes. Depending on surface chemistry, PAMAM dendrimers can open the tight junctions of epithelial barriers. This tight junction opening is in part mediated by internalization of the dendrimers. Transcellular transport of PAMAM dendrimers is mediated by a variety of endocytic mechanisms. Attachment or complexation of cytotoxic agents to PAMAM dendrimers enhances the transport of such drugs across epithelial barriers. A remaining challenge is the design and development of linker chemistries that are stable in the gastrointestinal tract (GIT) and the blood stream, but amenable to cleavage at the target site of action. Recent efforts have focused on the use of PAMAM dendrimers as penetration enhancers. Detailed in vivo oral bioavailability of PAMAM dendrimer-drug conjugates, as a function of physicochemical properties will further need to be assessed. Copyright © 2011 Elsevier B.V. All rights reserved.

Characteristics of Endotoxin-Altering Fractions Derived from Normal Serum III. Isolation and Properties of Horse Serum alpha(2)-Macroglobulin.

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Yoshioka, M; Konno, S

1970-05-01

The endotoxin-altering activity of fractions isolated from normal horse serum was examined by incubation of Salmonella typhosa strain 0-901 endotoxin (Boivin) in a solution of the fraction, and subsequent quantitation of any diminution in the capacity of endotoxin to be precipitated by specific anti-endotoxin antiserum. The horse serum fraction isolated by precipitation with ammonium sulfate at a concentration between 1.6 and 2.7 m was incubated with Pronase PA and then with trypsin. When this partly digested fraction was passed twice through a Sephadex G-200 column and eluted with 0.2 m tris(hydroxymethyl)aminomethane buffer, most of the endotoxinaltering activity was found in the first protein peak designated F-1a. F-1a was found to be homogeneous and corresponded to an alpha(2)-macroglobulin by the techniques of electrophoresis, immunodiffusion, and ultracentrifugation. Approximately 100-fold more F-1a than endotoxin was needed to reduce the antigenicity of the endotoxin by one-half. Alteration was increased when F-1a was incubated with the endotoxin at acid pH or at 45 C rather than at 37 C and was lost after heating F-1a at 56 C for 30 min. N-ethylmaleimide increased the endotoxin-altering activity of horse serum, F-1a, and human plasma fraction III(0), whereas p-chloromercuribenzoate did not. On the other hand, diazonium-1-H-tetrazole, iodoacetic acid, and benzylchloride suppressed the activity of F-1a. When the interaction of endotoxin and F-1a was examined by immunodiffusion techniques, depolymerization of the endotoxin molecule was indicated. The endotoxin-altering factor of horse serum is discussed in relation to the mechanisms of other known reagents, such as deoxycholate and sodium lauryl sulfate.

Characteristics of Endotoxin-Altering Fractions Derived from Normal Serum III. Isolation and Properties of Horse Serum α2-Macroglobulin

Science.gov (United States)

Yoshioka, Morimasa; Konno, Seishi

1970-01-01

The endotoxin-altering activity of fractions isolated from normal horse serum was examined by incubation of Salmonella typhosa strain 0-901 endotoxin (Boivin) in a solution of the fraction, and subsequent quantitation of any diminution in the capacity of endotoxin to be precipitated by specific anti-endotoxin antiserum. The horse serum fraction isolated by precipitation with ammonium sulfate at a concentration between 1.6 and 2.7 m was incubated with Pronase PA and then with trypsin. When this partly digested fraction was passed twice through a Sephadex G-200 column and eluted with 0.2 m tris(hydroxymethyl)aminomethane buffer, most of the endotoxinaltering activity was found in the first protein peak designated F-1a. F-1a was found to be homogeneous and corresponded to an α2-macroglobulin by the techniques of electrophoresis, immunodiffusion, and ultracentrifugation. Approximately 100-fold more F-1a than endotoxin was needed to reduce the antigenicity of the endotoxin by one-half. Alteration was increased when F-1a was incubated with the endotoxin at acid pH or at 45 C rather than at 37 C and was lost after heating F-1a at 56 C for 30 min. N-ethylmaleimide increased the endotoxin-altering activity of horse serum, F-1a, and human plasma fraction III0, whereas p-chloromercuribenzoate did not. On the other hand, diazonium-1-H-tetrazole, iodoacetic acid, and benzylchloride suppressed the activity of F-1a. When the interaction of endotoxin and F-1a was examined by immunodiffusion techniques, depolymerization of the endotoxin molecule was indicated. The endotoxin-altering factor of horse serum is discussed in relation to the mechanisms of other known reagents, such as deoxycholate and sodium lauryl sulfate. Images PMID:16557754

Exposure to airborne microorganisms and endotoxin in herb processing plants.

Science.gov (United States)

Dutkiewicz, J; Krysińska-Traczyk, E; Skórska, C; Sitkowska, J; Prazmo, Z; Golec, M

2001-01-01

Microbiological air sampling was performed in two herb processing plants located in eastern Poland. Air samples for determination of the levels of bacteria, fungi, dust and endotoxin were collected at 14 sites during cleaning, cutting, grinding, sieving, sorting and packing of 11 kinds of herbs (nettle, caraway, birch, celandine, marjoram, mint, peppermint, sage, St. John's wort, calamus, yarrow), used for production of medications, cosmetics and spices. It was found that processing of herbs was associated with a very high pollution of the air with bacteria, fungi, dust and endotoxin. The numbers of microorganisms (bacteria and fungi) in the air of herb processing plants ranged within 40.6-627.4 x 10(3) cfu/m3 (mean +/- S.D = 231.4 +/- 181.0 x 10(3) cfu/m3). The greatest concentrations were noted at the initial stages of production cycle, during cleaning, cutting and grinding of herbs. The numbers of airborne microorganisms were also significantly (pnettle, yarrow and mint. The values of the respirable fraction of airborne microflora in the examined facilities varied within a fairly wide range and were between 14.7-67.7%. The dominant microorganisms in the air of herb processing plants were mesophilic bacteria, among which endospore-forming bacilli (Bacillus spp.) and actinomycetes of the species Streptomyces albus were most numerous. Among Gram-negative bacteria, the most common was endotoxin-producing species Alcaligenes faecalis. Altogether, 37 species or genera of bacteria and 23 species or genera of fungi were identified in the air of herb processing plants, of these, 11 and 10 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of dust and bacterial endotoxin in the air of herb processing plants were large with extremely high levels at some sampling sites. The concentrations of airborne dust ranged within 3.2-946.0 mg/m3 (median 18.1 mg/m3), exceeding at 13 out of 14 sampling sites the Polish OEL

An Endotoxin Tolerance Signature Predicts Sepsis and Organ Dysfunction at Initial Clinical Presentation

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Olga M. Pena

2014-11-01

Interpretation: Our data support an updated model of sepsis pathogenesis in which endotoxin tolerance-mediated immune dysfunction (cellular reprogramming is present throughout the clinical course of disease and related to disease severity. Thus endotoxin tolerance might offer new insights guiding the development of new therapies and diagnostics for early sepsis.

Theoretical analyses of the refractive implications of transepithelial PRK ablations.

Science.gov (United States)

Arba Mosquera, Samuel; Awwad, Shady T

2013-07-01

To analyse the refractive implications of single-step, transepithelial photorefractive keratectomy (TransPRK) ablations. A simulation for quantifying the refractive implications of TransPRK ablations has been developed. The simulation includes a simple modelling of corneal epithelial profiles, epithelial ablation profiles as well as refractive ablation profiles, and allows the analytical quantification of the refractive implications of TransPRK in terms of wasted tissue, achieved optical zone (OZ) and induced refractive error. Wasted tissue occurs whenever the actual corneal epithelial profile is thinner than the applied epithelial ablation profile, achieved OZ is reduced whenever the actual corneal epithelial profile is thicker than the applied epithelial ablation profile and additional refractive errors are induced whenever the actual difference centre-to-periphery in the corneal epithelial profile deviates from the difference in the applied epithelial ablation profile. The refractive implications of TransPRK ablations can be quantified using simple theoretical simulations. These implications can be wasted tissue (∼14 µm, if the corneal epithelial profile is thinner than the ablated one), reduced OZ (if the corneal epithelial profile is thicker than ablated one, very severe for low corrections) and additional refractive errors (∼0.66 D, if the centre-to-periphery progression of the corneal epithelial profile deviates from the progression of the ablated one). When TransPRK profiles are applied to normal, not previously treated, non-pathologic corneas, no specific refractive implications associated to the transepithelial profile can be anticipated; TransPRK would provide refractive outcomes equal to those of standard PRK. Adjustments for the planned OZ and, in the event of retreatments, for the target sphere can be easily derived.

DMPD: Targeting bacterial endotoxin: two sides of a coin. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available n M. Ann N Y Acad Sci. 2007 Jan;1096:1-17. (.png) (.svg) (.html) (.csml) Show Targeting bacterial endotoxin: two sides of a coin. Pub...medID 17405910 Title Targeting bacterial endotoxin: two sides of a coin. Authors Bo

DMPD: Gram-negative endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 1916089 Gram-negative endotoxin: an extraordinary lipid with profound effects oneuk...ep;5(12):2652-60. (.png) (.svg) (.html) (.csml) Show Gram-negative endotoxin: an extraordinary lipid with profound effects...tive endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. Authors Raetz

Transepithelial transport of biperiden hydrochloride in Caco-2 cell monolayers.

Science.gov (United States)

Abalos, Ivana S; Rodríguez, Yanina I; Lozano, Verónica; Cereseto, Marina; Mussini, Maria V; Spinetto, Marta E; Chiale, Carlos; Pesce, Guido

2012-09-01

The aim of this research has been to determine the biperiden hydrochloride permeability in Caco-2 model, in order to classify it based on the Biopharmaceutics Classification System (BCS). The World Health Organization (WHO) as well as many other authors have provisionally assigned the drug as BCS class I (high solubility-high permeability) or III (high solubility-low permeability), based on different methods. We determined biperiden BCS class by comparing its permeability to 5 pre-defined compounds: atenolol and ranitidine hydrochloride (low permeability group) and metoprolol tartrate, sodium naproxen and theophylline (high permeability group). Since biperiden permeability was higher than those obtained for high permeability drugs, we classified it as a BCS class I compound. On the other hand, as no differences were obtained for permeability values when apical to basolateral and basolateral to apical fluxes were studied, this drug cannot act as a substrate of efflux transporters. As a consequence of our results, we suggest that the widely used antiparkinsonian drug, biperiden, should be candidate for a waiver of in vivo bioequivalence studies. Copyright © 2012 Elsevier B.V. All rights reserved.

Workplace Determinants of Endotoxin Exposure in Dental Healthcare Facilities in South Africa

Science.gov (United States)

Singh, Tanusha S.; Bello, Braimoh; Mabe, Onnicah D.; Renton, Kevin; Jeebhay, Mohamed F.

2010-01-01

Objectives: Aerosols generated during dental procedures have been reported to contain endotoxin as a result of bacterial contamination of dental unit water lines. This study investigated the determinants of airborne endotoxin exposure in dental healthcare settings. Methods: The study population included dental personnel (n = 454) from five academic dental institutions in South Africa. Personal air samples (n = 413) in various dental jobs and water samples (n = 403) from dental handpieces and basin taps were collected. The chromogenic-1000 limulus amebocyte lysate assay was used to determine endotoxin levels. Exposure metrics were developed on the basis of individually measured exposures and average levels within each job category. Analysis of variance and multivariate linear regression models were constructed to ascertain the determinants of exposure in the dental group. Results: There was a 2-fold variation in personal airborne endotoxin from the least exposed (administration) to the most exposed (laboratory) jobs (geometric mean levels: 2.38 versus 5.63 EU m−3). Three percent of personal samples were above DECOS recommended exposure limit (50 EU m−3). In the univariate linear models, the age of the dental units explained the most variability observed in the personal air samples (R2 = 0.20, P < 0.001), followed by the season of the year (R2 = 0.11, P < 0.001). Other variables such as institution and total number of dental units per institution also explained a modest degree of variability. A multivariate model explaining the greatest variability (adjusted R2 = 0.40, P < 0.001) included: the age of institution buildings, total number of dental units per institution, ambient temperature, ambient air velocity, endotoxin levels in water, job category (staff versus students), dental unit model type and age of dental unit. Conclusions: Apart from job type, dental unit characteristics are important predictors of airborne endotoxin

IgA against gut-derived endotoxins: does it contribute to suppression of hepatic inflammation in alcohol-induced liver disease?

DEFF Research Database (Denmark)

Parlesak, Alexandr; Schäfer, C.; Bode, C.

2002-01-01

Endotoxins of intestinal origin are supposed to play an important role in the development of alcoholic hepatitis in man. To estimate the role of immunoglobulin response to gut-derived endotoxin in the development of alcohol-induced liver disease, serum levels of IgA and IgG against fecal endotoxin......, endotoxin, and acute-phase proteins were measured in patients with different stages of alcoholic liver disease and in healthy controls. Antibodies of type IgA, but not IgG, against fecal endotoxins were significantly increased in patients with alcohol-induced liver disease. IgA antibodies against fecal...... endotoxin were found to be closely correlated with the plasma concentrations of alanine aminotransferase, gamma-glutamyl transferase, and C-reactive protein in patients with alcoholic liver disease. In conclusion, as IgA located in body tissue was shown to suppress the inflammatory process, enhanced...

Systemic anti-tumor necrosis factor antibody treatment exacerbates endotoxin-induced uveitis in the rat

NARCIS (Netherlands)

de Vos, A. F.; van Haren, M. A.; Verhagen, C.; Hoekzema, R.; Kijlstra, A.

1995-01-01

Tumor necrosis factor is released in the circulation and aqueous humor during endotoxin-induced uveitis, and induces acute uveitis when injected intraocularly in rats. To elucidate the role of tumor necrosis factor in the development of endotoxin-induced uveitis we analysed the effect of

Comparative Study of Plasma Endotoxin with Procalcitonin Levels in Diagnosis of Bacteremia in Intensive Care Unit Patients

Directory of Open Access Journals (Sweden)

Tao Wang

2016-01-01

Conclusions: Plasma endotoxin was more related to GN than to Gram-positive bacteremia, and that endotoxin level was species dependent, but PCT level remained relatively more stable within the GN bacteria caused bacteremia. Both GN and positive bacteria caused bacteremia in the ICU patients in different regions of China. And PCT is a more valuable biomarker than endotoxin in the diagnosis of bacteremia.

Multiple efflux pumps are involved in the transepithelial transport of colchicine: combined effect of p-glycoprotein and multidrug resistance-associated protein 2 leads to decreased intestinal absorption throughout the entire small intestine.

Science.gov (United States)

Dahan, Arik; Sabit, Hairat; Amidon, Gordon L

2009-10-01

proximal to distal segments, whereas MRP2 decreased from proximal to distal small intestinal regions. Overall, it was revealed that the combined effect of P-gp and MRP2, but not BCRP, dominates colchicine transepithelial transport, leading to complete coverage of the entire small intestine, and makes the efflux transport dominate the intestinal permeability process.

Studies on the pathogenesis of fever. VIII. Further observations on the role of endogenous pyrogen in endotoxin fever.

Science.gov (United States)

GILLMAN, S M; BORNSTEIN, D L; WOOD, W B

1961-11-01

Rabbits made granulocytopenic with nitrogen mustard have been shown to generate serum endogenous pyrogen when given a fever-producing dose of bacterial endotoxin. This finding is in accord with the hypothesis that endogenous pyrogen plays a central role in the pathogenesis of endotoxin fever. The fact that leucopenic animals produce less serum-endogenous pyrogen than normal animals given the same dose of endotoxin has also been confirmed and suggests that polymorphonuclear leucocytes constitute a major source of the endogenous pyrogen which is demonstrable in the circulation during endotoxin fever.

Distinct cellular sources of hepoxilin A3 and leukotriene B4 are used to coordinate bacterial-induced neutrophil transepithelial migration.

Science.gov (United States)

Pazos, Michael A; Pirzai, Waheed; Yonker, Lael M; Morisseau, Christophe; Gronert, Karsten; Hurley, Bryan P

2015-02-01

Neutrophilic infiltration is a leading contributor to pathology in a number of pulmonary disease states, including cystic fibrosis. Hepoxilin A3 (HXA3) is a chemotactic eicosanoid shown to mediate the transepithelial passage of neutrophils in response to infection in several model systems and at multiple mucosal surfaces. Another well-known eicosanoid mediating general neutrophil chemotaxis is leukotriene B4 (LTB4). We sought to distinguish the roles of each eicosanoid in the context of infection of lung epithelial monolayers by Pseudomonas aeruginosa. Using human and mouse in vitro transwell model systems, we used a combination of biosynthetic inhibitors, receptor antagonists, as well as mutant sources of neutrophils to assess the contribution of each chemoattractant in driving neutrophil transepithelial migration. We found that following chemotaxis to epithelial-derived HXA3 signals, neutrophil-derived LTB4 is required to amplify the magnitude of neutrophil migration. LTB4 signaling is not required for migration to HXA3 signals, but LTB4 generation by migrated neutrophils plays a significant role in augmenting the initial HXA3-mediated migration. We conclude that HXA3 and LTB4 serve independent roles to collectively coordinate an effective neutrophilic transepithelial migratory response. Copyright © 2015 by The American Association of Immunologists, Inc.

Conjugation of a cell-penetrating peptide to parathyroid hormone affects its structure, potency, and transepithelial permeation

DEFF Research Database (Denmark)

Kristensen, Mie; de Groot, Anne Marit; Berthelsen, Jens

2015-01-01

hormone, i.e. PTH(1-34), and to evaluate the effect with regards to secondary structure, potency in Saos-2 cells, immunogenicity, safety as well as the transepithelial permeation across monolayers by using the Caco-2 cell culture model. Further, co-administration of CPP and PTH(1-34) as an alternative...

Immunostimulatory Potential of β-Lactoglobulin Preparations: Effects Caused by Endotoxin Contamination

DEFF Research Database (Denmark)

Pedersen, Susanne Brix; Bovetto, L.; Fritsche, R.

2003-01-01

Background: The immunomodulating potential residing in cow's milk proteins is currently receiving increasing attention because of growing interest in functional foods and the complex problem of cow's milk allergy. One of the major cow's milk allergens, whey protein beta-lactoglobulin, has...... the immunomodulatory activity. Eventually, the immunostimulatory effect was found to be caused by endotoxin contamination.Conclusion: These results identify endotoxin as the main immunostimulatory component present in some commercial beta-lactoglobulin preparations. Moreover, the present study makes it evident...

Piroxicam Reverses Endotoxin-Induced Hypotension in Rats: Contribution of Vasoactive Eicosanoids and Nitric Oxide

Science.gov (United States)

Buharalioglu, C. Kemal; Korkmaz, Belma; Cuez, Tuba; Sahan-Firat, Seyhan; Sari, Ayşe Nihal; Malik, Kafait U.; Tunctan, Bahar

2011-01-01

Nitric oxide (NO) produced by inducible NO synthase (iNOS) is responsible for endotoxin-induced vascular hyporeactivity and hypotension resulting in multiple organ failure. Endotoxic shock is also characterized by decreased expression of constitutive cyclooxygenase (COX-1), cytochrome P450 (CYP) 4A and endothelial NOS (eNOS). Our previous studies demonstrated that dual inhibition of iNOS and COX with a selective COX-2 inhibitor, NS-398, or a non-selective COX inhibitor, indomethacin, restores blood pressure presumably due to increased production of 20-hydroxyeicosatetraenoic acid (20-HETE) derived from arachidonic acid (AA) by CYP4A in endotoxaemic rats. The aim of this study was to investigate the effects of piroxicam, a preferential COX-1 inhibitor, on the endotoxin-induced changes in blood pressure, expression of COX-1, inducible COX (COX-2), CYP4A1, eNOS, iNOS and heat shock protein 90 (hsp90), and production of PGI2, PGE2, 20-HETE and NO. Injection of endotoxin (10 mg/kg, i.p.) to male Wistar rats caused a fall in blood pressure and an increase in heart rate associated with elevated renal 6-keto-PGF1α and PGE2 levels as well as an increase in COX-2 protein expression. Endotoxin also caused an elevation in systemic and renal nitrite levels associated with increased renal iNOS protein expression. In contrast, systemic and renal 20-HETE levels and renal expression of eNOS, COX-1 and CYP4A1 were decreased in endotoxaemic rats. The effects of endotoxin, except for renal COX-1 and eNOS protein expression, were prevented by piroxicam (10 mg/kg, i.p.), given 1 hr after injection of endotoxin. Endotoxin did not change renal hsp90 protein expression. These data suggest that a decrease in the expression and activity of COX-2 and iNOS associated with an increase in CYP4A1 expression and 20-HETE synthesis contributes to the effect of piroxicam to prevent the hypotension during rat endotoxaemia. PMID:21463481

Influence of endotoxin-induced sepsis on the requirements of propofol-fentanyl infusion rate in pigs

DEFF Research Database (Denmark)

Bollen, Peter; Nielsen, Bjørn J; Toft, Palle

2007-01-01

Endotoxin-induced sepsis in pigs is a recognized experimental model for the study of human septic shock. Generally, pigs are brought into general anaesthesia before sepsis is induced. It is our experience that drug dosages of propofol and fentanyl need to be reduced during endotoxin-induced sepsis......, in order to prevent respiratory and cardiovascular depression, but the scientific evidence for this observation is lacking. Therefore, we measured the consumption of propofol and fentanyl at equal level of anaesthesia in pigs with (n = 5) and without (n = 5) endotoxin-induced sepsis, using the cerebral...... state index (CSI) as measure of anaesthetic depth. Infusion rates of propofol (P endotoxin-induced sepsis had an infusion rate of 2.2 mg/kg/hr (S.D. 0.5) for propofol and 12 microg/kg/hr (S.D. 2) for fentanyl, whereas...

Occupational exposure to pesticides and endotoxin and Parkinson disease in the Netherlands.

Science.gov (United States)

van der Mark, Marianne; Vermeulen, Roel; Nijssen, Peter C G; Mulleners, Wim M; Sas, Antonetta M G; van Laar, Teus; Brouwer, Maartje; Huss, Anke; Kromhout, Hans

2014-11-01

Previous research has indicated that occupational exposure to pesticides and possibly airborne endotoxin may increase the risk of developing Parkinson disease (PD). We studied the associations of PD with occupational exposure to pesticides, specifically to the functional subclasses insecticides, herbicides and fungicides, and to airborne endotoxin. In addition we evaluated specific pesticides (active ingredients) previously associated with PD. We used data from a hospital-based case-control study, including 444 patients with PD and 876 age and sex matched controls. Exposures to pesticides from application and re-entry work were estimated with the ALOHA+job-exposure matrix and with an exposure algorithm based on self-reported information on pesticide use. To assess exposure to specific active ingredients a crop-exposure matrix was developed. Endotoxin exposure was estimated with the DOM job-exposure matrix. The results showed almost no significant associations. However, ORs were elevated in the higher exposure categories for pesticides in general, insecticides, herbicides and fungicides, and below unity for endotoxin exposure. The analyses on specific active ingredients showed a significant association of PD risk with the fungicide benomyl. This study did not provide evidence for a relation between pesticide exposure and PD. However, the consistently elevated ORs in the higher exposure categories suggest that a positive association may exist. The possible association with the active ingredient benomyl requires follow-up in other studies. This study did not provide support for a possible association between endotoxin exposure and PD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Influence of apical enlargement and complementary canal preparation with the Self-Adjusting File on endotoxin reduction in retreatment cases.

Science.gov (United States)

Silva, E J N L; Ferreira, V M; Silva, C C; Herrera, D R; De-Deus, G; Gomes, B P

2017-07-01

To compare the effectiveness of large apical preparations and complementary canal preparation with the Self-Adjusting File (SAF) in removing endotoxins from the root canal of teeth with apical periodontitis. Ten single-rooted and single-canaled teeth with post-treatment apical periodontitis were selected. Endotoxin samples were taken after removal of the root filling (S1), after chemomechanical preparation (CMP) using 2.5% NaOCl and an R25 file (S2), after CMP using 2.5% NaOCl and an R40 file (S3) and after complementary CMP using the SAF system (S4). Limulus amebocyte lysate (LAL) was used to measure endotoxin levels. The Friedman and Wilcoxon tests were used to compare endotoxin levels at each clinical intervention (P file was able to significantly reduce endotoxin levels (P file (P  0.05) following the use of the R40 instrument. Apical enlargement protocols were effective in significantly reducing endotoxin levels. Complementary preparation with the SAF system failed to eliminate residual endotoxin contents beyond those obtained with the R40 instrument. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Synchronization modulation increases transepithelial potentials in MDCK monolayers through Na/K pumps.

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Vu Tran

Full Text Available Transepithelial potential (TEP is the voltage across a polarized epithelium. In epithelia that have active transport functions, the force for transmembrane flux of an ion is dictated by the electrochemical gradient in which TEP plays an essential role. In epithelial injury, disruption of the epithelial barrier collapses the TEP at the wound edge, resulting in the establishment of an endogenous wound electric field (∼100 mV/mm that is directed towards the center of the wound. This endogenous electric field is implicated to enhance wound healing by guiding cell migration. We thus seek techniques to enhance the TEP, which may increase the wound electric fields and enhance wound healing. We report a novel technique, termed synchronization modulation (SM using a train of electric pulses to synchronize the Na/K pump activity, and then modulating the pumping cycles to increase the efficiency of the Na/K pumps. Kidney epithelial monolayers (MDCK cells maintain a stable TEP and transepithelial resistance (TER. SM significantly increased TEP over four fold. Either ouabain or digoxin, which block Na/K pump, abolished SM-induced TEP increases. In addition to the pump activity, basolateral distribution of Na/K pumps is essential for an increase in TEP. Our study for the first time developed an electrical approach to significantly increase the TEP. This technique targeting the Na/K pump may be used to modulate TEP, and may have implication in wound healing and in diseases where TEP needs to be modulated.

Super-low dose endotoxin pre-conditioning exacerbates sepsis mortality.

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Chen, Keqiang; Geng, Shuo; Yuan, Ruoxi; Diao, Na; Upchurch, Zachary; Li, Liwu

2015-04-01

Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditionings with super-low or low dose endotoxin lipopolysaccharide (LPS) cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP). This is in opposite to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET) in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a novel mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

Super-low Dose Endotoxin Pre-conditioning Exacerbates Sepsis Mortality

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Keqiang Chen

2015-04-01

Full Text Available Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditioning with super-low or low dose endotoxin lipopolysaccharide (LPS cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP. This is in contrast to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

A pharmacological modification of pain and epithelial healing in contemporary transepithelial all-surface laser ablation (ASLA).

Science.gov (United States)

Aslanides, Ioannis M; Selimis, Vasilis D; Bessis, Nikolaos V; Georgoudis, Panagiotis N

2015-01-01

We report our experience with the use of the matrix regenerating agent (RGTA) Cacicol(®) after reverse transepithelial all-surface laser ablation (ASLA)-SCHWIND to assess the safety, efficacy, pain, and epithelial healing. Forty eyes of 20 myopic patients were prospectively recruited to a randomized fellow eye study. Patients underwent transepithelial ASLA in both eyes, with one of the eyes randomly assigned to the use of the RGTA Cacicol. Postoperative pain and vision were subjectively assessed with the use of a questionnaire on the operative day, at 24 hours, 48 hours and 72 hours. Epithelial defect area size was measured at 24 hours, 48 hours, and 72 hours. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were assessed at 1 month. Mean UDVA at 1 month was LogMAR 0.028. The epithelial defect area was 10.91 mm(2) and 13.28 mm(2) at 24 hours and 1.39 mm(2) and 1.24 mm(2) at 48 hours for treated and nontreated eyes, respectively. Overall, 50% and 65% of treated and nontreated eyes healed by 48 hours. There was no statistically significant difference in the subjective vision between the groups, although vision of patients in the RGTA group was reported to be better. Pain scores were better at 24 hours and 48 hours in the RGTA group but with no statistically significant difference. The use of RGTA Cacicol shows faster epithelial recovery after transepithelial ASLA for myopia. Subjectively reported scores of pain and subjective vision were better in the RGTA group, although the difference was not statistically significant. There seems to be a consensual acceleration of epithelial healing even in eyes that did not receive treatment. There were no adverse events and no incidents of inflammation, delayed healing, or haze.

Effect of endotoxin and allergens on neonatal lung function and infancy respiratory symptoms and eczema

NARCIS (Netherlands)

Abbing-Karahagopian, V.; Gugten, A.C. van der; Ent, C.K. van der; Uiterwaal, C.; Jongh, M. de; Oldenwening, M.; Brunekreef, B.; Gehring, U.

2012-01-01

BACKGROUND Exposure to endotoxin and allergens in house dust has been found to be associated with childhood wheeze and asthma. Neonatal lung function is rarely examined in relation to this exposure. OBJECTIVES To assess the association between exposure to endotoxin, house dust mite and cat

Sensitive measurement of endotoxin by radio-rocket immunoelectrophoresis using [125I]Staphylococcus aureus protein A

International Nuclear Information System (INIS)

Stevens, P.; Alam, S.; Young, L.S.; Chesebro, K.

1981-01-01

Antibody directed against the core glycolipid antigen (CGL) of the mutant Salmonella minnesota Re 595 has been shown to cross-react with endotoxin from bacteria within the group Enterobacteriaceae. Using this cross-reactive CGL antibody the authors have developed a sensitive (250 pg) radio-rocket immunoelectrophoretic technique to measure endotoxin. They used the principles of rocket immunoelectrophoresis and increased the sensitivity by using 125 I-labelled staphylococcal protein A which serves as a sensitive probe to bind to the Fc portion of the IgG complexed with antigen. The rocket-shaped [ 125 I]protein A labelled immune complexes were detected by radioautography. The sensitivity is 100-fold greater than conventional Coomassie brilliant blue staining. Measurement of CGL was inhibited by normal human serum. However, the assay had the capacity to quantitate endotoxin in buffer extracts of clinically isolated Escherichia coli, Serratia marcescens, Klebsiella pneumoniae but not Pseudomonas aeruginosa. Analysis of various preparations of CGL obtained from different investigators demonstrated wide variation in their immunoreactivity. Because of the significant cross-reaction to detect various endotoxins this method has the potential to measure endotoxemia and assess the immunochemical quality of various endotoxin preparations. Additionally, the techniques of using [ 125 I]protein A has wide applicability for the sensitive measurement of other antigens. (Auth.)

Transepithelial Transport of PEGylated Anionic Poly(amidoamine) Dendrimers: Implications for Oral Drug Delivery

OpenAIRE

Sweet, Deborah M.; Kolhatkar, Rohit B.; Ray, Abhijit; Swaan, Peter; Ghandehari, Hamidreza

2009-01-01

The purpose of this work was to assess the impact of PEGylation on transepithelial transport of anionic poly(amidoamine) dendrimers. Cytotoxicity, uptake and transport across Caco-2 cells of PEGylated G3.5 and G4.5 PAMAM dendrimers were studied. Methoxy polyethylene glycol (750 Da) was conjugated to carboxylic acid-terminated PAMAM dendrimers at feed ratios of 1, 2 and 4 PEG per dendrimer. Compared to the control, PEGylation of anionic dendrimers did not significantly alter cytotoxicity up to...

Occupational exposure to endotoxins and lung cancer risk: results of the ICARE Study.

Science.gov (United States)

Ben Khedher, Soumaya; Neri, Monica; Guida, Florence; Matrat, Mireille; Cenée, Sylvie; Sanchez, Marie; Menvielle, Gwenn; Molinié, Florence; Luce, Danièle; Stücker, Isabelle

2017-09-01

To investigate the role of occupational exposure to endotoxins in lung cancer in a French population-based case-control study (ICARE (Investigation of occupational and environmental causes of respiratory cancers)). Detailed information was collected on the occupational history and smoking habits from 2926 patients with histologically confirmed lung cancer and 3555 matched controls. We evaluated each subject's endotoxin exposure after cross referencing International Standard Classification of Occupations (ISCO) codes (for job tasks) and Nomenclature d'Activités Françaises (NAF) codes (for activity sectors). Endotoxin exposure levels were attributed to each work environment based on literature reports. ORs and 95% CIs were estimated using unconditional logistic regression models and controlled for main confounding factors. An inverse association between exposure to endotoxins and lung cancer was found (OR=0.80, 95% CI 0.66 to 0.95). Negative trends were shown with duration and cumulative exposure, and the risk was decreased decades after exposure cessation (all statistically significant). Lung cancer risk was particularly reduced among workers highly exposed (eg, in dairy, cattle, poultry, pig farms), but also in those weakly exposed (eg, in waste treatment). Statistically significant interactions were shown with smoking, and never/light smokers were more sensitive to an endotoxin effect than heavy smokers (eg, OR=0.14, 95% CI 0.06 to 0.32 and OR=0.80, 95% CI 0.45 to 1.40, respectively, for the quartiles with the highest cumulative exposure, compared with those never exposed). Pronounced inverse associations were shown with adenocarcinoma histological subtype (OR=0.37, 95% CI 0.25 to 0.55 in the highly exposed). Our findings suggest that exposure to endotoxins, even at a low level, reduces the risk of lung cancer. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is

Detection of endotoxins and other pyrogens using human whole blood.

Science.gov (United States)

Fennrich, S; Fischer, M; Hartung, T; Lexa, P; Montag-Lessing, T; Sonntag, H G; Weigandt, M; Wendel, A

1999-01-01

When cells of the immune system, i.e. primarily blood monocytes and macrophages, come into contact with pyrogens (fever-inducing contaminations) they release mediators transmitting the fever reaction through the organism to the thermoregulatory centres of the brain. The new test discussed here exploits this reaction for the detection of pyrogens: human whole blood taken from healthy volunteers is incubated in the presence of the test sample. If there is pyrogen contamination, the endogenous pyrogen interleukin-1 is released, which is then determined by ELISA. According to the pharmacopoeia, the rabbit pyrogen test determines the fever reaction following injection of a test sample. In comparison, the new whole blood assay is more sensitive, less expensive and determines the reaction of the targeted species. Compared to the well established in vitro alternative, i.e. the limulus amebocyte lysate assay (LAL), the new blood assay is not restricted to endotoxins of gram-negative bacteria, it is not affected by endotoxin-binding blood proteins and it reflects the potency of different endotoxin preparations in mammals. Here, interim results of the ongoing optimization and pre-validation are reported and the present state of the evaluation for biological and pharmaceutical drugs are presented.

Network topologies and dynamics leading to endotoxin tolerance and priming in innate immune cells.

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Yan Fu

Full Text Available The innate immune system, acting as the first line of host defense, senses and adapts to foreign challenges through complex intracellular and intercellular signaling networks. Endotoxin tolerance and priming elicited by macrophages are classic examples of the complex adaptation of innate immune cells. Upon repetitive exposures to different doses of bacterial endotoxin (lipopolysaccharide or other stimulants, macrophages show either suppressed or augmented inflammatory responses compared to a single exposure to the stimulant. Endotoxin tolerance and priming are critically involved in both immune homeostasis and the pathogenesis of diverse inflammatory diseases. However, the underlying molecular mechanisms are not well understood. By means of a computational search through the parameter space of a coarse-grained three-node network with a two-stage Metropolis sampling approach, we enumerated all the network topologies that can generate priming or tolerance. We discovered three major mechanisms for priming (pathway synergy, suppressor deactivation, activator induction and one for tolerance (inhibitor persistence. These results not only explain existing experimental observations, but also reveal intriguing test scenarios for future experimental studies to clarify mechanisms of endotoxin priming and tolerance.

Detoxication of endotoxins from the enteric group of bacteria using gamma-irradiation

Energy Technology Data Exchange (ETDEWEB)

Tumanian, M A; Dunlishcheva, A P; Sinilova, N G; Ivanov, K K

1975-03-01

A study was made of the effect of gamma radiation on the toxic properties of endotoxins of the O-somatic antigens and lipopolysaccharides separated from various representatives of the enterobacteriaceae: S. typhi 2 4446, S. paratyphi B42, B. proteus vulgaris 1 and mirabilis 4, E. coli K12 and 5396/38 and Sh. dysenteriae flexneri 516 and 550. An irradiation dose of 1 mrad led to an insignificant decrease in toxicity, while a dose of 3 mrad led to a decrease in toxicity by a factor of 3 to 4 in comparison with the toxicity of the initial preparation. The decrease in toxicity under the effect of irradiation is apparently connected with the lipid part of the endotoxin molecule. The irradiation results in a decrease in the molecular weight of the endotoxin. The infrared spectrum of the molecule shows considerable changes at high radiation doses. (SJR)

The Chemical Composition of Endotoxin Isolated from Intestinal Strain of Desulfovibrio desulfuricans

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Jolanta Lodowska

2012-01-01

Full Text Available Desulfovibrio desulfuricans anaerobes are constituents of human alimentary tract microflora. There are suggestions that they take part in the pathogenesis of periodontitis and some gastrointestinal inflammatory disorders, such as ulcerative colitis or Crohn’s disease. Endotoxin is one of Gram-negative bacteria cellular components that influence these microorganisms pathogenicity. Endotoxin is a lipid-polisaccharide heteropolymer consisting of three elements: lipid A, core oligosaccharide, and O-specific polysaccharide, also called antigen-O. The biological activity of lipopolysaccharide (LPS is determined by its structure. In this study, we show that rhamnose, fucose, mannose, glucose, galactose, heptose, and 2-keto-3-deoxyoctulosonic acid (Kdo are constituents of D. desulfuricans endotoxin oligosaccharide core and O-antigen. Lipid A of these bacteria LPS is composed of glucosamine disaccharide substituted by 3-acyloxyacyl residues: ester-bound 3-(dodecanoyloxytetradecanoic, 3-(hexadecanoyloxytetradecanoic acid, and amide-bound 3-(tetradecanoyloxytetradecanoic acid.

Acrolein Disrupts Tight Junction Proteins and Causes Endoplasmic Reticulum Stress-Mediated Epithelial Cell Death Leading to Intestinal Barrier Dysfunction and Permeability.

Science.gov (United States)

Chen, Wei-Yang; Wang, Min; Zhang, Jingwen; Barve, Shirish S; McClain, Craig J; Joshi-Barve, Swati

2017-12-01

Increasing evidence suggests that environmental and dietary factors can affect intestinal epithelial integrity leading to gut permeability and bacterial translocation. Intestinal barrier dysfunction is a pathogenic process associated with many chronic disorders. Acrolein is an environmental and dietary pollutant and a lipid-derived endogenous metabolite. The impact of acrolein on the intestine has not been investigated before and is evaluated in this study, both in vitro and in vivo. Our data demonstrate that oral acrolein exposure in mice caused damage to the intestinal epithelial barrier, resulting in increased permeability and subsequently translocation of bacterial endotoxin-lipopolysaccharide into the blood. Similar results were seen in vitro using established Caco-2 cell monolayers wherein acrolein decreased barrier function and increased permeability. Acrolein also caused the down-regulation and/or redistribution of three representative tight junction proteins (ie, zonula occludens-1, Occludin, Claudin-1) that critically regulate epithelial paracellular permeability. In addition, acrolein induced endoplasmic reticulum stress-mediated death of epithelial cells, which is an important mechanism contributing to intestinal barrier damage/dysfunction, and gut permeability. Overall, we demonstrate that exposure to acrolein affects the intestinal epithelium by decrease/redistribution of tight junction proteins and endoplasmic reticulum stress-mediated epithelial cell death, thereby resulting in loss of barrier integrity and function. Our findings highlight the adverse consequences of environmental and dietary pollutants on intestinal barrier integrity/function with relevance to gut permeability and the development of disease. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Residual endotoxin contaminations in recombinant proteins are sufficient to activate human CD1c+ dendritic cells.

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Harald Schwarz

Full Text Available Many commercially available recombinant proteins are produced in Escherichia coli, and most suppliers guarantee contamination levels of less than 1 endotoxin unit (EU. When we analysed commercially available proteins for their endotoxin content, we found contamination levels in the same range as generally stated in the data sheets, but also some that were higher. To analyse whether these low levels of contamination have an effect on immune cells, we stimulated the monocytic cell line THP-1, primary human monocytes, in vitro differentiated human monocyte-derived dendritic cells, and primary human CD1c+ dendritic cells (DCs with very low concentrations of lipopolysaccharide (LPS; ranging from 0.002-2 ng/ml. We show that CD1c+ DCs especially can be activated by minimal amounts of LPS, equivalent to the levels of endotoxin contamination we detected in some commercially available proteins. Notably, the enhanced endotoxin sensitivity of CD1c+ DCs was closely correlated with high CD14 expression levels observed in CD1c+ DCs that had been maintained in cell culture medium for 24 hours. When working with cells that are particularly sensitive to LPS, even low endotoxin contamination may generate erroneous data. We therefore recommend that recombinant proteins be thoroughly screened for endotoxin contamination using the limulus amebocyte lysate test, fluorescence-based assays, or a luciferase based NF-κB reporter assay involving highly LPS-sensitive cells overexpressing TLR4, MD-2 and CD14.

Detection of endotoxins in radiopharmaceutical preparations. II. Comparison of the sensitivity of methods using the rabbit and the Limulus amoebocyte lysate for the detection of endotoxins

Energy Technology Data Exchange (ETDEWEB)

Bruneau, J; Cohen, Y; Merlin, L; Peysson, S

1986-01-01

The rise of the rabbit internal temperature after i.v. injection of an endotoxin solution is proportional to concentration. Gelation of Limulus amoebocyte, when in presence of an endotoxin solution, is also related to concentration. We compared the sensitivity of these two methods. With our experimental procedure, the rabbit is sensitive to a 0.40 ng/mL solution and the Limulus amoebocyte lysate to a 0.14 ng/mL solution. The rabbit sensitivity increase is related to the per kilogramme injected volume, whereas sensitivity is not related to the volume to check in the case of the lysate.

Monitoring total endotoxin and (1 --> 3)-beta-D-glucan at the air exhaust of concentrated animal feeding operations.

Science.gov (United States)

Yang, Xufei; Wang, Xinlei; Zhang, Yuanhui; Lee, Jongmin; Su, Jingwei; Gates, Richard S

2013-10-01

Mitigation of bioaerosol emissions from concentrated animal feeding operations (CAFOs) demands knowledge of bioaerosol concentrations feeding into an end-of-pipe air treatment process. The aim of this preliminary study was to measure total endotoxin and (1 --> 3)-beta-glucan concentrations at the air exhaust of 18 commercial CAFOs and to examine their variability with animal operation type (swine farrowing, swine gestation, swine weaning, swine finishing, manure belt laying hen, and tom turkey) and season (cold, mild, and hot). The measured airborne concentrations of total endotoxin ranged from 98 to 23,157 endotoxin units (EU)/m3, and the airborne concentrations of total (1 --> 3)-beta-D-glucan ranged from 2.4 to 537.9 ng/m3. Animal operation type in this study had a significant effect on airborne concentrations of total endotoxin and (1 --> 3)-beta-D-glucan but no significant effect on their concentrations in total suspended particulate (TSP). Both endotoxin and (1 --> 3)-beta-D-glucan attained their highest airborne concentrations in visited tom turkey buildings. Comparatively, season had no significant effect on airborne concentrations of total endotoxin or (1 --> 3)-beta-D-glucan. Endotoxin and (1 --> 3)-beta-glucan concentrations in TSP dust appeared to increase as the weather became warmer, and this seasonal effect was significant in swine buildings. Elevated indoor temperatures in the hot season were considered to facilitate the growth and propagation of bacteria and fungi, thus leading to higher biocomponent concentrations in TSP.

Effectiveness of castor oil extract on Escherichia coli and its endotoxins in root canals.

Science.gov (United States)

Valera, Marcia Carneiro; Maekawa, Lilian Eiko; Chung, Adriana; de Oliveira, Luciane Dias; Carvalho, Claudio Antonio Talge; Koga-Ito, Cristiane Yumi; Jorge, Antonio Olavo Cardoso

2012-01-01

This in vitro study sought to evaluate the effectiveness of castor oil extract used as an irrigating solution on Escherichia coli and its endotoxins in root canals. Sixty single-rooted teeth were prepared (using castor oil extract as irrigating solution) and divided into five groups (n = 12): Group 1 samples were treated with calcium hydroxide (Ca(OH)2), Group 2 samples were treated with polymyxin B, Group 3 samples were treated with Ca(OH)2 and 2% chlorhexidine gel (CHX), and Group 4 samples were treated with castor oil extract. A control group used physiological saline solution as an irrigant. Canal content samples were collected at four different times: immediately after instrumentation, seven days after instrumentation, after 14 days of intracanal medication, and seven days after removal of intracanal medication. A plating method was used to assess antimicrobial activity and the quantification of endotoxins was evaluated by the chromogenic Limulus lysate assay. Data were submitted to ANOVA and a Dunn test (a = 5%). Irrigation with castor oil extract decreased E. coli counts but had no effect on the level of endotoxins. Samples taken seven days after removal of medication revealed a significant reduction in endotoxin levels in Groups 3 and 4. Compared to the saline solution irrigation, castor oil extract decreased microorganism counts in root canals immediately after canal preparation. None of the medications used completely eliminated endotoxins in the root canal.

A NEW ANIMAL-MODEL FOR HUMAN PREECLAMPSIA - ULTRA-LOW-DOSE ENDOTOXIN INFUSION IN PREGNANT RATS

NARCIS (Netherlands)

FAAS, MM; SCHUILING, GA; BALLER, JFW; VISSCHER, CA; BAKKER, WW

OBJECTIVE: An animal model for preeclampsia was developed by means of an ultra-low-dose endotoxin infusion protocol in conscious pregnant rats. STUDY DESIGN: Rats received a permanent jugular vein cannula on day 0 of pregnancy, through which endotoxin (1.0 mu/kg body weight) (n = 10) or saline

Transepithelial transport of aliphatic carboxylic acids studied in Madin Darby canine kidney (MDCK) cell monolayers

International Nuclear Information System (INIS)

Cho, M.J.; Adson, A.; Kezdy, F.J.

1990-01-01

Transport of 14C-labeled acetic, propionic (PA), butyric, valeric, heptanoic (HA), and octanoic (OA) acids across the Madin Darby canine kidney (MDCK) epithelial cell monolayer grown on a porous polycarbonate membrane was studied in Hanks' balanced salt solution (HBSS) at 37 degrees C in both apical-to-basolateral and basolateral-to-apical directions. At micromolar concentrations of solutes, metabolic decomposition was significant as evidenced by [14C]CO2 production during the OA transport. The apparent permeability (Pe) indicates that as lipophilicity increases, diffusion across the unstirred boundary layer becomes rate limiting. In support of this notion, transport of OA and HA was enhanced by agitation, showed an activation energy of 3.7 kcal/mol for OA, and resulted in identical Pe values for both transport directions. Analysis of Pe changes with varying alkyl chain length resulted in a delta G of -0.68 +/- 0.09 kcal/mol for -CH2-group transfer from an aqueous phase to the MDCK cells. When the intercellular tight junctions were opened by the divalent chelator EGTA in Ca2+/Mg2(+)-free HBSS, transport of the fluid-phase marker Lucifer yellow greatly increased because of paracellular leakage. PA transport also showed a significant increase, but OA transport was independent of EGTA. Although albumin also undergoes paracellular transport in the presence of EGTA and OA binds strongly to albumin, OA transport in EGTA solution was unchanged by albumin. These observations indicate that transmembrane transport is the major mechanism for lipophilic substances. The present study, together with earlier work on the transport of polar substances, shows that the MDCK cell monolayer is an excellent model of the transepithelial transport barrier

Dephosphorylation of endotoxin by alkaline phosphatase in vivo

NARCIS (Netherlands)

Poelstra, Klaas; Bakker, W.W; Klok, P.A; Kamps, J.AAM; Hardonk, M.J; Meijer, D.K F

1997-01-01

Natural substrates for alkaline phosphatase (AP) are at present not identified despite extensive investigations. Difficulties in imagining a possible physiological function involve its extremely high pH optimum for the usual exogenous substrates and its localization as an ecto-enzyme. As endotoxin

A Comparison of Different Corneal Iontophoresis Protocols for Promoting Transepithelial Riboflavin Penetration.

Science.gov (United States)

Gore, Daniel M; O'Brart, David P; French, Paul; Dunsby, Chris; Allan, Bruce D

2015-12-01

To measure corneal riboflavin penetration using different transepithelial iontophoresis protocols. Freshly enucleated rabbit eyes were divided into nine treatment groups of 4 eyes. One group, in which 0.1% wt/vol riboflavin was applied for 30 minutes without iontophoresis after corneal epithelial debridement, acted as a control. The remaining groups were treated with an intact epithelium using different riboflavin formulations and varying iontophoresis current, soak, and rinse times. After riboflavin application, eyes were snap frozen in liquid nitrogen. Corneal cross sections 35 μm thick were then imaged immediately by two-photon fluorescence microscopy, using image processing software to quantify stromal riboflavin concentration at different corneal depths. In the epithelium-on iontophoresis treatment groups, greater stromal riboflavin penetration was achieved with higher-concentration riboflavin solutions, greater iontophoresis dosage, and longer solution contact times. A protocol utilizing 0.25% wt/vol riboflavin with benzalkonium chloride (BAC) 0.01% and two cycles of applied current and subsequent soaking (1 mA 5 minutes, soak 5 minutes; 0.5 mA 5 minutes, soak 5 minutes) achieved similar stromal riboflavin penetration to epithelium-off controls. The best-performing non-BAC-containing protocol produced stromal riboflavin penetration approximately 60% that of epithelium-off controls. Riboflavin solutions containing saline resulted in minimal stromal penetration. Riboflavin loading within the epithelium was equivalent to or higher than that in the subjacent stroma, despite rinsing the ocular surface with balanced salt solution. Modified iontophoresis protocols can significantly improve transepithelial riboflavin penetration in experimental corneal collagen cross-linking.

Sensitive measurement of endotoxin by radio-rocket immunoelectrophoresis using (/sup 125/I)Staphylococcus aureus protein A

Energy Technology Data Exchange (ETDEWEB)

Stevens, P; Alam, S; Young, L S; Chesebro, K [California Univ., Los Angeles (USA). Center for the Health Sciences

1981-06-16

Antibody directed against the core glycolipid antigen (CGL) of the mutant Salmonella minnesota Re 595 has been shown to cross-react with endotoxin from bacteria within the group Enterobacteriaceae. Using this cross-reactive CGL antibody the authors have developed a sensitive (250 pg) radio-rocket immunoelectrophoretic technique to measure endotoxin. They used the principles of rocket immunoelectrophoresis and increased the sensitivity by using /sup 125/I-labelled staphylococcal protein A which serves as a sensitive probe to bind to the Fc portion of the IgG complexed with antigen. The rocket-shaped (/sup 125/I)protein A labelled immune complexes were detected by radioautography. The sensitivity is 100-fold greater than conventional Coomassie brilliant blue staining. Measurement of CGL was inhibited by normal human serum. However, the assay had the capacity to quantitate endotoxin in buffer extracts of clinically isolated Escherichia coli, Serratia marcescens, Klebsiella pneumoniae but not Pseudomonas aeruginosa. Analysis of various preparations of CGL obtained from different investigators demonstrated wide variation in their immunoreactivity. Because of the significant cross-reaction to detect various endotoxins this method has the potential to measure endotoxemia and assess the immunochemical quality of various endotoxin preparations. Additionally, the techniques of using (/sup 125/I)protein A has wide applicability for the sensitive measurement of other antigens.

Activation of innate immune genes in caprine blood leukocytes after systemic endotoxin challenge

DEFF Research Database (Denmark)

Salvesen, Øyvind; Reiten, Malin R; Heegaard, Peter M. H.

2016-01-01

observed peaking at 2 h, corroborating the increasing evidence that ISGs respond immediately to bacterial endotoxins. A slower response was manifested by four extrahepatic acute phase proteins (APP) (SAA3, HP, LF and LCN2) reaching maximum levels at 5 h. We report an immediate induction of ISGs...... insights into the dynamic regulation of innate immune genes, as well as raising new questions regarding the importance of ISGs and extrahepatic APPs in leukocytes after systemic endotoxin challenge....

Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis

DEFF Research Database (Denmark)

Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath

2012-01-01

Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here...... present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin...

Protective effects of bacterial endotoxin in reconstruction of hematopoiesis after irradiation

Energy Technology Data Exchange (ETDEWEB)

Wenzhong, Zhao; Renqian, Zhong [Second Military medical Coll., Shanghai, SH (China). Dept. of Radiation Medicine

1989-06-01

The mechanism of protective effects of bacterial endotoxin (ET) in reconstruction of hemopoiesis post-irradiation has been studied. The results showed that (1) in normal men, dogs, rabbits and rats, after im injection of typhobacterial endotoxin (ETt), the peripheral blood leucocytes (PBL) increased in number remarkably; (2) the injection of microdoses of ETt into hypothalamus of the rabbits and rats caused no obvious change in number of PBL, suggesting that there was neither regulation on the granulomacrophagopoiesis of the vegetative nervous center in hypothalamus nor the regulative effect of the hypothalamo-pituitary endocrine system. The curves of the stimulating factor (CSF) levels in serum after injection of bacillus coli endotoxin (ETc) were compared between the mouse bone marrow cell (BMC) membrane {sup 3}H-galactose incorporation method and the agar cellular colony culture technique. It was shown that they had obvious relationships with the dose-response curve of purified CSF-1. There was no effect on the incorporation value and colony number when ETc was added to culture well directly. The protective effects of the ETc-serum on the 8 Gy irradiated mice was realized by inducing GM-CSF and promoting the reconstruction of hematopoiesis.

Effects of Endotoxin and Psychological Stress on Redox Physiology, Immunity and Feather Corticosterone in Greenfinches.

Directory of Open Access Journals (Sweden)

Richard Meitern

Full Text Available Assessment of costs accompanying activation of immune system and related neuroendocrine pathways is essential for understanding the selective forces operating on these systems. Here we attempted to detect such costs in terms of disruption to redox balance and interference between different immune system components in captive wild-caught greenfinches (Carduelis chloris. Study birds were subjected to an endotoxin-induced inflammatory challenge and temporary exposure to a psychological stressor (an image of a predator in a 2*2 factorial experiment. Injection of bacterial endotoxin resulted in up-regulation of two markers of antioxidant protection - erythrocyte glutathione, and plasma oxygen radical absorbance (OXY. These findings suggest that inflammatory responses alter redox homeostasis. However, no effect on markers of oxidative damage to proteins or DNA in erythrocytes could be detected. We found no evidence that the endotoxin injection interfered with antibody production against Brucella abortus antigen or the intensity of chronic coccidiosis. The hypothesis of within-immune system trade-offs as a cost of immunity was thus not supported in our model system. We showed for the first time that administration of endotoxin can reduce the level of corticosterone deposited into feathers. This finding suggests a down-regulation of the corticosterone secretion cascade due to an endotoxin-induced immune response, a phenomenon that has not been reported previously. Exposure to the predator image did not affect any of the measured physiological parameters.

Invited review: Role of bacterial endotoxins in the etiopathogenesis of periparturient diseases of transition dairy cows.

Science.gov (United States)

Eckel, Emily F; Ametaj, Burim N

2016-08-01

The dairy industry continues to suffer severe economic losses due to the increased disease incidence cows experience during the transition period. It has long been the classical view that the major contributing factor to the development of these periparturient diseases is the considerable increase in nutritional demands for milk production. This classical view, however, fails to account for the substantial correlation between both metabolic and infectious diseases and the detrimental effects that can occur with the provision of high-energy diets to support these nutritional demands. Currently, increasing evidence implicates bacterial endotoxins in the etiopathology of most periparturient diseases. Bacterial endotoxins are components of the outer cell wall of gram-negative and gram-positive bacteria that are highly immunostimulatory and can trigger proinflammatory immune responses. The ability of endotoxins to translocate from the mucosal tissues, including the gastrointestinal tract, mammary gland, and uterus, into the systemic circulation has been observed. Once they have entered the circulation, endotoxins potentially contribute to disease either directly, through eliciting an inflammatory response, or indirectly through other factors such as the overreaction of the natural protective mechanisms of the host. Although the evidence implicating a role of endotoxins in the pathogenesis of transition diseases continues to grow, our current knowledge of the host response to mucosal endotoxin exposure and pathogenic mechanisms remain largely unknown. Developing our understanding of the connection between endotoxemia and dairy cattle disease holds significant potential for the future development of preventative measures that could benefit the productivity of the dairy industry as well as animal welfare. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Comparison of single-step reverse transepithelial all-surface laser ablation (ASLA to alcohol-assisted photorefractive keratectomy

Directory of Open Access Journals (Sweden)

Aslanides IM

2012-06-01

Full Text Available Ioannis M Aslanides,1 Sara Padroni,1 Samuel Arba Mosquera,2 Antonis Ioannides,1 Achyut Mukherjee11Emmetropia Mediterranean Eye Institute, Heraklion, Crete, Greece; 2Schwind eye-tech-solutions GmbH, Kleinostheim, GermanyPurpose: To evaluate postoperative pain, corneal epithelial healing, development of corneal haze, refractive outcomes, and corneal aberrations in a novel one-step, modified transepithelial photorefractive keratectomy (PRK, termed All-surface laser ablation (ASLA, compared to conventional, alcohol-assisted PRK.Materials and methods: Sixty eyes of 30 myopic patients were prospectively recruited to a randomized fellow eye study. Patients underwent conventional alcohol-assisted PRK in one eye (control group and ASLA-modified transepithelial PRK in the other (30 eyes in each treatment arm. Primary endpoints were postoperative pain and haze scores at 1 day, 3 days, 1 week, and 1, 3, 6, and 12 months. Secondary endpoints included visual acuity at 1, 3, 6, and 12 months, corneal aberrations at 3, 6, and 12 months, and early and late onset haze. Refractive predictability, safety, and efficacy of the two methods were considered.Results: The average age of the cohort was 29 years (standard deviation [SD]: 9; range: 18–46, and the average spherical equivalent refractive error was -4.18 diopters (SD: 1.9. At 3 days after surgery, the average pain score was 64% lower in the ASLA group (P < 0.0005. At this point, 96% of ASLA eyes had no epithelial defect, whereas 43% in the alcohol-assisted group did not achieve complete epithelial healing, and required replacement of bandage contact lens. The haze level was consistently lower in the ASLA group at all time points from 1 to 6 months.Conclusion: This study shows that the ASLA technique may have a future role in refractive surgery, due to the fact that it offers faster epithelial healing, lower pain scores, and significantly less haze formation.Keywords: cornea, ASLA, PRK, alcohol

A biological study establishing the endotoxin limit for in vitro proliferation of human mesenchymal stem cells

Directory of Open Access Journals (Sweden)

Yusuke Nomura

2017-12-01

Conclusions: Since endotoxins can affect various cellular functions, an endotoxin limit should be set for in vitro MSC cultures. The lowest observed adverse effect level was determined to be 0.1 ng/ml based on the effect on MSC proliferation.

Effect of hyperbaric air on endotoxin from Bacteroides fragilis strains

Czech Academy of Sciences Publication Activity Database

Chmelař, D.; Kašíková, A.; Martineková, P.; Hájek, M.; Rozložník, M.; Brabec, Marek; Janečková, J.; Vobejdová, J.; Čižnár, I.

2018-01-01

Roč. 63, č. 3 (2018), s. 283-290 ISSN 0015-5632 Institutional support: RVO:67985807 Keywords : endotoxin * hyperbaric condition Subject RIV: EE - Microbiology, Virology Impact factor: 1.521, year: 2016

Effect of radio-detoxified endotoxin on the liver microsomal drug metabolizing enzyme system in rats

International Nuclear Information System (INIS)

Bertok, L.; Szeberenyi, S.

1983-01-01

E. coli endotoxin (LPS) depresses the hepatic microsomal mono-oxygenase activity. Radio-detoxified LPS (TOLERIN: 60 Co irradiated endotoxin preparation) decreases this biotransforming activity to a smaller extent. Phenobarbital, an inducer of this mono-oxygenase system, failed to induce in LPS-treated animals. In radio-detoxified LPS-treated rats, phenobarbital induced the mono-oxygenase and almost fully restored the biotransformation

Determination of bacterial endotoxins in blood of animals and humans subjected to irradiation

Energy Technology Data Exchange (ETDEWEB)

Kiselev, P N; Shchul' s, T S [Tsentral' nyj Nauchno-Issledovatel' skij Rentgeno-Radiologicheskij Inst., Leningrad (USSR)

1981-01-01

The content of Gram-negative bacterium endotoxins in the irradiated organism was determined by the use of actinomycin D sensitizing the organism to the effect of such toxins. Regularities in the accumulation of Gram-negative bacterium endotoxins in the irradiated organism were studied as well as the dependence of animal sensitization on the actinomycin D dose. Possibilities for the development of endotoxemia in oncologic patients in the process of radiotheraphy were traced. It is shown that the radiotherapy of the intestine containing large quantaties of bacteria and their toxins is accompanied by endotoxemia; in the first part of the radiotherapy course its manifestation depends on the irradiation dose; having reached a specific level, endotoxemia retains its symptoms till the end of irradiation. It is indicated that the determination of bacterium endotoxins is of interest when studying not only the development of endotoxemia in the organism exposed to radiation, hut also many other toxemic states.

Common studied polymorphisms do not affect plasma cytokine levels upon endotoxin exposure in humans

DEFF Research Database (Denmark)

Taudorf, Sarah; Krabbe, K.S.; Berg, R.M.

2008-01-01

The aim of this study was to investigate to what extent single nucleotide polymorphisms (SNPs) in promoter regions of genes of Toll-like receptor (TLR)-4, tumour necrosis factor (TNF)-alpha, interleukin (IL)-18, interferon (IFN)-gamma, IL-6 and IL-10 affect the cytokine response during a controlled......-607, IFN-gamma+874, IL-6-174, IL-10-592 and IL-10-1082) and endotoxin-induced changes in plasma levels of TNF-alpha, IL-6 and IL-10. IL-18 levels were unaffected by endotoxin. In conclusion, the investigated SNPs did not affect endotoxin-induced low-grade cytokine production of TNF-alpha, IL-6, IL-18 or IL......-10 in healthy young men. Previous reports of a major heritability factor in the inflammatory response may be due to other target genes or effects in older age groups or women Udgivelsesdato: 2008/4...

Changes in regional plasma extravasation in rats following endotoxin infusion

International Nuclear Information System (INIS)

van Lambalgen, A.A.; van den Bos, G.C.; Thijs, L.G.

1987-01-01

Regional differences in plasma extravasation during endotoxin shock in rats and a possible relationship with changes in regional blood flow were studied with radioactive isotopes ( 125 I-HSA, 51Cr-labeled red blood cells, microspheres) in anesthetized rats (pentobarbital). Shock was induced by intravenous infusion of endotoxin (Eschericia coli; 10 mg X kg-1) for 60 min (starting at t = 0); at t = 120 min, the experiments were terminated. These rats (n = 8) were compared with time-matched control rats (n = 8). A third group (rats killed 7.5 min after injection of 125 I-HSA, i.e., no extravasation; n = 8) served as baseline. The amount of plasma extravasated in 2 hr of endotoxin shock was significantly increased over control values in skin (by 67%), colon (88%), skeletal muscle (105%), stomach (230%), pancreas (300%), and diaphragm (1300%). Losses of 125 I-HSA into intestinal lumen and peritoneal cavity had also increased over control values by 146 and 380%, respectively. Blood flow was compromised in most organs except heart and diaphragm. Extravasation when normalized for total plasma supply was correlated with total blood supply; the more the blood supply decreased, the higher the normalized extravasation. In the diaphragm, however, blood supply and plasma leakage increased together. Decreased blood supply and plasma extravasation may be related but they could also be simultaneously occurring independent phenomena with a common origin

Single-Step Transepithelial PRK vs Alcohol-Assisted PRK in Myopia and Compound Myopic Astigmatism Correction

OpenAIRE

Kaluzny, Bartlomiej J.; Cieslinska, Iwona; Mosquera, Samuel A.; Verma, Shwetabh

2016-01-01

Abstract Transepithelial photorefractive keratectomy (tPRK), where both the epithelium and stroma are removed in a single-step, is a relatively new procedure of laser refractive error correction. This study compares the 3-month results of myopia and compound myopic astigmatism correction by tPRK or conventional alcohol-assisted PRK (aaPRK). This prospective, nonrandomized, case?control study recruited 148 consecutive patients; 93 underwent tPRK (173 eyes) and 55 aaPRK (103 eyes). Refractive r...

Structural studies of {delta}-endotoxin Cry 1 C from Bacillus thuringiensis

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, B.G.; Garratt, R.C.; Oliva, G. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica; Lemos, M.V.F. [UNESP, Jaboticabal, SP (Brazil). Dept. de Biologia Aplicada Agropecuaria; Arantes, O.M.N. [Universidade Estadual de Londrina, PR (Brazil). Dept. de Biologia Geral

1996-12-31

Full text. The {delta}-endotoxins are a family of crystal protein by a soil bacterium, Bacillus thuringiensis. The study of these proteins has been of great interest due to their highly specific activity against insects of the orders Lepidoptera, Diptera and Coleoptera. Thus, the {delta}a-endotoxins have been used for more than two decades as biological insecticides to control agricultural pests and, more recently, insects vectors of some diseases. The knowledge of their three-dimensional structures is very important to understand their mechanism of action and their high specificity. To date, the structure of only three proteins of the {delta}-endotoxins family have been reported: Cry3A, a coleopteran-specific toxin (beetle toxin){sup 1}, Cry1Aa, a lepidopteran-specific toxin (butterfly toxin){sup 2} and CytB, a dipteran-specific toxin (mosquito toxin){sup 3} Our work is aimed at the determination of the crystallographic structure by X-ray diffraction of {delta}-endotoxin Cry1C, also toxic to insects of the Lepidoptera order but towards families other than those affected by Cry1Aa. A comparison between these structures may lead to important conclusions about the reasons for the specificity and would allow the planning of mutants with more efficient activity. The cry1C gene was cloned into an adequate vector and expressed in an acrystalliferous B. thuringiensis strain. After cell culture and sporulation the microcrystals of Cry1C were separated by ultra-centrifugation in sacharose. The protoxin inclusion bodies were activated by commercial trpsin and the protease-resistant core was purified by anion-exchange chromatography. Crystallization experiments are being conducted in order to obtain single crystals suitable for diffraction measurements. We intend to use the Protein Crystallograph Station of the LNLS to collect data as soon as it is available and we have suitable crystals. (author) 3 refs.

Structural studies of δ-endotoxin Cry 1 C from Bacillus thuringiensis

International Nuclear Information System (INIS)

Guimaraes, B.G.; Garratt, R.C.; Oliva, G.; Lemos, M.V.F.; Arantes, O.M.N.

1996-01-01

Full text. The δ-endotoxins are a family of crystal protein by a soil bacterium, Bacillus thuringiensis. The study of these proteins has been of great interest due to their highly specific activity against insects of the orders Lepidoptera, Diptera and Coleoptera. Thus, the δa-endotoxins have been used for more than two decades as biological insecticides to control agricultural pests and, more recently, insects vectors of some diseases. The knowledge of their three-dimensional structures is very important to understand their mechanism of action and their high specificity. To date, the structure of only three proteins of the δ-endotoxins family have been reported: Cry3A, a coleopteran-specific toxin (beetle toxin) 1 , Cry1Aa, a lepidopteran-specific toxin (butterfly toxin) 2 and CytB, a dipteran-specific toxin (mosquito toxin) 3 Our work is aimed at the determination of the crystallographic structure by X-ray diffraction of δ-endotoxin Cry1C, also toxic to insects of the Lepidoptera order but towards families other than those affected by Cry1Aa. A comparison between these structures may lead to important conclusions about the reasons for the specificity and would allow the planning of mutants with more efficient activity. The cry1C gene was cloned into an adequate vector and expressed in an acrystalliferous B. thuringiensis strain. After cell culture and sporulation the microcrystals of Cry1C were separated by ultra-centrifugation in sacharose. The protoxin inclusion bodies were activated by commercial trpsin and the protease-resistant core was purified by anion-exchange chromatography. Crystallization experiments are being conducted in order to obtain single crystals suitable for diffraction measurements. We intend to use the Protein Crystallograph Station of the LNLS to collect data as soon as it is available and we have suitable crystals. (author)

Blockade by fenspiride of endotoxin-induced neutrophil migration in the rat.

Science.gov (United States)

Cunha, F Q; Boukili, M A; da Motta, J I; Vargaftig, B B; Ferreira, S H

1993-07-06

Fenspiride, an antiinflammatory drug with low anti-cyclooxygenase activity, administered orally at 60-200 mg/kg inhibited neutrophil migration into peritoneal and air pouches cavities as well as exudation into peritoneal cavities induced by endotoxin but not induced by carrageenin. Up to 100 microM, fenspiride failed to inhibit the in vitro release of a neutrophil chemotactic activity by endotoxin-stimulated macrophages and the in vivo migration into the peritoneal cavities induced by the supernatant of those macrophages. The release of tumour necrosis factor by stimulated macrophages was inhibited by fenspiride in a dose-dependent manner. These results suggest that the antiinflammatory effects of fenspiride are associated with the inhibition of the tumour necrosis factor release by resident macrophages.

Endotoxins in surgical instruments of hip arthroplasty.

Science.gov (United States)

Goveia, Vania Regina; Mendoza, Isabel Yovana Quispe; Guimarães, Gilberto Lima; Ercole, Flavia Falci; Couto, Bráulio Roberto Gonçalves Marinho; Leite, Edna Marilea Meireles; Stoianoff, Maria Aparecida Resende; Ferreira, José Antonio Guimarães

2016-01-01

To investigate endotoxins in sterilized surgical instruments used in hip arthroplasties. A descriptive exploratory study conducted in a public teaching hospital. Six types of surgical instruments were selected, namely: acetabulum rasp, femoral rasp, femoral head remover, chisel box, flexible bone reamer and femoral head test. The selection was based on the analysis of the difficulty in removing bone and blood residues during cleaning. The sample was made up of 60 surgical instruments, which were tested for endotoxins in three different stages. The EndosafeTM Gel-Clot LAL (Limulus Amebocyte Lysate method) was used. There was consistent gel formation with positive analysis in eight instruments, corresponding to 13.3%, being four femoral rasps and four bone reamers. Endotoxins in quantity ≥0.125 UE/mL were detected in 13.3% of the instruments tested. Investigar endotoxinas em instrumentais cirúrgicos esterilizados empregados em artroplastias do quadril. Estudo exploratório, descritivo, desenvolvido em um hospital público de ensino. Foram selecionados seis tipos de instrumentais, a saber: raspa acetabular, raspa femural, saca-cabeça de fêmur, formão box, fresa de fêmur e cabeça de prova de fêmur. A seleção foi feita a partir da análise da dificuldade para a remoção de resíduos de sangue e osso durante a limpeza. A amostra foi constituída por 60 instrumentais cirúrgicos, que foram testados para endotoxinas em três momentos distintos. Foi utilizado o método de gel-clot pelo Limulus Amebócito Lisado (LAL) Endosafe(tm). Houve formação de gel consistente com análise positiva em oito instrumentais, o que corresponde a 13,3%, sendo quatro raspas de fêmur e quatro fresas de fêmur. Foram detectadas endotoxinas em quantidade ≥0,125 UE/mL em 13,3% dos instrumentais testados.

cAMP Stimulates Transepithelial Short-Circuit Current and Fluid Transport Across Porcine Ciliary Epithelium.

Science.gov (United States)

Cheng, Angela King-Wah; Civan, Mortimer M; To, Chi-Ho; Do, Chi-Wai

2016-12-01

To investigate the effects of cAMP on transepithelial electrical parameters and fluid transport across porcine ciliary epithelium. Transepithelial electrical parameters were determined by mounting freshly isolated porcine ciliary epithelium in a modified Ussing chamber. Similarly, fluid movement across intact ciliary body was measured with a custom-made fluid flow chamber. Addition of 1, 10, and 100 μM 8-Br-cAMP (cAMP) to the aqueous side (nonpigmented ciliary epithelium, NPE) induced a sustained increase in short-circuit current (Isc). Addition of niflumic acid (NFA) to the aqueous surface effectively blocked the cAMP-induced Isc stimulation. The administration of cAMP to the stromal side (pigmented ciliary epithelium, PE) triggered a significant stimulation of Isc only at 100 μM. No additive effect was observed with bilateral application of cAMP. Likewise, forskolin caused a significant stimulation of Isc when applied to the aqueous side. Concomitantly, cAMP and forskolin increased fluid transport across porcine ciliary epithelium, and this stimulation was effectively inhibited by aqueous NFA. Depleting Cl- in the bathing solution abolished the baseline Isc and inhibited the subsequent stimulation by cAMP. Pretreatment with protein kinase A (PKA) blockers (H89/KT5720) significantly inhibited the cAMP- and forskolin-induced Isc responses. Our results suggest that cAMP triggers a sustained stimulation of Cl- and fluid transport across porcine ciliary epithelium; Cl- channels in the NPE cells are potentially a cellular site for this PKA-sensitive cAMP-mediated response.

Antibiotic-induced endotoxin release in patients with gram-negative urosepsis: a double-blind study comparing imipenem and ceftazidime

NARCIS (Netherlands)

Prins, J. M.; van Agtmael, M. A.; Kuijper, E. J.; van Deventer, S. J.; Speelman, P.

1995-01-01

The clinical significance of differences between antibiotics in endotoxin-liberating potential is unknown. Thirty patients with gram-negative urosepsis were randomized between imipenem and ceftazidime, which have, respectively, a low and a high endotoxin-liberating potential in vitro. In patients

Modeling the LPS Neutralization Activity of Anti-Endotoxins

Directory of Open Access Journals (Sweden)

Virapong Prachayasittikul

2009-05-01

Full Text Available Bacterial lipopolysaccharides (LPS, also known as endotoxins, are major structural components of the outer membrane of Gram-negative bacteria that serve as a barrier and protective shield between them and their surrounding environment. LPS is considered to be a major virulence factor as it strongly stimulates the secretion of pro-inflammatory cytokines which mediate the host immune response and culminating in septic shock. Quantitative structure-activity relationship studies of the LPS neutralization activities of anti-endotoxins were performed using charge and quantum chemical descriptors. Artificial neural network implementing the back-propagation algorithm was selected for the multivariate analysis. The predicted activities from leave-one-out cross-validation were well correlated with the experimental values as observed from the correlation coefficient and root mean square error of 0.930 and 0.162, respectively. Similarly, the external testing set also yielded good predictivity with correlation coefficient and root mean square error of 0.983 and 0.130. The model holds great potential for the rational design of novel and robust compounds with enhanced neutralization activity.

Cytokine release from human peripheral blood leucocytes incubated with endotoxin with and without prior infection with influenza virus

DEFF Research Database (Denmark)

Banner, Jytte; Smith, H; Sweet, C

1993-01-01

Previous work with a neonatal ferret model for human SIDS had indicated that inflammation caused by a combination of influenza virus and bacterial endotoxin may be a cause of human SIDS. To determine whether cytokines may be involved in this inflammatory response, levels of interleukin (IL)-1 beta......, IL-6 and tumour necrosis factor (TNF)-alpha were examined, using ELISA assays, in culture supernatants of human peripheral blood leucocytes infected with influenza virus and subsequently incubated with endotoxin. Levels of TNF-alpha were increased compared to cells incubated with virus or endotoxin...... alone. Levels of IL-1 beta were also increased whereas levels of IL-6 were generally not enhanced. Cytokines appeared within 1-2 h of stimulation with virus or endotoxin and increased subsequently to reach maximum titres between 16 and 20 h post treatment. While levels of cytokine were much lower when...

Detection of bacterial endotoxin in food: New planar interdigital sensors based approach

KAUST Repository

Abdul Rahman, Mohd Syaifudin

2013-02-01

Food poisoning caused by endotoxins or Lipopolysaccharide (LPS) are associated with Gram-negative bacteria. Two major food-borne pathogens, Escherichia coli and Salmonella are examples of Gram-negative bacteria which cause a large number of outbreaks of food poisoning. New types of planar interdigital sensors have been fabricated with different coating materials to assess their response to endotoxins. A carboxyl-functional polymer, APTES (3-Aminopropyltriethoxysilane) and Thionine were chosen to be coated onto FR4 interdigital sensors. The chosen coating materials have carboxylic or amine functional groups, which were optimized to be stable in water. All coated sensors were immobilized with PmB (Polymyxin B) which has specific binding properties to LPS. The sensors were tested with different concentrations of LPS O111:B4, ranging from 0.1 to 1000 μg/ml. Analyses of sensors\\' performance were based on the impedance spectroscopy method. The impedance spectra were modeled using a constant phase-element (CPE) equivalent circuit, and a principal component analysis (PCA) was used for data classification. Sensor coated with APTES has shown better selectivity for LPS detection. The experiments were repeated by coating APTES and immobilizing PmB to a new improve designed of novel interdigital sensors (thin film silicon based sensors). These sensors were observed to have better sensitivity and selectivity to the target biomolecules of LPS. Further experiments were conducted to study the effect of different coating thickness on sensor sensitivity, selectivity and stability. Different food samples contaminated with endotoxin were also tested to verify that the interdigital sensing approach is able to be used for endotoxin detection. © 2012 Elsevier Ltd. All rights reserved.

Measurement of endotoxin. II. Comparison of reactivities measured by radioimmunoassay and with the limulus test

Energy Technology Data Exchange (ETDEWEB)

Kimura, H [Okayama Univ. (Japan). School of Medicine

1976-08-01

Various endotoxins and the ether extracts of grampositive bacteria were measured immunologically by radioimmunoassay and also biologically by the Limulus test. The minimum amount of endotoxin detectable with the Limulus test was in the range from 1 ng/ml to 1 ..mu..g/ml, with the lysate of sensitivity, 100 ng ml (E. coli 0111: B4(B) lipopolysaccharide). On the other hand, by the radioimmunoassay they were estimated in the range of 0.3 to 10 times of dry weight. Endotoxin-like activity was detected in the ether extracts of grampositive bacteria at a minimum concentration between 1 ..mu..g/ml and 100 ..mu..g/ml with the Limulus test. However, most of them were estimated by the radioimmunoassay to be under 1/50 of dry weight. Various substances such as thrombin, thromboplastin, polynosinic-polycytidylic acid, polyadenylic-polyuridylic acid, carrageenan and human colonic mucosal antigen had cross reactivities of various degrees in the minimum concentration from 10 ..mu..g/ml to 10 mg/ml. Compounds such as thrombin and thromboplastin cross-reacting in the Limulus test were scarcely measured by the radioimmunoassay except for polynucleotides. From this study, it has become clear that the radioimmunoassay method is quite specific and accurate for quantitative measurements of endotoxin.

Immunological studies on albino rats against crude endotoxins of ...

African Journals Online (AJOL)

The genus Aeromonas comprises a group of organisms widely distributed in the environment, isolated from water, shallow tube wells, dug wells, piped water supply from sewage, children and adults with diarrhoea, and associated with disease in animals and man. The present work studied the effect of crude endotoxin ...

[The importance of endotoxin producing bacterias for practical purposes

Science.gov (United States)

Schimmel, Dietrich

1994-01-01

Lipopolysaccharides (endotoxin) cause according to resorption out of the intestinal tract or aerogenic inhalation or by a septic infection clinical signs. The clinical reactions are praeshock symptoms, acute forms of shock and death. The experimental intratracheally administration of lipopolysaccharides into calves caused pneumonic lesions without bacterial experimental infection.

[The protective properties of the endotoxin protein].

Science.gov (United States)

Levenson, V I; Belkin, Z P; Egorova, T P

1991-08-01

The isolation and properties of endotoxin protein, or lipid A-associated protein (LAP), from Shigella sonnei were described earlier (Zh. mikrobiol. epidemiol. immunobiol., 1991, No. 4, pp. 11-17, and No. 7). In this report the data on its protective activity are presented. In experiments on mice one nanogram of LAP injected i. v. protected 50% of the animals against i. p. challenge with 40 LD50 of virulent S. sonnei. Guinea pigs injected s. c. with 10 micrograms of LAP were protected against local (keratoconjunctival) challenge with S. sonnei, the efficiency of immunization being 58%. LAP preparations containing no detectable amounts of O-antigen (less than 0.003%) were found to have a protective effect. Hyperimmune anti-LAP rabbit serum prevented local infection when incubated with S. sonnei challenge inoculum before injection into guinea pigs. Both active and passive protection induced by LAP was specific since no effect was observed in animals challenged with Shigella flexneri. In the homologous system the protective effect of anti-LAP serum was abolished by the addition of protein-free LPS. These results are compatible with the hypothesis that the protective activity of LAP depends on the presence of minute amounts of O-antigen whose immunogenic effect is greatly amplified by the protein component of the natural endotoxin complex.

Determinants of house dust, endotoxin, and β-(1→3)-d-glucan in homes of Danish children

DEFF Research Database (Denmark)

Holst, Gitte Juel; Høst, Arne; Doekes, G

2015-01-01

Little is known about the geographic variation and determinants of bacterial endotoxin and β -(1,3)-d-glucan in Danish house dust. In a population of 317 children, we: (i) described loads and concentrations of floor dust, endotoxin, and β-(1→3)-d-glucan and (ii) their correlations and (iii......) assessed their determinants; (iv) Finally, we compared our findings with previous European studies. Bedroom floor dust was analyzed for endotoxin content by the kinetic limulus amoebocyte lysate assay and for β-(1→3)-d-glucan by the inhibition enzyme immunoassay. The parents answered questions regarding...... potential determinants. We found: geometric means (geometric standard deviations) 186 mg/m(2) (4.3) for dust; 5.46 × 10(3) EU/m(2) (8.0) and 31.1 × 10(3) EU/g (2.6) for endotoxin; and 142 μg/m(2) (14.3) and 0.71 × 10(3) μg/g (7.3) for β-(1→3)-d-glucan. High correlations (r > 0.75) were found between floor...

Relation of structure to function for the US reference standard endotoxin after exposure to 60Co radiation

International Nuclear Information System (INIS)

Csako, G.; Suba, E.A.; Ahlgren, A.; Tsai, C.M.; Elin, R.J.

1986-01-01

The structure and function of the highly purified US reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a 60 Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins

c-Kit mutation reduce intestinal epithelial cell proliferation and migration, but not influence intestinal permeability stimulated by lipopolysaccharide.

Science.gov (United States)

Xue, Hong; Wang, Feng Yun; Kang, Qian; Tang, Xu Dong

2018-06-20

The proto-oncogene c-kit, as a marker of interstitial cells of Cajal (ICCs) in the gastrointestinal tract, plays an important role in the ICCs. Although limited evidences showed c-kit is present in the colonic epithelium but its roles remain unclear. In the present study, we aimed to investigate the expression, location and function of c-kit in the intestinal epithelium. Immunofluorescence, western blotting, and RT-PCR were performed to detect the expression and location of c-kit in the intestinal mucosa of WT mice. We investigated intestinal epithelial proliferation and migration in vivo by performing 5-Bromodeoxyuridine (BrdU) incorporation and Ki-67 staining in WT and Wads m/m mice. An Ussing chamber with fluorescein-isothiocyanate dextran 4000 was used to detect the transepithelial electric resistance (TER), short circuit current (ISC) and permeability across ex vivo colon segments under control and endotoxaemia conditions. We demonstrated that c-kit was located and expressed in the gut crypt compartment in WT mice, which was demonstrated in the c-kit mutant mice (Wads m/m ). In addition, both the number of proliferating cells and the percentage of the distance migrated were lower in the Wads m/m mice than those in the WT mice. Moreover, the intestinal permeability, TER and tight junction were unaltered in the Wads m/m mice under endotoxic conditions compared with those in both the control condition and the WT mice. Altogether, these observations imply that the expression of c-kit in the colonic epithelium is involved in the proliferation and permeability of the colonic epithelium. Copyright © 2018. Published by Elsevier GmbH.

Spectral OCT with speckle contrast reduction for evaluation of the healing process after PRK and transepithelial PRK

OpenAIRE

Kaluzny, Bartlomiej J.; Szkulmowski, Maciej; Bukowska, Danuta M.; Wojtkowski, Maciej

2014-01-01

We evaluate Spectral OCT (SOCT) with a speckle contrast reduction technique using resonant scanner for assessment of corneal surface changes after excimer laser photorefractive keratectomy (PRK) and we compare healing process between conventional PRK and transepithelial PRK. The measurements were performed before and after the surgery. Obtained results show that SOCT with a resonant scanner speckle contrast reduction is capable of providing information regarding the healing process after PRK....

Developments in permeable and low permeability barriers

International Nuclear Information System (INIS)

Jefferis, S.A.; Norris, G.H.; Thomas, A.O.

1997-01-01

The concept of the reactive treatment zone whereby pollutants are attenuated as they move along a pathway in the ground has enabled a re-thinking of many of the concepts of containment. In particular it offers the potential for the control of the flux from a contaminated area by controlling the contaminant concentration in the pathway(s) as well as or instead of using a low permeability barrier. The paper outlines the basic concepts of the reactive treatment zone and the use of permeable and low permeability reactive systems. The paper then gives a case history of the installation of a permeable barrier using an in-situ reaction chamber

Endotoxins in surgical instruments of hip arthroplasty

OpenAIRE

Goveia, Vania Regina; Mendoza, Isabel Yovana Quispe; Guimarães, Gilberto Lima; Ercole, Flavia Falci; Couto, Bráulio Roberto Gonçalves Marinho; Leite, Edna Marilea Meireles; Stoianoff, Maria Aparecida Resende; Ferreira, José Antonio Guimarães

2016-01-01

Abstract OBJECTIVE To investigate endotoxins in sterilized surgical instruments used in hip arthroplasties. METHOD A descriptive exploratory study conducted in a public teaching hospital. Six types of surgical instruments were selected, namely: acetabulum rasp, femoral rasp, femoral head remover, chisel box, flexible bone reamer and femoral head test. The selection was based on the analysis of the difficulty in removing bone and blood residues during cleaning. The sample was made up of 60...

Lipopolysaccharide precipitates hepatic encephalopathy and increases blood-brain barrier permeability in mice with acute liver failure.

Science.gov (United States)

Chastre, Anne; Bélanger, Mireille; Nguyen, Bich N; Butterworth, Roger F

2014-03-01

Acute liver failure (ALF) is frequently complicated by infection leading to precipitation of central nervous system complications such as hepatic encephalopathy (HE) and increased mortality. There is evidence to suggest that when infection occurs in ALF patients, the resulting pro-inflammatory mechanisms may be amplified that could, in turn, have a major impact on blood-brain barrier (BBB) function. The aim of this study was to investigate the role of endotoxemia on the progression of encephalopathy in relation to BBB permeability during ALF. Adult male C57-BL6 mice with ALF resulting from azoxymethane-induced toxic liver injury were administered trace amounts of the endotoxin component lipopolysaccharide (LPS). Effects on the magnitude of the systemic inflammatory response, liver pathology and BBB integrity were measured as a function of progression of HE, defined as time to loss of corneal reflex (coma). Lipopolysaccharide caused additional two- to seven-fold (P liver pathology and associated increases of circulating transaminases as well as increased hyperammonaemia consistent with a further loss of viable hepatocytes. LPS treatment of ALF mice led to a rapid precipitation of hepatic coma and the BBB became permeable to the 25-kDa protein immunoglobulin G (IgG). This extravasation of IgG was accompanied by ignificant up-regulation of matrix metalloproteinase-9 (MMP-9), an endopeptidase known to modulate opening of the BBB in a wide range of neurological disorders. These findings represent the first direct evidence of inflammation-related BBB permeability changes in ALF. © 2013 John Wiley & Sons A/S. Publishing by John Wiley & Sons Ltd.

Induction of generalized Shwartzman reaction (GSR) in irradiated rabbits by a single injection of endotoxin

International Nuclear Information System (INIS)

Wronowski, T.; Uchanska-Dudzinska, B.; Teisseyre, E.; Kopec, M.

1976-01-01

Rabbits were prepared to GSR by either a single dose 30 μg/kg of Salmonella enteritidis endotoxin or by a single whole-body exposure to 850 R of x ray. After 24 hrs provocative dose of endotoxin 50 μg/kg was injected. Histological examinations of kidneys revealed that GSR occurred with equal frequency in both groups of rabbits but was more severe in the animals prepared by irradiation. Protamine gelation test detected soluble fibrin complexes in plasma in about 50% of rabbits 24 hrs after either of the preparatory procedures and virtually in 100% after the provocative endotoxin dose. During the preparatory phase of GSR the irradiation induced a profound decrease in blood lymphocyte count and in the weight of thymus and spleen. It is postulated that early postexposure lysis of lymphatic cells participates in mechanisms leading to thrombotic phenomena after irradiation

Effect of diatrizoate (Angiografin) on the aortic endothelium in rats during the course of endotoxin shock

Energy Technology Data Exchange (ETDEWEB)

Gospos, C; Freudenberg, N; Hauenstein, K H; Kauffmann, G W; Koch, H K

1982-08-01

Investigations have been carried out on the endothelial changes produced by diatrizoate (Angiografin) during the course of endotoxin shock. A single injection was given directly into the aorta of 1 ml of the contrast medium, with an iodine content of 300 mg/ml. The increased proliferation of the aortic endothelium could be shown to be due to the endotoxin shock, but was not further increased by administration of the contrast medium.

The role of endotoxin in grain dust exposure and airway obstruction.

Science.gov (United States)

Von Essen, S

1997-05-01

Grain dust exposure is a common cause of respiratory symptoms in grain workers, feed mill employees, and farmers. Many of these workers develop wheezing and acute and chronic bronchitis symptoms, which can be associated with obstructive changes on pulmonary function testing. It has recently been demonstrated that grain dust exposure causes neutrophilic airways inflammation and systemic symptoms related to release of interleukin-1, tumor necrosis factor, interleukin-6, and other mediators of inflammation. Although grain dust is a heterogenous substance, endotoxin has received the greatest amount of attention as a possible cause of the airway inflammation that occurs after grain dust exposure. Although endotoxin undoubtedly causes a portion of the changes seen after grain dust exposure, it is becoming clear that other substances play a role as well.

Crustal permeability

Science.gov (United States)

Gleeson, Tom; Ingebritsen, Steven E.

2016-01-01

Permeability is the primary control on fluid flow in the Earth’s crust and is key to a surprisingly wide range of geological processes, because it controls the advection of heat and solutes and the generation of anomalous pore pressures.  The practical importance of permeability – and the potential for large, dynamic changes in permeability – is highlighted by ongoing issues associated with hydraulic fracturing for hydrocarbon production (“fracking”), enhanced geothermal systems, and geologic carbon sequestration.  Although there are thousands of research papers on crustal permeability, this is the first book-length treatment.  This book bridges the historical dichotomy between the hydrogeologic perspective of permeability as a static material property and the perspective of other Earth scientists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. 

Differential effects of air conditioning type on residential endotoxin levels in a semi-arid climate.

Science.gov (United States)

Johnston, J D; Kruman, B A; Nelson, M C; Merrill, R M; Graul, R J; Hoybjerg, T G; Tuttle, S C; Myers, S J; Cook, R B; Weber, K S

2017-09-01

Residential endotoxin exposure is associated with protective and pathogenic health outcomes. Evaporative coolers, an energy-efficient type of air conditioner used in dry climates, are a potential source of indoor endotoxins; however, this association is largely unstudied. We collected settled dust biannually from four locations in homes with evaporative coolers (n=18) and central air conditioners (n=22) in Utah County, Utah (USA), during winter (Jan-Apr) and summer (Aug-Sept), 2014. Dust samples (n=281) were analyzed by the Limulus amebocyte lysate test. Housing factors were measured by survey, and indoor temperature and relative humidity measures were collected during both seasons. Endotoxin concentrations (EU/mg) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons. Endotoxin surface loads (EU/m 2 ) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons and in upholstered furniture during winter. For the nine significant season-by-location comparisons, EU/mg and EU/m 2 were approximately three to six times greater in homes using evaporative coolers. A plausible explanation for these findings is that evaporative coolers serve as a reservoir and distribution system for Gram-negative bacteria or their cell wall components in homes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

DMPD: The role of macrophages in the hypothalamic-pituitary-adrenal activation inresponse to endotoxin (LPS). [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available response to endotoxin (LPS). Derijk RH, van Rooijen N, Berkenbosch F. Res Immunol. 1992 Feb;143(2):224-9. (....e hypothalamic-pituitary-adrenal activation inresponse to endotoxin (LPS). Authors Derijk RH, van Rooijen N, Berk

Sex differences in the pro-inflammatory cytokine response to endotoxin unfold in vivo but not ex vivo in healthy humans.

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Wegner, Alexander; Benson, Sven; Rebernik, Laura; Spreitzer, Ingo; Jäger, Marcus; Schedlowski, Manfred; Elsenbruch, Sigrid; Engler, Harald

2017-07-01

Clinical data indicate that inflammatory responses differ across sexes, but the mechanisms remain elusive. Herein, we assessed in vivo and ex vivo cytokine responses to bacterial endotoxin in healthy men and women to elucidate the role of systemic and cellular factors underlying sex differences in inflammatory responses. Participants received an i.v. injection of low-dose endotoxin (0.4 ng/kg body mass), and plasma TNF-α and IL-6 responses were analyzed over a period of 6 h. In parallel, ex vivo cytokine production was measured in endotoxin-stimulated blood samples obtained immediately before in vivo endotoxin administration. As glucocorticoids (GCs) play an important role in the negative feedback regulation of the inflammatory response, we additionally analyzed plasma cortisol concentrations and ex vivo GC sensitivity of cytokine production. Results revealed greater in vivo pro-inflammatory responses in women compared with men, with significantly higher increases in plasma TNF-α and IL-6 concentrations. In addition, the endotoxin-induced rise in plasma cortisol was more pronounced in women. In contrast, no sex differences in ex vivo cytokine production and GC sensitivity were observed. Together, these findings demonstrate major differences in in vivo and ex vivo responses to endotoxin and underscore the importance of systemic factors underlying sex differences in the inflammatory response.

Multiple linear regression and artificial neural networks for delta-endotoxin and protease yields modelling of Bacillus thuringiensis.

Science.gov (United States)

Ennouri, Karim; Ben Ayed, Rayda; Triki, Mohamed Ali; Ottaviani, Ennio; Mazzarello, Maura; Hertelli, Fathi; Zouari, Nabil

2017-07-01

The aim of the present work was to develop a model that supplies accurate predictions of the yields of delta-endotoxins and proteases produced by B. thuringiensis var. kurstaki HD-1. Using available medium ingredients as variables, a mathematical method, based on Plackett-Burman design (PB), was employed to analyze and compare data generated by the Bootstrap method and processed by multiple linear regressions (MLR) and artificial neural networks (ANN) including multilayer perceptron (MLP) and radial basis function (RBF) models. The predictive ability of these models was evaluated by comparison of output data through the determination of coefficient (R 2 ) and mean square error (MSE) values. The results demonstrate that the prediction of the yields of delta-endotoxin and protease was more accurate by ANN technique (87 and 89% for delta-endotoxin and protease determination coefficients, respectively) when compared with MLR method (73.1 and 77.2% for delta-endotoxin and protease determination coefficients, respectively), suggesting that the proposed ANNs, especially MLP, is a suitable new approach for determining yields of bacterial products that allow us to make more appropriate predictions in a shorter time and with less engineering effort.

Optimization of airborne endotoxin exposure assessment: Effects of filter type, transport conditions, extraction solutions, and storage of samples and extracts

NARCIS (Netherlands)

Spaan, S.; Heederik, D.J.J.; Thorne, P.S.; Wouters, I.M.

2007-01-01

Endotoxin exposure occurs in homes and occupational environments and is known to cause adverse health effects. In order to compare results from different studies and establish standards, airborne endotoxin exposures should be assessed using standardized methods. Although the European Committee for

Mitochondrial DAMPs induce endotoxin tolerance in human monocytes: an observation in patients with myocardial infarction.

Directory of Open Access Journals (Sweden)

Irene Fernández-Ruiz

Full Text Available Monocyte exposure to mitochondrial Danger Associated Molecular Patterns (DAMPs, including mitochondrial DNA (mtDNA, induces a transient state in which these cells are refractory to further endotoxin stimulation. In this context, IRAK-M up-regulation and impaired p65 activity were observed. This phenomenon, termed endotoxin tolerance (ET, is characterized by decreased production of cytokines in response to the pro-inflammatory stimulus. We also show that monocytes isolated from patients with myocardial infarction (MI exhibited high levels of circulating mtDNA, which correlated with ET status. Moreover, a significant incidence of infection was observed in those patients with a strong tolerant phenotype. The present data extend our current understanding of the implications of endotoxin tolerance. Furthermore, our data suggest that the levels of mitochondrial antigens in plasma, such as plasma mtDNA, should be useful as a marker of increased risk of susceptibility to nosocomial infections in MI and in other pathologies involving tissue damage.

Analysis of different coating thickness on new type of planar interdigital sensors for endotoxin detection

KAUST Repository

Syaifudin, A. R Mohd

2013-05-01

New types of planar interdigital sensors have been fabricated on Silicon/Silicon Dioxide (Si/SiO2) wafers. The sensors were coated with pre-cursor silica functionalized with APTES (3-aminopropyltrietoxysilane) at different thicknesses. All sensors were then immobilized with Polymyxin, B (PmB). PmB is an antimicrobial peptide produced by the Gram-positive bacterium-Bacillus, has been immobilized on the coated sensors because of its specific binding properties to endotoxin. Studies were conducted to analyze the effect of different thicknesses of coatings on the sensitivity and selectivity of the sensors. It was observed sensors coated with 3 layers of coating has better sensitivity and selectivity to the target molecules (endotoxin) compared to sensors with 5 layers of coating. The repeatability and stability of the coated sensors were tested by multiple standard endotoxin measurement and it was observed that the sensors give a good reproducibility and stability up to six continuous measurements before the coating degrades. © 2013 IEEE.

Probiotic yogurt in the elderly with intestinal bacterial overgrowth: endotoxaemia and innate immune functions

DEFF Research Database (Denmark)

Schiffrin, E.J.; Parlesak, Alexandr; Bode, C.

2009-01-01

and after a period of 4 weeks of probiotic yoghurt administration. Intestinal permeability, plasma endotoxin levels, phagocytic activity of leucocytes, cytokine production by monocytes and free radical response of neutrophils were determined. Intestinal permeability was similar for the two groups...... and was unaffected by probiotic treatment. Both plasma endotoxin levels and the basal phagocytic activity of leucocytes decreased after yoghurt intake in the two groups. Exposure of monocytes and neutrophils ex vivo led to an increased cytokine response and free radical response, respectively. The normalisation...

Plasma endothelin-1 and tumor necrosis factor-alpha concentrations in pregnant and cyclic rats after low-dose endotoxin infusion

NARCIS (Netherlands)

Faas, MM; Bakker, WW; Valkhof, N; Baller, JFW; Schuiling, GA

Plasma endothelin-1 and tumor necrosis factor-alpha were determined in pregnant and cyclic rats after infusion of either endotoxin (1.0 mu g/kg of body weight) or saline solution. After endotoxin, but not after saline solution, administration there was a transient endothelin-1 response in pregnant

Some effects of prostaglandins E1 and E2 and of endotoxin injected into the hypothalamus of young chicks: dissociation between endotoxin fever and the effects of prostaglandins.

Science.gov (United States)

Artunkal, A A; Marley, E; Stephenson, J D

1977-09-01

Prostaglandins E1 and E2 elevated body temperature of young chicks when injected into the hypothalamus at thermoneutrality (31 degrees C). In contrast, they lowered body temperature when so injected below thermoneutrality (16degreesC): the relation of the fall in body temperature to increased heat loss and decreased heat production was examined. 2 The above effects below thermoneutrality were potentiated by pretreatment with inhibitors of prostaglandin synthetase and possible reasons for this potentation are given. 3 The O-somatic antigen of Shigella dysenteriae consistently evoked hyperthermia when injected into the hypothalamus, irrespective of whether the chicks were within or below thermoneutrality. 4 Pretreatment with prostaglandin synthetase inhibitors failed to prevent the onset of endotoxin fever; however, duration of the fever, induced by intrahypothalamic injection of the O-somatic antigen of Shigella dysenteriae was reduced. 5 The intrahypothalamic injection, belwo thermoneutrality of prostaglandins E1, E2, noradrenaline, 5-hydroxytryptamine or carbachol reversed endotoxin fever, inducing even substantial falls in body temperature. 6 While the results cast some doubts on the role of prostaglandins of the E series as mediators of endotoxin fever in chicks, they cannot be eliminated as mediators until the significance of the reduction in duration of the pyrexic response by indomethacin and 5,8,11,14-eicosatetraynoic acid, and the degree of synthesis inhibition attained, are known.

The putative P-gp inhibitor telmisartan does not affect the transcellular permeability and cellular uptake of the calcium channel antagonist verapamil in the P-glycoprotein expressing cell line MDCK II MDR1

DEFF Research Database (Denmark)

Saaby, Lasse; Tfelt-Hansen, Peer; Brodin, Birger

2015-01-01

monolayers with a permeability of 5.7 × 10−5 cm sec−1 compared to an apical to basolateral permeability of 1.3 × 10−5 cm sec-1. The efflux could be inhibited with the P-gp inhibitor zosuquidar. Zosuquidar (0.4 μmol/L) reduced the efflux ratio (PB-A/PA-B) for verapamil 4.6–1.6. The presence of telmisartan......Verapamil is used in high doses for the treatment of cluster headache. Verapamil has been described as a P-glycoprotein (P-gp, ABCB1) substrate. We wished to evaluate in vitro whether co administration of a P-gp inhibitor with verapamil could be a feasible strategy for increasing CNS uptake...... of verapamil. Fluxes of radiolabelled verapamil across MDCK II MDR1 monolayers were measured in the absence and presence of the putative P-gp inhibitor telmisartan (a clinically approved drug compound). Verapamil displayed a vectorial basolateral-to-apical transepithelial efflux across the MDCK II MDR1...

A study on bacterial endotoxins test of radiopharmaceuticals with limulus agent

Energy Technology Data Exchange (ETDEWEB)

Suozhen, Bai; Kai, Luyu; Cheng, Luo [Academia Sinica, Beijing, BJ (China). Inst. of Atomic Energy; Ruiting, Zhang; Zhenmin, Xia [National Inst. for the Control of Pharmaceutical and Biological Products (China)

1989-08-01

The feasibility of endotoxins test of radiopharmaceuticals with limulus agent and the approach to take off the inhibition/enhancement effect of radiopharmaceuticals on limulus agent have been studied. Results of the test for 8 radiopharmaceuticals have been given.

Radiation induced alterations in the endotoxin of S. typhimurium

Energy Technology Data Exchange (ETDEWEB)

Nerkar, D P; Govekar, L G; Kumta, U S; Sreenivasan, A [Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.

1977-09-01

The lipopolysaccharide (LPS) of S. typhimurium has been shown to be significantly detoxified after in vivo irradiation at 500 krad. Radiation is thus a useful method for converting endotoxin into toxoid. The structural alterations in the detoxified LPS were shown to be mainly in the lipid A molecule, resulting in the loss of ..beta..-hydroxymyristic acid.

40 CFR 180.1154 - CryIA(c) and CryIC derived delta-endotoxins of Bacillus thuringiensis var. kurstaki encapsulated...

Science.gov (United States)

2010-07-01

... expression plasmid and cloning vector genetic constructs. 180.1154 Section 180.1154 Protection of Environment... RESIDUES IN FOOD Exemptions From Tolerances § 180.1154 CryIA(c) and CryIC derived delta-endotoxins of... plasmid and cloning vector genetic constructs. CryIA(c) and CryIC derived delta-endotoxins of Bacillus...

House dust mite allergen Der p 1 effects on sinonasal epithelial tight junctions.

Science.gov (United States)

Henriquez, Oswaldo A; Den Beste, Kyle; Hoddeson, Elizabeth K; Parkos, Charles A; Nusrat, Asma; Wise, Sarah K

2013-08-01

Epithelial permeability is highly dependent upon the integrity of tight junctions, which are cell-cell adhesion complexes located at the apical aspect of the lateral membrane of polarized epithelial cells. We hypothesize that sinonasal epithelial exposure to Der p 1 house dust mite antigen decreases expression of tight junction proteins (TJPs), representing a potential mechanism for increased permeability and presentation of antigens across the sinonasal epithelial layer. Confluent cultured primary human sinonasal epithelial cells were exposed to recombinant Der p 1 antigen vs control, and transepithelial resistance measurements were performed over 24 hours. Antibody staining for a panel of TJPs was examined with immunofluorescence/confocal microscopy and Western blotting. Tissue for these experiments was obtained from 4 patients total. Der p 1 exposed sinonasal cells showed a marked decrease in transepithelial resistance when compared to control cells. In addition, results of Western immunoblot and immunofluorescent labeling demonstrated decreased expression of TJPs claudin-1 and junction adhesion molecule-A (JAM-A) in Der p 1-exposed cultured sinonasal cells vs controls. Der p 1 antigen exposure decreases sinonasal epithelium TJP expression, most notably seen in JAM-A and claudin-1 in these preliminary experiments. This decreased TJP expression likely contributes to increased epithelial permeability and represents a potential mechanism for transepithelial antigen exposure in allergic rhinitis. © 2013 ARS-AAOA, LLC.

House Dust Mite Der p 1 Effects on Sinonasal Epithelial Tight Junctions

Science.gov (United States)

Henriquez, Oswaldo A.; Beste, Kyle Den; Hoddeson, Elizabeth K.; Parkos, Charles A.; Nusrat, Asma; Wise, Sarah K.

2013-01-01

Background Epithelial permeability is highly dependent upon the integrity of tight junctions, cell-cell adhesion complexes located at the apical aspect of the lateral membrane of polarized epithelial cells. We hypothesize that sinonasal epithelial exposure to Der p 1 house dust mite antigen decreases expression of tight junction proteins (TJPs), representing a potential mechanism for increased permeability and presentation of antigens across the sinonasal epithelial layer. Methods Confluent cultured primary human sinonasal epithelial cells were exposed to recombinant Der p 1 antigen versus control, and transepithelial resistance measurements were performed over 24 hours. Antibody staining for a panel of tight junction proteins was examined with immunofluorescence/confocal microscopy and Western blotting. Tissue for these experiments was obtained from 4 patients total. Results Der p 1 exposed sinonasal cells showed a marked decrease in transepithelial resistance when compared to control cells. In addition, results of Western immunoblot and immunofluorescent labeling demonstrated decreased expression of TJPs claudin-1 and junction adhesion molecule-A (JAM-A) in Der p 1 exposed cultured sinonasal cells versus controls. Conclusion Der p 1 antigen exposure decreases sinonasal epithelium TJP expression, most notably seen in JAM-A and claudin-1 in these preliminary experiments. This decreased TJP expression likely contributes to increased epithelial permeability and represents a potential mechanism for transepithelial antigen exposure in allergic rhinitis. PMID:23592402

Clinical observation of transepithelial photorefractive keratectomy for myopia

Directory of Open Access Journals (Sweden)

Xiao-Ning Yang

2013-10-01

Full Text Available AIM: To assess the effectiveness and safety of transepithelial photorefractive keratectomy(TransPRKusing the AMARIS laser platform. METHODS: Eighty myopic cases(156 eyeswith or without astigmatism were treated by TransPRK. In all eyes, treatments were planned with Custom Ablation Manager Software and ablations performed with the SCHWIND AMARIS system. Clinical outcomes of visual acuity, manifest refraction, intraocular pressure, and corneal topography were observed and analyzed. The follow-up period was one year.RESULTS: All patients completed the 1-year follow-up. After one-year follow-up, 47 cases(92 eyes, 58.8%achieved an uncorrected distance visual acuity(UDVA≥1.0. Twenty cases(40 eyes, 25%was 0.8 and 13 cases(24 eyes, 16.3%was 0.6. Sixty-three cases(121 eyes, 78.8%were close to or above best corrected visual acuity(BCVA. Seventeen cases(34 eyes, 21.2%were slightly lower than BCVA 1 row or two. Nine cases(18 eyes, 11.3%got dry eye postoperatively. 16 cases(32 eyes, 20%complain of glare and poor night vision. CONCLUSION: The results show that TransPRK for myopia with or without astigmatism is safe and effective. The postoperative visual outcomes are stable.

Endotoxin and tumor necrosis factor-receptor levels in portal and hepatic vein of patients with alcoholic liver cirrhosis receiving elective transjugular intrahepatic portosystemic shunt

DEFF Research Database (Denmark)

Trebicka, Jonel; Krag, Aleksander; Gansweid, Stefan

2011-01-01

In cirrhosis portal hypertension can promote bacterial translocation and increase serum endotoxin levels. Vice versa, endotoxin aggravates portal hypertension by induction of systemic and splanchnic vasodilation, and by triggering hepatic inflammatory response via tumor necrosis factor α (TNFα......). However, the hepatic elimination of endotoxin in cirrhotic patients with severe portal hypertension, in the absence of acute complications, has not been investigated so far....

Structural and functional features of self-assembling protein nanoparticles produced in endotoxin-free Escherichia coli.

Science.gov (United States)

Rueda, Fabián; Céspedes, María Virtudes; Sánchez-Chardi, Alejandro; Seras-Franzoso, Joaquin; Pesarrodona, Mireia; Ferrer-Miralles, Neus; Vázquez, Esther; Rinas, Ursula; Unzueta, Ugutz; Mamat, Uwe; Mangues, Ramón; García-Fruitós, Elena; Villaverde, Antonio

2016-04-08

Production of recombinant drugs in process-friendly endotoxin-free bacterial factories targets to a lessened complexity of the purification process combined with minimized biological hazards during product application. The development of nanostructured recombinant materials in innovative nanomedical activities expands such a need beyond plain functional polypeptides to complex protein assemblies. While Escherichia coli has been recently modified for the production of endotoxin-free proteins, no data has been so far recorded regarding how the system performs in the fabrication of smart nanostructured materials. We have here explored the nanoarchitecture and in vitro and in vivo functionalities of CXCR4-targeted, self-assembling protein nanoparticles intended for intracellular delivery of drugs and imaging agents in colorectal cancer. Interestingly, endotoxin-free materials exhibit a distinguishable architecture and altered size and target cell penetrability than counterparts produced in conventional E. coli strains. These variant nanoparticles show an eventual proper biodistribution and highly specific and exclusive accumulation in tumor upon administration in colorectal cancer mice models, indicating a convenient display and function of the tumor homing peptides and high particle stability under physiological conditions. The observations made here support the emerging endotoxin-free E. coli system as a robust protein material producer but are also indicative of a particular conformational status and organization of either building blocks or oligomers. This appears to be promoted by multifactorial stress-inducing conditions upon engineering of the E. coli cell envelope, which impacts on the protein quality control of the cell factory.

[Interference for Various Quench Agents of Chemical Disinfectants on Detection of Endotoxin Activities in Water].

Science.gov (United States)

Zhang, Can; Liu, Wen-jun; Shi, Yun; An, Dai-zhi; Bai, Miao; Xu, Wen

2015-05-01

The quenching agents such as histidine, glycine, ascorbic acid, Tween-80, sodium sulfite and sodium hyposulfite are commonly used for quenching the residual disinfectant in water. In this paper, in order to select the optimal type and concentration range of quenching agents prior to the Limulus assays, the interference effects of each quenching agent at different concentrations on endotoxin detection were investigated by the Limulus assays of kinetic-turbidity. Our results identified that, as for 0-1.0% concentration of histidine, ascorbic acid, Tween-80, sodium sulfite (pH unadjusted and pH neutral), interference on the Limulus assays was existed. Hence, these quenching agents could not be applied as neutralizers prior to Limulus assays. Although, there was no interference on endotoxin detection for the glycine, a yellow color, developed by the quenching products of glycine and glutaric dialdehyde, contributed to false positive results. Hence, glycine should not be used as quenching agents in Limulus assays for samples containing glutaric dialdehyde. Compared with other quenching agents as histidine, glycine, ascorbic acid, Tween-80, sodium sulfite, 0-1.0% concentration of sodium hyposulfite elicited no obvious interference, while 1.0%-5.0% concentration of sodium hyposulfite illustrated exhibition effect for endotoxin detection. All in all, compared with other quenching agents as histidine, glycine, ascorbic acid, Tween-80 and sodium sulfite, sodium hyposulfite is suitable for quenching chemicals prior to endotoxin detection and less than 0.5% of concentration is allowable.

Development of an in vitro Endotoxin Test for Monoolein–Water ...

African Journals Online (AJOL)

Erah

Loaded Monoolein Gel Intended to Treat. Chronic Osteomyelitis. J. Pharmacol. Toxicol.,. 2008; 3(5): 386-393. 13 Magalahaes PO, Lopes AM, Mazolla PG, Rangel-. Yagui C, Penna TCV, Pessoa Jr A. Methods of. Endotoxins. Removal from. Biological. Preparations: a Review. J Pharm Pharmaceut. Sci. 2007; 10(3): 388-404.

Microbiological assessment of house and imported bottled water by comparison of bacterial endotoxin concentration, heterotrophic plate count, and fecal coliform count.

Science.gov (United States)

Reyes, Mayra I; Pérez, Cynthia M; Negrón, Edna L

2008-03-01

Consumers increasingly use bottled water and home water treatment systems to avoid direct tap water. According to the International Bottled Water Association (IBWA), an industry trade group, 5 billion gallons of bottled water were consumed by North Americans in 2001. The principal aim of this study was to assess the microbial quality of in-house and imported bottled water for human consumption, by measurement and comparison of the concentration of bacterial endotoxin and standard cultivable methods of indicator microorganisms, specifically, heterotrophic and fecal coliform plate counts. A total of 21 brands of commercial bottled water, consisting of 10 imported and 11 in-house brands, selected at random from 96 brands that are consumed in Puerto Rico, were tested at three different time intervals. The Standard Limulus Amebocyte Lysate test, gel clot method, was used to measure the endotoxin concentrations. The minimum endotoxin concentration in 63 water samples was less than 0.0625 EU/mL, while the maximum was 32 EU/mL. The minimum bacterial count showed no growth, while the maximum was 7,500 CFU/mL. Bacterial isolates like P. fluorescens, Corynebacterium sp. J-K, S. paucimobilis, P. versicularis, A. baumannii, P. chlororaphis, F. indologenes, A. faecalis and P. cepacia were identified. Repeated measures analysis of variance demonstrated that endotoxin concentration did not change over time, while there was a statistically significant (p bacterial count over time. In addition, multiple linear regression analysis demonstrated that a unit change in the concentration of endotoxin across time was associated with a significant (p bacterial growth was not detected in some water samples, endotoxin was present. Measurement of Gram-negative bacterial endotoxins is one of the methods that have been suggested as a rapid way of determining bacteriological water quality.

The effect of endotoxin and anti-endotoxin serum on synovial fluid parameters in the horse

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R.D. Gottschalk

1998-07-01

Full Text Available The effects of a commercially available equine hyperimmune anti-endotoxin serum on synovial fluid parameters were evaluated in an induced synovitis model in normal horses. Four groups of 3 horses each received lipopolysaccharide (LPS plus hyperimmune antiendotoxin (anti-LPS, LPS, anti-LPS, and Ringers lactate (control respectively injected into the left intercarpal joint. Synovial fluid parameters were measured at 4, 8, 24 and 72 h. It was found that anti-LPS had no attenuating effect on the LPS and that it induced a synovitis almost equivalent to that induced by LPS alone. The introduction of sterile Ringers lactate solution into the carpal joint together with repeated aseptic arthrocentesis induces a mild inflammatory response.

Effect of permeability enhancers on paracellular permeability of acyclovir.

Science.gov (United States)

Ates, Muge; Kaynak, Mustafa Sinan; Sahin, Selma

2016-06-01

According to Biopharmaceutics Classification System (BCS), acyclovir is a class III (high solubility, low permeability) compound, and it is transported through paracellular route by passive diffusion. The aim of this study was to investigate the effect of various pharmaceutical excipients on the intestinal permeability of acyclovir. The single-pass in-situ intestinal perfusion (SPIP) method was used to estimate the permeability values of acyclovir and metoprolol across different intestinal segments (jejunum, ileum and colon). Permeability coefficient (Peff ) of acyclovir was determined in the absence and presence of a permeation enhancer such as dimethyl β-cyclodextrin (DM-β-CD), sodium lauryl sulfate (SLS), sodium caprate (Cap-Na) and chitosan chloride. All enhancers increased the permeability of paracellularly transported acyclovir. Although Cap-Na has the highest permeability-enhancing effect in all segments, permeation-enhancing effect of chitosan and SLS was only significant in ileum. On the other hand, DM-β-CD slightly decreased the permeability in all intestinal segments. These findings have potential implication concerning the enhancement of absorption of paracellularly transported compounds with limited oral bioavailability. In the case of acyclovir, Cap-Na either alone or in combination with SLS or chitosan has the potential to improve its absorption and bioavailability and has yet to be explored. © 2016 Royal Pharmaceutical Society.

Ultraviolet A: Visible spectral absorbance of the human cornea after transepithelial soaking with dextran-enriched and dextran-free riboflavin 0.1% ophthalmic solutions.

Science.gov (United States)

Lombardo, Marco; Micali, Norberto; Villari, Valentina; Serrao, Sebastiano; Pucci, Giuseppe; Barberi, Riccardo; Lombardo, Giuseppe

2015-10-01

To evaluate the stromal concentration of 2 commercially available transepithelial riboflavin 0.1% solutions in human donor corneas with the use of spectrophotometry. University of Calabria, Rende, Italy. Experimental study. The absorbance spectra of 12 corneal tissues were measured in the 330 to 700 nm wavelength range using a purpose-designed spectrophotometry setup before and after transepithelial corneal soaking with a 15% dextran-enriched riboflavin 0.1% solution (n = 6) or a hypotonic dextran-free riboflavin 0.1% solution (n = 6). Both ophthalmic solutions contained ethylenediaminetetraacetic acid and trometamol as enhancers. In addition, 4 deepithelialized corneal tissues underwent stromal soaking with a 20% dextran-enriched riboflavin 0.1% solution and were used as controls. All the riboflavin solutions were applied topically for 30 minutes. The stromal concentration of riboflavin was quantified by analysis of absorbance spectra of the cornea collected before and after application of each solution. The mean stromal riboflavin concentration was 0.012% ± 0.003% (SD), 0.0005% ± 0.0003% (P dextran-enriched, 15% dextran-enriched, and hypotonic dextran-free solutions, respectively. The difference of stromal riboflavin concentration between the 2 transepithelial solutions was statistically significant (P Dextran-enriched solutions required complete corneal deepithelialization to permit effective stromal soaking with riboflavin. Nevertheless, riboflavin in hypotonic dextran-free solution with enhancers permeates across stroma through an intact epithelium. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Influence of CO2 on electrophysiology and ionic permeability of the basolateral membrane of frog skin

International Nuclear Information System (INIS)

Stoddard, J.S.

1984-01-01

When short-circuited epithelia of frog skin bathed in an alkaline Ringer solution equilibrated with room air, are exposed to a Ringer solution equilibrated with 5% CO 2 , inhibition of transepithelial Na + transport is observed accompanied by a marked depolarization of the basolateral membrane voltage as measured with intracellular microelectrodes. To study further the mechanisms involved, basolateral membrane influxes and effluxes of 24 Na, 42 K, and 36 Cl were measured in control and CO 2 -treated isolated epithelia. In control epithelia, studies of the bidirectional 24 Na fluxes confirmed the existence of an important basolateral membrane permeability to Na + . In control epithelia, the apical membranes of the cells were found to be virtually impermeable to Cl - , while basolateral membranes were highly permeable to Cl - . Although CO 2 caused a partial inhibition of pump activity as assessed from decreases of pump-mediated Na + efflux and K + influx, CO 2 caused little or no change of the leak influx of Na + or K + . K + efflux was increased markedly with CO 2 resulting in a net loss of K + from the cells. Cl - influx was increased and Cl - efflux was decreased by CO 2 leading to a net influx of Cl - . Analysis of the data according to criteria involving changes of flux, ionic equilibrium potentials, mass and charge balance restrictions indicated that the principle changes involve a transient decrease in electrical conductance to K + with a concurrent increase in electrical conductance to HCO 3 - (OH - or H + ) of the basolateral membranes of the cells

(−-Epigallocatechin gallate inhibits endotoxin-induced expression of inflammatory cytokines in human cerebral microvascular endothelial cells

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Li Jieliang

2012-07-01

Full Text Available Abstract Background (−-Epigallocatechin gallate (EGCG is a major polyphenol component of green tea that has antioxidant activities. Lipopolysaccharide (LPS induces inflammatory cytokine production and impairs blood–brain barrier (BBB integrity. We examined the effect of EGCG on LPS-induced expression of the inflammatory cytokines in human cerebral microvascular endothelial cells (hCMECs and BBB permeability. Methods The expression of TNF-α, IL-1β and monocyte chemotactic protein-1 (MCP-1/CCL2 was determined by quantitative real time PCR (qRT-PCR and ELISA. Intercellular adhesion molecule 1 (ICAM-1 and vascular cell adhesion molecule (VCAM in hCMECs were examined by qRT-PCR and Western blotting. Monocytes that adhered to LPS-stimulated endothelial cells were measured by monocyte adhesion assay. Tight junctional factors were detected by qRT-PCR (Claudin 5 and Occludin and immunofluorescence staining (Claudin 5 and ZO-1. The permeability of the hCMEC monolayer was determined by fluorescence spectrophotometry of transmembrane fluorescin and transendothelial electrical resistance (TEER. NF-kB activation was measured by luciferase assay. Results EGCG significantly suppressed the LPS-induced expression of IL-1β and TNF-α in hCMECs. EGCG also inhibited the expression of MCP-1/CCL2, VCAM-1 and ICAM-1. Functional analysis showed that EGCG induced the expression of tight junction proteins (Occludin and Claudin-5 in hCMECs. Investigation of the mechanism showed that EGCG had the ability to inhibit LPS-mediated NF-κB activation. In addition, 67-kD laminin receptor was involved in the anti-inflammatory effect of EGCG. Conclusions Our results demonstrated that LPS induced inflammatory cytokine production in hCMECs, which could be attenuated by EGCG. These data indicate that EGCG has a therapeutic potential for endotoxin-mediated endothelial inflammation.

[Detection of endotoxins of Gram-negative bacteria on the basis of electromagnetic radiation frequency spectrum].

Science.gov (United States)

Likhoded, V G; Kuleshova, N V; Sergieva, N V; Konev, Iu V; Trubnikova, I A; Sudzhian, E V

2007-01-01

Method of Gram-negative bacteria endotoxins detection on the basis of their own spectrum of electromagnetic radiation frequency was developed. Frequency spectrum typical for chemotype Re glycolipid, which is a part of lypopolysaccharides in the majority of Gram-negative bacteria, was used. Two devices--"Mini- Expert-DT" (manufactured by IMEDIS, Moscow) and "Bicom" (manufactured by Regumed, Germany)--were used as generators of electromagnetic radiation. Detection of endotoxin using these devices was performed by electropuncture vegetative resonance test. Immunoenzyme reaction with antibodies to chemotype Re glycolipid was used during analysis of preparations for assessment of resonance-frequency method specificity. The study showed that resonance-frequency method can detect lypopolysaccharides of different enterobacteria in quantities up to 0.1 pg as well as bacteria which contain lypopolysaccharides. At the same time, this method does not detect such bacteria as Staphylococcus aureus, Bifidobacterium spp., Lactobacillus spp., and Candida albicans. The method does not require preliminary processing of blood samples and can be used for diagnostics of endotoxinemia, and detection of endotoxins in blood samples or injection solutions.

Renal excretion of prostaglandin metabolites, arginine vasopressin, and sodium during endotoxin and endogenous pyrogen induced fever in the goat.

Science.gov (United States)

Jónasson, H; Basu, S; Andersson, B; Kindahl, H

1984-04-01

Responses to intravenous injections of an endotoxin (E. coli-lipopolysaccharide, 1 microgram/kg b.wt.) and endogenous pyrogen were studied in euhydrated and hyperhydrated goats. The biphasic febrile response to the endotoxin was associated with a pronounced increase in the renal excretion of measured prostaglandin (PG) metabolites (11-ketotetranor PGF metabolites). This increase was time-correlated with the elevation of the rectal temperature, and (in hyperhydrated animals) with an inhibition of the water diuresis and an increase in renal excretion of arginine vasopressin (AVP). Other effects of the endotoxin were an immediate depression of renal Na and K excretion followed by the development of pronounced natriuresis, and a reduction of plasma Fe and Zn concentrations. The appearance of the febrile reactions (peripheral vasoconstriction and shivering) was accompanied by miosis. The maximum elevation of the rectal temperature was significantly greater during euhydration than during hyperhydration. Also endogenous pyrogen elicited miosis concomitant with febrile reactions, and an elevation of the renal excretion of PG metabolites which was closely correlated in time with the monophasic febrile response, and (during hyperhydration) with temporary inhibition of the water diuresis and an increase in the renal AVP excretion. However, the responses were much weaker than the corresponding endotoxin effects. No appreciable changes in renal excretion of Na and K were observed in response to the endogenous pyrogen. It is concluded that the observed effects on renal cation excretion were manifestations of direct endotoxin influences on kidney function.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of cage vs. floor litter environments on the pulmonary hypertensive response to intravenous endotoxin and on blood-gas values in broilers.

Science.gov (United States)

Wang, W; Erf, G F; Wideman, R F

2002-11-01

Intravenous endotoxin has been shown to trigger a delayed pulmonary hypertensive response that varies widely in magnitude and duration among individual broilers. It was proposed that this individual variability may reflect immunological differences acquired during previous respiratory challenges that might have subsequently altered the endotoxin-initiated biochemical cascade. In Experiment 1, we tested the hypothesis that, when compared with broilers reared in clean stainless steel cages (Cage group), broilers reared on floor litter (Floor group) should experience a greater respiratory challenge and therefore may consistently exhibit a more enhanced pulmonary hypertensive response to intravenous endotoxin. Birds in the Cage group were grown in stainless steel cages at a low density (72 birds/8 m2 chamber), and fecal and dander materials were removed daily. Birds in the Floor group were reared on wood-shavings litter at a higher density (110 birds/8 m2 chamber). Pulmonary and systemic mean arterial pressures and blood-gas values were evaluated prior to and following the intravenous administration of 1 mg Salmonella typhimurium endotoxin. Broilers in the Floor and Cage groups exhibited pulmonary hypertensive responses to endotoxin that were very similar in terms of time of onset, duration, and magnitude, as well as variability in the response among individuals. Systemic hypotension also developed similarly in both groups following endotoxin injection. Blood-gas values indicated that the partial pressure of CO2 and the HCO3- concentration in arterial blood were higher (P broilers, and confirmed the negative impact of floor rearing on blood-gas values. We conclude that broilers reared on the floor inhaled litter dust and noxious fumes, which impaired pulmonary gas exchange and increased the arterial partial pressure of CO2 when compared with broilers reared in clean stainless steel cages. Nevertheless, the pulmonary hypertensive response to endotoxin did not differ

Measurement of endotoxin levels in blood of hemodialysis Patients by 'Lal' test and comparision of its efficacy with blood culture

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Gh Vazirzadeh

2006-01-01

Full Text Available Introduction: Presently, bacteremia is the principal cause of morbidity in patients undergoing hemodialysis. Gram-negative bacteria account for approximately 50 percent of documented infections. Endotoxins released during lysis of gram negative bacteremia result in inflammatory and defense response by the body and if not treated promptly result in septic shock and ultimately death of the patient. This study describes the detection of endotoxins in blood of patients with bacteremia due to gram - negative bacteria by LAL test. Method: Blood samples of 278 hemodialysis patients were analyzed in this study and pathogens were isolated from blood culture samples. Then, their antibiotic sensitivity was determined. In patients with positive blood culture, endotoxin levels were measured by LAL-test. Results: Frequency of bacteremia in patients was 13.6% . The prevalence of gram – negative bacteremia was 44.7%. E coli were the major pathogens, while staphylococcus aureus was the most common gram positive bacterium. Endotoxin was detected in 15 patients (3.8 ± 1.08 EU/ml . The sensitivity and specificity of endotoxins for gram – negative bacteremia were 88% and 95%, respectively. Conclusion: The results indicate that the LAL method is a fast, sensitive and simple method. There was no significant difference between the results of blood culture and LAL – test ( P > 0.05 .

Modulation of Intestinal Barrier and Bacterial Endotoxin Production Contributes to the Beneficial Effect of Nicotinic Acid on Alcohol-Induced Endotoxemia and Hepatic Inflammation in Rats

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Wei Zhong

2015-10-01

Full Text Available Alcohol consumption causes nicotinic acid deficiency. The present study was undertaken to determine whether dietary nicotinic acid supplementation provides beneficial effects on alcohol-induced endotoxin signaling and the possible mechanisms at the gut-liver axis. Male Sprague-Dawley rats were pair-fed the Lieber-DeCarli liquid diets containing ethanol or isocaloric maltose dextrin for eight weeks, with or without dietary supplementation with 750 mg/liter nicotinic acid. Chronic alcohol feeding elevated the plasma endotoxin level and activated hepatic endotoxin signaling cascade, which were attenuated by nicotinic acid supplementation. Alcohol consumption remarkably decreased the mRNA levels of claudin-1, claudin-5, and ZO-1 in the distal intestine, whereas nicotinic acid significantly up-regulated these genes. The concentrations of endotoxin, ethanol, and acetaldehyde in the intestinal contents were increased by alcohol exposure, and niacin supplementation reduced the intestinal endotoxin and acetaldehyde levels. Nicotinic acid supplementation upregulated the intestinal genes involved in aldehyde detoxification via transcriptional regulation. These results demonstrate that modulation of the intestinal barrier function and bacterial endotoxin production accounts for the inhibitory effects of nicotinic acid on alcohol-induced endotoxemia and hepatic inflammation.

Nonabsorbable Antibiotics Reduce Bacterial and Endotoxin Translocation in Hepatectomised Rats

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S. K. Kakkos

1997-01-01

Full Text Available There is increasing evidence that septic complications, occurring after major hepatectomies, may be caused by gram negative bacteria, translocating from the gut. We investigated in rats, the effect of extended hepatectomy on the structure and morphology of the intestinal mucosa as well as on the translocation of intestinal bacteria and endotoxins. We also examined the effect of nonabsorbable antibiotics on reducing the intestinal flora and consequently the phenomenon of translocation by administering neomycin sulphate and cefazoline. Hepatectomy was found to increase translocation, while administration of nonabsorbable antibiotics decreased it significantly. In addition, hepatectomy increased the aerobic cecal bacterial population, which normalised in the group receiving antibiotics. Among the histological parameters evaluated, villus height demonstrated a significant reduction after hepatectomy, while the number of villi per cm and the number of mitoses per crypt, remained unchanged. Our results indicate that administration of nonabsorbable antibiotics presents a positive effect on bacterial and endotoxin translocation after extended hepatectomy, and this may be related to reduction of colonic bacterial load as an intraluminal effect of antibiotics.

Suitability of Torrent Permeability Tester to measure air-permeability of covercrete

Energy Technology Data Exchange (ETDEWEB)

Andrade, C.; Gonzales-Gasca, C. [Institute of Construction Sciences ' Eduardo Torroja' , Madrid (Spain); Torrent, R. [Portland Cement Institute, (Argentina)

2000-07-01

Suitability of the Torrent Permeability Tester (TPT) to measure the permeability of covercrete to air, both in the laboratory and the field, is investigated, and test results obtained in laboratory studies are discussed. The tests performed included the determination of air permeability (TPT method), oxygen permeability (Cembureau method) and capillary suction, rapid chloride permeability test (ASTM C 1202), as well as a one-year carbonation depth test. Concrete specimens of various compositions and curing regimes were used in the tests; the gas-permeability tests were repeated on the same specimens after 28 days, than again at 6 months and 12 months. Test results confirmed the suitability of the TPT as a useful tool in the characterization of the quality the of concrete cover. It was found to be sensitive to changes in concrete quality; repeatable for sensitive properties such as gas permeability ; also, it was found to correlate well with other durability-related properties. 10 refs., 8 tabs., 8 figs.

Intestinal endotoxins as co-factors of liver injury in obstructive jaundice.

Science.gov (United States)

Mentes, B B; Tatlicioglu, E; Akyol, G; Uluoglu, O; Sultan, N; Yilmaz, E; Celebi, M; Taneri, F; Ferahkose, Z

1996-01-01

The concept of endotoxin-mediated rather than direct liver injury in biliary obstruction was investigated using the experimental rat model of bile duct ligation (BDL) and small bowel bacterial overgrowth (SBBO). Small identical doses of intravenous endotoxin (bacterial LPS) caused a significantly more severe liver injury in rats with BDL, compared with sham-operated rats, suggesting the possible contribution of LPS in this type of liver damage. BDL was then combined with surgically created jejunal self-filling blind loops, which resulted in SBBO. Plasma LPS level increased significantly, and once again a more severe liver injury, determined by liver histology and serum gamma-glutamyl transpeptidase levels, was observed compared with the control group of rats with BDL+self-emptying blind loops. The data presented suggest that small amounts of exogenous LPS and/or the ordinarily innocous amounts of LPS constantly absorbed from the intestinal tract may be critical in the hepatic damage caused by obstruction of the biliary tract.

Occupational exposure to pesticides and endotoxin and Parkinson disease in the Netherlands

NARCIS (Netherlands)

van der Mark, Marianne; Vermeulen, Roel; Nijssen, Peter C. G.; Mulleners, Wim M.; Sas, Antonetta M. G.; van Laar, Teus; Brouwer, Maartje; Huss, Anke; Kromhout, Hans

2014-01-01

Objectives Previous research has indicated that occupational exposure to pesticides and possibly airborne endotoxin may increase the risk of developing Parkinson disease (PD). We studied the associations of PD with occupational exposure to pesticides, specifically to the functional subclasses

Development of an in vitro Endotoxin Test for Monoolein–Water ...

African Journals Online (AJOL)

Purpose: Drugs that are administered by parenteral route must be apyrogenic. The aim of this study was to develop an in vitro endotoxin test for liquid crystalline gels for use as implants, using a monoolein–water liquid crystalline gel as a model. Methods: The gel-clot technique was used. The gel was dissolved first in ...

A systematic evaluation of solubility enhancing excipients to enable the generation of permeability data for poorly soluble compounds in Caco-2 model.

Science.gov (United States)

Shah, Devang; Paruchury, Sundeep; Matta, Muralikrishna; Chowan, Gajendra; Subramanian, Murali; Saxena, Ajay; Soars, Matthew G; Herbst, John; Haskell, Roy; Marathe, Punit; Mandlekar, Sandhya

2014-01-01

The study presented here identified and utilized a panel of solubility enhancing excipients to enable the generation of flux data in the Human colon carcinoma (Caco-2) system for compounds with poor solubility. Solubility enhancing excipients Dimethyl acetamide (DMA) 1 % v/v, polyethylene glycol (PEG) 400 1% v/v, povidone 1% w/v, poloxamer 188 2.5% w/v and bovine serum albumin (BSA) 4% w/v did not compromise Caco-2 monolayer integrity as assessed by trans-epithelial resistance measurement (TEER) and Lucifer yellow (LY) permeation. Further, these excipients did not affect P-glycoprotein (P-gp) mediated bidirectional transport of digoxin, permeabilities of high (propranolol) or low permeability (atenolol) compounds, and were found to be inert to Breast cancer resistant protein (BCRP) mediated transport of cladribine. This approach was validated further using poorly soluble tool compounds, atazanavir (poloxamer 188 2.5% w/v) and cyclosporine A (BSA 4% w/v) and also applied to new chemical entity (NCE) BMS-A in BSA 4% w/v, for which Caco-2 data could not be generated using the traditional methodology due to poor solubility (solubility of atazanavir by >8 fold whereas BSA 4% w/v increased the solubility of cyclosporine A and BMS-A by >2-4 fold thereby enabling permeability as well as efflux liability estimation in the Caco-2 model with reasonable recovery values. To conclude, addition of excipients such as poloxamer 188 2.5% w/v and BSA 4% w/v to HBSS leads to a significant improvement in the solubility of the poorly soluble compounds resulting in enhanced recoveries without modulating transporter-mediated efflux, expanding the applicability of Caco-2 assays to poorly soluble compounds.

Endotoxin exposure and lung cancer risk: a systematic review and meta-analysis of the published literature on agriculture and cotton textile workers.

NARCIS (Netherlands)

Lenters, V.C.; Basinas, I.; Beane Freeman, L.E.; Boffetta, P.; Checkoway, H.; Coggon, D.; Portengen, L.; Sim, M.; Wouters, I.M.; Heederik, D.; Vermeulen, R.

2010-01-01

OBJECTIVE: To examine the association between exposure to endotoxins and lung cancer risk by conducting a systematic review and meta-analysis of epidemiologic studies of workers in the cotton textile and agricultural industries; industries known for high exposure levels of endotoxins. METHODS: Risk

Effects of antibiotic decontamination of the GI tract and pretreatment with sublethal doses of endotoxins on survival after whole-liver irradiation and 2/3 partial hepatectomy (PH)

International Nuclear Information System (INIS)

Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Leitch, J.M.

1984-01-01

Thirty-two rats were preconditioned by I.P. injection of sublethal doses of E. Coli endotoxin two weeks before irradiation. Thirty-two other animals were sham injected with endotoxin free water. One week before irradiation half of the endotoxin treated animals and half the sham-injected animals received non-absorbable antibiotics in their drinking water to decontaminate the intestinal tract. All 64 animals were exposed to 30 Gy whole-liver gamma-irradiation after surgically exposing the liver and moving the G.I. tract, spleen, and stomach out of the radiation field. Immediately after irradiation a 2/3 PH was performed. The animals were checked daily for 100 days postirradiation. Median survival times for sham-treated, decontaminated, endotoxin-treated, and endotoxin-treated + decontaminated animals were, respectively, 16, 26, 38, and 85 days. All animals died within 100 days except in the group receiving both endotoxin and antibiotic treatments. One third of these animals are still alive 100 days after irradiation. The significance of these results with respect to mechanisms of hepatic radiation injury are discussed

Analysis of the levels of endotoxin and β-d-glucan in the synovial fluid of hemodialysis patients.

Science.gov (United States)

Shiota, E; Maekawa, M; Kono, T

2001-12-01

Abstract We analyzed the levels of endotoxin and β-d-glucan, which possibly induce cytokine production, in the synovial fluid of patients on long-term hemodialysis and compared the results to those in patients with osteoarthritis and rheumatoid arthritis. We studied 42 knees in 42 hemodialysis patients, 21 in 21 osteoarthritis patients, and 26 in 26 rheumatoid arthritis patients. The mean ages were 60.7, 63.2, and 59.7 years, respectively. The duration of hemodialysis in the long-term hemodialysis group averaged 14.0 years. The concentrations of endotoxin and β-d-glucan in the synovial fluid of these three groups were measured. The concentration of endotoxin was the same in the three groups. However, the concentration of β-d-glucan was significantly higher in long-term hemodialysis patients. This finding suggests that β-d-glucan may have some relation to the pathogenesis of the synovitis which exists in the hydrarthrosis of long-term hemodialysis patients.

Endotoxin exposure and lung cancer risk: a systematic review and meta-analysis of the published literature on agriculture and cotton textile workers.

Science.gov (United States)

Lenters, Virissa; Basinas, Ioannis; Beane-Freeman, Laura; Boffetta, Paolo; Checkoway, Harvey; Coggon, David; Portengen, Lützen; Sim, Malcolm; Wouters, Inge M; Heederik, Dick; Vermeulen, Roel

2010-04-01

To examine the association between exposure to endotoxins and lung cancer risk by conducting a systematic review and meta-analysis of epidemiologic studies of workers in the cotton textile and agricultural industries; industries known for high exposure levels of endotoxins. Risk estimates were extracted from studies published before 2009 that met predefined quality criteria, including 8 cohort, 1 case-cohort, and 2 case-control studies of cotton textile industry workers, and 15 cohort and 2 case-control studies of agricultural workers. Summary risk estimates were calculated using random effects meta-analyses. Potential sources of heterogeneity were explored through subgroup analyses. The summary risk of lung cancer was 0.72 (95% CI, 0.57-0.90) for textile workers and 0.62 (0.52-0.75) for agricultural workers. The relative risk of lung cancer was below 1.0 for most subgroups defined according to sex, study design, outcome, smoking adjustment, and geographic area. Two studies provided quantitative estimates of endotoxin exposure and both studies tended to support a dose-dependent protective effect of endotoxins on lung cancer risk. Despite several limitations, this meta-analysis based on high-quality studies adds weight to the hypothesis that occupational exposure to endotoxin in cotton textile production and agriculture is protective against lung cancer.

Exposure to airborne culturable microorganisms and endotoxin in two Italian poultry slaughterhouses.

Science.gov (United States)

Paba, Emilia; Chiominto, Alessandra; Marcelloni, Anna Maria; Proietto, Anna Rita; Sisto, Renata

2014-01-01

Even if slaughterhouses' workers handle large amounts of organic material and are potentially exposed to a wide range of biological agents, relatively little and not recent data are available. The main objective of this study was to characterize indoor concentrations of airborne bacteria, fungi, and endotoxin mod = Im (endotoxin∼Gram-negative*plant*filter) in two Italian poultry slaughterhouses. Air samples near air handling units inlets were also collected. Since there are not standardized protocols for endotoxin sampling and extraction procedures, an additional aim of the study was to compare the extraction efficiency of three different filter.. The study was also aimed at determining the correlation between concentrations of Gram-negative bacteria and endotoxin. In Plant A bacterial levels ranged from 17.5 to 2.6×10(3) CFU/m3. The highest concentrations were observed in evisceration area of chickens, between the automatic detachment of the neck and washing offal, and near birds coupling before hair-chilling. The highest mean value of Gram-negative (266.5 CFU/m3) was found near the washing offal of turkeys. In Plant B bacterial concentration ranged from 35 to 8×10(3) CFU/m3. The highest concentration. with the highest value of Gram-negative (248 CFU/m3), was found after defeathering. Fungal concentrations were overall lower than those found for bacteria (range: 0-205 CFU/m3 in Plant A and 0-146.2 CFU/m3 in Plant B). The microbial flora was dominated by Gram-negative and coagulase-negative staphylococci for bacteria and by species belonging to Cladosporium, Penicillium and Aspergillus genera for molds. The highest endotoxin concentrations were measured in washing offal for Plant A (range: 122.7-165.9 EU/m3) and after defeathering for Plant B (range: 0.83-38.85 EU/m3). In this study airborne microorganisms concentrations were lower than those found in similar occupational settings and below the occupational limits proposed by some authors. However, these

Binding and transepithelial transport of immunoglobulins by intestinal M cells: demonstration using monoclonal IgA antibodies against enteric viral proteins

OpenAIRE

1989-01-01

M cells of intestinal epithelia overlying lymphoid follicles endocytose luminal macromolecules and microorganisms and deliver them to underlying lymphoid tissue. The effect of luminal secretory IgA antibodies on adherence and transepithelial transport of antigens and microorganisms by M cells is unknown. We have studied the interaction of monoclonal IgA antibodies directed against specific enteric viruses, or the hapten trinitrophenyl (TNP), with M cells. To produce monospecific IgA antibodie...

Action of Chlorhexidine, Zingiber officinale, and Calcium Hydroxide on Candida albicans, Enterococcus faecalis, Escherichia coli, and Endotoxin in the Root Canals.

Science.gov (United States)

Valera, Marcia C; Oliveira, Sarah Ac; Maekawa, Lilian E; Cardoso, Flávia Gr; Chung, Adriana; Silva, Stephanie Fp; Carvalho, Cláudio At

2016-02-01

The purpose of this in vitro study was to evaluate the antimicrobial activity of 2% chlorhexidine gel (CHX) as auxiliary chemical substance and intracanal medications on Candida albicans, Enterococcus faecalis, Escherichia coli, and their endotoxins in the root canals. The study was conducted on 48 single-rooted human teeth divided into four groups (n = 12), according to intracanal medications used: (1) Calcium hydroxide + apyrogenic saline solution (Ca(OH)2 + SS), (2) 20% ginger glycolic extract (GEN), (3) calcium hydroxide + 20% ginger glycolic extract (Ca(OH)2 + GEN), (4) apyrogenic SS (control). Collections were made from the root canal content before preparation (baseline-S1), immediately after instrumentation (S2), 7 days after instrumentation (S3), after 14 days the action of intracanal medication (S4), and 7 days after removal of the intracanal medication (S5). The antimicrobial activity and endotoxin content were analyzed for all collections. The results were statistically analyzed by the Kruskal-Wallis and Dunn tests at a significance level of 5%. After instrumentation with CHX, there was complete elimination of E. coli and C. albicans, except for E. faecalis, which was significantly reduced and then completely eliminated after intracanal medication. There was significant reduction of endotoxin after instrumentation. Comparison of collection after instrumentation and intracanal medication revealed reduction of endotoxins in all groups; this reduction was greater in group Ca(OH)2 followed by the group GEN. It was concluded that the instrumentation using CHX and intracanal medication used were able to eliminate the microorganisms from the root canal; the endotoxins were reduced, yet not completely eliminated. This study is important and relevant for searching alternatives during endodontic therapy, since it aims to study the effect of Zingiber officinale on microorganisms and endotoxins present in root canals.

De Novo Endotoxin-Induced Production of Antibodies against the Bile Salt Export Pump Associated with Bacterial Infection following Major Hepatectomy

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Kun-Ming Chan

2018-01-01

Full Text Available Background. Clinically severe infection-related inflammation after major liver resection may cause hyperbilirubinemia. This study aims to clarify the impact of bacterial infection and endotoxins on the hepatobiliary transporter system and to explore possible mechanisms of endotoxin-related postoperative hyperbilirubinemia. Method. Mice that underwent major hepatectomy with removal of at least 70% of liver volume were exposed to lipopolysaccharide (LPS at different dosages. Subsequently, hepatobiliary transporter compounds related to bile salt excretion were further investigated. Results. The expression of genes related to hepatobiliary transporter compounds was not significantly different in the liver tissue of mice after major hepatectomy and LPS exposure. However, bile salt export pump (BSEP protein expression within the liver tissue of mice treated with LPS after major hepatectomy was relatively weaker and was even further reduced in the high-dose LPS group. The formation of antibodies against the BSEP in response to endotoxin exposure was also detected. Conclusion. This study illustrates a possible mechanism whereby the dysfunction of hepatobiliary transporter systems caused by endotoxin-induced autoantibodies may be involved in the development of postoperative jaundice associated with bacterial infection after major hepatectomy.

Expression of cyclin D{sub 1} during endotoxin-induced aleveolar type II cell hyperplasia in rat lung and the detection of apoptotic cells during the remodeling process

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Tesfaigzi, J.; Wood, M.B.; Johnson, N.F.

1995-12-01

Our studies have shown that endotoxin intratracheally instilled into the rat lung induces proliferation of alveolar type II cells. In that study, the alveolar type II cells. In that study, the alveolar type II cell hyperplasia occurred 2 d after instillation of endotoxin and persisted for a further 2 d. After hyperplasia, the lung remodeled and returned to a normal state within 24-48 h. Understanding the mechanisms involved in the remodeling process of this transient hyperplasia may be useful to identify molecular changes that are altered in neoplasia. The purpose of the present study was to corroborate induction of epithelial cell hyperplasia by endotoxin and to delineate mechanisms involved in tissue remodeling after endotoxin-induced alveolar type II cell hyperplasia. In conclusion, immonostaining with cyclin D1 and cytokeratin shows that endotoxin induced epithelial cell proliferation and resulted in hyperplasia in the lung which persisted through 4 d post-instillation.

Transepithelial transfer of phenanthrene, but not of benzo[a]pyrene, is inhibited by fatty acids in the proximal intestine of rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

de Gelder, Stefan; Sundh, Henrik; Pelgrim, Thamar N M; Rasinger, Josef D; van Daal, Lotte; Flik, Gert; Berntssen, Marc H G; Klaren, Peter H M

2018-01-01

The inclusion of vegetable oils in aquafeeds introduces contaminating polycyclic aromatic hydrocarbons (PAHs) in salmonids. Since lipophilic PAHs solubilize in micelles composed of lipids, bile salts and fatty acids, dietary lipid composition can alter intestinal transepithelial PAH transfer. We studied the uptake of two PAHs, viz. benzo[a]pyrene (BaP) and phenanthrene (PHE), in rainbow trout (Oncorhynchus mykiss) intestine. We also investigated the effects of two fatty acids, viz. fish oil-derived eicosapentaenoic acid (EPA, 20:5n-3) and vegetable oil-derived oleic acid (18:1n-9) on intestinal uptake. Radiolabeled PAHs were solubilized in micelles composed of tritiated EPA and oleic acid, respectively, and administrated to intestinal segments mounted in Ussing chambers. In the absence of micelles, PHE accumulation was two times higher than BaP in the mucosal and serosal layers of proximal and distal intestine. Administration of PHE in micelles composed of oleic acid resulted in a 50% lower accumulation of PHE in the mucosal layers of the proximal intestine compared to EPA-composed micelles. Accumulation of EPA and oleic acid in the proximal intestinal mucosa correlated negatively with the transepithelial transfer of these fatty acids across the proximal intestinal epithelium. Transepithelial PHE transfer across the proximal intestine was reduced by 30% in co-exposure with EPA-composed micelles compared to 80% with oleic acid micelles. BaP was not transferred across the intestine. We conclude that the lipid composition of an aquafeed is an important determinant of PAH bioavailability. Therefore, lipid composition should be an important consideration in choosing vegetable oils as alternatives for fish oil in aquafeeds. Copyright © 2017 Elsevier Inc. All rights reserved.

Single-Step Transepithelial PRK vs Alcohol-Assisted PRK in Myopia and Compound Myopic Astigmatism Correction.

Science.gov (United States)

Kaluzny, Bartlomiej J; Cieslinska, Iwona; Mosquera, Samuel A; Verma, Shwetabh

2016-02-01

Transepithelial photorefractive keratectomy (tPRK), where both the epithelium and stroma are removed in a single-step, is a relatively new procedure of laser refractive error correction. This study compares the 3-month results of myopia and compound myopic astigmatism correction by tPRK or conventional alcohol-assisted PRK (aaPRK).This prospective, nonrandomized, case-control study recruited 148 consecutive patients; 93 underwent tPRK (173 eyes) and 55 aaPRK (103 eyes). Refractive results, predictability, safety, and efficacy were evaluated during the 3-month follow-up. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and mean refractive spherical equivalent (MRSE).Mean preoperative MRSE was -4.30 ± 1.72 D and -4.33 ± 1.96 D, respectively (P = 0.87). The 3-month follow-up rate was 82.1% in the tPRK group (n = 145) and 86.4% in aaPRK group (n = 90), P = 0.81. Postoperative UDVA was 20/20 or better in 97% and 94% of eyes, respectively (P = 0.45). In the tPRK and aaPRK groups, respectively, 13% and 21% of eyes lost 1 line of CDVA, and 30% and 31% gained 1 or 2 lines (P = 0.48). Mean postoperative MRSE was -0.14 ± 0.26 D in the tPRK group and -0.12 ± 0.20 D in the aaPRK group (P = 0.9). The correlation between attempted versus achieved MRSE was equally high in both groups.Single-step transepithelial PRK and conventional PRK provide very similar results 3 months postoperatively. These procedures are predictable, effective, and safe for correction of myopia and compound myopic astigmatism.

In vitro antimicrobial and anti-endotoxin action of Zingiber Officinale as auxiliary chemical and medicament combined to calcium hydroxide and chlorhexidine.

Science.gov (United States)

Valera, Marcia Carneiro; Cardoso, Flávia Goulart da Rosa; Maekawa, Lilian Eiko; Camargo, Carlos Henrique Ribeiro; de Oliveira, Luciane Dias; Carvalho, Cláudio Antônio Talge

2015-01-01

This study was conducted in vitro to compare the effectiveness of Zingiber Officinale as an auxiliary chemical substance followed by placement of different intra-canal medication in removing endotoxins and cultivable micro-organisms from infected root canals. Seventy-two root canals were contaminated with Enterococcus faecalis, Candida albicans and Escherichia coli for 28 days. After, the teeth were instrumented using Zingiber Officinale and divided into six groups according to the intra-canal medication: chlorhexidine gel; calcium hydroxide + chlorhexidine gel; glycolic ginger extract; calcium hydroxide + glycolic ginger extract; calcium hydroxide + saline solution and saline solution (control). Sample collections were performed after root canal contamination (Baseline; S1), after instrumentation (S2), 7 days after instrumentation (S3), after 14 days with intra-canal medication (S4) and 7 days after removal of intra-canal medication (S5). The results were analyzed by the Kruskal-Wallis and Dunn tests. It was observed that in S2 and S3 there was significant reduction of the micro-organisms and the quantity of endotoxins after instrumentation. In samples S4 and S5 there was complete elimination of micro-organisms and significant reduction of endotoxins. It was concluded that Zingiber Officinale as an auxiliary chemical substance was effective on the micro-organisms tested, yet was unable to eliminate the endotoxins. Similarly, the intra-canal medication were effective on micro-organisms, yet did not completely eliminate the endotoxins.

Model-aided optimization of delta-endotoxin-formation in continuous culture systems

Energy Technology Data Exchange (ETDEWEB)

Schulz, V; Schorcht, R; Ignatenko, Yu N; Sakharova, Z V; Khovrychev, M P

1985-01-01

A mathematical model of growth, sporulation and delta-endotoxin-formation of bac. thuringiensis is given. The results of model-aided optimization of steady-state continuous culture systems indicate that the productivity in the one-stage system is 1.9% higher and in the two-stage system is 18.5% higher than in the batch process.

Effect of enrofloxacin treatment on plasma endotoxin during bovine Escherichia coli mastitis

NARCIS (Netherlands)

Dosogne, H.; Meyer, E.; Sturk, A.; van Loon, J.; Massart-Leën, A. M.; Burvenich, C.

2002-01-01

OBJECTIVE AND DESIGN: To investigate the effect of enrofloxacin on endotoxin resorption during bovine Escherichia coli mastitis. ANIMALS: 12 healthy early post partum Holstein cows. TREATMENT: Mastitis was induced by intramammary infusion of 10(4) cfu E. coli P4:032. Six cows were treated twice

Comparison of single-step reverse transepithelial all-surface laser ablation (ASLA) to alcohol-assisted photorefractive keratectomy.

Science.gov (United States)

Aslanides, Ioannis M; Padroni, Sara; Arba Mosquera, Samuel; Ioannides, Antonis; Mukherjee, Achyut

2012-01-01

To evaluate postoperative pain, corneal epithelial healing, development of corneal haze, refractive outcomes, and corneal aberrations in a novel one-step, modified transepithelial photorefractive keratectomy (PRK), termed All-surface laser ablation (ASLA), compared to conventional, alcohol-assisted PRK. Sixty eyes of 30 myopic patients were prospectively recruited to a randomized fellow eye study. Patients underwent conventional alcohol-assisted PRK in one eye (control group) and ASLA-modified transepithelial PRK in the other (30 eyes in each treatment arm). Primary endpoints were postoperative pain and haze scores at 1 day, 3 days, 1 week, and 1, 3, 6, and 12 months. Secondary endpoints included visual acuity at 1, 3, 6, and 12 months, corneal aberrations at 3, 6, and 12 months, and early and late onset haze. Refractive predictability, safety, and efficacy of the two methods were considered. The average age of the cohort was 29 years (standard deviation [SD]: 9; range: 18-46), and the average spherical equivalent refractive error was -4.18 diopters (SD: 1.9). At 3 days after surgery, the average pain score was 64% lower in the ASLA group (P < 0.0005). At this point, 96% of ASLA eyes had no epithelial defect, whereas 43% in the alcohol-assisted group did not achieve complete epithelial healing, and required replacement of bandage contact lens. The haze level was consistently lower in the ASLA group at all time points from 1 to 6 months. This study shows that the ASLA technique may have a future role in refractive surgery, due to the fact that it offers faster epithelial healing, lower pain scores, and significantly less haze formation.

A histological study of rabbit corneas after transepithelial corneal crosslinking using partial epithelial photoablation or ethanol treatment.

Science.gov (United States)

Ozmen, Mehmet Cuneyt; Hondur, Ahmet; Yilmaz, Guldal; Bilgihan, Kamil; Hasanreisoglu, Berati

2014-01-01

To evaluate the histological changes after transepithelial corneal crosslinking (CXL) using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study. Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement (group I). Four eyes received partial thickness epithelial ablation with excimer laser (group II). Twelve eyes were treated with different durations (30s and 60s) and concentrations (18% to 48%) of ethanol (group III). Riboflavin was applied for 30min intervals along with topical proparacaine drops with benzalkonium chloride, and 370 nm irradiation was performed for 30min, while riboflavin was instilled every 3min. Four eyes (group IV) received 48% ethanol for 30s without riboflavin and irradiation. Eyes were collected after 24h and examined histologically. All eyes in group I showed keratocyte loss in the superficial 300 µ of corneal storma. In group II, 1-4 layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 µ to 300 µ of cornea. Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24% concentration and up to 60s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thickness excimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.

A histological study of rabbit corneas after transepithelial corneal crosslinking using partial epithelial photoablation or ethanol treatment

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Mehmet Cuneyt Ozmen

2014-12-01

Full Text Available AIM: To evaluate the histological changes after transepithelial corneal crosslinking (CXL using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study.METHODS: Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement (group I. Four eyes received partial thickness epithelial ablation with excimer laser (group II. Twelve eyes were treated with different durations (30s and 60s and concentrations (18% to 48% of ethanol (group III. Riboflavin was applied for 30min intervals along with topical proparacaine drops with benzalkonium chloride, and 370 nm irradiation was performed for 30min, while riboflavin was instilled every 3min. Four eyes (group IV received 48% ethanol for 30s without riboflavin and irradiation. Eyes were collected after 24h and examined histologically.RESULTS: All eyes in group I showed keratocyte loss in the superficial 300 µ of corneal storma. In group II, 1-4 layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 µ to 300 µ of cornea.CONCLUSION: Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24% concentration and up to 60s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thickness excimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.

Effects of aging on endotoxin tolerance induced by lipopolysaccharides derived from Porphyromonas gingivalis and Escherichia coli.

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Ying Sun

Full Text Available Periodontitis is a bacterially induced chronic inflammatory disease. Exposure of the host to periodontal pathogens and their virulence factors induces a state of hyporesponsiveness to subsequent stimulations, termed endotoxin tolerance. Aging has a profound effect on immune response to bacteria challenge. The aim of this study was to explore the effects of aging on endotoxin tolerance induced by Porphyromonas gingivalis (P. gingivalis lipopolysaccharide (LPS and Escherichia coli (E. coli LPS in murine peritoneal macrophages.We studied the cytokine production (TNF-α and IL-10 and Toll-like receptor 2, 4 (TLR2, 4 gene and protein expressions in peritoneal macrophages from young (2-month-old and middle-aged (12-month-old ICR mice following single or repeated P. gingivalis LPS or E. coli LPS stimulation. Pretreatment of peritoneal macrophages with P. gingivalis LPS or E. coli LPS resulted in a reduction in TNF-α production and an increase in IL-10 production upon secondary stimulation (p<0.05, and the markedly lower levels of TNF-α and higher levels of IL-10 were observed in macrophages from young mice compared with those from middle-aged mice (p<0.05. In addition, LPS restimulations also led to the significantly lower expression levels of TLR2, 4 mRNA and protein in macrophages from young mice (p<0.05.Repeated LPS stimulations triggered endotoxin tolerance in peritoneal macrophages and the ability to develop tolerance in young mice was more excellent. The impaired ability to develop endotoxin tolerance resulted from aging might be related to TLR2, 4 and might lead to the incontrollable periodontal inflammation in older adults.

Exposure to biohazards in wood dust: bacteria, fungi, endotoxins, and (1-->3)-beta-D-glucans.

Science.gov (United States)

Alwis, K U; Mandryk, J; Hocking, A D

1999-09-01

Personal exposure to fungi, bacteria, endotoxin, and (1-->3)-beta-D-glucan was determined at different woodworking sites--logging sites, sawmills, woodchipping sites, and joineries. Exposure levels to fungi at logging sites and sawmills were in the range of 10(3)-10(4) cfu/m3, at the woodchipping mill, 10(3)-10(5) cfu/m3, and at joineries, 10(2)-10(4) cfu/m3. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and a joinery exceeded the standard. The geometric mean personal (1-->3)-beta-D-glucan exposure level at the woodchipping mill was 2.32 ng/m3, at sawmills, 1.37 ng/m3, at logging sites, 2.02 ng/m3, and at joineries, 0.43 ng/m3. Highly significant associations were found between mean personal inhalable endotoxin exposures and Gram-negative bacteria levels (p 3)-beta-D-glucan exposures and fungi levels (p = 0.0003). The prevalence of cough, phlegm, chronic bronchitis, nasal symptoms, frequent headaches, and eye and throat irritations was significantly higher among woodworkers than controls. Dose-response relationships were found between personal exposures and work-related symptoms among joinery workers and sawmill and chip mill workers.

Protective properties of plasma of burnt and irradiated rats against lethal effect of endotoxins in vivo

Energy Technology Data Exchange (ETDEWEB)

Budagov, R S; Chureyeva, L N

1984-10-01

The purpose of this work was to estimate protective properties of plasma in disease with increased endotoxemia. Burns and acute radiation sickness were used as models of suppression of physiological mechanisms of detoxication. Experiments were performed on male Wistar rats and mice, which received 3rd degree burns over 15% of the body surface, whole body gamma irradiation at 7.5 Gr or both. At 3 hours, 3, 7 and 12 days after the exposure the animals were decapitated and blood collected. The irradiated mice received 0.2 ml endotoxin intraperitoneally, 1.0 ml freshly prepared rat plasma, then the lethality of the mice in 24 hours was observed. It was found that the plasma of intact rats was capable of decreasing the lethal effects of S. typhimurium and E. coli endotoxins in vivo in mice. Deep skin burns, acute radiation sickness and the combined effects of radiation and thermal injury did not change this phenomenon. The plasma of the experimental rats retained the protective properties at various periods of time after the thermal, radiation and combined exposures. The functioning of the humoral detoxication mechanism is radioresistant, indirectly indicating the nonimmunoglobulin nature of endotoxin inactivators. 19 references.

Directed evolution of an LBP/CD14 inhibitory peptide and its anti-endotoxin activity.

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Li Fang

Full Text Available BACKGROUND: LPS-binding protein (LBP and its ligand CD14 are located upstream of the signaling pathway for LPS-induced inflammation. Blocking LBP and CD14 binding might prevent LPS-induced inflammation. In previous studies, we obtained a peptide analog (MP12 for the LBP/CD14 binding site and showed that this peptide analog had anti-endotoxin activity. In this study, we used in vitro directed evolution for this peptide analog to improve its in vivo and in vitro anti-endotoxin activity. METHODS: We used error-prone PCR (ep-PCR and induced mutations in the C-terminus of LBP and attached the PCR products to T7 phages to establish a mutant phage display library. The positive clones that competed with LBP for CD14 binding was obtained by screening. We used both in vivo and in vitro experiments to compare the anti-endotoxin activities of a polypeptide designated P1 contained in a positive clone and MP12. RESULTS: 11 positive clones were obtained from among target phages. Sequencing showed that 9 positive clones had a threonine (T to methionine (M mutation in amino acid 287 of LBP. Compared to polypeptide MP12, polypeptide P1 significantly inhibited LPS-induced TNF-α expression and NF-κB activity in U937 cells (P<0.05. Compared to MP12, P1 significantly improved arterial oxygen pressure, an oxygenation index, and lung pathology scores in LPS-induced ARDS rats (P<0.05. CONCLUSION: By in vitro directed evolution of peptide analogs for the LBP/CD14 binding site, we established a new polypeptide (P1 with a threonine (T-to-methionine (M mutation in amino acid 287 of LBP. This polypeptide had high anti-endotoxin activity in vitro and in vivo, which suggested that amino acid 287 in the C-terminus of LBP may play an important role in LBP binding with CD14.

Spectral OCT with speckle contrast reduction for evaluation of the healing process after PRK and transepithelial PRK.

Science.gov (United States)

Kaluzny, Bartlomiej J; Szkulmowski, Maciej; Bukowska, Danuta M; Wojtkowski, Maciej

2014-04-01

We evaluate Spectral OCT (SOCT) with a speckle contrast reduction technique using resonant scanner for assessment of corneal surface changes after excimer laser photorefractive keratectomy (PRK) and we compare healing process between conventional PRK and transepithelial PRK. The measurements were performed before and after the surgery. Obtained results show that SOCT with a resonant scanner speckle contrast reduction is capable of providing information regarding the healing process after PRK. The main difference between the healing processes of PRK and TransPRK, assessed by SOCT, was the time to cover the stroma with epithelium, which was shorter in the TransPRK group.

Innate immune defenses exhibit circadian rhythmicity and differential temporal sensitivity to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus)

DEFF Research Database (Denmark)

Lazado, Carlo Cabacang; Skov, Peter Vilhelm; Pedersen, Per Bovbjerg

2016-01-01

The present study investigated the daily dynamics of humoral immune defenses and the temporal influence in the sensitivity of these responses to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus). The first experiment subjected the fish to two photoperiod conditions, 12L:12D (LD) and 0L...... experiment, fish were injected with bacterial endotoxin lipopolysaccharide (LPS) either at ZT3 (day) or at ZT15 (night) to evaluate the temporal sensitivity of humoral immunity to a pathogen-associated molecular pattern. The results demonstrated that responses to LPS were gated by the time of day. LPS...... significantly modulated serum ALP and ANTI activities but only when the endotoxin was administered at ZT3. Serum LYZ and PER were stimulated at both injection times but with differing response profiles. Modulated LYZ activity was persistent when injected at ZT3 but transient when LPS was applied at ZT15...

Optimized conditions for MDCK permeability and turbidimetric solubility studies using compounds representative of BCS classes I-IV.

Science.gov (United States)

Taub, Mitchell E; Kristensen, Lisbeth; Frokjaer, Sven

2002-05-01

The solubility enhancing effects of various excipients, including their compatibility with in vitro permeability (P(app)) systems, was investigated using drugs representative of Biopharmaceutics Classification System (BCS) classes I-IV. Turbidimetric solubility determination using nephelometry and transport experiments using MDCK Strain I cell monolayers were employed. The highest usable concentration of each excipient [dimethyl sulfoxide (DMSO), ethanol, hydroxypropyl-beta-cyclodextrin (HPCD), and sodium taurocholate] was determined by monitoring apical (AP) to basolateral (BL) [14C]mannitol apparent permeability (P(app)) and the transepithelial electrical resistance (TEER) in transport experiments done at pH 6.0 and 7.4. The excipients were used in conjunction with compounds demonstrating relatively low aqueous solubility (amphotericin B, danazol, mefenamic acid, and phenytoin) in order to obtain a drug concentration >50 microM in the donor compartment. The addition of at least one of the selected excipients enhanced the solubility of the inherently poorly soluble compounds to >50 microM as determined via turbidimetric evaluation at pH 6.0 and 7.4. Ethanol and DMSO were found to be generally disruptive to the MDCK monolayer and were not nearly as useful as HPCD and sodium taurocholate. Sodium taurocholate (5 mM) was compatible with MDCK monolayers under all conditions investigated. Additionally, a novel in vitro system aimed at more accurately simulating in vivo conditions, i.e., a pH gradient (6.0 AP/7.4 BL), sodium taurocholate (5 mM, AP), and bovine serum albumin (0.25%, BL), was shown to generate more reliable P(app) values for compounds that are poorly soluble and/or highly protein bound.

Hypo-responsiveness of interleukin-8 production in human embryonic epithelial intestine 407 cells independent of NF-κB pathway: New lessons from endotoxin and ribotoxic deoxynivalenol

International Nuclear Information System (INIS)

Moon, Yuseok; Yang, Hyun; Park, Seung-Hwan

2008-01-01

Mucosal epithelium senses external toxic insults and transmits the danger signals into the epithelial cells in order to activate a broad range of inflammatory responses. However, pre-exposure to the commensal endotoxins can induce inflammatory tolerance and maintain the homeostasis without excessive immune responses. We recently reported that ribotoxin deoxynivalenol (DON) and its derivatives elicited the pro-inflammatory response as the mucosal insults in human epithelial cells. Taking the knowledge into consideration, we tested the hypothesis that endotoxin pre-exposure can attenuate ribotoxin-induced epithelial interleukin-8 (IL-8) production via a tolerance mechanism. Pre-exposure to endotoxin repressed IL-8 release and its gene expression. However, inflammatory tolerance was not mediated by the attenuated NF-κB activation which has been generally recognized as the major mediator of LPS-mediated toll-like receptor (TLR) signaling pathway. Instead, pre-exposure to endotoxin was observed to trigger the delayed induction of peroxisome proliferator-activated receptor gamma (PPAR-γ) which contributed to the diminished IL-8 production in the human epithelial cells. Moreover, endogenous PPAR-γ agonist suppressed toxicant-mediated interleukin-8 production and IL-8 mRNA stability. Taken together, endotoxin induced hypo-production of pro-inflammatory cytokine IL-8 in the human epithelial cells, which was associated with the delayed activation of PPAR-γ expression by pre-existing endotoxin

Ascorbic acid suppresses endotoxemia and NF-κB signaling cascade in alcoholic liver fibrosis in guinea pigs: A mechanistic approach

Energy Technology Data Exchange (ETDEWEB)

Abhilash, P.A.; Harikrishnan, R.; Indira, M., E-mail: indiramadambath@gmail.com

2014-01-15

Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-κB activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4 g/kg b.wt for 90 days. After 90 days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250 mg/kg b.wt) and AA (250 mg/kg b.wt) supplemented groups and maintained for 30 days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKKβ and the protein expressions of phospho-IκBα, NF-κB, TNF-α, TGF-β{sub 1} and IL-6 were also altered in ethanol group. The expressions of fibrosis markers α-SMA, α{sub 1} (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-κB activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKKβ, which decreased the activation of NF-κB and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. - Highlights: • Alcohol increases intestinal bacterial overgrowth and permeability of endotoxin. • Endotoxin mediated inflammation plays a major role in alcoholic liver fibrosis. • Ascorbic acid reduces endotoxemia, NF-κB activation and proinflammatory cytokines. • AA's action is by inhibition of SIBO, IKKβ and alteration of

Histopathological and ultrastructural effects of delta-endotoxins of Bacillus thuringiensis serovar israelensis in the midgut of Simulium pertinax larvae (Diptera, Simuliidae

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CFG Cavados

2004-08-01

Full Text Available The bacterium Bacillus thuringiensis (Bt produces parasporal crystals containing delta-endotoxins responsible for selective insecticidal activity on larvae. Upon ingestion, these crystals are solubilized in the midgut lumen and converted into active toxins that bind to receptors present on the microvilli causing serious damage to the epithelial columnar cells. We investigated the effect of these endotoxins on larvae of the Simulium pertinax, a common black fly in Brazil, using several concentrations during 4 h of the serovar israelensis strain IPS-82 (LFB-FIOCRUZ 584, serotype H-14 type strain of the Institute Pasteur, Paris. Light and electron microscope observations revealed, by time and endotoxin concentration, increasing damages of the larvae midgut epithelium. The most characteristic effects were midgut columnar cell vacuolization, microvilli damages, epithelium cell contents passing into the midgut lumen and finally the cell death. This article is the first report of the histopathological effects of the Bti endotoxins in the midgut of S. pertinax larvae and the data obtained may contribute to a better understanding of the mode of action of this bacterial strain used as bioinsecticide against black fly larvae.

Endotoxin levels in settled airborne dust in European schools : The HITEA school study

NARCIS (Netherlands)

Jacobs, J. H.; Krop, E. J M; Borras-Santos, A.; Zock, J. P.; Taubel, M.; Hyvarinnen, A.; Pekkanen, J.; Doekes, G.; Heederik, D. J J

2014-01-01

Indoor exposure to microbial agents is known to influence respiratory health. Besides home exposure, exposure in schools can affect respiratory health. In this study, we measured endotoxin in settled dust in primary schools in three European countries from three different geographical regions with

Enhancement of intrinsic antitumor activity in spore-endotoxin mixtures of Bacillus thuringiensis by exposure to ultraviolet radiation

Energy Technology Data Exchange (ETDEWEB)

Zamola, B; Karminski-Zamola, G; Fuks, Z; Kubovic, M [Zagreb Univ. (Yugoslavia); Wrishcer, M [Institut Rudjer Boskovic, Zagreb (Yugoslavia)

1985-03-01

Irradiation of spore-endotoxin mixtures from Bacillus thuringiensis cultures at 254 nm (60 ..mu..W cm/sup -2/) enhances their intrinsic antitumor potency as well as that of either component. The extent of enhancement depends on the length of exposure (optimum: 35 min) and may thus be due to photochemical changes of the endotoxin protein or/and to photoproduction of additional compounds with antitumor activity. Antitumor effects, expressed as survival rates of C57BL/6 mice inoculated with Lewis' mouse lung carcinoma and subjected to treatments 24 h later, depended on the number of doses of preparations administered (mixture, separated components).

Notional Permeability

NARCIS (Netherlands)

Kik, R.; Van den Bos, J.P.; Maertens, J.; Verhagen, H.J.; Van der Meer, J.W.

2012-01-01

Different layer design of a rock slope and under layers has a large effect on the strengths on the rock slope itself. In the stability formula developed of VAN DER MEER [1988] this effect is represented by the term Notional Permeability with symbol P. A more open, or permeable, structure underneath

High-permeability criterion for BCS classification: segmental/pH dependent permeability considerations.

Science.gov (United States)

Dahan, Arik; Miller, Jonathan M; Hilfinger, John M; Yamashita, Shinji; Yu, Lawrence X; Lennernäs, Hans; Amidon, Gordon L

2010-10-04

The FDA classifies a drug substance as high-permeability when the fraction of dose absorbed (F(abs)) in humans is 90% or higher. This direct correlation between human permeability and F(abs) has been recently controversial, since the β-blocker sotalol showed high F(abs) (90%) and low Caco-2 permeability. The purpose of this study was to investigate the scientific basis for this disparity between permeability and F(abs). The effective permeabilities (P(eff)) of sotalol and metoprolol, a FDA standard for the low/high P(eff) class boundary, were investigated in the rat perfusion model, in three different intestinal segments with pHs corresponding to the physiological pH in each region: (1) proximal jejunum, pH 6.5; (2) mid small intestine, pH 7.0; and (3) distal ileum, pH 7.5. Both metoprolol and sotalol showed pH-dependent permeability, with higher P(eff) at higher pH. At any given pH, sotalol showed lower permeability than metoprolol; however, the permeability of sotalol determined at pH 7.5 exceeded/matched metoprolol's at pH 6.5 and 7.0, respectively. Physicochemical analysis based on ionization, pK(a) and partitioning of these drugs predicted the same trend and clarified the mechanism behind these observed results. Experimental octanol-buffer partitioning experiments confirmed the theoretical curves. An oral dose of metoprolol has been reported to be completely absorbed in the upper small intestine; it follows, hence, that metoprolol's P(eff) value at pH 7.5 is not likely physiologically relevant for an immediate release dosage form, and the permeability at pH 6.5 represents the actual relevant value for the low/high permeability class boundary. Although sotalol's permeability is low at pH 6.5 and 7.0, at pH 7.5 it exceeds/matches the threshold of metoprolol at pH 6.5 and 7.0, most likely responsible for its high F(abs). In conclusion, we have shown that, in fact, there is no discrepancy between P(eff) and F(abs) in sotalol's absorption; the data emphasize that

Quantifying Dustiness, Specific Allergens, and Endotoxin in Bulk Soya Imports

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Howard J. Mason

2017-11-01

Full Text Available Soya is an important bulk agricultural product often transported by sea as chipped beans and/or the bean husks after pelletisation. There are proven allergens in both forms. Bulk handling of soya imports can generate air pollution containing dust, allergens, and pyrogens, posing health risks to dockside workers and surrounding populations. Using an International Organization for Standardization (ISO standardised rotating drum dustiness test in seven imported soya bulks, we compared the generated levels of dust and two major soya allergens in three particle sizes related to respiratory health. Extractable levels of allergen and endotoxin from the bulks showed 30–60 fold differences, with levels of one allergen (hydrophobic seed protein and endotoxin higher in husk. The generated levels of dust and allergens in the three particle sizes also showed very wide variations between bulks, with aerolysed levels of allergen influenced by both the inherent dustiness and the extractable allergen in each bulk. Percentage allergen aerolysed from pelletized husk—often assumed to be of low dustiness—after transportation was not lower than that from chipped beans. Thus, not all soya bulks pose the same inhalation health risk and reinforces the importance of controlling dust generation from handling all soya bulk to as low as reasonably practicable.

Tolerance of monocytes and macrophages in response to bacterial endotoxin

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Ewelina Wiśnik

2017-03-01

Full Text Available Monocytes belong to myeloid effector cells, which constitute the first line of defense against pathogens, also called the nonspecific immune system and play an important role in the maintenance of tissue homeostasis. In response to stimulation, monocytes differentiate into macrophages capable of microorganism phagocytosis and secrete factors that play a key role in the regulation of immune responses. However excessive exposure of monocytes/macrophages to the lipopolysaccharide (LPS of Gram negative bacteria leads to the acquisition of immune tolerance by these cells. Such state results from disruption of different biological processes, for example intracellular signaling pathways and is accompanied by a number of disease states (immune, inflammatory or neoplastic conditions. Regulation of monocytes/macrophages activity is controlled by miRNAs, which are involved in the modulation of immune tolerance acquired by these cells. Moreover, the tolerance to endotoxin is conditioned by the posttranscriptional processes and posttranslational epigenetic modifications leading to the impairment of normal immune response for example by alterations in the expression of many genes encoding immune signaling mediators. The aim of this paper is to provide an overview existing knowledge on the modulation of activity of monocytes/macrophages in response to bacterial endotoxin and impaired immune responses.

Sensitisation to common allergens and respiratory symptoms in endotoxin exposed workers: a pooled analysis

NARCIS (Netherlands)

Basinas, I.|info:eu-repo/dai/nl/313908206; Schlünssen, V.; Heederik, D.|info:eu-repo/dai/nl/072910542; Sigsgaard, T.; Smit, L.A.|info:eu-repo/dai/nl/311470882; Samadi, S.|info:eu-repo/dai/nl/304838551; Omland, O.; Hjort, C.; Madsen, A.M.; Skov, S.; Wouters, I.M.|info:eu-repo/dai/nl/274156652

2012-01-01

OBJECTIVE: To test the hypotheses that current endotoxin exposure is inversely associated with allergic sensitisation and positively associated with non-allergic respiratory diseases in four occupationally exposed populations using a standardised analytical approach. METHODS: Data were pooled from

Permeability measuremens of brazilian Eucalyptus

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Marcio Rogério da Silva

2010-09-01

Full Text Available The permeability of Brazilian Eucalyptus grandis and Eucalyptus citriodora wood was measured in a custom build gas analysis chamber in order to determine which species could be successfully treated with preservatives. Liquid permeability was tested using an emulsion of Neen oil and a control of distillated water. Air was used to test the gas phase permeability. For both Eucalyptus grandis and Eucalyptus citriodora, the longitudinal permeability of gas was shown to be about twice as great as the liquid phase permeability. No radial permeability was observed for either wood. The permeability of air and water through the sapwood of Eucalyptus grandis was greater than that through the sapwood of Eucalyptus citriodora. The permeability of neen oil preservative through the sapwood of Eucalyptus grandis was also greater than through the sapwood of E. Citradora, but the difference was not statistically significant. Scanning Electron Microscopy images showed that the distribution and obstruction in the vessels could be correlated with observed permeability properties. Irrespective of the causes of differences in permeability between the species, the fluid phase flux through the sapwood of both species was significant, indicating that both Eucalyptus grandis and Eucalyptus citriodora could be successfully treated with wood preservative.

Dust, endotoxin, fungi, and bacteria exposure as determined by work task, season, and type of plant in a flower greenhouse

DEFF Research Database (Denmark)

Thilsing, T.; Madsen, A. M.; Basinas, I.

2015-01-01

BACKGROUND: Greenhouse workers are exposed to dust, endotoxin, fungi, and bacteria potentially causing airway inflammation as well as systemic symptoms. Knowledge about determinants of exposure is a prerequisite for efficient prevention through knowledge-based reduction in exposure. The objective......, Lavandula, Rhipsalideae, and Helleborus. The samples were gravimetrically analysed for inhalable dust. Endotoxin was assessed by the Limulus Amoebocyte Lysate test and culture-based quantification of bacteria and fungi was performed. Information on the performed tasks during sampling was extracted from...... and between 0.84 and 1097 EU m(-3) for endotoxin exposure, with the highest mean levels measured during Lavandula and Campanula handling, respectively. Personal exposure to fungi ranged between 1.8x10(2) and 3.4x10(6) colony-forming units (CFU) m(-3) and to bacteria between 1.6x10(1) and 4.2x10(5) CFU m(-3...

Intestinal Permeability: The Basics

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Ingvar Bjarnason

1995-01-01

Full Text Available The authors review some of the more fundamental principles underlying the noninvasive assessment of intestinal permeability in humans, the choice of test markers and their analyses, and the practical aspects of test dose composition and how these can be changed to allow the specific assessment of regional permeability changes and other intestinal functions. The implications of increased intestinal permeability in the pathogenesis of human disease is discussed in relation to findings in patients with Crohn’s disease. A common feature of increased intestinal permeability is the development of a low grade enteropathy, and while quantitatively similar changes may be found in Crohn’s disease these seem to predict relapse of disease. Moreover, factors associated with relapse of Crohn’s disease have in common an action to increase intestinal permeability. While increased intestinal permeability does not seem to be important in the etiology of Crohn’s disease it may be a central mechanism in the clinical relapse of disease.

Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis.

Science.gov (United States)

Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath; Mörgelin, Matthias; van der Plas, Mariena J A; Rydengård, Victoria; Malmsten, Martin; Albiger, Barbara; Schmidtchen, Artur

2012-01-01

Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin in vitro and in vivo. Furthermore, they interfere with coagulation by modulating contact activation and tissue factor-mediated clotting in vitro, leading to normalization of coagulation responses in vivo, a previously unknown function of host defense peptides. In a mouse model of Pseudomonas aeruginosa sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate bacterial levels, pro-inflammatory responses, and coagulation, renders them attractive therapeutic candidates for the treatment of invasive infections and sepsis.

Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis.

Directory of Open Access Journals (Sweden)

Martina Kalle

Full Text Available Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin in vitro and in vivo. Furthermore, they interfere with coagulation by modulating contact activation and tissue factor-mediated clotting in vitro, leading to normalization of coagulation responses in vivo, a previously unknown function of host defense peptides. In a mouse model of Pseudomonas aeruginosa sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate bacterial levels, pro-inflammatory responses, and coagulation, renders them attractive therapeutic candidates for the treatment of invasive infections and sepsis.

Effects of Bacillus thuringiensis CRY1A(c) d-endotoxin on growth ...

African Journals Online (AJOL)

The recent introduction of Bt maize and Bt cotton transgenic crops into Africa has raised concerns on their potential short and long-term ecological effects on the environment. The effects of Bacillus thuringiensis (Bt) Cry1A(c) d-endotoxin on the growth, nodulation and productivity of two leguminous plants grown in clay soil ...

The effects of adrenal hormones, endotoxin and turpentine on serum components of the plaice (Pleuronectes platessa L.).

Science.gov (United States)

White, A; Fletcher, T C

1982-01-01

1. Within 24 hr of injection into plaice, cortisol, deoxycorticosterone, adrenalin or endotoxin cause an increase (P less than 0.001) in circulating C-reactive protein (CRP). Turpentine and soluble dexamethasone have no effect. 2. The increase in CRP with endotoxin is not enhanced with adrenalin or deoxycorticosterone, and in conjunction with cortisol the increase is additive. 3. Changes in CRP are independent of the amounts of serum amyloid P-component or total protein. 4. Turpentine, cortisol and adrenalin cause a rapid increase in circulating glucose. 5. It is concluded that some adrenal hormones stimulate the CRP acute phase response in plaice, without an apparent provoking agent.

Effects of garlic oil and two of its major organosulfur compounds, diallyl disulfide and diallyl trisulfide, on intestinal damage in rats injected with endotoxin

International Nuclear Information System (INIS)

Chiang, Y.-H.; Jen, L.-N.; Su, H.-Y.; Lii, C.-K.; Sheen, L.-Y.; Liu, C.-T.

2006-01-01

Garlic and its active components are known to possess antioxidant and antiinflammatory effects. The present study investigated the effects of garlic oil and its organosulfur compounds on endotoxin-induced intestinal mucosal damage. Wistar rats received by gavage 50 or 200 mg/kg body weight garlic oil (GO), 0.5 mmol/kg body weight diallyl disulfide or diallyl trisulfide, or the vehicle (corn oil; 2 ml/kg body weight) every other day for 2 weeks before being injected with endotoxin (i.p., 5 mg/kg body weight). Control rats were administered with corn oil and were injected with sterile saline. Samples for the measurement of proinflammatory cytokines were collected 3 h after injection, and all other samples were collected 18 h after injection. The low dose of GO suppressed endotoxin-induced inducible nitric oxide synthase (iNOS) activity, ulceration, and apoptosis in the intestinal mucosa (P < 0.05). The high dose of GO significantly lowered the peripheral level of nitrate/nitrite and endotoxin-induced iNOS activity in the intestinal mucosa (P < 0.05) but worsened intestinal mucosal damage accompanied by elevated peripheral proinflammatory cytokines. Diallyl trisulfide but not diallyl disulfide showed similar toxic effect as that of high-dose GO. These results suggest the preventive effect and possible toxicity of garlic oil and its organosulfur compounds in endotoxin-induced systemic inflammation and intestinal damage

Modulation of reactive oxygen species production alters responses of lung inflammatory cells to endotoxin

Czech Academy of Sciences Publication Activity Database

Krejčová, Daniela; Konopka, Roman; Lojek, Antonín; Číž, Milan; Kubala, Lukáš

2006-01-01

Roč. 40, č. 1 (2006), S112-S112 ISSN 1071-5762 R&D Projects: GA ČR(CZ) GA524/06/1197 Institutional research plan: CEZ:AV0Z50040507 Keywords : myeloperoxidase * inflammation * endotoxin Subject RIV: BO - Biophysics

The osmolyte xylitol reduces the salt concentration of airway surface liquid and may enhance bacterial killing

Science.gov (United States)

Zabner, Joseph; Seiler, Michael P.; Launspach, Janice L.; Karp, Philip H.; Kearney, William R.; Look, Dwight C.; Smith, Jeffrey J.; Welsh, Michael J.

2000-10-01

The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibrosis (CF). We tested the hypothesis that an osmolyte with a low transepithelial permeability may lower the ASL salt concentration, thereby enhancing innate immunity. We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro. Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control. Xylitol may be of value in decreasing ASL salt concentration and enhancing the innate antimicrobial defense at the airway surface.

Permeability of porour rhyolite

Science.gov (United States)

Cashman, K.; Rust, A.; Wright, H.; Roberge, J.

2003-04-01

The development of permeability in bubble-bearing magmas determines the efficiency of volatile escape during their ascent through volcanic conduits, which, in turn, controls their explosive potential. As permeability requires bubble connectivity, relationships between permeability and porosity in silicic magmas must be controlled by the formation, growth, deformation and coalescence of their constituent bubbles. Although permeability data on porous volcanic pyroclasts are limited, the database can be greatly extended by including data for ceramic and metallic foams1. Several studies indicate that a single number does not adequately describe the permeability of a foam because inertial effects, which predominate at high flow rates, cause deviations from Darcy's law. These studies suggest that permeability is best modeled using the Forschheimer equation to determine both the Darcy permeability (k1) and the non-Darcian (k2) permeability. Importantly, at the high porosities of ceramic foams (75-95%), both k1 and k2 are strongly dependent on pore size and geometry, suggesting that measurement of these parameters provides important information on foam structure. We determined both the connected porosity (by He-pycnometry) and the permeability (k1 and k2) of rhyolitic samples having a wide range in porosity (22-85%) and vesicle textures. In general, these data support previous observations of a power law relationship between connected porosity and Darcy permeability2. In detail, variations in k1 increase at higher porosities. Similarly, k2 generally increases in both mean and standard deviation with increasing porosity. Measurements made on three mutually perpendicular cores from individual pumice clasts suggest that some of the variability can be explained by anisotropy in the vesicle structure. By comparison with ceramic foams, we suggest that the remaining variability results from differences either in average vesicle size or, more likely, in the size of apertures

Ascorbic acid deficiency increases endotoxin influx to portal blood and liver inflammatory gene expressions in ODS rats.

Science.gov (United States)

Tokuda, Yuki; Miura, Natsuko; Kobayashi, Misato; Hoshinaga, Yukiko; Murai, Atsushi; Aoyama, Hiroaki; Ito, Hiroyuki; Morita, Tatsuya; Horio, Fumihiko

2015-02-01

The aim of this study was to determine whether ascorbic acid (AsA) deficiency-induced endotoxin influx into portal blood from the gastrointestinal tract contributes to the inflammatory changes in the liver. The mechanisms by which AsA deficiency provokes inflammatory changes in the liver were investigated in Osteogenic Disorder Shionogi (ODS) rats (which are unable to synthesize AsA). Male ODS rats (6-wk-old) were fed a diet containing sufficient (300 mg/kg) AsA (control group) or a diet without AsA (AsA-deficient group) for 14 or 18 d. On day 14, the hepatic mRNA levels of acute-phase proteins and inflammation-related genes were significantly higher in the AsA-deficient group than the control group, and these elevations by AsA deficiency were exacerbated on day 18. The serum concentrations of interleukin (IL)-1β and IL-6, which induce acute-phase proteins in the liver, were also significantly elevated on day 14 in the AsA-deficient group compared with the respective values in the control group. IL-1β mRNA levels in the liver, spleen, and lung were increased by AsA deficiency. Moreover, on both days 14 and 18, the portal blood endotoxin concentration was significantly higher in the AsA-deficient group than in the control group, and a significant correlation between serum IL-1β concentrations and portal endotoxin concentrations was found in AsA-deficient rats. In the histologic analysis of the ileum tissues, the number of goblet cells per villi was increased by AsA deficiency. These results suggest that AsA deficiency-induced endotoxin influx into portal blood from the gastrointestinal tract contributes to the inflammatory changes in the liver. Copyright © 2015 Elsevier Inc. All rights reserved.

Detection of microorganisms, endotoxins and aluminum in mobile dialysis services

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Priscila Rodrigues de Jesus

2017-11-01

Full Text Available Hemodialysis water and dialysates are fundamental in the treatment of kidney disease. During just one hemodialysis session, 120 liters of dialysate are consumed. Thus, it is essential that the parameters of chemical and microbiological quality of the fluids used in dialysis systems are carefully observed. In this study, water samples were collected at 12 hospitals in the state of Rio de Janeiro. The samples were obtained at three points of fluid reservoirs: pre-, post-osmosis and dialysis solution. After collection, colony forming units (CFU, total coliforms and Escherichia coli 100 mL-1 were quantified. Later, isolated colonies and endotoxin content were identified by biochemical assays. Data about total aluminum levels per sample (mg L-1 were also obtained. Samples of all mobile dialysis services and points of collection were contaminated above the levels set out by national laws, in particular by Pseudomonas aeruginosa. Endotoxin levels were also above the recommended by current legislation (> 0.25 EU mL-1. Only three samples contained detectable levels of aluminum, which were found to be above the recommended values for the corresponding resolution (0.01 mg L-1. Finally, there were no observable amounts of total coliforms and E. coli 100 mL-1 sample. The data from this study are an important step forward in the standardization and control of chemical/microbiological quality of mobile dialysis services.

Study on security of sterile and non-pyrogenic disposable wares for medical use. Inactivation of endotoxins by γ-ray radiation in the presence of various drugs

International Nuclear Information System (INIS)

Hosobuchi, Kazunari; Tanamoto, Kenichi; Haijima, Yuji

1997-01-01

To efficiently inactivate endotoxins, γ-ray radiation to disposable wares for medical use was conducted using 185TBq 60 Co-radiation system in a medium added with various drugs. Endotoxin derived from E. coli R3F653 was used as the subject. Hydrogen peroxide solution, ethyl alcohol, or sodium hydrochloride were added to the basal medium. The activity of endotoxin was determined by limulus test with toxicolor system. The activity was markedly decreased by standing in 0.03% sodium hydrochloride solution for several days, whereas it was little affected in solutions of other two drugs at any concentration. However, γ-ray radiation in the medium added with either of those drugs caused to reduce the endotoxin activity dose-dependently. Such reducing effects by γ-ray radiation were most marked in the medium containing Na-hydrochloride at 0.03 or 0.3%, suggesting that there might be interaction of γ-ray and Na-hydrochloride. (M.N.)

Intestinal permeability study of minoxidil: assessment of minoxidil as a high permeability reference drug for biopharmaceutics classification.

Science.gov (United States)

Ozawa, Makoto; Tsume, Yasuhiro; Zur, Moran; Dahan, Arik; Amidon, Gordon L

2015-01-05

The purpose of this study was to evaluate minoxidil as a high permeability reference drug for Biopharmaceutics Classification System (BCS). The permeability of minoxidil was determined in in situ intestinal perfusion studies in rodents and permeability studies across Caco-2 cell monolayers. The permeability of minoxidil was compared with that of metoprolol, an FDA reference drug for BCS classification. In rat perfusion studies, the permeability of minoxidil was somewhat higher than that of metoprolol in the jejunum, while minoxidil showed lower permeability than metoprolol in the ileum. The permeability of minoxidil was independent of intestinal segment, while the permeability of metoprolol was region-dependent. Similarly, in mouse perfusion study, the jejunal permeability of minoxidil was 2.5-fold higher than that of metoprolol. Minoxidil and metoprolol showed similar permeability in Caco-2 study at apical pH of 6.5 and basolateral pH of 7.4. The permeability of minoxidil was independent of pH, while metoprolol showed pH-dependent transport in Caco-2 study. Minoxidil exhibited similar permeability in the absorptive direction (AP-BL) in comparison with secretory direction (BL-AP), while metoprolol had higher efflux ratio (ER > 2) at apical pH of 6.5 and basolateral pH of 7.4. No concentration-dependent transport was observed for either minoxidil or metoprolol transport in Caco-2 study. Verapamil did not alter the transport of either compounds across Caco-2 cell monolayers. The permeability of minoxidil was independent of both pH and intestinal segment in intestinal perfusion studies and Caco-2 studies. Caco-2 studies also showed no involvement of carrier mediated transport in the absorption process of minoxidil. These results suggest that minoxidil may be an acceptable reference drug for BCS high permeability classification. However, minoxidil exhibited higher jejunal permeability than metoprolol and thus to use minoxidil as a reference drug would raise the

Effect of ultrasonic activation on the reduction of bacteria and endotoxins in root canals: a randomized clinical trial.

Science.gov (United States)

Nakamura, V C; Pinheiro, E T; Prado, L C; Silveira, A C; Carvalho, A P L; Mayer, M P A; Gavini, G

2018-01-01

This randomized clinical trial aimed to compare the effectiveness of ultrasonic activation with that of nonactivated irrigation on the removal of bacteria and endotoxin from root canals. Fifty patients with necrotic pulps and asymptomatic apical periodontitis were randomly allocated into two groups according to the final irrigation protocol after root canal preparation: Group UI - ultrasonic irrigation (n = 25) and Group NI - needle irrigation (n = 25). The root canals were medicated with calcium hydroxide for 14 days. Microbiological sampling was performed before (S1) and after the root canal preparation (S2), after the irrigation protocols (S3) and after the removal of the intracanal medication (S4). Total bacteria counts were determined by qPCR and the endotoxin levels by the limulus amebocyte lysate assay. Intragroup analyses were performed using the Wilcoxon test for related samples, whereas intergroup analyses were performed using the Mann-Whitney U-test (P  0.05). Ultrasonic activation was more effective than nonactivated irrigation for reducing the number of bacteria but not the endotoxin levels in root canals of teeth with apical periodontitis. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Activity of wild-type and hybrid Bacillus thuringiensis delta-endotoxins against Agrotis ipsilon

NARCIS (Netherlands)

Maagd, de R.A.; Weemen-Hendriks, M.; Molthoff, J.W.; Naimov, S.

2003-01-01

Twelve Cry1 and two Cry9 ?-endotoxins fromBacillus thuringiensis were tested for their activity against black cutworm (Agrotis ipsilon).A. ipsilon was not susceptible to many toxins, but three toxins had significant activity. Cry9Ca was the most toxic, followed by Cry1Aa and Cry1Fb. Hybrids between

[In vitro examination of the influence of lipase and amylase on dog's pancreas tissue incubated with endotoxins, phospholipase A2 or cytokines].

Science.gov (United States)

Kerekes, László; Antal-Szalmás, Péter; Dezso, Balázs; Sipka, Sándor; Furka, Andrea; Mikó, Irén; Sápy, Péter

2005-04-01

Proinflammatory cytokines are elevated during acute pancreatitis. The endotoxins and Phospholipase A2 (PLA2) also have important role in acute pancreatitis. The aim of this study was to determine, what factors are responsible for the tissue damage in acute pancreatitis. The examinations were performed on fixed and frozen sections of healthy dog's pancreas tissue. Direct effects of endotoxins, PLA2, and proinflammatory cytokines together with pancreas enzymes were examined on pancreatic tissue. Pancreas enzymes themselves did not cause any change in the structure of pancreas. The common influence of endotoxins, PLA2 and pancreas enzymes was examined, and finally the effect of proinflammatory cytokines and enzymes was examined on pancreas tissue. Our results show, that besides enzymes many other factors are necessary to inflict tissue damage in acute pancreatitis, but for necrosis the presence of TNF alfa is a must.

Metabolic evidence that serosal sodium does not recycle through the active transepithelial transport pathway of toad bladder.

Science.gov (United States)

Canessa, M; Labarca, P; Leaf, A

1976-12-25

The possibility that sodium from the serosal bathing medium "back diffuses" into the active sodium transport pool within the mucosal epithelial cell of the isolated toad bladder was examined by determining the effect on the metabolism of the tissue of removing sodium from the serosal medium. It was expected that if recycling of serosal sodium did occur through the active transepithelial transport pathway of the isolated toad bladder, removal of sodium from the serosal medium would reduce the rate of CO2 production by the tissue and enhance of stoichiometric ratio of sodium ions transported across the bladder per molecula of sodium transport dependent CO2 produced simultaneously by the bladder (JNa/JCO2). The data revealed no significant change in this ratio (17.19 with serosal sodium and 16.13 after replacing serosal sodium with choline). Further, when transepithelial sodium transport was inhibited (a) by adding amiloride to the mucosal medium, or (b) by removing sodium from the mucosal medium, subsequent removal of sodium from the serosal medium, or (c) addition of ouabain failed to depress the basal rate of CO2 production by the bladder [(a)rate of basal, nontransport related, CO2 production (JbCO2) equals 1.54 +/- 0.52 with serosal sodium and 1.54 +/- 0.37 without serosal sodium; (b) Jb CO2 equals 2.18 +/- 0.21 with serosal sodium and 2.09 +/- 0.21 without serosal sodium; (c) 1.14 +/- 0.26 without ouabain and 1.13 +/- 0.25 with ouabain; unite of JbCO2 are nmoles mg d.w.-1 min-1]. The results support the hypothesis that little, if any, recycling of serosal sodium occurs in the total bladder.

40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...

Science.gov (United States)

2010-07-01

... thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens is exempt from the...

Esophageal acid sensitivity and mucosal integrity in patients with functional heartburn.

Science.gov (United States)

Weijenborg, P W; Smout, A J P M; Bredenoord, A J

2016-11-01

Patients with functional heartburn (FH) experience troublesome heartburn that is not related to gastroesophageal reflux. The etiology of the heartburn sensation in FH patients is unknown. In patients with reflux disease, esophageal hypersensitivity seems associated with impaired mucosal integrity. We aimed to determine esophageal sensitivity and mucosal integrity in FH and non-erosive reflux disease (NERD) patients. In this prospective experimental study, we performed an acid perfusion test and upper endoscopy with biopsies in 12 patients with NERD and nine patients with FH. Mucosal integrity was measured during endoscopy using electrical tissue impedance spectroscopy and biopsy specimens were analyzed in Ussing chambers for transepithelial electrical resistance and transepithelial permeability. Lag time to heartburn perception was significantly longer in FH patients (median 12 min) than in NERD patients (median 3 min). Once perceived, intensity of heartburn was scored equal with median visual analog scale 6.5 and 7.1 respectively. Esophageal mucosal integrity was also comparable between FH and NERD patients, both in vivo extracellular impedance and ex vivo transepithelial resistance and permeability were similar. Patients with FH did not show acid hypersensitivity as seen in patients with NERD. However, once perceived, intensity of heartburn is similar. Esophageal mucosal integrity is similar between NERD and FH patients, and is therefore unlikely to be the underlying cause of the observed difference in esophageal acid perception. © 2016 John Wiley & Sons Ltd.

Mechanisms of transepithelial ammonia excretion and luminal alkalinization in the gut of an intestinal air-breathing fish, Misgurnus anguilliacaudatus.

Science.gov (United States)

Wilson, Jonathan M; Moreira-Silva, Joana; Delgado, Inês L S; Ebanks, Sue C; Vijayan, Mathilakath M; Coimbra, João; Grosell, Martin

2013-02-15

The weatherloach, Misgurnus angulliacaudatus, is an intestinal air-breathing, freshwater fish that has the unique ability to excrete ammonia through gut volatilization when branchial and cutaneous routes are compromised during high environmental ammonia or air exposure. We hypothesized that transepithelial gut NH(4)(+) transport is facilitated by an apical Na(+)/H(+) (NH(4)(+)) exchanger (NHE) and a basolateral Na(+)/K(+)(NH(4)(+))-ATPase, and that gut boundary layer alkalinization (NH(4)(+) → NH(3) + H(+)) is facilitated by apical HCO(3)(-) secretion through a Cl(-)/HCO(3)(-) anion exchanger. This was tested using a pharmacological approach with anterior (digestive) and posterior (respiratory) intestine preparations mounted in pH-stat-equipped Ussing chambers. The anterior intestine had a markedly higher conductance, increased short-circuit current, and greater net base (J(base)) and ammonia excretion rates (J(amm)) than the posterior intestine. In the anterior intestine, HCO(3)(-) accounted for 70% of J(base). In the presence of an imposed serosal-mucosal ammonia gradient, inhibitors of both NHE (EIPA, 0.1 mmol l(-1)) and Na(+)/K(+)-ATPase (ouabain, 0.1 mmol l(-1)) significantly inhibited J(amm) in the anterior intestine, although only EIPA had an effect in the posterior intestine. In addition, the anion exchange inhibitor DIDS significantly reduced J(base) in the anterior intestine although only at a high dose (1 mmol l(-1)). Carbonic anhydrase does not appear to be associated with gut alkalinization under these conditions as ethoxzolamide was without effect on J(base). Membrane fluidity of the posterior intestine was low, suggesting low permeability, which was also reflected in a lower mucosal-serosal J(amm) in the presence of an imposed gradient, in contrast to that in the anterior intestine. To conclude, although the posterior intestine is highly modified for gas exchange, it is the anterior intestine that is the likely site of ammonia excretion and

Biophysical mechanisms of endotoxin neutralization by cationic amphiphilic peptides.

Science.gov (United States)

Kaconis, Yani; Kowalski, Ina; Howe, Jörg; Brauser, Annemarie; Richter, Walter; Razquin-Olazarán, Iosu; Iñigo-Pestaña, Melania; Garidel, Patrick; Rössle, Manfred; Martinez de Tejada, Guillermo; Gutsmann, Thomas; Brandenburg, Klaus

2011-06-08

Bacterial endotoxins (lipopolysaccharides (LPS)) are strong elicitors of the human immune system by interacting with serum and membrane proteins such as lipopolysaccharide-binding protein (LBP) and CD14 with high specificity. At LPS concentrations as low as 0.3 ng/ml, such interactions may lead to severe pathophysiological effects, including sepsis and septic shock. One approach to inhibit an uncontrolled inflammatory reaction is the use of appropriate polycationic and amphiphilic antimicrobial peptides, here called synthetic anti-LPS peptides (SALPs). We designed various SALP structures and investigated their ability to inhibit LPS-induced cytokine secretion in vitro, their protective effect in a mouse model of sepsis, and their cytotoxicity in physiological human cells. Using a variety of biophysical techniques, we investigated selected SALPs with considerable differences in their biological responses to characterize and understand the mechanism of LPS inactivation by SALPs. Our investigations show that neutralization of LPS by peptides is associated with a fluidization of the LPS acyl chains, a strong exothermic Coulomb interaction between the two compounds, and a drastic change of the LPS aggregate type from cubic into multilamellar, with an increase in the aggregate sizes, inhibiting the binding of LBP and other mammalian proteins to the endotoxin. At the same time, peptide binding to phospholipids of human origin (e.g., phosphatidylcholine) does not cause essential structural changes, such as changes in membrane fluidity and bilayer structure. The absence of cytotoxicity is explained by the high specificity of the interaction of the peptides with LPS. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Sub-core permeability and relative permeability characterization with Positron Emission Tomography

Science.gov (United States)

Zahasky, C.; Benson, S. M.

2017-12-01

This study utilizes preclinical micro-Positron Emission Tomography (PET) to image and quantify the transport behavior of pulses of a conservative aqueous radiotracer injected during single and multiphase flow experiments in a Berea sandstone core with axial parallel bedding heterogeneity. The core is discretized into streamtubes, and using the micro-PET data, expressions are derived from spatial moment analysis for calculating sub-core scale tracer flux and pore water velocity. Using the flux and velocity data, it is then possible to calculate porosity and saturation from volumetric flux balance, and calculate permeability and water relative permeability from Darcy's law. Full 3D simulations are then constructed based on this core characterization. Simulation results are compared with experimental results in order to test the assumptions of the simple streamtube model. Errors and limitations of this analysis will be discussed. These new methods of imaging and sub-core permeability and relative permeability measurements enable experimental quantification of transport behavior across scales.

Permeability prediction in chalks

DEFF Research Database (Denmark)

Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Prasad, Manika

2011-01-01

The velocity of elastic waves is the primary datum available for acquiring information about subsurface characteristics such as lithology and porosity. Cheap and quick (spatial coverage, ease of measurement) information of permeability can be achieved, if sonic velocity is used for permeability p...... significantly using the effective specific surface as the fluid-flow concept. The FZI unit is appropriate for highly permeable sedimentary rocks such as sandstones and limestones that have small surface areas....

Determination of bacterial endotoxin (pyrogen) in radiopharmaceuticals by the gel clot method. Validation; Determinacao de endotoxina bacteriana (pirogenio) em radiofarmacos pelo metodo de formacao de gel. Validacao

Energy Technology Data Exchange (ETDEWEB)

Fukumori, Neuza Taeko Okasaki

2008-07-01

Before the Limulus amebocyte lysate (LAL) test, the only available means of pirogenicity testing for parenteral drugs and medical devices was the United States Pharmacopoeia (USP) rabbit pyrogen test. Especially for radiopharmaceuticals, the LAL assay is the elective way to determine bacterial endotoxin. The aim of this work was to validate the gel clot method for some radiopharmaceuticals without measurable interference. The FDA's LALTest guideline defines interference as a condition that causes a significant difference between the endpoints of a positive water control and positive product control series using a standard endotoxin. Experiments were performed in accordance to the USP bacterial endotoxins test in the {sup 131}I- m-iodobenzylguanidine; the radioisotopes Gallium-67 and Thallium-201; the lyophilized reagents DTPA, Phytate, GHA, HSA and Colloidal Tin. The Maximum Valid Dilution (MVD) was calculated for each product based upon the clinical dose of the material and a twofold serial dilution below the MVD was performed in duplicate to detect interferences. The labeled sensitivity of the used LAL reagent was 0.125 EU mL{sup -1} (Endotoxin Units per milliliter). For validation, a dilution series was performed, a twofold dilution of control standard endotoxin (CSE) from 0.5 to 0.03 EU mL{sup -1}, to confirm the labeled sensitivity of the LAL reagent being tested in sterile and non pyrogenic water, in quadruplicate. The same dilution series was performed with the CSE and the product in the 1:100 dilution factor, in three consecutive batches of each radiopharmaceutical. The products {sup 131}I-m-iodobenzylguanidine, Gallium-67, Thallium-201, DTPA, HSA and Colloidal Tin were found compatible with the LAL test at a 1:100 dilution factor. Phytate and GHA showed some interference in the gel clot test. Other techniques to determine endotoxins as the chromogenic (color development) and the turbidimetric test (turbidity development), were also assessed to get valuable

Determination of bacterial endotoxin (pyrogen) in radiopharmaceuticals by the gel clot method. Validation; Determinacao de endotoxina bacteriana (pirogenio) em radiofarmacos pelo metodo de formacao de gel. Validacao

Energy Technology Data Exchange (ETDEWEB)

Fukumori, Neuza Taeko Okasaki

2008-07-01

Before the Limulus amebocyte lysate (LAL) test, the only available means of pirogenicity testing for parenteral drugs and medical devices was the United States Pharmacopoeia (USP) rabbit pyrogen test. Especially for radiopharmaceuticals, the LAL assay is the elective way to determine bacterial endotoxin. The aim of this work was to validate the gel clot method for some radiopharmaceuticals without measurable interference. The FDA's LALTest guideline defines interference as a condition that causes a significant difference between the endpoints of a positive water control and positive product control series using a standard endotoxin. Experiments were performed in accordance to the USP bacterial endotoxins test in the {sup 131}I- m-iodobenzylguanidine; the radioisotopes Gallium-67 and Thallium-201; the lyophilized reagents DTPA, Phytate, GHA, HSA and Colloidal Tin. The Maximum Valid Dilution (MVD) was calculated for each product based upon the clinical dose of the material and a twofold serial dilution below the MVD was performed in duplicate to detect interferences. The labeled sensitivity of the used LAL reagent was 0.125 EU mL{sup -1} (Endotoxin Units per milliliter). For validation, a dilution series was performed, a twofold dilution of control standard endotoxin (CSE) from 0.5 to 0.03 EU mL{sup -1}, to confirm the labeled sensitivity of the LAL reagent being tested in sterile and non pyrogenic water, in quadruplicate. The same dilution series was performed with the CSE and the product in the 1:100 dilution factor, in three consecutive batches of each radiopharmaceutical. The products {sup 131}I-m-iodobenzylguanidine, Gallium-67, Thallium-201, DTPA, HSA and Colloidal Tin were found compatible with the LAL test at a 1:100 dilution factor. Phytate and GHA showed some interference in the gel clot test. Other techniques to determine endotoxins as the chromogenic (color development) and the turbidimetric test (turbidity development), were also assessed to get

Emissies van endotoxinen uit de veehouderij: een literatuurstudie voor ontwikkeling van een toetsingskader = Emissions of endotoxins from animal production: a literature survey for development of an assessment framework

NARCIS (Netherlands)

Winkel, A.; Wouters, I.M.; Aarnink, A.J.A.; Heederik, D.J.J.; Ogink, N.W.M.

2014-01-01

In this literature review, the state of knowledge is summarized on endotoxin emissions from animal production. Furthermore, the design of an assessment framework for endotoxins for use in permit granting is explored. Finally, lacking knowledge to develop such a framework has been determined.

Limulus amebocyte lysate technique (LAL) for bacterial endotoxin control in radiodiagnosis agents (kits) and radioisotopes

International Nuclear Information System (INIS)

Morote, M.; Robles, A.; Ramos, B.; Otero, M.

1997-01-01

A procedure based on a fast technique of LAL individual kits has been devised to control bacterial endotoxins in radiodiagnosis agents (RDA): HEMTEC, DEIDA, PPI, AMD, GHCa, RENTEC, DMSA, MAA, TSC, HERTEC, DTPA, BRATEC and EDTMP as well as in radioisotopes I-131 and Tc99m. The procedures begins with the determination of the following values, injection volume (IV), endotoxin limits (EL), maximum valid dilution (MVD), total mass (TM), reconstitution volume (RV), concentration (mg/ml), and final dilution (FD). Subsequently, a procedure is carried out to conduct an 'in vitro' control of the radiodiagnosis agents and radioisotopes with LAL individual kits; the procedures includes: reconstitution of the sample to be controlled, dilution, inoculation of the diluted sample in LAL tubes and incubation at 37 o C for an hour. Finally, results are interpreted through the observation of gel formation or not in LAL tubes

Pantoea agglomerans: a mysterious bacterium of evil and good. Part II--Deleterious effects: Dust-borne endotoxins and allergens--focus on grain dust, other agricultural dusts and wood dust.

Science.gov (United States)

Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Skórska, Czesława; Góra-Florek, Anna; Milanowski, Janusz

2016-01-01

Pantoea agglomerans, a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been identified by an interdisciplinary group from Lublin, eastern Poland, as a causative agent of work-related diseases associated with exposure to grain dust and other agricultural dusts. The concentration of P. agglomerans in grain as well as in the settled grain and flour dust was found to be high, ranging from 10(4)-10(8) CFU/g, while in the air polluted with grain or flour dust it ranged from 10(3)-10(5) CFU/m(3) and formed 73.2-96% of the total airborne Gram-negative bacteria. The concentration of P. agglomerans was also relatively high in the air of the facilities processing herbs and other plant materials, while it was lower in animal farms and in wood processing facilities. Pantoea agglomerans produces a biologically-potent endotoxin (cell wall lipopolysaccharide, LPS). The significant part of this endotoxin occurs in dusts in the form of virus-sized globular nanoparticles measuring 10-50 nm that could be described as the 'endotoxin super-macromolecules'. A highly significant relationship was found (R=0.804, P=0.000927) between the concentration of the viable P. agglomerans in the air of various agricultural and wood industry settings and the concentration of bacterial endotoxin in the air, as assessed by the Limulus test. Although this result may be interfered by the presence of endotoxin produced by other Gram-negative species, it unequivocally suggests the primary role of the P. agglomerans endotoxin as an adverse agent in the agricultural working environment, causing toxic pneumonitis (ODTS). Numerous experiments by the inhalation exposure of animals to various extracts of P. agglomerans strains isolated from grain dust, including endotoxin isolated with trichloroacetic acid (LPS-TCA), endotoxin nanoparticles isolated in sucrose gradient (VECN), and mixture of proteins and endotoxin obtained

Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.

Science.gov (United States)

Li, Hui; Kayhanian, Masoud; Harvey, John T

2013-03-30

Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability. Copyright © 2013 Elsevier Ltd. All rights reserved.

Short-chain inulin-like fructans reduce endotoxin and bacterial translocations and attenuate development of TNBS-induced colitis in rats.

Science.gov (United States)

Ito, Hiroyuki; Tanabe, Hiroki; Kawagishi, Hirokazu; Tadashi, Wada; Yasuhiko, Tomono; Sugiyama, Kimio; Kiriyama, Shuhachi; Morita, Tatsuya

2009-10-01

Anti-inflammatory effects of short-chain inulin-like fructans (SCF) on trinitrobenzene sulfonic acid (TNBS)-induced colitis were investigated in rats, focusing specifically on endotoxin and bacterial translocations. SCF with degrees of polymerization (DP) of 4 and 8 were used. Rats were fed either control diet or diets including 60 g DP4 or DP8 per kilogram for 7 days, and then received intracolonic TNBS and were fed the respective diets for a further 10 days. DP4 and DP8 significantly reduced colonic injuries as assessed by damage score, but the reduction of colonic myeloperoxidase activity was manifest solely with DP8. At 3 days after colitis induction, bacterial translocation to the mesenteric lymph node was significantly lower in the DP4 and DP8 groups, but significant reduction in the portal endotoxin concentration was achieved solely in the DP8 group. Immediately prior to colitis induction, cecal immunoglobulin A and mucin concentrations were higher in the DP4 and DP8 groups, but these changes were abolished at 10 days post colitis induction. The data suggest that SCF exert prophylactic effects against TNBS colitis, presumably as a result of inhibitory effects on endotoxin and bacterial translocations.

Relative Permeability of Fractured Rock

Energy Technology Data Exchange (ETDEWEB)

Mark D. Habana

2002-06-30

Contemporary understanding of multiphase flow through fractures is limited. Different studies using synthetic fractures and various fluids have yielded different relative permeability-saturation relations. This study aimed to extend the understanding of multiphase flow by conducting nitrogen-water relative permeability experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach was used. However, steady state was achieved only at the endpoint saturations. Several difficulties were encountered that are attributed to phase interference and changes in fracture aperture and surface roughness, along with fracture propagation/initiation. Absolute permeabilities were determined using nitrogen and water. The permeability values obtained change with the number of load cycles. Determining the absolute permeability of a core is especially important in a fractured rock. The rock may change as asperities are destroyed and fractures propagate or st rain harden as the net stresses vary. Pressure spikes occurred in water a solute permeability experiments. Conceptual models of an elastic fracture network can explain the pressure spike behavior. At the endpoint saturations the water relative permeabilities obtained are much less than the nitrogen gas relative permeabilities. Saturations were determined by weighing and by resistivity calculations. The resistivity-saturation relationship developed for the core gave saturation values that differ by 5% from the value determined by weighing. Further work is required to complete the relative permeability curve. The steady-state experimental approach encountered difficulties due to phase interference and fracture change. Steady state may not be reached until an impractical length of time. Thus, unsteady-state methods should be pursued. In unsteady-state experiments the challenge will be in quantifying rock fracture change in addition to fluid flow changes.

Dust, endotoxin, fungi, and bacteria exposure as determined by work task, season, and type of plant in a flower greenhouse.

Science.gov (United States)

Thilsing, Trine; Madsen, Anne Mette; Basinas, Ioannis; Schlünssen, Vivi; Tendal, Kira; Bælum, Jesper

2015-03-01

Greenhouse workers are exposed to dust, endotoxin, fungi, and bacteria potentially causing airway inflammation as well as systemic symptoms. Knowledge about determinants of exposure is a prerequisite for efficient prevention through knowledge-based reduction in exposure. The objective of this study was to assess the occupational exposure in a flower greenhouse and to investigate the impact of work tasks on the intensity and variability in exposure. Seventy-six personal full-shift exposure measurements were performed on 38 employees in a Danish flower greenhouse producing Campanula, Lavandula, Rhipsalideae, and Helleborus. The samples were gravimetrically analysed for inhalable dust. Endotoxin was assessed by the Limulus Amoebocyte Lysate test and culture-based quantification of bacteria and fungi was performed. Information on the performed tasks during sampling was extracted from the greenhouse electronic task logging system. Associations between log-transformed exposure outcomes, season, and work tasks were examined in linear mixed-effects regression with worker identity as random effect. Measured concentrations ranged between 0.04 and 2.41mg m(-3) for inhalable dust and between 0.84 and 1097 EU m(-3) for endotoxin exposure, with the highest mean levels measured during Lavandula and Campanula handling, respectively. Personal exposure to fungi ranged between 1.8×10(2) and 3.4×10(6) colony-forming units (CFU) m(-3) and to bacteria between 1.6×10(1) and 4.2×10(5) CFU m(-3). Exposure to dust, endotoxin, fungi, and bacteria differed between seasons. Packing Lavandula, sticking, potting, and grading Rhipsalideae, and all examined tasks related to Campanula production except sticking increased dust exposure. Endotoxin exposure was increased during sticking Campanula and pinching or packing Rhipsalideae, and fungi exposure was elevated by subtasks performed in the research and development area for Campanula, and by potting, packing/dumping Campanula. Sticking and

Importance of bacterial endotoxin (LPS in endodontics A importância da endotoxina bacteriana (LPS na endodontia atual

Directory of Open Access Journals (Sweden)

Mario Roberto Leonardo

2004-06-01

Full Text Available New knowledge of the structure and biological activity of endotoxins (LPS has revolutionized concepts concerning their mechanisms of action and forms of inactivation. Since the 1980's, technological advances in microbiological culture and identification have shown that anaerobic microorganisms, especially Gram-negative, predominate in root canals of teeth with pulp necrosis and radiographically visible chronic periapical lesions. Gram-negative bacteria not only have different factors of virulence and generate sub-products that are toxic to apical and periapical tissues, as also contain endotoxin (LPS on their cell wall. This is especially important because endotoxin is released during multiplication or bacterial death, causing a series of biological effects that lead to an inflammatory reaction and resorption of mineralized tissues. Thus, due to the role of endotoxin in the pathogenesis of periapical lesions, we reviewed the literature concerning the biological activity of endotoxin and the relevance of its inactivation during treatment of teeth with pulp necrosis and chronic periapical lesion.O conhecimento mais aprofundado sobre a estrutura e atividade biológica das endotoxinas (LPS revolucionou os conceitos sobre seu mecanismo de ação e formas de inativação. A partir da década de 80, os avanços tecnológicos na cultura e identificação microbiológica demonstraram que, em canais radiculares de dentes portadores de necrose pulpar e lesão periapical crônica, visível radiograficamente, predominam microrganismos anaeróbios, particularmente os gram-negativos. Como se sabe, os microrganismos gram-negativos, além de possuírem diferentes fatores de virulência e gerarem produtos e sub-produtos tóxicos aos tecidos apicais e periapicais, contêm endotoxina em sua parede celular. Esse conhecimento é particularmente importante, uma vez que a endotoxina é liberada durante a multiplicação ou morte bacteriana, exercendo uma série de

Discrimination between low dietary zinc and endotoxin exposure : a model study on weaning rats

NARCIS (Netherlands)

Wouwe, van J.P.; Veldhuizen, M.; Hamer, van den C.J.A.; de Goeij, J.J.M.

1990-01-01

To establish a parameter for zinc status that is independent of the occurrence of infection, we studied the effects of low dietary zinc and endotoxin in weaning rats 21 d after 65Zn intubation. We monitored aspects of zinc status (tissue zinc content, 65Zn distribution, and specific 65Zn activity in

40 CFR 180.1108 - Delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas...

Science.gov (United States)

2010-07-01

... thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... into killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens is...

Electrokinetic effects and fluid permeability

International Nuclear Information System (INIS)

Berryman, J.G.

2003-01-01

Fluid permeability of porous media depends mainly on connectivity of the pore space and two physical parameters: porosity and a pertinent length-scale parameter. Electrical imaging methods typically establish connectivity and directly measure electrical conductivity, which can then often be related to porosity by Archie's law. When electrical phase measurements are made in addition to the amplitude measurements, information about the pertinent length scale can then be obtained. Since fluid permeability controls the ability to flush unwanted fluid contaminants from the subsurface, inexpensive maps of permeability could improve planning strategies for remediation efforts. Detailed knowledge of fluid permeability is also important for oil field exploitation, where knowledge of permeability distribution in three dimensions is a common requirement for petroleum reservoir simulation and analysis, as well as for estimates on the economics of recovery

Pantoea agglomerans : a mysterious bacterium of evil and good. Part II. Deleterious effects: Dust-borne endotoxins and allergens – focus on grain dust, other agricultural dusts and wood dust

Directory of Open Access Journals (Sweden)

Jacek Dutkiewicz

2015-12-01

Full Text Available Pantoea agglomerans , a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been identified by an interdisciplinary group from Lublin, eastern Poland, as a causative agent of work-related diseases associated with exposure to grain dust and other agricultural dusts. The concentration of [i]P. agglomerans[/i] in grain as well as in the settled grain and flour dust was found to be high, ranging from 10 4 –10 8 CFU/g, while in the air polluted with grain or flour dust it ranged from 10 3 –10 5 CFU/m 3 and formed 73.2–96% of the total airborne Gram-negative bacteria. The concentration of P. agglomerans was also relatively high in the air of the facilities processing herbs and other plant materials, while it was lower in animal farms and in wood processing facilities. Pantoea agglomerans produces a biologically-potent endotoxin (cell wall lipopolysaccharide, LPS. The significant part of this endotoxin occurs in dusts in the form of virus-sized globular nanoparticles measuring 10–50 nm that could be described as the ‘endotoxin super-macromolecules’. A highly significant relationship was found (R=0.804, P=0.000927 between the concentration of the viable P. agglomerans in the air of various agricultural and wood industry settings and the concentration of bacterial endotoxin in the air, as assessed by the Limulus test. Although this result may be interfered by the presence of endotoxin produced by other Gram-negative species, it unequivocally suggests the primary role of the P. agglomerans endotoxin as an adverse agent in the agricultural working environment, causing toxic pneumonitis (ODTS. Numerous experiments by the inhalation exposure of animals to various extracts of P. agglomerans strains isolated from grain dust, including endotoxin isolated with trichloroacetic acid (LPS-TCA, endotoxin nanoparticles isolated in sucrose gradient (VECN, and mixture of

Fucoidan Extracted from Fucus evanescens Prevents Endotoxin-Induced Damage in a Mouse Model of Endotoxemia

Directory of Open Access Journals (Sweden)

Tatyana A. Kuznetsova

2014-01-01

Full Text Available An important problem of treating patients with endotoxemia is to find drugs to reduce the negative effects of endotoxin on the organism. We tested fucoidan (sulfated polysaccharide from the brown alga Fucus evanescens as a potential drug in a mouse model of endotoxemia inducted by lipopolysaccharide (LPS. The survival time of mice injected with LPS increased under fucoidan treatment compared with the group of mice injected with LPS only. The preventive administration of fucoidan to mice with endotoxemia resulted in inhibition of increased levels of proinflammatory cytokines (TNFα and IL-6, as well as decreasing of the processes of hypercoagulability. The parenteral or per os administration of fucoidan resulted in decreasing the degree of microcirculatory disorders and secondary dystrophic-destructive changes in parenchymal organs of mice with endotoxemia. Taken together, these results demonstrate that fucoidan prevents endotoxin-induced damage in a mouse model of endotoxemia and increases the mice’s resistance to LPS.

Facile biofunctionalization of silver nanoparticles for enhanced antibacterial properties, endotoxin removal, and biofilm control

Directory of Open Access Journals (Sweden)

Lambadi PR

2015-03-01

Full Text Available Paramesh Ramulu Lambadi,1,* Tarun Kumar Sharma,1,* Piyush Kumar,1 Priyanka Vasnani,2 Sitaramanjaneya Mouli Thalluri,2 Neha Bisht,1 Ranjana Pathania,1,2 Naveen Kumar Navani1,21Department of Biotechnology, 2Centre of Nanotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, India*These authors contributed equally to this workAbstract: Infectious diseases cause a huge burden on healthcare systems worldwide. Pathogenic bacteria establish infection by developing antibiotic resistance and modulating the host’s immune system, whereas opportunistic pathogens like Pseudomonas aeruginosa adapt to adverse conditions owing to their ability to form biofilms. In the present study, silver nanoparticles were biofunctionalized with polymyxin B, an antibacterial peptide using a facile method. The biofunctionalized nanoparticles (polymyxin B-capped silver nanoparticles, PBSNPs were assessed for antibacterial activity against multiple drug-resistant clinical strain Vibrio fluvialis and nosocomial pathogen P. aeruginosa. The results of antibacterial assay revealed that PBSNPs had an approximately 3-fold higher effect than the citrate-capped nanoparticles (CSNPs. Morphological damage to the cell membrane was followed by scanning electron microscopy, testifying PBSNPs to be more potent in controlling the bacterial growth as compared with CSNPs. The bactericidal effect of PBSNPs was further confirmed by Live/Dead staining assays. Apart from the antibacterial activity, the biofunctionalized nanoparticles were found to resist biofilm formation. Electroplating of PBSNPs onto stainless steel surgical blades retained the antibacterial activity against P. aeruginosa. Further, the affinity of polymyxin for endotoxin was exploited for its removal using PBSNPs. It was found that the prepared nanoparticles removed 97% of the endotoxin from the solution. Such multifarious uses of metal nanoparticles are an attractive means of enhancing the potency of antimicrobial

Biophysical analysis of the interaction of granulysin-derived peptides with enterobacterial endotoxins.

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Chen, Xi; Howe, Jörg; Andrä, Jörg; Rössle, Manfred; Richter, Walter; da Silva, Ana Paula Galvão; Krensky, Alan M; Clayberger, Carol; Brandenburg, Klaus

2007-10-01

To combat infections by Gram-negative bacteria, it is not only necessary to kill the bacteria but also to neutralize pathogenicity factors such as endotoxin (lipopolysaccharide, LPS). The development of antimicrobial peptides based on mammalian endotoxin-binding proteins is a promising tool in the fight against bacterial infections, and septic shock syndrome. Here, synthetic peptides derived from granulysin (Gra-pep) were investigated in microbiological and biophysical assays to understand their interaction with LPS. We analyzed the influence of the binding of Gra-pep on (1) the acyl chain melting of the hydrophobic moiety of LPS, lipid A, by Fourier-transform spectroscopy, (2) the aggregate structure of LPS by small-angle X-ray scattering and cryo-transmission electron microscopy, and 3) the enthalpy change by isothermal titration calorimetry. In addition, the influence of Gra-pep on the incorporation of LPS and LPS-LBP (lipopolysaccharide-binding protein) complexes into negatively charged liposomes was monitored. Our findings demonstrate a characteristic change in the aggregate structure of LPS into multilamellar stacks in the presence of Gra-pep, but little or no change of acyl chain fluidity. Neutralization of LPS by Gra-pep is not due to a scavenging effect in solution, but rather proceeds after incorporation into target membranes, suggesting a requisite membrane-bound step.

The Structural Basis for Lipid and Endotoxin Binding in RP105-MD-1, and Consequences for Regulation of Host Lipopolysaccharide Sensitivity.

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Ortiz-Suarez, Maite L; Bond, Peter J

2016-01-05

MD-1 is a member of the MD-2-related lipid-recognition (ML) family, and associates with RP105, a cell-surface protein that resembles Toll-like receptor 4 (TLR4). The RP105⋅MD-1 complex has been proposed to play a role in fine-tuning the innate immune response to endotoxin such as bacterial lipopolysaccharide (LPS) via TLR4⋅MD-2, but controversy surrounds its mechanism. We have used atomically detailed simulations to reveal the structural basis for ligand binding and consequent functional dynamics of MD-1 and the RP105 complex. We rationalize reports of endogenous phospholipid binding, by showing that they prevent collapse of the malleable MD-1 fold, before refining crystallographic models and uncovering likely binding modes for LPS analogs. Subsequent binding affinity calculations reveal that endotoxin specificity arises from the entropic cost of expanding the MD-1 cavity to accommodate bulky lipid tails, and support the role of MD-1 as a "sink" that sequesters endotoxin from TLR4 and stabilizes RP105/TLR4 interactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Immunity to endotoxin and Asp299Gly polymorphism of TLR-4 in adult patients with early and late onset of asthma

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Yu. A. Bisyuk

2015-06-01

Full Text Available Aim. The gene polymorphism of Asp299Gly TLR-4 may be associated with the risk of asthma development. Methods and results. The gene polymorphism of TLR-4 (Asp299Gly receptor has been researched in 262 early-onset and in 69 late-onset asthma patients. The state of anti-endotoxin immunity was assessed by determination of specific antibodies to the endotoxin of A, M, G classes and sCD14 by ELISA. The polymorphism was analyzed by the allele-specific polymerase chain reaction with electrophoretic detection. It was estimated that the risk of early-onset asthma in the population of Crimea is associated with genotypes AG and GG (Asp299Gly of TLR-4. There were increased levels of anti-endotoxin IgM and decreased of sIgA in patients with late-onset asthma and AA genotype as compared to other genotypes. Conclusion. The gene polymorphism of Asp299Gly TLR-4 is associated with the risk of early-onset asthma development in Crimea population.

Na⁺ Recirculation and Isosmotic Transport

DEFF Research Database (Denmark)

Larsen, Erik Hviid; Møbjerg, N

2006-01-01

of the absorbate. Mathematical modeling reproducing bioelectric and hydrosmotic properties of small intestine and proximal tubule, respectively, predicts a significant range of observations such as isosmotic transport, hyposmotic transport, solvent drag, anomalous solvent drag, the residual hydraulic permeability...... in proximal tubule of AQP1 (-/-) mice, and the inverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow. The model reproduces the volume responses of cells and lateral intercellular space (lis) following replacement of luminal Na...... external baths. Hyperosmolarity of lis is governed by the hydraulic permeability of the apical plasma membrane and tight junction with 6-7 mOsm in small intestine and

Novel endotoxin-sequestering compounds with terephthalaldehyde-bis-guanylhydrazone scaffolds.

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Khownium, Kriangsak; Wood, Stewart J; Miller, Kelly A; Balakrishna, Rajalakshmi; Nguyen, Thuan B; Kimbrell, Matthew R; Georg, Gunda I; David, Sunil A

2006-03-01

We have shown that lipopolyamines bind to the lipid A moiety of lipopolysaccharide, a constituent of Gram-negative bacterial membranes, and neutralize its toxicity in animal models of endotoxic shock. In an effort to identify non-polyamine scaffolds with similar endotoxin-recognizing features, we had observed an unusually high frequency of hits containing guanylhydrazone scaffolds in high-throughput screens. We now describe the syntheses and preliminary structure-activity relationships in a homologous series of bis-guanylhydrazone compounds decorated with hydrophobic functionalities. These first-generation compounds bind and neutralize lipopolysaccharide with a potency comparable to that of polymyxin B, a peptide antibiotic known to sequester LPS.

Maternal endotoxin-induced fetal growth restriction in rats: Fetal responses in toll-like receptor

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Banun Kusumawardani

2012-09-01

Full Text Available Background: Porphyromonas gingivalis as a major etiology of periodontal disease can produce virulence factor, lipopolysaccharide/LPS, which is expected to play a role in the intrauterine fetal growth. Trophoblast at the maternal-fetal interface actively participates in response to infection through the expression of a family of natural immune receptors, toll-like receptor (TLR. Purpose: the aims of study were to identify endotoxin concentration in maternal blood serum of Porphyromonas gingivalis-infected pregnant rats, to characterize the TLR-4 expression in trophoblast cells, and to determine its effect on fetal growth. Methods: Female rats were infected with live-Porphyromonas gingivalis at concentration of 2 x 109 cells/ml into subgingival sulcus area of the maxillary first molar before and/or during pregnancy. They were sacrified on 14th and 20th gestational day. Fetuses were evaluated for weight and length. Endotoxin was detected by limulus amebocyte lysate assay in the maternal blood serum. The TLR-4 expression in trophoblast cells was detected by immunohistochemistry. Compact rock material gas permeability properties

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Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

2014-09-15

Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

Permeability During Magma Expansion and Compaction

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Gonnermann, Helge. M.; Giachetti, Thomas; Fliedner, Céline; Nguyen, Chinh T.; Houghton, Bruce F.; Crozier, Joshua A.; Carey, Rebecca J.

2017-12-01

Plinian lapilli from the 1060 Common Era Glass Mountain rhyolitic eruption of Medicine Lake Volcano, California, were collected and analyzed for vesicularity and permeability. A subset of the samples were deformed at a temperature of 975°, under shear and normal stress, and postdeformation porosities and permeabilities were measured. Almost all undeformed samples fall within a narrow range of vesicularity (0.7-0.9), encompassing permeabilities between approximately 10-15 m2 and 10-10 m2. A percolation threshold of approximately 0.7 is required to fit the data by a power law, whereas a percolation threshold of approximately 0.5 is estimated by fitting connected and total vesicularity using percolation modeling. The Glass Mountain samples completely overlap with a range of explosively erupted silicic samples, and it remains unclear whether the erupting magmas became permeable at porosities of approximately 0.7 or at lower values. Sample deformation resulted in compaction and vesicle connectivity either increased or decreased. At small strains permeability of some samples increased, but at higher strains permeability decreased. Samples remain permeable down to vesicularities of less than 0.2, consistent with a potential hysteresis in permeability-porosity between expansion (vesiculation) and compaction (outgassing). We attribute this to retention of vesicle interconnectivity, albeit at reduced vesicle size, as well as bubble coalescence during shear deformation. We provide an equation that approximates the change in permeability during compaction. Based on a comparison with data from effusively erupted silicic samples, we propose that this equation can be used to model the change in permeability during compaction of effusively erupting magmas.

Endotoxins and cytokines during liver transplantation : Changes in plasma levels and effects on clinical outcome

NARCIS (Netherlands)

Maring, JK; Klompmaker, IJ; Zwaveling, JH; van der Meer, J; Limburg, PC; Slooff, MJH

Endotoxins, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and IL-6 are believed to have a key role in liver transplantation, The origin and course of these factors is not completely known. In this prospective study of 40 patients, we sought more understanding of the relations

Anti-inflammatory effect of cinnamaldehyde and linalool from the leaf essential oil of Cinnamomum osmophloeum Kanehira in endotoxin-induced mice.

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Lee, Shih-Chieh; Wang, Shih-Yun; Li, Chien-Chun; Liu, Cheng-Tzu

2018-01-01

Cinnamomum osmophloeum Kanehira is a Taiwan native plant that belongs to genus Cinnamomum and is also known as pseudocinnamomum or indigenous cinnamon. Its leaf is traditionally used by local people in cooking and as folk therapy. We previously demonstrated the chemical composition and anti-inflammatory effect of leaf essential oil of Cinnamomum osmophloeum Kanehira of linalool chemotype in streptozotocin-induced diabetic rats and on endotoxin-injected mice. The aim of the present study is to evaluate whether cinnamaldehyde and linalool the active anti-inflammatory compounds in leaf essential oil of Cinnamomum osmophloeum Kanehira. Before the injection of endotoxin, C57BL/6 mice of the experimental groups were administered cinnamaldehyde (0.45 or 0.9 mg/kg body weight) or linalool (2.6 or 5.2 mg/kg body weight), mice of the positive control group were administered the leaf essential oil (13 mg/kg body weight), and mice of the negative group were administered vehicle (corn oil, 4 mL/kg body weight) by gavage every other day for two weeks. All mice received endotoxin (i.p. 10 mg/mL/kg body weight) the next day after the final administration and were killed 12 h after the injection. Normal control mice were pretreated with vehicle followed by the injection with saline. None of the treatment found to affect body weight or food or water intake of mice before the injection of endotoxin. Cinnamaldehyde and linalool were found significantly reversed endotoxin-induced body weight loss and lymphoid organ enlargement compared with vehicle (P essential oil, which was 0.9 mg/kg and 5.2 mg/kg, respectively, showed similar or slightly less inhibitory activity for most of these inflammatory parameters compared with that of the leaf essential oil. Our data confirmed the potential use of leaf essential oil of Cinnamomum osmophloeum Kanehira as an anti-inflammatory natural product and provide evidence for cinnamaldehyde and linalool as two potent agents for prophylactic use

Chloride channels in toad skin

DEFF Research Database (Denmark)

Larsen, Erik Hviid; Rasmussen, B E

1982-01-01

A study of the voltage and time dependence of a transepithelial Cl- current in toad skin (Bufo bufo) by the voltage-clamp method leads to the conclusion that potential has a dual role for Cl- transport. One is to control the permeability of an apical membrane Cl-pathway, the other is to drive Cl-...

Effect of ionizing radiations on bacterial endotoxins: comparison between gamma radiations and accelerated electrons

Energy Technology Data Exchange (ETDEWEB)

Guyomard, S; Goury, V; Darbord, J C

1988-01-01

Determinations of the effect of radiation sterilization processing on purified endotoxins, in aqueous solution or on dried support, are reported. These observations allow us to accept gamma radiations for sterilization of parenteral devices with an estimated probability of existence of non apyrogenic items, based upon a similar definition of the usual Sterility Assurance Level (SAL = 10/sup -6/).

Fourier Transform Infrared Spectroscopy as a Tool in Analysis of Proteus mirabilis Endotoxins.

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Żarnowiec, Paulina; Czerwonka, Grzegorz; Kaca, Wiesław

2017-01-01

Fourier transform infrared spectroscopy (FT-IR) was used to scan whole bacterial cells as well as lipopolysaccharides (LPSs, endotoxins) isolated from them. Proteus mirabilis cells, with chemically defined LPSs, served as a model for the ATR FT-IR method. The paper focuses on three steps of infrared spectroscopy: (1) sample preparation, (2) IR scanning, and (3) multivariate analysis of IR data (principal component analysis, PCA).

Comparative evaluation of Comfilcon A and Senofilcon A bandage contact lenses after transepithelial photorefractive keratectomy

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Achyut Mukherjee

2015-01-01

Conclusion: The variation in material characteristics and lens geometry of different silicone hydrogel lenses affects their clinical characteristics in therapeutic roles. Other factors than oxygen permeability may affect pain and epithelial healing, with superior pain relief from the less permeable Senofilcon lens in this study.

A vegetable oil feeding history affects digestibility and intestinal fatty acid uptake in juvenile rainbow trout Oncorhynchus mykiss.

Science.gov (United States)

Geurden, Inge; Jutfelt, Fredrik; Olsen, Rolf-Erik; Sundell, Kristina S

2009-04-01

Future expansion of aquaculture relies on the use of alternatives to fish oil in fish feed. This study examined to what extent the nature of the feed oil affects intestinal lipid uptake properties in rainbow trout. The fish were fed a diet containing fish (FO), rapeseed (RO) or linseed (LO) oil for 8 weeks after which absorptive properties were assessed. Differences in digestibility due to feed oil history were measured using diet FO with an indigestible marker. Intestinal integrity, paracellular permeability, in vitro transepithelial fatty acid transport (3H-18:3n-3 and 14C-16:0) and their incorporation into intestinal epithelia were compared using Ussing chambers. Feed oil history did not affect the triacylglycerol/phosphatidylcholine ratio (TAG/PC) of the newly synthesized lipids in the segments. The lower TAG/PC ratio with 16:0 (2:1) than with 18:3 (10:1) showed the preferential incorporation of 16:0 into polar lipids. The FO-feeding history decreased permeability and increased transepithelial resistance of the intestinal segments. Transepithelial passage rates of 18:3n-3 were higher when pre-fed LO compared to RO or FO. Similarly, pre-feeding LO increased apparent lipid and fatty acid digestibilities compared to RO or FO. These results demonstrate that the absorptive intestinal functions in fish can be altered by the feed oil history and that the effect remains after a return to a standard fish oil diet.

Film Permeability Determination Using Static Permeability Cells

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The permeability of tarps to soil fumigant pesticides varies depending on the active ingredient chemical: dimethyl disulfide (DMDS), methyl bromide, chloropicrin, or other. The diffusion rate can be represented by the mass transfer coefficient (MTC).

Permeability testing of biomaterial membranes

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Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail: schlosshauer@nmi.de

2008-09-01

The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

Permeability testing of biomaterial membranes

International Nuclear Information System (INIS)

Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B; Ahlers, M

2008-01-01

The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation

Distribution of iodine-labelled fibrinogen in rat during endotoxin shock

Energy Technology Data Exchange (ETDEWEB)

Toth, J [Semmelweis Orvostudomanyi Egyetem, Budapest (Hungary); Spett, B; Bertok, L; Kocsar, L [Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszsegugyi Kutato Intezet, Budapest (Hungary)

1978-10-01

Animals of the experimental and control groups received 10-10 microcurie i.v. /sup 125/I-fibrinogen. The fibrinogen forms a deposit on the surface of the microthrombi and we can find more activity where the thrombi were formed. 60 minutes after administering endotoxin the activity of the ilium of the shocked animals increased significantly (exceeding that of the control group by 37%). A considerable difference may be observed also 120 minutes later, and the activity of the liver amounts to twice the activity of control animals two hours after i.v. /sup 125/I-fibrinogen injection.

Children’s residential exposure to selected allergens and microbial indicators: endotoxins and (1→3-β-D-glucans

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Anna Kozajda

2013-12-01

Full Text Available Objectives: The study was aimed at assessment of exposure to endotoxins, (1→3-β-D-glucans and mite, cockroach, cat, dog allergens present in settled dust in premises of children as agents which may be significantly correlated with the occurrence of allergic symptoms and diseases in children. Materials and Methods: The study covered 50 homes of one- or two-year-old children in Poland. Samples of settled dust were taken from the floor and the child's bed. The levels of (1→3-β-D-glucans (floor, endotoxins (floor and allergens of mite, cat, dog and cockroach (floor and bed were analyzed. Results: Average geometric concentrations (geometric standard deviation of endotoxins, (1→3-β-D-glucans, Der p1, Fel d1, Can f1 and Bla g1 in children homes were on the floor 42 166.0 EU/g (3.2, 20 478.4 ng/g (2.38, 93.9 ng/g (6.58, 119.8 ng/g (13.0, 288.9 ng/g (3.4, 0.72 U/g (4.4 and in their beds (only allergens 597.8 ng/g (14.2, 54.1 ng/g (4.4, 158.6 ng/g (3.1 0.6 U/g (2.9, respectively. When the floor was covered with the carpet, higher concentrations of endotoxins, (1→3-β-D-glucans and allergens (each type were found in the settled dust (p < 0.05. The trend was opposite in case of allergens (except dog analyzed from bed dust and significantly higher concentrations were found in the rooms with smooth floor (p < 0.05. Conclusions: Among the analyzed factors only the type of floor significantly modified both the level of biological indicators and allergens. The results of this study could be the base for verifying a hypothesis that carpeting may have a protective role against high levels of cockroach, dog and cat allergens.

Permeability-Porosity Relationships of Subduction Zone Sediments

Science.gov (United States)

Gamage, K.; Screaton, E.; Bekins, B.; Aiello, I.

2008-12-01

Permeability-porosity relationships for sediments from Northern Barbados, Costa Rica, Nankai, and Peru subduction zones were examined based on their sediment type and grain size distribution. Greater correlation was observed between permeability and porosity for siliciclastic sediments, diatom oozes, and nannofossil chalk than for nannofossil oozes. For siliciclastic sediments, grouping of sediments by clay content yields relationships that are generally consistent with results from other marine settings and suggest decreasing permeability for a given porosity as clay content increases. Correction of measured porosities for smectite content generally improves the quality of permeability-porosity relationships. The relationship between permeability and porosity for diatom oozes may be controlled by the amount of clay present in the ooze, causing diatom oozes to behave similarly to siliciclastic sediments. For a given porosity the nannofossil oozes have higher permeability values by 1.5 orders of magnitude than the siliciclastic sediments. However, the use of a permeability-porosity relation may not be appropriate for unconsolidated carbonates such as nannofossil oozes. This study provided insight to the effects of porosity correction for smectite, variations in lithology and grain size in permeability-porosity relationships. However, further progress in delineating controls on permeability will require more careful and better documented permeability tests on characterized samples.

Gas and Water Permeability of Concrete

Energy Technology Data Exchange (ETDEWEB)

Villar, M. V.; Martin, P. L.; Romero, F. J.; Gutierrez-Rodirgo, V.; Barcala, J. M.

2012-11-01

The gas pressure of concrete samples was measured in an unsteady-state equipment working under low injection pressures and in a newly fine tuned steady-state setup working under different pressures. These measurements allowed the estimation of the intrinsic and relative gas permeability of the concrete and of the effect of boundary conditions on them. Permeability decreased with water content, but it was also greatly affected by the hydraulic history of concrete, i.e. if it had been previously dried or wetted. In particular, and for a given degree of saturation, the gas permeability of concrete previously saturated was lower than if the concrete had been just air dried or saturated after air drying. In any case, the gas permeability was about two orders of magnitude higher than the liquid water permeability (10-16 vs. 10-18 m2), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, increasing as the former increased and decreasing as the latter increased, i.e. decreasing as the effective pressure increased. Overall the increase of pressure head or injection pressure implied a decrease in gas permeability. External,microcracking during air-drying could not be ruled out as responsible for the decrease of permeability with confining pressure. The apparent permeability obtained applying the Klinkenberg method for a given effective pressure was only slightly smaller than the average of all the values measured for the same confining pressure range. For this reason it is considered that the Klinkenberg effect was not relevant in the range of pressures applied. (Author) 37 refs.

Application of the Na+ recirculation theory to ion coupled water transport in low- and high resistance osmoregulatory epithelia

DEFF Research Database (Denmark)

Larsen, Erik Hviid; Møbjerg, Nadja; Nielsen, Robert

2007-01-01

approaches: (i) An isotope tracer method in small intestine. Simultaneous measurement of water flow and ion transport in toad skin epithelium demonstrating, (ii) occasional hyposmotic absorbates, and (iii) reduced fluid absorption in the presence of serosal bumetanide. (iv) Studies of the metabolic cost......, the residual hydraulic permeability in proximal tubule of AQP1(-/-) mice, the adverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow, and in a non-contradictory way the wide range of metabolic efficiencies from above to below 18 Na+/O2...

Specificity of Bacillus thuringiensis endotoxins is correlated with the presence of high-affinity binding sites in the brush border membrane of target insect midguts

International Nuclear Information System (INIS)

Hofmann, C.; Vanderbruggen, H.; Hoefte, H.; Van Rie, J.; Jansens, S.; Van Mellaert, H.

1988-01-01

Binding studies were performed with two 125 I-labeled Bacillus thuringiensis δ-endotoxins on brush border membrane vesicles prepared from the larval midgut of the tobacco hornworm Manduca sexta or the cabbage butterfly Pieris brassicae. One δ-endotoxin, Bt2-protoxin, is a 130-kDa recombinant crystalline protein from B. thuringiensis subsp. berliner. It kills larvae of both insect species. The active Bt2-toxin is a 60-kDa proteolytic fragment of the Bt2-protoxin. It binds saturably and with high affinity to brush border membrane vesicles from the midgut of both species. The other δ-endotoxin, Bt4412-protoxin, is a 136-kDa crystalline protein from B. thuringiensis subsp. thuringiensis, which is highly toxic for P. brassicae, but not for M. sexta larvae. Bt4412-toxin, obtained after proteolytic activation of Bt4412-protoxin, shows high-affinity saturable binding to P. brassicae vesicles but not to M. sexta vesicles. The correlation between toxicity and specific binding is further strengthened by competition studies. Other B. thuringiensis δ-endotoxins active against M. sexta compete for binding of 125 I-labeled Bt2-toxin to M. sexta vesicles, whereas toxins active against dipteran or coleopteran larvae do not compete. Bt2-toxin and Bt4412-toxin bind to different sites on P. brassicae vesicles

Permeability of cork to gases.

Science.gov (United States)

Faria, David P; Fonseca, Ana L; Pereira, Helen; Teodoro, Orlando M N D

2011-04-27

The permeability of gases through uncompressed cork was investigated. More than 100 samples were assessed from different plank qualities to provide a picture of the permeability distribution. A novel technique based on a mass spectrometer leak detector was used to directly measure the helium flow through the central area of small disks 10 mm in diameter and 2 mm thick. The permeability for nitrogen, oxygen, and other gases was measured by the pressure rise technique. Boiled and nonboiled cork samples from different sections were evaluated. An asymmetric frequency distribution ranging 3 orders of magnitude (roughly from 1 to 1000 μmol/(cm·atm·day)) for selected samples without macroscopic defects was found, having a peak below 100 μmol/(cm·atm·day). Correlation was found between density and permeability: higher density samples tend to show lower permeability. However, boiled cork showed a mean lower permeability despite having a lower density. The transport mechanism of gases through cork was also examined. Calculations suggest that gases permeate uncompressed cork mainly through small channels between cells under a molecular flow regime. The diameter of such channels was estimated to be in the range of 100 nm, in agreement with the plasmodesmata size in the cork cell walls.

GLOMERULAR INFLAMMATION IN PREGNANT RATS AFTER INFUSION OF LOW-DOSE ENDOTOXIN - AN IMMUNOHISTOLOGICAL STUDY IN EXPERIMENTAL PREECLAMPSIA

NARCIS (Netherlands)

FAAS, MM; SCHUILING, GA; BALLER, JFW; BAKKER, WW

1995-01-01

Increased endotoxin sensitivity during pregnancy occurs in many animals, including rats. The mechanism of this phenomenon is not understood. In the present study it was investigated whether this increased sensitivity is reflected by an altered inflammatory pattern. Inflammatory cell influx, the

Dragon enhances BMP signaling and increases transepithelial resistance in kidney epithelial cells.

Science.gov (United States)

Xia, Yin; Babitt, Jodie L; Bouley, Richard; Zhang, Ying; Da Silva, Nicolas; Chen, Shanzhuo; Zhuang, Zhenjie; Samad, Tarek A; Brenner, Gary J; Anderson, Jennifer L; Hong, Charles C; Schneyer, Alan L; Brown, Dennis; Lin, Herbert Y

2010-04-01

The neuronal adhesion protein Dragon acts as a bone morphogenetic protein (BMP) coreceptor that enhances BMP signaling. Given the importance of BMP signaling in nephrogenesis and its putative role in the response to injury in the adult kidney, we studied the localization and function of Dragon in the kidney. We observed that Dragon localized predominantly to the apical surfaces of tubular epithelial cells in the thick ascending limbs, distal convoluted tubules, and collecting ducts of mice. Dragon expression was weak in the proximal tubules and glomeruli. In mouse inner medullary collecting duct (mIMCD3) cells, Dragon generated BMP signals in a ligand-dependent manner, and BMP4 is the predominant endogenous ligand for the Dragon coreceptor. In mIMCD3 cells, BMP4 normally signaled through BMPRII, but Dragon enhanced its signaling through the BMP type II receptor ActRIIA. Dragon and BMP4 increased transepithelial resistance (TER) through the Smad1/5/8 pathway. In epithelial cells isolated from the proximal tubule and intercalated cells of collecting ducts, we observed coexpression of ActRIIA, Dragon, and BMP4 but not BMPRII. Taken together, these results suggest that Dragon may enhance BMP signaling in renal tubular epithelial cells and maintain normal renal physiology.

Effects of the immunomodulator, VGX-1027, in endotoxin-induced uveitis in Lewis rats

DEFF Research Database (Denmark)

Mangano, K; Sardesai, N Y; Quattrocchi, C

2008-01-01

VGX-1027 is a novel, low molecular weight, immunomodulatory compound that has shown efficacy against a variety of immuno-inflammatory disease models in animals including autoimmune diabetes in NOD mice, collagen-induced arthritis and chemically induced inflammatory colitis. Here, we have studied ...... the effects of VGX-1027 on the development of endotoxin-induced uveitis (EIU) in male Lewis rats, as a model of inflammatory ocular diseases in humans....

Aerosolization of fungi, (1→3)-β-D glucan, and endotoxin from flood-affected materials collected in New Orleans homes

Science.gov (United States)

Adhikari, Atin; Jung, Jaehee; Reponen, Tiina; Lewis, Jocelyn Suzanne; DeGrasse, Enjoli C.; Grimsley, L. Faye; Chew, Ginger L.; Grinshpun, Sergey A.

2015-01-01

Standing water and sediments remaining on flood-affected materials were the breeding ground for many microorganisms in flooded homes following Hurricane Katrina. The purpose of this laboratory study was to examine the aerosolization of culturable and total fungi, (1→3)-β-D glucan, and endotoxin from eight flood-affected floor and bedding materials collected in New Orleans homes, following Hurricane Katrina. Aerosolization was examined using the Fungal Spore Source Strength Tester (FSSST) connected to a BioSampler. Dust samples were collected by vacuuming. A two-stage cyclone sampler was used for size-selective analysis of aerosolized glucan and endotoxin. On average, levels of culturable fungi ranged from undetectable (lower limit = 8.3×104) to 2.6×105 CFU/m2; total fungi ranged from 2.07×105 to 1.6×106 spores/m2; (1→3)-β-D glucan and endotoxin were 2.0×103 – 2.9×104 ng/m2 and 7.0×102 – 9.3×104 EU/m2, respectively. The results showed that 5–15 min sampling is sufficient for detecting aerosolizable biocontaminants with the FSSST. Smaller particle size fractions (1.8 μm) fractions, which raises additional exposure concerns. Vacuuming was found to overestimate inhalation exposure risks by a factor of approximately 102 for (1→3)-β-D glucan and by 103 to 104 for endotoxin as detected by the FSSST. The information generated from this study is important with respect to restoration and rejuvenation of the flood-affected areas in New Orleans. We believe the findings will be significant during similar disasters in other regions of the world including major coastal floods from tsunamis. PMID:19201399

An anti-interleukin-2 receptor drug attenuates T- helper 1 lymphocytes-mediated inflammation in an acute model of endotoxin-induced uveitis.

Directory of Open Access Journals (Sweden)

Salvador Mérida

Full Text Available The aim of the present study was to evaluate the anti-inflammatory efficacy of Daclizumab, an anti-interleukin-2 receptor drug, in an experimental uveitis model upon a subcutaneous injection of lipopolysaccharide into Lewis rats, a valuable model for ocular acute inflammatory processes. The integrity of the blood-aqueous barrier was assessed 24 h after endotoxin-induced uveitis by evaluating two parameters: cell count and protein concentration in aqueous humors. The histopathology of all the ocular structures (cornea, lens, sclera, choroid, retina, uvea, and anterior and posterior chambers was also considered. Enzyme-linked immunosorbent assays of the aqueous humor samples were performed to quantify the levels of the different chemokine and cytokine proteins. Similarly, a biochemical analysis of oxidative stress-related markers was also assessed. The inflammation observed in the anterior chamber of the eyes when Daclizumab was administered with endotoxin was largely prevented since the aqueous humor protein concentration substantially lowered concomitantly with a significant reduction in the uveal and vitreous histopathological grading. Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon-γ, also significantly reduced with related anti-oxidant systems recovery. Daclizumab treatment in endotoxin-induced uveitis reduced Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon gamma, by about 60-70% and presented a preventive role in endotoxin-induced oxidative stress. This antioxidant protective effect of Daclizumab may be related to several of the observed Daclizumab effects in our study, including IL-6 cytokine regulatory properties and a substantial concomitant drop in INFγ. Concurrently, Daclizumab treatment triggered a significant reduction in both the uveal histopathological grading and protein concentration in aqueous humors, but not in cellular infiltration.

Clogging in permeable concrete: A review.

Science.gov (United States)

Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

2017-05-15

Permeable concrete (or "pervious concrete" in North America) is used to reduce local flooding in urban areas and is an important sustainable urban drainage system. However, permeable concrete exhibits reduction in permeability due to clogging by particulates, which severely limits service life. This paper reviews the clogging mechanism and current mitigating strategies in order to inform future research needs. The pore structure of permeable concrete and characteristics of flowing particulates influence clogging, which occurs when particles build-up and block connected porosity. Permeable concrete requires regular maintenance by vacuum sweeping and pressure washing, but the effectiveness and viability of these methods is questionable. The potential for clogging is related to the tortuosity of the connected porosity, with greater tortuosity resulting in increased potential for clogging. Research is required to develop permeable concrete that can be poured on-site, which produces a pore structure with significantly reduced tortuosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentration of airborne Staphylococcus aureus (MRSA and MSSA), total bacteria, and endotoxins in pig farms.

Science.gov (United States)

Masclaux, Frederic G; Sakwinska, Olga; Charrière, Nicole; Semaani, Eulalia; Oppliger, Anne

2013-06-01

Pigs are very often colonized by Staphylococcus aureus and transmission of such pig-associated S. aureus to humans can cause serious medical, hygiene, and economic problems. The transmission route of zoonotic pathogens colonizing farm animals to humans is not well established and bioaerosols could play an important role. The aim of this study was to assess the potential occupational risk of working with S. aureus-colonized pigs in Switzerland. We estimated the airborne contamination by S. aureus in 37 pig farms (20 nursery and 17 fattening units; 25 in summer, 12 in winter). Quantification of total airborne bacterial DNA, airborne Staphylococcus sp. DNA, fungi, and airborne endotoxins was also performed. In this experiment, the presence of cultivable airborne methicillin-resistant S. aureus (MRSA) CC398 in a pig farm in Switzerland was reported for the first time. Airborne methicillin-sensitive S. aureus (MSSA) was found in ~30% of farms. The average airborne concentration of DNA copy number of total bacteria and Staphylococcus sp. measured by quantitative polymerase chain reaction was very high, respectively reaching values of 75 (± 28) × 10(7) and 35 (± 9.8) × 10(5) copy numbers m(-3) in summer and 96 (± 19) × 10(8) and 40 (± 12) × 10(6) copy numbers m(-3) in winter. Total mean airborne concentrations of endotoxins (1298 units of endotoxin m(-3)) and fungi (5707 colony-forming units m(-3)) exceeded the Swiss recommended values and were higher in winter than in summer. In conclusion, Swiss pig farmers will have to tackle a new emerging occupational risk, which could also have a strong impact on public health. The need to inform pig farmers about biological occupational risks is therefore crucial.

A System Dynamics Model to Predict the Human Monocyte Response to Endotoxins

Directory of Open Access Journals (Sweden)

Enrique Álvarez

2017-08-01

Full Text Available System dynamics is a powerful tool that allows modeling of complex and highly networked systems such as those found in the human immune system. We have developed a model that reproduces how the exposure of human monocytes to lipopolysaccharides (LPSs induces an inflammatory state characterized by high production of tumor necrosis factor alpha (TNFα, which is rapidly modulated to enter into a tolerant state, known as endotoxin tolerance (ET. The model contains two subsystems with a total of six states, seven flows, two auxiliary variables, and 14 parameters that interact through six differential and nine algebraic equations. The parameters were estimated and optimized to obtain a model that fits the experimental data obtained from human monocytes treated with various LPS doses. In contrast to publications on other animal models, stimulation of human monocytes with super-low-dose LPSs did not alter the response to a second LPSs challenge, neither inducing ET, nor enhancing the inflammatory response. Moreover, the model confirms the low production of TNFα and increased levels of C–C motif ligand 2 when monocytes exhibit a tolerant state similar to that of patients with sepsis. At present, the model can help us better understand the ET response and might offer new insights on sepsis diagnostics and prognosis by examining the monocyte response to endotoxins in patients with sepsis.

The effectiveness of various biofiltration substrates in removing bacteria, endotoxins, and dust from ventilation system exhaust from a chicken hatchery.

Science.gov (United States)

Tymczyna, L; Chmielowiec-Korzeniowska, A; Drabik, A

2007-10-01

The objective of this study was to evaluate the effectiveness of various organic and organic-mineral biofilter media in purifying ventilation exhaust from a chicken hatchery room. Three different substrates were tested. Efficiency levels for the removal of dust, gram-negative bacteria, and bacterial endotoxin were recorded. The microbiological properties of the substrates were also studied. All of the biofilter substrates were highly effective in removing gram-negative bacteria, moderately effective in reducing dust levels, and only slightly effective in removing endotoxin. The substrate that was most efficient in retaining bioaerosols was the organic-mineral medium containing 20% halloysite, 40% compost, and 40% peat, which generally had at least satisfactory efficiency values for removing all of the contaminants tested.

Geothermal Permeability Enhancement - Final Report

Energy Technology Data Exchange (ETDEWEB)

Joe Beall; Mark Walters

2009-06-30

The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

A Reconciliation of Packed Column Permeability Data: Column Permeability as a Function of Particle Porosity

Directory of Open Access Journals (Sweden)

Hubert M. Quinn

2014-01-01

Full Text Available In his textbook teaching of packed bed permeability, Georges Guiochon uses mobile phase velocity as the fluid velocity term in his elaboration of the Darcy permeability equation. Although this velocity frame makes a lot of sense from a thermodynamic point of view, it is valid only with respect to permeability at a single theoretical boundary condition. In his more recent writings, however, Guiochon has departed from his long-standing mode of discussing permeability in terms of the Darcy equation and has embraced the well-known Kozeny-Blake equation. In this paper, his teaching pertaining to the constant in the Kozeny-Blake equation is examined and, as a result, a new correlation coefficient is identified and defined herein based on the velocity frame used in his teaching. This coefficient correlates pressure drop and fluid velocity as a function of particle porosity. We show that in their experimental protocols, Guiochon et al. have not adhered to a strict material balance of permeability which creates a mismatch of particle porosity and leads to erroneous conclusions regarding the value of the permeability coefficient in the Kozeny-Blake equation. By correcting the experimental data to properly reflect particle porosity we reconcile the experimental results of Guiochon and Giddings, resulting in a permeability reference chart which is presented here for the first time. This reference chart demonstrates that Guiochon’s experimental data, when properly normalized for particle porosity and other related discrepancies, corroborates the value of 267 for the constant in the Kozeny-Blake equation which was derived by Giddings in 1965.

Crustal permeability: Introduction to the special issue

Science.gov (United States)

Ingebritsen, Steven E.; Gleeson, Tom

2015-01-01

The topic of crustal permeability is of broad interest in light of the controlling effect of permeability on diverse geologic processes and also timely in light of the practical challenges associated with emerging technologies such as hydraulic fracturing for oil and gas production (‘fracking’), enhanced geothermal systems, and geologic carbon sequestration. This special issue of Geofluids is also motivated by the historical dichotomy between the hydrogeologic concept of permeability as a static material property that exerts control on fluid flow and the perspective of economic geologists, geophysicists, and crustal petrologists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. Issues associated with fracking, enhanced geothermal systems, and geologic carbon sequestration have already begun to promote a constructive dialog between the static and dynamic views of permeability, and here we have made a conscious effort to include both viewpoints. This special issue also focuses on the quantification of permeability, encompassing both direct measurement of permeability in the uppermost crust and inferential permeability estimates, mainly for the deeper crust.

Antibiotics protect against fructose-induced hepatic lipid accumulation in mice: role of endotoxin.

Science.gov (United States)

Bergheim, Ina; Weber, Synia; Vos, Miriam; Krämer, Sigrid; Volynets, Valentina; Kaserouni, Seline; McClain, Craig J; Bischoff, Stephan C

2008-06-01

Consumption of refined carbohydrates in soft drinks has been postulated to be a key factor in the development of non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to test the effects of ad libitum access to different sugars consumed in drinking water on hepatic fat accumulation. For 8 weeks, C57BL/J6 mice had free access to solutions containing 30% glucose, fructose, sucrose, or water sweetened with artificial sweetener (AS) or plain water. Body weight, caloric intake, hepatic steatosis and lipid peroxidation were assessed. Total caloric intake and weight gain were highest in mice exposed to glucose. In contrast, hepatic lipid accumulation was significantly higher in mice consuming fructose compared to all other groups. Moreover, endotoxin levels in portal blood and lipid peroxidation as well as TNFalpha expression were significantly higher in fructose fed mice than in all other groups. Concomitant treatment of fructose fed mice with antibiotics (e.g., polymyxin B and neomycin) markedly reduced hepatic lipid accumulation in fructose fed mice. These data support the hypothesis that high fructose consumption may not only lead to liver damage through overfeeding but also may be directly pro-inflammatory by increasing intestinal translocation of endotoxin.

Modulation of Intestinal Epithelial Permeability in Differentiated Caco-2 Cells Exposed to Aflatoxin M1 and Ochratoxin A Individually or Collectively

Directory of Open Access Journals (Sweden)

Yanan Gao

2017-12-01

Full Text Available Aflatoxin M1 (AFM1 and ochratoxin A (OTA are mycotoxins commonly found in milk; however, their effects on intestinal epithelial cells have not been reported. In the present study, we show that AFM1 (0.12 and 12 μM and OTA (0.2 and 20 μM individually or collectively increased the paracellular flux of lucifer yellow and fluorescein isothiocyanate (FITC-dextrans (4 and 40 kDa and decreased transepithelial electrical resistance values in differentiated Caco-2 cells after 48 h of exposure, indicating increased epithelial permeability. Immunoblotting and immunofluorescent analysis revealed that AFM1, OTA, and their combination decreased the expression levels of tight junction (TJ proteins and disrupted their structures, namely, claudin-3, claudin-4, occludin, and zonula occludens-1 (ZO-1, and p44/42 mitogen-activated protein kinase (MAPK partially involved in the mycotoxins-induced disruption of intestinal barrier. The effects of a combination of AFM1 and OTA on intestinal barrier function were more significant (p < 0.05 than those of AFM1 and OTA alone, yielding additive or synergistic effects. The additive or synergistic effects of AFM1 and OTA on intestinal barrier function might affect human health, especially in children, and toxin risks should be considered.

Elimination of Proteus mirabilis 51Cr endotoxin from the liver in rats

International Nuclear Information System (INIS)

Lipinska-Piotrowska, I.

1977-01-01

Using isotope methods, elimination of the endotoxin of Proteus mirabilis labelled with chromium (CrEPm) from the liver of rats was studied. The following studies were carried out: intravital exploration of the liver with a scintillation probe, measurements of radioactivity of organs and excreted urine and stools, scintigraphy of the liver, binding of CrEPm by subcellular fractions of hepatocytes, and the influence of selected drugs (polymyxin and hydrocortisone) on elimination of CrEPm from the liver and organelles of hepatocytes. (author)

Effect of temperature on sandstone permeability

DEFF Research Database (Denmark)

Rosenbrand, Esther; Kjøller, Claus

Hot water injection in geothermal sandstone aquifers is considered for seasonal energy storage in Denmark. However, an increase in the aquifer temperature might reduce permeability, and thereby increase production costs. An understanding of the factors that control permeability is required in order...... and the Klinkenberg procedure showed the expected correlation between the two measures, however, differences could be around one order of magnitude. In tight gas sandstones, permeability is often sensitive to net stress, which might change due to the pore pressure change in the Klinkenberg procedure. Besides...... affecting the Klinkenberg procedure, the combined effect of slip and changes in permeability would affect production during pressure depletion in tight gas sandstone reservoirs; therefore effects of gas slip and net stress on permeability were combined in a model based on the Klinkenberg equation. A lower...

Endotoxin in Dairy Cattle：Production, Effects and Control Technology%奶牛内毒素的产生、影响和防控技术

Institute of Scientific and Technical Information of China (English)

王凯军; 谭支良; 张佩华; 韩奇鹏

2016-01-01

内毒素也称为脂多糖，是革兰氏阴性细菌死亡后或快速繁殖时细菌细胞壁破裂后释放的一种物质，在动物机体中普遍存在，过量时导致机体产生免疫应激。本文介绍了奶牛内毒素产生的原因和作用机制及其对奶牛采食量，血液中蛋白质、氨基酸，乳中乳蛋白、乳脂的影响，减少奶牛内毒素的途径，为降低内毒素对奶牛生产的影响提供参考。%Endotoxin, also known as lipopolysaccharide, is produced when the gram-negative bacteria are dead or multiply rapidly. It commonly exists in ruminants and results in immunological stress when overdose. This article elaborated the production and action mechanism of endotoxin in dairy cattle, the effects on feed intake, proteins and amino acids in blood, milk protein and milk fat, and the ways to decrease endotoxin in dairy cat-tle, which will give help for decreasing endotoxin in dairy cattle production.

Activity of Bacillus thuringiensis D(delta)-endotoxins against codling moth (Cydia pomonella L.) larvae

NARCIS (Netherlands)

Boncheva, R.; Dukiandjiev, S.; Minkov, I.; Maagd, de R.A.; Naimov, S.

2006-01-01

Solubilized protoxins of nine Cry1 and one hybrid Cry1 ¿-endotoxin from Bacillus thuringiensis were tested for their activity against larvae of the codling moth (Cydia pomonella L). Cry1Da was the most toxic, followed by Cry1Ab, Cry1Ba, and Cry1Ac, while Cry1Aa, Cry1Fa, Cry1Ia, and SN19 were still

Oral administration of Saccharomyces boulardii ameliorates carbon tetrachloride-induced liver fibrosis in rats via reducing intestinal permeability and modulating gut microbial composition.

Science.gov (United States)

Li, Ming; Zhu, Lin; Xie, Ao; Yuan, Jieli

2015-02-01

To investigate the effects of orally administrated Saccharomyces boulardii (S. boulardii) on the progress of carbon tetrachloride (CCl4)-induced liver fibrosis, 34 male Wistar rats were randomly divided into four experimental groups including the control group (n = 8), the cirrhotic group (n = 10), the preventive group (n = 8), and the treatment group (n = 8). Results showed that the liver expression levels of collagen, type I, alpha 1 (Col1A1), alpha smooth muscle actin (αSMA), transforming growth factor beta (TGF-β) and the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde (MDA) increased significantly in cirrhotic rats compared with control and decreased by S. boulardii administration. Treatment of S. boulardii also attenuated the increased endotoxin levels and pro-inflammatory cytokines in CCl4-treated rats. And, these were associated with the changes of intestinal permeability and fecal microbial composition. Our study suggested that oral administration of S. boulardii can promote the liver function of CCl4-treated rats, and the preventive treatment of this probiotic yeast may decelerate the progress of liver fibrosis.

Bacillus thuringiensis delta-endotoxin Cry1 hybrid proteins with increased activity against the Colorado potato beetle

NARCIS (Netherlands)

Naimov, S.; Weemen-Hendriks, M.; Dukiandjiev, S.; Maagd, de R.A.

2001-01-01

Cry1 delta-endotoxins of Bacillus thuringiensis are generally active against lepidopteran insects, but Cry1Ba and Cry1Ia have additional, though low, levels of activity against coleopterans such as the Colorado potato beetle. Here we report the construction of Cry1Ba/Cry1Ia hybrid toxins which have

A low concentration of ethanol reduces the chemiluminescence of human granulocytes and monocytes but not the tumor necrosis factor alpha production by monocytes after endotoxin stimulation

DEFF Research Database (Denmark)

Parlesak, Alexandr; Diedrich, J. P.; Schäfer, Christian

1998-01-01

necrosis factor alpha (TNF-alpha) from Mphi. Further, the efficiency of ethanol to inactivate chemically generated ROS was tested. Significant stimulation of ROS release occurred at endotoxin concentrations of 1 ng/ml or higher in both PMNs and Mphi. Ethanol significantly suppressed the formation of ROS...... immunogens and to increase the susceptibility of alcohol abusers to infectious diseases. As endotoxemia is common in alcohol abusers, we investigated the effect of ethanol (21.7 mmol/liter) on the luminol-amplified chemiluminescence of PMNs and Mphi after endotoxin stimulation and the release of tumor...... identical (6 to 8 ng/ml) in both PMNs and Mphi, independent of the presence of ethanol. In contrast to ROS formation, ethanol had no effect on the amount of TNF-alpha produced by endotoxin-stimulated Mphi. Ethanol was shown to be unable to decrease the levels of chemically generated ROS under physiological...

The release of endotoxin, TNF and IL-6 during the antibiotic treatment of experimental Gram-negative sepsis

NARCIS (Netherlands)

Dofferhoff, A.S.M.; Potthoff, H.; Bom, V.J.J.; Bartels, H.L.; De Vries-Hospers, H.G.; Bijzet, J.; Weits, J.; Buurman, W.; Bleichrodt, R.P.

1995-01-01

To evaluate the role of different antibiotics in the release of endotoxin and the production of tumor necrosis factor-α (TNF) and interleukin 6 (IL-6) during the treatment of experimental Escherichia coli septical peritonitis, we obtained serial blood samples from septic rats treated with placebo,

Suppression of cellular immunity in obstructive jaundice is caused by endotoxins: a study with germ-free rats

NARCIS (Netherlands)

Greve, J. W.; Gouma, D. J.; Soeters, P. B.; Buurman, W. A.

1990-01-01

The increased susceptibility to infections after surgery in jaundiced patients is considered to be caused by an impairment of cellular immunity and/or nutritional status. Endotoxins are suggested to play a role in the pathogenesis. However, the mechanism of action is unknown. Germ-free rats were

Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

Energy Technology Data Exchange (ETDEWEB)

Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical–Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

2015-04-15

Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R{sup 2} = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q{sup 2}{sub ext} = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin

Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

International Nuclear Information System (INIS)

Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

2015-01-01

Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R 2 = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q 2 ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin sensitization and

Defining clogging potential for permeable concrete.

Science.gov (United States)

Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

2018-08-15

Permeable concrete is used to reduce urban flooding as it allows water to flow through normally impermeable infrastructure. It is prone to clogging by particulate matter and predicting the long-term performance of permeable concrete is challenging as there is currently no reliable means of characterising clogging potential. This paper reports on the performance of a range of laboratory-prepared and commercial permeable concretes, close packed glass spheres and aggregate particles of varying size, exposed to different clogging methods to understand this phenomena. New methods were developed to study clogging and define clogging potential. The tests involved applying flowing water containing sand and/or clay in cycles, and measuring the change in permeability. Substantial permeability reductions were observed in all samples, particularly when exposed to sand and clay simultaneously. Three methods were used to define clogging potential based on measuring the initial permeability decay, half-life cycle and number of cycles to full clogging. We show for the first time strong linear correlations between these parameters for a wide range of samples, indicating their use for service-life prediction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Different Methods of Predicting Permeability in Shale

DEFF Research Database (Denmark)

Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

by two to five orders of magnitudes at lower vertical effective stress below 40 MPa as the content of clay minerals increases causing heterogeneity in shale material. Indirect permeability from consolidation can give maximum and minimum values of shale permeability needed in simulating fluid flow......Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...... effective stress to 9 μD at high vertical effective stress of 100 MPa. The indirect permeability calculated from consolidation tests falls in the same magnitude at higher vertical effective stress, above 40 MPa, as that of the Kozeny model for shale samples with high non-clay content ≥ 70% but are higher...

Effect of endotoxin shock on the elimination of /sup 133/Xe by the lungs

Energy Technology Data Exchange (ETDEWEB)

Toth, T [Semmelweis Orvostudomanyi Egyetem, Budapest (Hungary); Spett, B; Bertok, L [Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszseguegyi Kutato Intezet, Budapest (Hungary); Vittay, P; Kopcsanyi, Zs; Jakab, T [Orvostovabbkepzoe Intezet, Budapest (Hungary)

1979-07-01

Experimental shock was induced in rats by the administration of 2 mg E.coli 089 endotoxin. 3 hours later 6.142 MBq /sup 133/Xe, dissolved in 1 ml physiological saline, was administered and the changes of radioactivity were followed over the lungs by a gamma-camera. The biological half-life of the isotope was 1.06 s in the control animals and 1.69 s in the animals in shock.

A rapid kinetic chromogenic method for quantification of bacterial endotoxins in lyophilized reagents for labeling with 99mTc radiopharmaceuticals

International Nuclear Information System (INIS)

Fukumori, Neuza T.O.; Campos, Domingos G.; Silva, Laercio; Fernandes, Adriana V.; Mengatti, Jair; Silva, Constancia P.G.; Matsuda, Margareth M.N.

2009-01-01

A rapid quantitative kinetic chromogenic test in an automated Portable Test System (PTS) has been developed for determination of bacterial endotoxins in water, in-process and end-products using the Limulus amebocyte lysate (LAL). The aim of this work was to validate the method for lyophilized reagents for labeling with 99m Tc radiopharmaceuticals with no interfering factors. Experiments were performed in three consecutive batches of the lyophilized reagents Methylenediphosphonic Acid (MDP) and Pyrophosphate (PYRO) produced at IPEN-CNEN/ SP using the PTS from Endosafe, Inc. TM , Charleston, SC. The Maximum Valid Dilution (MVD) was calculated to establish the extent of dilution to avoid interfering test conditions (MVD=500). Better results were obtained above 1:20 dilution factor for MDP and 1:100 for PYRO. The parameters of coefficient correlation (R) -0.980, RPPC between 50 - 200% and coefficient variation (CV) of the samples less than 25% were satisfied and the endotoxin concentration was lower than the lowest concentration of the standard curve (0.05 EU mL -1 ), therefore less than the established limit in pharmacopoeias. The PTS is a rapid, simple and accurate technique using the quantitative kinetic chromogenic method for bacterial endotoxin determination. For this reason, it is very practical in the radiopharmaceutical area and it trends to be the method of choice for the pyrogen test. For MDP and PYRO, the validation was successfully performed. (author)

Quantifying porosity, compressibility and permeability in Shale

DEFF Research Database (Denmark)

Mbia, Ernest Ncha; Fabricius, Ida Lykke; Frykman, Peter

strain data. We found that Kozeny's modelled permeability fall in the same order of magnitude with measured permeability for shale rich in kaolinite but overestimates permeability by two to three orders of magnitudes for shale with high content of smectite. The empirical Yang and Aplin model gives good...... permeability estimate comparable to the measured one for shale rich in smectite. This is probably because Yang and Aplin model was calibrated in London clay which is rich in smectite....

Iontophoresis Transcorneal Delivery Technique for Transepithelial Corneal Collagen Crosslinking With Riboflavin in a Rabbit Model.

Science.gov (United States)

Cassagne, Myriam; Laurent, Camille; Rodrigues, Magda; Galinier, Anne; Spoerl, Eberhard; Galiacy, Stéphane D; Soler, Vincent; Fournié, Pierre; Malecaze, François

2016-02-01

We compared an iontophoresis riboflavin delivery technique for transepithelial corneal collagen crosslinking (I-CXL) with a conventional CXL (C-CXL). We designed three experimental sets using 152 New Zealand rabbits to study riboflavin application by iontophoresis using charged riboflavin solution (Ricrolin+) with a 1-mA current for 5 minutes. The first set was to compare riboflavin concentration measured by HPLC in corneas after iontophoresis or conventional riboflavin application. The second set was to analyze autofluorescence and stromal collagen modification immediately and 14 days after I-CXL or C-CXL, by using nonlinear two-photon microscopy (TP) and second harmonic generation (SHG). In the third set, physical modifications after I-CXL and C-CXL were evaluated by stress-strain measurements and by studying corneal resistance against collagenase digestion. Based on HPLC analysis, we found that iontophoresis allowed riboflavin diffusion with 2-fold less riboflavin concentration than conventional application (936.2 ± 312.5 and 1708 ± 908.3 ng/mL, respectively, P riboflavin delivery in crosslinking treatments, preserving the epithelium.

Microorganism Removal in Permeable Pavement Parking Lots ...

Science.gov (United States)

Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.

Some aspects of endotoxins and corpus luteum function in ruminants

International Nuclear Information System (INIS)

Edqvist, L.E.; Fredriksson, G.; Kindahl, H.

1984-01-01

Following parturition in cattle, prostaglandin levels are high for 10-20 days. The duration and possibly the magnitude of the release seem to be related to the time required for completion of uterine involution. Animals showing clinical signs of postpartum uterine disorder have a prolonged release of prostaglandin. The intravenous administration of an endotoxin from Salmonella typhimurium to goats induces a massive prostaglandin release terminating corpus luteum function, resulting in short oestrous cycles in non-pregnant animals and abortions in pregnant animals. The possibility exists that postpartum uterine infections may be partly responsible for the postpartum prostaglandin release and that this bacteriologic/endocrine interrelationship represents a way in which the uterus eliminates infectious agents, particularly gram-negative bacteria. (author)

A synthetic cryIC gene, encoding a Bacillus thuringiensis δ-endotoxin, confers Spodoptera resistance in alfalfa and tobacco

NARCIS (Netherlands)

Strizhov, N.; Keller, M.; Mathur, J.; Koncz-Kaiman, Z.; Bosch, D.; Prudovksy, E.; Schell, J.; Sneh, B.; Koncz, C.; Zilberstein, A.

1996-01-01

Spodoptera species, representing widespread polyphagous insect pests, are resistant to Bacillus thuringiensis δ-endotoxins used thus far as insecticides in transgenic plants. Here we describe the chemical synthesis of a cryIC gene by a novel template directed ligation–PCR method. This simple and

Use of Interface Treatment to Reduce Emissions from Residuals in Lower Permeability Zones to Groundwater flowing Through More Permeable Zones (Invited)

Science.gov (United States)

Johnson, P.; Cavanagh, B.; Clifton, L.; Daniels, E.; Dahlen, P.

2013-12-01

Many soil and groundwater remediation technologies rely on fluid flow for contaminant extraction or reactant delivery (e.g., soil vapor extraction, pump and treat, in situ chemical oxidation, air sparging, enhanced bioremediation). Given that most unconsolidated and consolidated settings have permeability contrasts, the outcome is often preferential treatment of more permeable zones and ineffective treatment of the lower permeability zones. When this happens, post-treatment contaminant emissions from low permeability zone residuals can cause unacceptable long-term impacts to groundwater in the transmissive zones. As complete remediation of the impacted lower permeability zones may not be practicable with conventional technologies, one might explore options that lead to reduction of the contaminant emissions to acceptable levels, rather than full remediation of the lower permeability layers. This could be accomplished either by creating a sustained emission reaction/attenuation zone at the high-low permeability interface, or by creating a clean soil zone extending sufficiently far into the lower permeability layer to cause the necessary reduction in contaminant concentration gradient and diffusive emission. These options are explored in proof-of-concept laboratory-scale physical model experiments. The physical models are prepared with two layers of contrasting permeability and either dissolved matrix storage or nonaqueous phase liquid (NAPL) in the lower permeability layer. A dissolved oxidant is then delivered to the interface via flow across the higher permeability layer and changes in contaminant emissions from the low permeability zone are monitored before, during, and after oxidant delivery. The use of three oxidants (dissolved oxygen, hydrogen peroxide and sodium persulfate) for treatment of emissions from petroleum hydrocarbon residuals is examined.

Endotoxin, ergosterol, fungal DNA and allergens in dust from schools in Johor Bahru, Malaysia- associations with asthma and respiratory infections in pupils.

Science.gov (United States)

Norbäck, Dan; Markowicz, Pawel; Cai, Gui-Hong; Hashim, Zailina; Ali, Faridah; Zheng, Yi-Wu; Lai, Xu-Xin; Spangfort, Michael Dho; Larsson, Lennart; Hashim, Jamal Hisham

2014-01-01

There are few studies on associations between respiratory health and allergens, fungal and bacterial compounds in schools in tropical countries. The aim was to study associations between respiratory symptoms in pupils and ethnicity, chemical microbial markers, allergens and fungal DNA in settled dust in schools in Malaysia. Totally 462 pupils (96%) from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated. Dust was vacuumed from 32 classrooms and analysed for levels of different types of endotoxin as 3-hydroxy fatty acids (3-OH), muramic acid, ergosterol, allergens and five fungal DNA sequences. Multiple logistic regression was applied. Totally 13.1% pupils reported doctor's diagnosed asthma, 10.3% wheeze and 21.1% pollen or pet allergy. Indian and Chinese children had less atopy and asthma than Malay. Carbon dioxide levels were low (380-690 ppm). No cat (Fel d1), dog (Can f 1) or horse allergens (Ecu cx) were detected. The levels of Bloomia tropicalis (Blo t), house dust mite allergens (Der p 1, Der f 1, Der m 1) and cockroach allergens (Per a 1 and Bla g 1) were low. There were positive associations between levels of Aspergillus versicolor DNA and daytime breathlessness, between C14 3-OH and respiratory infections and between ergosterol and doctors diagnosed asthma. There were negative (protective) associations between levels of C10 3-OH and wheeze, between C16 3-OH and day time and night time breathlessness, between cockroach allergens and doctors diagnosed asthma. Moreover there were negative associations between amount of fine dust, total endotoxin (LPS) and respiratory infections. In conclusion, endotoxin at school seems to be mainly protective for respiratory illness but different types of endotoxin could have different effects. Fungal contamination measured as ergosterol and Aspergillus versicolor DNA can be risk factors for respiratory illness. The ethnical differences for atopy and asthma deserve further attention.

Endotoxin, ergosterol, fungal DNA and allergens in dust from schools in Johor Bahru, Malaysia- associations with asthma and respiratory infections in pupils.

Directory of Open Access Journals (Sweden)

Dan Norbäck

Full Text Available There are few studies on associations between respiratory health and allergens, fungal and bacterial compounds in schools in tropical countries. The aim was to study associations between respiratory symptoms in pupils and ethnicity, chemical microbial markers, allergens and fungal DNA in settled dust in schools in Malaysia. Totally 462 pupils (96% from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated. Dust was vacuumed from 32 classrooms and analysed for levels of different types of endotoxin as 3-hydroxy fatty acids (3-OH, muramic acid, ergosterol, allergens and five fungal DNA sequences. Multiple logistic regression was applied. Totally 13.1% pupils reported doctor's diagnosed asthma, 10.3% wheeze and 21.1% pollen or pet allergy. Indian and Chinese children had less atopy and asthma than Malay. Carbon dioxide levels were low (380-690 ppm. No cat (Fel d1, dog (Can f 1 or horse allergens (Ecu cx were detected. The levels of Bloomia tropicalis (Blo t, house dust mite allergens (Der p 1, Der f 1, Der m 1 and cockroach allergens (Per a 1 and Bla g 1 were low. There were positive associations between levels of Aspergillus versicolor DNA and daytime breathlessness, between C14 3-OH and respiratory infections and between ergosterol and doctors diagnosed asthma. There were negative (protective associations between levels of C10 3-OH and wheeze, between C16 3-OH and day time and night time breathlessness, between cockroach allergens and doctors diagnosed asthma. Moreover there were negative associations between amount of fine dust, total endotoxin (LPS and respiratory infections. In conclusion, endotoxin at school seems to be mainly protective for respiratory illness but different types of endotoxin could have different effects. Fungal contamination measured as ergosterol and Aspergillus versicolor DNA can be risk factors for respiratory illness. The ethnical differences for atopy and asthma deserve further attention.

Cow allergen (Bos d2) and endotoxin concentrations are higher in the settled dust of homes proximate to industrial-scale dairy operations.

Science.gov (United States)

Williams, D' Ann L; McCormack, Meredith C; Matsui, Elizabeth C; Diette, Gregory B; McKenzie, Shawn E; Geyh, Alison S; Breysse, Patrick N

2016-01-01

Airborne contaminants produced by industrial agricultural facilities contain chemical and biological compounds that can impact the health of residents living in close proximity. Settled dust can be a reservoir for these contaminants and can influence long-term exposures. In this study, we sampled the indoor- and outdoor-settled dust from 40 homes that varied in proximity to industrial-scale dairies (ISD; industrial-scale dairy, a term used in this paper to describe a large dairy farm and adjacent waste sprayfields, concentrated animal feeding operation or animal feeding operation, that uses industrial processes) in the Yakima Valley, Washington. We analyzed settled dust samples for cow allergen (Bos d2, a cow allergen associated with dander, hair, sweat and urine, it is a member of the lipocalin family of allergens associated with mammals), mouse allergen (Mus m1; major mouse allergen, a mouse urinary allergen, in the lipocalin family), dust mite allergens (Der p1 (Dermatophagoides pteronissinus 1) and Der f1 (Dermatophagoides farinae 1)), and endotoxin (a component of the cell walls of gram negative bacteria, lipopolysaccharide, which can be found in air and dust and can produce a strong inflammatory response). A concentration gradient was observed for Bos d2 and endotoxin measured in outdoor-settled dust samples based on proximity to ISD. Indoor-settled dust concentrations of Bos d2 and endotoxin were also highest in proximal homes. While the associated health effects of exposure to cow allergen in settled dust is unknown, endotoxin at concentrations observed in these proximal homes (100 EU/mg) has been associated with increased negative respiratory health effects. These findings document that biological contaminants emitted from ISDs are elevated in indoor- and outdoor-settled dust samples at homes close to these facilities and extend to as much as three miles (4.8 km) away.

Controlling DC permeability in cast steels

Energy Technology Data Exchange (ETDEWEB)

Sumner, Aaran, E-mail: aaran.sumner@nottingham.ac.uk [University of Nottingham, Nottingham University Park Campus, Nottingham NG7 2RD, England (United Kingdom); Gerada, Chris, E-mail: chris.gerada@nottingham.ac.uk [Electrical Machines, University of Nottingham, Tower Building, Nottingham NG7 2RD, England (United Kingdom); Brown, Neil, E-mail: neil.brown@cummins.com [Advanced Electrical Machines Research and Technology at Cummins Power Generation, Peterborough PE2 6FZ, England (United Kingdom); Clare, Adam, E-mail: adam.clare@nottingham.ac.uk [Advanced Manufacturing, University of Nottingham, University Park Campus, Nottingham NG7 2RD, England (United Kingdom)

2017-05-01

Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels. - Highlights: • A range of structural steels had their

Controlling DC permeability in cast steels

International Nuclear Information System (INIS)

Sumner, Aaran; Gerada, Chris; Brown, Neil; Clare, Adam

2017-01-01

Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels. - Highlights: • A range of structural steels had their

Elimination of Proteus mirabilis /sup 51/Cr endotoxin from the liver in rats

Energy Technology Data Exchange (ETDEWEB)

Lipinska-Piotrowska, I [Akademia Medyczna, Lodz (Poland)

1977-01-01

Using isotope methods, elimination of the endotoxin of Proteus mirabilis labelled with chromium (CrEPm) from the liver of rats was studied. The following studies were carried out: intravital exploration of the liver with a scintillation probe, measurements of radioactivity of organs and excreted urine and stools, scintigraphy of the liver, binding of CrEPm by subcellular fractions of hepatocytes, and the influence of selected drugs (polymyxin and hydrocortisone) on elimination of CrEPm from the liver and organelles of hepatocytes.

On-line Biomass Estimation in a Batch Biotechnological Process: Bacillus thuringiensis δ - endotoxins production.

OpenAIRE

Amicarelli, Adriana

2010-01-01

In this Chapter it has been addressed the problem of the biomass estimation in a batch biotechnological process: the Bacillus thuringiensis (Bt) δ-endotoxins production process. Different alternatives that can be successfully used in this sense were presented. It has been exposed the design of various biomass estimators, namely: a phenomenological biomass estimator, a standard EKF biomass estimator, a biomass estimator based on ANN, a decentralized Kalman Filter, and a biomass concentration ...

Frictional stability-permeability relationships for fractures in shales

Science.gov (United States)

Fang, Yi; Elsworth, Derek; Wang, Chaoyi; Ishibashi, Takuya; Fitts, Jeffrey P.

2017-03-01

There is wide concern that fluid injection in the subsurface, such as for the stimulation of shale reservoirs or for geological CO2 sequestration (GCS), has the potential to induce seismicity that may change reservoir permeability due to fault slip. However, the impact of induced seismicity on fracture permeability evolution remains unclear due to the spectrum of modes of fault reactivation (e.g., stable versus unstable). As seismicity is controlled by the frictional response of fractures, we explore friction-stability-permeability relationships through the concurrent measurement of frictional and hydraulic properties of artificial fractures in Green River shale (GRS) and Opalinus shale (OPS). We observe that carbonate-rich GRS shows higher frictional strength but weak neutral frictional stability. The GRS fracture permeability declines during shearing while an increased sliding velocity reduces the rate of permeability decline. By comparison, the phyllosilicate-rich OPS has lower friction and strong stability while the fracture permeability is reduced due to the swelling behavior that dominates over the shearing induced permeability reduction. Hence, we conclude that the friction-stability-permeability relationship of a fracture is largely controlled by mineral composition and that shale mineral compositions with strong frictional stability may be particularly subject to permanent permeability reduction during fluid infiltration.

Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

Science.gov (United States)

Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

2015-01-01

Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R2=0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q2ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. PMID:25560673

IGF-1 decreases portal vein endotoxin via regulating intestinal tight junctions and plays a role in attenuating portal hypertension of cirrhotic rats.

Science.gov (United States)

Zhao, Tian-Yu; Su, Li-Ping; Ma, Chun-Ye; Zhai, Xiao-Han; Duan, Zhi-Jun; Zhu, Ying; Zhao, Gang; Li, Chun-Yan; Wang, Li-Xia; Yang, Dong

2015-07-08

Intestinal barrier dysfunction is not only the consequence of liver cirrhosis, but also an active participant in the development of liver cirrhosis. Previous studies showed that external administration of insulin-like growth factor 1 (IGF-1) improved intestinal barrier function in liver cirrhosis. However, the mechanism of IGF-1 on intestinal barrier in liver cirrhosis is not fully elucidated. The present study aims to investigate the mechanisms of IGF-1 improving intestinal barrier function via regulating tight junctions in intestines. We used carbon tetrachloride induced liver cirrhotic rats to investigate the effect of IGF-1 on intestinal claudin-1 and occludin expressions, serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, severity of liver fibrosis, portal pressures, enterocytic apoptosis and lipopolysaccharides (LPS) levels in portal vein. The changes of IGF-1 in serum during the development of rat liver cirrhosis were also evaluated. Additionally, we assessed the effect of IGF-1 on claudin-1 and occludin expressions, changes of transepithelial electrical resistance (TEER) and apoptosis in Caco-2 cells to confirm in vivo findings. Serum IGF-1 levels were decreased in the development of rat liver cirrhosis, and external administration of IGF-1 restored serum IGF-1 levels. External administration of IGF-1 reduced serum ALT and AST levels, severity of liver fibrosis, LPS levels in portal vein, enterocytic apoptosis and portal pressure in cirrhotic rats. External administration of IGF-1 increased the expressions of claudin-1 and occludin in enterocytes, and attenuated tight junction dysfunction in intestines of cirrhotic rats. LPS decreased TEER in Caco-2 cell monolayer. LPS also decreased claudin-1 and occludin expressions and increased apoptosis in Caco-2 cells. Furthermore, IGF-1 attenuated the effect of LPS on TEER, claudin-1 expression, occludin expression and apoptosis in Caco-2 cells. Tight junction dysfunction develops during the

Transverse Chemotactic Migration of Bacteria from High to Low Permeability Regions in a Dual Permeability Porous Microfluidic Device

Science.gov (United States)

Singh, R.; Olson, M. S.

2011-12-01

Low permeability regions sandwiched between high permeability regions such as clay lenses are difficult to treat using conventional treatment methods. Trace concentrations of contaminants such as non-aqueous phase liquids (NAPLs) remain trapped in these regions and over the time diffuse out into surrounding water thereby acting as a long term source of groundwater contamination. Bacterial chemotaxis (directed migration toward a contaminant source), may be helpful in enhancing bioremediation of such contaminated sites. This study is focused on simulating a two-dimensional dual-permeability groundwater contamination scenario using microfluidic devices and evaluating transverse chemotactic migration of bacteria from high to low permeability regions. A novel bi-layer polydimethylsiloxane (PDMS) microfluidic device was fabricated using photolithography and soft lithography techniques to simulate contamination of a dual- permeability region due to leakage from an underground storage tank into a low permeability region. This device consists of a porous channel through which a bacterial suspension (Escherchia Coli HCB33) is flown and another channel for injecting contaminant/chemo-attractant (DL-aspertic acid) into the porous channel. The pore arrangement in the porous channel contains a 2-D low permeability region surrounded by high permeability regions on both sides. Experiments were performed under chemotactic and non-chemotactic (replacing attractant with buffer solution in the non porous channel) conditions. Images were captured in transverse pore throats at cross-sections 4.9, 9.8, and 19.6 mm downstream from the attractant injection point and bacteria were enumerated in the middle of each pore throat. Bacterial chemotaxis was quantified in terms of the change in relative bacterial counts in each pore throat at cross-sections 9.8 and 19.6 mm with respect to counts at the cross-section at 4.9 mm. Under non-chemotactic conditions, relative bacterial count was observed

Modelling of water permeability in cementitious materials

DEFF Research Database (Denmark)

Guang, Ye; Lura, Pietro; van Breugel, K.

2006-01-01

This paper presents a network model to predict the permeability of cement paste from a numerical simulation of its microstructure. Based on a linked list pore network structure, the effective hydraulic conductivity is estimated and the fluid flow is calculated according to the Hagen-Poiseuille law....... The pressure gradient at all nodes is calculated with the Gauss elimination method and the absolute permeability of the pore network is calculated directly from Darcy's law. Finally, the permeability model is validated by comparison with direct water permeability measurements. According to this model...

Bentonite Permeability at Elevated Temperature

Directory of Open Access Journals (Sweden)

Katherine A. Daniels

2017-01-01

Full Text Available Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability.

Increased proximal reflux in a hypersensitive esophagus might explain symptoms resistant to proton pump inhibitors in patients with gastroesophageal reflux disease.

Science.gov (United States)

Rohof, Wout O; Bennink, Roelof J; de Jonge, Hugo; Boeckxstaens, Guy E

2014-10-01

Approximately 30% of patients with gastroesophageal reflux disease have symptoms resistant to treatment with proton pump inhibitors (PPIs). Several mechanisms such as esophageal hypersensitivity, increased mucosal permeability, and possibly the position of the gastric acid pocket might underlie a partial response to PPIs. To what extent these mechanisms interact and contribute to PPI-resistant symptoms, however, has not been investigated previously. In 18 gastroesophageal reflux disease patients (9 PPI responders and 9 PPI partial responders), esophageal sensitivity, mucosal permeability, and postprandial reflux parameters were determined during PPI use. Esophageal sensitivity for distension was measured by gradual balloon inflation at 5 and 15 cm above the lower esophageal sphincter. The mucosal permeability of 4 esophageal biopsy specimens per patient was determined in Ussing chambers by measuring the transepithelial electrical resistance and transmucosal flux of fluorescein. Postprandial reflux parameters were determined using concurrent high-resolution manometry/pH impedance after a standardized meal. In addition, the acid pocket was visualized using scintigraphy. No difference in the rate of postprandial acid reflux, in the pH of the acid pocket (PPI responders 3.7 ± 0.7 vs PPI partial responders 4.2 ± 0.4; P = .54), or in the position of the acid pocket was observed in PPI partial responders compared with PPI responders. In addition, the permeability of the esophageal mucosa was similar in both groups, as shown by a similar transepithelial electrical resistance and flux of fluorescein. PPI partial responders had more reflux episodes with a higher mean proximal extent, compared with PPI responders, and were more sensitive to balloon distension, both in the upper and lower esophagus. PPI-resistant symptoms most likely are explained by increased proximal reflux in a hypersensitive esophagus and less likely by increased mucosal permeability or the position of

Negative permeability from random particle composites

Energy Technology Data Exchange (ETDEWEB)

Hussain, Shahid, E-mail: shussain2@qinetiq.com

2017-04-15

Artificial media, such as those composed of periodically-spaced wires for negative permittivity and split ring resonators for negative permeability have been extensively investigated for negative refractive index (NRI) applications (Smith et al., 2004; Pendry et al., 1999) [1,2]. This paper presents an alternative method for producing negative permeability: granular (or particulate) composites incorporating magnetic fillers. Artificial media, such as split-ring resonators, are designed to produce a magnetic resonance feature, which results in negative permeability over a narrow frequency range about the resonance frequency. The position of the feature is dependent upon the size of the inclusion. The material in this case is anisotropic, such that the feature is only observable when the materials are orientated in a specific direction relative to the applied field. A similar resonance can be generated in magnetic granular (particulate) materials: ferromagnetic resonance from the natural spin resonance of particles. Although the theoretical resonance profiles in granular composites shows the permeability dipping to negative values, this is rarely observed experimentally due to resonance damping effects. Results are presented for iron in spherical form and in flake form, dispersed in insulating host matrices. The two particle shapes show different permeability performance, with the magnetic flakes producing a negative contribution. This is attributed to the stronger coupling with the magnetic field resulting from the high aspect ratio of the flakes. The accompanying ferromagnetic resonance is strong enough to overcome the effects of damping and produce negative permeability. The size of random particle composites is not dictated by the wavelength of the applied field, so the materials are potentially much thinner than other, more traditional artificial composites at microwave frequencies. - Highlights: • Negative permeability from random particle composites is

Permeability enhancement by shock cooling

Science.gov (United States)

Griffiths, Luke; Heap, Michael; Reuschlé, Thierry; Baud, Patrick; Schmittbuhl, Jean

2015-04-01

The permeability of an efficient reservoir, e.g. a geothermal reservoir, should be sufficient to permit the circulation of fluids. Generally speaking, permeability decreases over the life cycle of the geothermal system. As a result, is usually necessary to artificially maintain and enhance the natural permeability of these systems. One of the methods of enhancement -- studied here -- is thermal stimulation (injecting cold water at low pressure). This goal of this method is to encourage new thermal cracks within the reservoir host rocks, thereby increasing reservoir permeability. To investigate the development of thermal microcracking in the laboratory we selected two granites: a fine-grained (Garibaldi Grey granite, grain size = 0.5 mm) and a course-grained granite (Lanhelin granite, grain size = 2 mm). Both granites have an initial porosity of about 1%. Our samples were heated to a range of temperatures (100-1000 °C) and were either cooled slowly (1 °C/min) or shock cooled (100 °C/s). A systematic microstructural (2D crack area density, using standard stereological techniques, and 3D BET specific surface area measurements) and rock physical property (porosity, P-wave velocity, uniaxial compressive strength, and permeability) analysis was undertaken to understand the influence of slow and shock cooling on our reservoir granites. Microstructurally, we observe that the 2D crack surface area per unit volume and the specific surface area increase as a result of thermal stressing, and, for the same maximum temperature, crack surface area is higher in the shock cooled samples. This observation is echoed by our rock physical property measurements: we see greater changes for the shock cooled samples. We can conclude that shock cooling is an extremely efficient method of generating thermal microcracks and modifying rock physical properties. Our study highlights that thermal treatments are likely to be an efficient method for the "matrix" permeability enhancement of

Different domains of Bacillus thuringiensis delta-endotoxins can bind to insect midgut membrane proteins on ligand blots

NARCIS (Netherlands)

Maagd, de R.A.; Klei, van der H.; Bakker, P.L.; Stiekema, W.J.; Bosch, D.

1996-01-01

We investigated the role of the constituent domains of the CryIA(b) and CryIA(c) δ-endotoxins in binding to midgut epithelial cell membrane proteins of Spodoptera exigua and Manduca sexta on ligand blots. A collection of wild- type and CryIC-CryIA hybrid toxins was used for this purpose. As

Herbal medicines that benefit epidermal permeability barrier function

Directory of Open Access Journals (Sweden)

Lizhi Hu

2015-06-01

Full Text Available Epidermal permeability barrier function plays a critical role in regulating cutaneous functions. Hence, researchers have been searching for effective and affordable regimens to enhance epidermal permeability barrier function. In addition to topical stratum corneum lipids, peroxisome proliferator-activated receptor, and liver X receptor ligands, herbal medicines have been proven to benefit epidermal permeability barrier function in both normal and diseased skin, including atopic dermatitis, glucocorticoid-induced skin damage, and UVB-damaged skin. The potential mechanisms by which herbal medicines improve the permeability barrier include stimulation of epidermal differentiation, lipid production, antimicrobial peptide expression, and antioxidation. Therefore, utilization of herbal medicines could be a valuable alternative approach to enhance epidermal permeability barrier function in order to prevent and/or treat skin disorders associated with permeability barrier abnormalities.

Surface-subsurface turbulent interaction at the interface of a permeable bed: influence of the wall permeability

Science.gov (United States)

Kim, T.; Blois, G.; Best, J.; Christensen, K. T.

2017-12-01

Coarse-gravel river beds possess a high degree of permeability. Flow interactions between surface and subsurface flow across the bed interface is key to a number of natural processes occurring in the hyporheic zone. In fact, it is increasingly recognized that these interactions drive mass, momentum and energy transport across the interface, and consequently control biochemical processes as well as stability of sediments. The current study explores the role of the wall permeability in surface and subsurface flow interaction under controlled experimental conditions on a physical model of a gravel bed. The present wall model was constructed by five layers of cubically arranged spheres (d=25.4mm, where d is a diameter) providing 48% of porosity. Surface topography was removed by cutting half of a diameter on the top layer of spheres to render the flow surface smooth and highlight the impact of the permeability on the overlying flow. An impermeable smooth wall was also considered as a baseline of comparison for the permeable wall flow. To obtain basic flow statistics, low-frame-rate high-resolution PIV measurements were performed first in the streamwise-wall-normal (x-y) plane and refractive-index matching was employed to optically access the flow within the permeable wall. Time-resolved PIV experiments in the same facility were followed to investigate the flow interaction across the wall interface in sptaio-temporal domain. In this paper, a detailed analysis of the first and second order velocity statistics as well as the amplitude modulation for the flow overlying the permeable smooth wall will be presented.

Single-step transepithelial ASLA (SCHWIND with mitomycin-C for the correction of high myopia: long term follow-up

Directory of Open Access Journals (Sweden)

Aslanides IM

2014-12-01

Full Text Available Ioannis M Aslanides, Panagiotis N Georgoudis, Vasilis D Selimis, Achyut N Mukherjee Emmetropia Mediterranean Eye Institute, Heraklion, Crete, Greece Purpose: We wanted to compare the outcomes of single-step modified transepithelial photorefractive keratectomy (tPRK termed a SCHWIND all surface laser ablation (ASLA versus conventional alcohol-assisted photorefractive keratectomy (PRK and laser-assisted in situ keratomileusis (LASIK for the correction of higher myopia of 6.00 diopters (D or more, in an area with high risk of haze due to high intensity of sunlight.Methods: We used a prospective interventional cohort with matched retrospective control groups. Patients with >6 D myopia and <3.5 D of astigmatism were included. All treatments were performed with the SCHWIND Amaris system using aspheric ablation profiles. Mitomycin C was used in all PRK and ASLA cases. Outcomes were postoperative refraction, visual acuity, stability, and complications. The follow-up period was up to 12 months.Results: In total, 101 eyes were included after exclusions. Mean preoperative spherical equivalent refraction was −7.9 D, −8.2 D, and −7.4 D in the ASLA (n=41, PRK (n=29, and LASIK (n=31 groups. Mean postoperative spherical equivalent at 12 months postoperatively was −0.1 (standard deviation [SD]: 0.34, −0.2 (SD: 0.59, and −0.08 (SD: 0.36 in the ASLA, PRK, and LASIK groups, with 91.4%, 85.7%, and 83.9% within 0.5 D of target, respectively. Refractive outcomes and regression at 12 months did not vary among groups (P>0.05. Mean logMAR (logarithm of the minimum angle of resolution uncorrected distance visual acuity at 12 months was 0.00 (SD: 0.05, 0.06 (SD: 0.1, and 0.05 (SD: 0.09 in the ASLA, PRK, and LASIK groups, with significantly better vision in the tPRK group versus LASIK (P=0.01 and PRK (P=0.01 groups.Conclusion: ASLA (SCHWIND tPRK with mitomycin C for high myopia demonstrates comparable refractive outcomes to LASIK and PRK, with relatively

A hybrid Bacillus thuringiensis delta-endotoxin gene gives resistance against a coleopteran and a lepidopteran pest in transgenic potato

NARCIS (Netherlands)

Naimov, S.; Dukiandjiev, S.; Maagd, de R.A.

2003-01-01

Expression of Bacillus thuringiensis delta-endotoxins has proven to be a successful strategy for obtaining insect resistance in transgenic plants. Drawbacks of expression of a single resistance gene are the limited target spectrum and the potential for rapid adaptation of the pest. Hybrid toxins

Active intestinal drug absorption and the solubility-permeability interplay.

Science.gov (United States)

Porat, Daniel; Dahan, Arik

2018-02-15

The solubility-permeability interplay deals with the question: what is the concomitant effect on the drug's apparent permeability when increasing the apparent solubility with a solubility-enabling formulation? The solubility and the permeability are closely related, exhibit certain interplay between them, and ongoing research throughout the past decade shows that treating the one irrespectively of the other may be insufficient. The aim of this article is to provide an overview of the current knowledge on the solubility-permeability interplay when using solubility-enabling formulations for oral lipophilic drugs, highlighting active permeability aspects. A solubility-enabling formulation may affect the permeability in opposite directions; the passive permeability may decrease as a result of the apparent solubility increase, according to the solubility-permeability tradeoff, but at the same time, certain components of the formulation may inhibit/saturate efflux transporters (when relevant), resulting in significant apparent permeability increase. In these cases, excipients with both solubilizing and e.g. P-gp inhibitory properties may lead to concomitant increase of both the solubility and the permeability. Intelligent development of such formulation will account for the simultaneous effects of the excipients' nature/concentrations on the two arms composing the overall permeability: the passive and the active arms. Overall, thorough mechanistic understanding of the various factors involved in the solubility-permeability interplay may allow developing better solubility-enabling formulations, thereby exploiting the advantages analyzed in this article, offering oral delivery solution even for BCS class IV drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Principal permeability determination from multiple horizontal well tests

Energy Technology Data Exchange (ETDEWEB)

Economides, M. [Texas A and M Univ., TX (United States); Munoz, A.; Ehlig-Economides, C.

1998-12-31

A method for obtaining principal permeability magnitudes and direction that requires only the linear flow regime from transient tests in three horizontal wells oriented in three distinct and arbitrary directions, is described. Well design optimization strategies require knowledge of both the principal permeability orientation as well as the horizontal permeability magnitudes. When the degree of horizontal permeability anisotropy (i.e. permeability in the bedding plane with respect to direction) is significant, the productivity of a long horizontal well will depend greatly on its direction, especially when the well is first brought into production. Productivities have been found to deviate substantially among wells in the same reservoir and this deviation has been attributed to differences in well orientation. In view of this fact, measuring permeability anisotropy becomes a compelling necessity. The success of the proposed method is illustrated by a case study in which the principal permeability magnitudes and direction from three wells were used to predict the productivity of a fourth well within 10 per cent. Use of the computed principal permeabilities from the case study, it was possible to forecast the cumulative production to show the significance of well trajectory optimization on the discounted cash flow and the net present value. 20 refs., 3 figs.

Permeability Tests on Eastern Scheldt Sand

DEFF Research Database (Denmark)

Jakobsen, Kim Parsberg

on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

Damage-induced permeability changes around underground excavations

International Nuclear Information System (INIS)

Coll, C.

2005-07-01

The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

Long-term Metal Performance of Three Permeable Pavements

Science.gov (United States)

EPA constructed a 4,000-m2 parking lot surfaced with three permeable pavements (permeable interlocking concrete pavers, pervious concrete, and porous asphalt) on the Edison Environmental Center in Edison, NJ in 2009. Samples from each permeable pavement infiltrate were collected...

Permeable Pavement Research - Edison, New Jersey

Science.gov (United States)

This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

Permeability Barrier Generation in the Martian Lithosphere

Science.gov (United States)

Schools, Joe; Montési, Laurent

2015-11-01

Permeability barriers develop when a magma produced in the interior of a planet rises into the cooler lithosphere and crystallizes more rapidly than the lithosphere can deform (Sparks and Parmentier, 1991). Crystallization products may then clog the porous network in which melt is propagating, reducing the permeability to almost zero, i.e., forming a permeability barrier. Subsequent melts cannot cross the barrier. Permeability barriers have been useful to explain variations in crustal thickness at mid-ocean ridges on Earth (Magde et al., 1997; Hebert and Montési, 2011; Montési et al., 2011). We explore here under what conditions permeability barriers may form on Mars.We use the MELTS thermodynamic calculator (Ghiorso and Sack, 1995; Ghiorso et al., 2002; Asimow et al., 2004) in conjunction with estimated Martian mantle compositions (Morgan and Anders, 1979; Wänke and Dreibus, 1994; Lodders and Fegley, 1997; Sanloup et al., 1999; Taylor 2013) to model the formation of permeability barriers in the lithosphere of Mars. In order to represent potential past and present conditions of Mars, we vary the lithospheric thickness, mantle potential temperature (heat flux), oxygen fugacity, and water content.Our results show that permeability layers can develop in the thermal boundary layer of the simulated Martian lithosphere if the mantle potential temperature is higher than ~1500°C. The various Martian mantle compositions yield barriers in the same locations, under matching variable conditions. There is no significant difference in barrier location over the range of accepted Martian oxygen fugacity values. Water content is the most significant influence on barrier development as it reduces the temperature of crystallization, allowing melt to rise further into the lithosphere. Our lower temperature and thicker lithosphere model runs, which are likely the most similar to modern Mars, show no permeability barrier generation. Losing the possibility of having a permeability

Molecular basis for endotoxin neutralization by amphipathic peptides derived from the alpha-helical cationic core-region of NK-lysin.

Science.gov (United States)

Brandenburg, Klaus; Garidel, Patrick; Fukuoka, Satoshi; Howe, Jörg; Koch, Michel H J; Gutsmann, Thomas; Andrä, Jörg

2010-08-01

An analysis of the interaction of the NK-lysin derived peptide NK-2 and of analogs thereof with bacterial lipopolysaccharide (LPS, endotoxin) was performed to determine the most important biophysical parameters for an effective LPS neutralization. We used microcalorimetry, FTIR spectroscopy, Zeta potential measurements, and small-angle X-ray scattering to analyze the peptide:LPS binding enthalpy, the accessible LPS surface charge, the fluidity of the LPS hydrocarbon chains, their phase transition enthalpy change, the aggregate structure of LPS, and how these parameters are modulated by the peptides. We conclude that (i) a high peptide:LPS binding affinity, which is facilitated by electrostatic and hydrophobic interactions and which leads to a positive Zeta potential, (ii) the formation of peptide-enriched domains, which destabilize the lipid packing, demonstrated by a drastic decrease of phase transition enthalpy change of LPS, and (iii) the multilamellarization of the LPS aggregate structure are crucial for an effective endotoxin neutralization by cationic peptides.

Permeability of skin and oral mucosa to water and horseradish peroxidase as related to the thickness of the permeability barrier

International Nuclear Information System (INIS)

Squier, C.A.; Hall, B.K.

1985-01-01

The permeability of porcine skin and keratinized and nonkeratinized oral mucosa to tritium-labeled water and horseradish peroxidase (HRPO) was determined using perfusion chambers. Small blocks from each tissue were also incubated with HRPO and the extent of penetration visualized microscopically; this enabled measurements to be made of the thickness of the permeability barrier to this water-soluble tracer. Results obtained after inverting the oral mucosa in the chambers or adding metabolic inhibitors indicated that both compounds diffuse across the tissue. The permeability constants derived directly in the study showed that skin was less permeable than oral mucosa and that the floor of the mouth was significantly more permeable than all other regions. When these constants were normalized in terms of a standard permeability barrier thickness and the different tissues compared, the values obtained for skin were again less than those of the oral regions but, of these, the buccal mucosa was significantly higher. The difference in permeability between epidermis and keratinized oral epithelium may be due to differences in the volume density of membrane-coating granules known to exist between the tissues; differences between the oral mucosal regions may reflect differences in the nature of the intercellular barrier material

Update to Permeable Pavement Research at the Edison ...

Science.gov (United States)

The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavements including interlocking concrete permeable pavers, pervious concrete, and porous asphalt. The permeable pavements are limited to parking spaces while adjacent driving lanes are impermeable and drain to the permeable surfaces. The parking lot is instrumented for continuous monitoring with thermistors and water content reflectometers that measure moisture as infiltrate passes through the storage gallery beneath the permeable pavements into the underlying native soil. Each permeable surface of the parking lot has four lined sections that capture infiltrate in tanks for water quality analyses; these tanks are capable of holding volumes up to 4.1 m3, which represents up to 38 mm (1.5 in.) for direct rainfall on the porous pavement and runoff from adjacent driving lanes that drain into the permeable surface.Previous technical releases concerning the demonstration site focused on monitoring techniques, observed chloride and nutrient concentrations, surface hydrology, and infiltration and evaporation rates. This presentation summarizes these past findings and addresses current water quality efforts including pH, solids analysis, total organic carbon, and chemical oxygen demand. Stormwater runoff continues to be a major cause of water pollution in

Susceptibility to endotoxin induced uveitis is not reduced in mice deficient in BLT1, the high affinity leukotriene B4 receptor

OpenAIRE

Smith, J R; Subbarao, K; Franc, D T; Haribabu, B; Rosenbaum, J T

2004-01-01

Aim: To investigate the role of arachidonic acid derived chemotactic factor, LTB4, in the development of endotoxin induced uveitis (EIU), using mice deficient in the BLT1 gene which encodes the high affinity LTB4 receptor.

Biostable glucose permeable polymer

DEFF Research Database (Denmark)

2017-01-01

A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

High-Glucose or -Fructose Diet Cause Changes of the Gut Microbiota and Metabolic Disorders in Mice without Body Weight Change

Directory of Open Access Journals (Sweden)

Moon Ho Do

2018-06-01

Full Text Available High fat diet-induced changes in gut microbiota have been linked to intestinal permeability and metabolic endotoxemia, which is related to metabolic disorders. However, the influence of a high-glucose (HGD or high-fructose (HFrD diet on gut microbiota is largely unknown. We performed changes of gut microbiota in HGD- or HFrD-fed C57BL/6J mice by 16S rRNA analysis. Gut microbiota-derived endotoxin-induced metabolic disorders were evaluated by glucose and insulin tolerance test, gut permeability, Western blot and histological analysis. We found that the HGD and HFrD groups had comparatively higher blood glucose and endotoxin levels, fat mass, dyslipidemia, and glucose intolerance without changes in bodyweight. The HGD- and HFrD-fed mice lost gut microbial diversity, characterized by a lower proportion of Bacteroidetes and a markedly increased proportion of Proteobacteria. Moreover, the HGD and HFrD groups had increased gut permeability due to alterations to the tight junction proteins caused by gut inflammation. Hepatic inflammation and lipid accumulation were also markedly increased in the HGD and HFrD groups. High levels of glucose or fructose in the diet regulate the gut microbiota and increase intestinal permeability, which precedes the development of metabolic endotoxemia, inflammation, and lipid accumulation, ultimately leading to hepatic steatosis and normal-weight obesity.

Effect of gamma rays on gram negative bacterial endotoxin

International Nuclear Information System (INIS)

Hilmy, N.; Dzulkarnain, B.

1977-01-01

Escherichia coli br and a Flavobacterium sp., isolated from Tjiptomangunkusumo Hospital in Jakarta, were used as bacterial endotoxin (pyrogen) source. Suspensoion of 10 7 , 10 6 , and 10 5 bacteria in sterile and pyrogen free Sodium Chloride Injection, that had been treated by heat at 80 deg C for 15 minutes or treated by irradiation with a dose of 2.5 x 10 6 rad, were injected each to nine rabbits. Maximum temperature rises were registered and compared. Data were interpreted according to the requirements of Indonesian Pharmacopea (1972) and British Pharmacopea (1973). The results showed that a dose of 2.5 x 10 6 rad did not reduce the pyrogenic activity. The rate of bacterial multiplications in the pharmaceutical preparations were tested by using sterile Dextrose (2.5%) and Sodium Chloride Injection as medium; storage time were 0; 6; and 24 hours. (author)

Soils - Mean Permeability

Data.gov (United States)

Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas. The...

Effect of aggregate grain size distribution on properties of permeable ...

African Journals Online (AJOL)

) ratio on the mechanical properties of permeable concrete is investigated. The aim of this study is to prepare permeable concrete mixture with optimum properties in terms of strength and permeability. For this purpose, five different permeable ...

Permeability, storage and hydraulic diffusivity controlled by earthquakes

Science.gov (United States)

Brodsky, E. E.; Fulton, P. M.; Xue, L.

2016-12-01

Earthquakes can increase permeability in fractured rocks. In the farfield, such permeability increases are attributed to seismic waves and can last for months after the initial earthquake. Laboratory studies suggest that unclogging of fractures by the transient flow driven by seismic waves is a viable mechanism. These dynamic permeability increases may contribute to permeability enhancement in the seismic clouds accompanying hydraulic fracking. Permeability enhancement by seismic waves could potentially be engineered and the experiments suggest the process will be most effective at a preferred frequency. We have recently observed similar processes inside active fault zones after major earthquakes. A borehole observatory in the fault that generated the M9.0 2011 Tohoku earthquake reveals a sequence of temperature pulses during the secondary aftershock sequence of an M7.3 aftershock. The pulses are attributed to fluid advection by a flow through a zone of transiently increased permeability. Directly after the M7.3 earthquake, the newly damaged fault zone is highly susceptible to further permeability enhancement, but ultimately heals within a month and becomes no longer as sensitive. The observation suggests that the newly damaged fault zone is more prone to fluid pulsing than would be expected based on the long-term permeability structure. Even longer term healing is seen inside the fault zone of the 2008 M7.9 Wenchuan earthquake. The competition between damage and healing (or clogging and unclogging) results in dynamically controlled permeability, storage and hydraulic diffusivity. Recent measurements of in situ fault zone architecture at the 1-10 meter scale suggest that active fault zones often have hydraulic diffusivities near 10-2 m2/s. This uniformity is true even within the damage zone of the San Andreas fault where permeability and storage increases balance each other to achieve this value of diffusivity over a 400 m wide region. We speculate that fault zones

A drainage data-based calculation method for coalbed permeability

International Nuclear Information System (INIS)

Lai, Feng-peng; Li, Zhi-ping; Fu, Ying-kun; Yang, Zhi-hao

2013-01-01

This paper establishes a drainage data-based calculation method for coalbed permeability. The method combines material balance and production equations. We use a material balance equation to derive the average pressure of the coalbed in the production process. The dimensionless water production index is introduced into the production equation for the water production stage. In the subsequent stage, which uses both gas and water, the gas and water production ratio is introduced to eliminate the effect of flush-flow radius, skin factor, and other uncertain factors in the calculation of coalbed methane permeability. The relationship between permeability and surface cumulative liquid production can be described as a single-variable cubic equation by derivation. The trend shows that the permeability initially declines and then increases after ten wells in the southern Qinshui coalbed methane field. The results show an exponential relationship between permeability and cumulative water production. The relationship between permeability and cumulative gas production is represented by a linear curve and that between permeability and surface cumulative liquid production is represented by a cubic polynomial curve. The regression result of the permeability and surface cumulative liquid production agrees with the theoretical mathematical relationship. (paper)

Adsorption of endotoxins on Ca2+ -iminodiacetic acid by metal ion affinity chromatography.

Science.gov (United States)

Lopes, André Moreni; Romeu, Jorge Sánchez; Meireles, Rolando Páez; Perera, Gabriel Marquez; Morales, Rolando Perdomo; Pessoa, Adalberto; Cárdenas, Lourdes Zumalacárregui

2012-11-01

Endotoxins (also known as lipopolysaccharides (LPS)) are undesirable by-products of recombinant proteins, purified from Escherichia coli. LPS can be considered stable under a wide range of temperature and pH, making their removal one of the most difficult tasks in downstream processes during protein purification. The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration. Immobilized metal affinity chromatography (IMAC) enables the affinity interactions between the metal ions (immobilized on the support through the chelating compound) and the target molecules, thus enabling high-efficiency separation of the target molecules from other components present in a mixture. Affinity chromatography is applied with Ca2+ -iminodiacetic acid (IDA) to remove most of the LPS contaminants from the end product (more than 90%). In this study, the adsorption of LPS on an IDA-Ca2+ was investigated. The adsorption Freundlich isotherm of LPS-IDA-Ca2+ provides a theoretical basis for LPS removal. It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2+ ligands on the beads. The factors such as pH (4.0 or 5.5) and ionic strength (1.0 mol/L) are essential to obtain effective removal of LPS for contaminant levels between endotoxin' concentration values less than 100 EU/mL and 100 000 EU/mL. This new protocol represents a substantial advantage in time, effort, and production costs.

Evaluation of permeability of compacted bentonite ground considering heterogeneity by geostatistics

International Nuclear Information System (INIS)

Tanaka, Yukihisa; Nakamura, Kunihiko; Kudo, Kohji; Hironaga, Michihiko; Nakagami, Motonori; Niwase, Kazuhito; Komatsu, Shin-ichi

2007-01-01

The permeability of the bentonite ground as an engineered barrier is possibly designed to the value which is lower than that determined in terms of required performance because of heterogeneous distribution of permeability in the ground, which might be considerable when the ground is created by the compaction method. The effect of heterogeneity in the ground on the permeability of the bentonite ground should be evaluated by overall permeability of the ground, whereas in practice, the effect is evaluated by the distribution of permeability in the ground. Thus, in this study, overall permeability of the bentonite ground is evaluated from the permeability of the bentonite ground is evaluated from the permeability distribution determined using the geostatistical method with the dry density data as well as permeability data of the undisturbed sample recovered from the bentonite ground. Consequently, it was proved through this study that possibility of overestimation of permeability of the bentonite ground can be reduced if the overall permeability is used. (author)

In vivo human buccal permeability of nicotine

DEFF Research Database (Denmark)

Adrian, Charlotte L; Olin, Helle B D; Dalhoff, Kim

2006-01-01

The aim was to examine the in vivo buccal pH-dependent permeability of nicotine in humans and furthermore compare the in vivo permeability of nicotine to previous in vitro permeability data. The buccal permeability of nicotine was examined in a three-way cross-over study in eight healthy non......-smokers using a buccal perfusion cell. The disappearance of nicotine from perfusion solutions with pH 6.0, 7.4, and 8.1 was studied for 3h. The apparent permeability of nicotine (P(app)) was determined at each pH value. Parotid saliva was collected in an attempt to assess systemic levels of nicotine....... The disappearance rate of nicotine increased significantly as the pH increased, which resulted in P(app) values of 0.57+/-0.55 x 10(-4), 2.10+/-0.23 x 10(-4), and 3.96+/-0.54 x 10(-4)cms(-1) (mean+/-S.D.) at pH 6.0, 7.4, and 8.1, respectively. A linear relationship (R(2)=0.993) was obtained between the P...

The permeability and consolidation of deep-sea sediments

International Nuclear Information System (INIS)

Schultheiss, P.J.; Gunn, D.E.

1985-01-01

This report presents permeability and consolidation data for a wide range of sediment types. Permeability is one of the two parameters which are needed to directly quantify pore water advection in deep sea sediments and which are being investigated in high-level radioactive waste study areas. While it is desirable that these parameters should be measured in situ it is argued that values of permeability can be measured sufficiently accurately in the laboratory from core samples. Consequently, an apparatus has been developed which enables sediment permeability to be measured at decreasing void ratios during a back-pressured consolidation test. Data presented in this report from over 60 samples have established the major differences in permeability between various sediment types and how permeability changes as a function of burial depth and void ratio. Samples from two study areas in the North Atlantic Ocean, King's Trough Flank (KTF) and Great Meteor East (GME), have been compared with samples of Red Clay (RC) obtained from the NW Pacific Ocean. Results are presented and discussed. (author)

Transformable ferroelectric control of dynamic magnetic permeability

Science.gov (United States)

Jiang, Changjun; Jia, Chenglong; Wang, Fenglong; Zhou, Cai; Xue, Desheng

2018-02-01

Magnetic permeability, which measures the response of a material to an applied magnetic field, is crucial to the performance of magnetic devices and related technologies. Its dynamic value is usually a complex number with real and imaginary parts that describe, respectively, how much magnetic power can be stored and lost in the material. Control of permeability is therefore closely related to energy redistribution within a magnetic system or energy exchange between magnetic and other degrees of freedom via certain spin-dependent interactions. To avoid a high power consumption, direct manipulation of the permeability with an electric field through magnetoelectric coupling leads to high efficiency and simple operation, but remains a big challenge in both the fundamental physics and material science. Here we report unambiguous evidence of ferroelectric control of dynamic magnetic permeability in a Co /Pb (Mg1/3Nb2/3) 0.7Ti0.3O3 (Co/PMN-PT) heterostructure, in which the ferroelectric PMN-PT acts as an energy source for the ferromagnetic Co film via an interfacial linear magnetoelectric interaction. The electric field tuning of the magnitude and line shape of the permeability offers a highly localized means of controlling magnetization with ultralow power consumption. Additionally, the emergence of negative permeability promises a new way of realizing functional nanoscale metamaterials with adjustable refraction index.

Accurate control testing for clay liner permeability

Energy Technology Data Exchange (ETDEWEB)

Mitchell, R J

1991-08-01

Two series of centrifuge tests were carried out to evaluate the use of centrifuge modelling as a method of accurate control testing of clay liner permeability. The first series used a large 3 m radius geotechnical centrifuge and the second series a small 0.5 m radius machine built specifically for research on clay liners. Two permeability cells were fabricated in order to provide direct data comparisons between the two methods of permeability testing. In both cases, the centrifuge method proved to be effective and efficient, and was found to be free of both the technical difficulties and leakage risks normally associated with laboratory permeability testing of fine grained soils. Two materials were tested, a consolidated kaolin clay having an average permeability coefficient of 1.2{times}10{sup -9} m/s and a compacted illite clay having a permeability coefficient of 2.0{times}10{sup -11} m/s. Four additional tests were carried out to demonstrate that the 0.5 m radius centrifuge could be used for linear performance modelling to evaluate factors such as volumetric water content, compaction method and density, leachate compatibility and other construction effects on liner leakage. The main advantages of centrifuge testing of clay liners are rapid and accurate evaluation of hydraulic properties and realistic stress modelling for performance evaluations. 8 refs., 12 figs., 7 tabs.

Cell permeability beyond the rule of 5.

Science.gov (United States)

Matsson, Pär; Doak, Bradley C; Over, Björn; Kihlberg, Jan

2016-06-01

Drug discovery for difficult targets that have large and flat binding sites is often better suited to compounds beyond the "rule of 5" (bRo5). However, such compounds carry higher pharmacokinetic risks, such as low solubility and permeability, and increased efflux and metabolism. Interestingly, recent drug approvals and studies suggest that cell permeable and orally bioavailable drugs can be discovered far into bRo5 space. Tactics such as reduction or shielding of polarity by N-methylation, bulky side chains and intramolecular hydrogen bonds may be used to increase cell permeability in this space, but often results in decreased solubility. Conformationally flexible compounds can, however, combine high permeability and solubility, properties that are keys for cell permeability and intestinal absorption. Recent developments in computational conformational analysis will aid design of such compounds and hence prediction of cell permeability. Transporter mediated efflux occurs for most investigated drugs in bRo5 space, however it is commonly overcome by high local intestinal concentrations on oral administration. In contrast, there is little data to support significant impact of transporter-mediated intestinal absorption in bRo5 space. Current knowledge of compound properties that govern transporter effects of bRo5 drugs is limited and requires further fundamental and comprehensive studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Analysis of endotoxin and endothelin-1 levels in patients with type 1 hepatorenal syndrome

Directory of Open Access Journals (Sweden)

GAO Baoxiu

2014-01-01

Full Text Available ObjectiveTo analyze the clinical data, laboratory parameters, infection rate, and serum procalcitonin (PCT and ET-1 levels of patients with cirrhotic ascites and type 1 hepatorenal syndrome (HRS and to investigate the roles of endotoxin and ET-1 in the development of HRS. MethodsBetween January 2009 and October 2012, 56 inpatients with cirrhotic ascites and type 1 HRS (HRS group and 60 inpatients with cirrhotic ascites who had normal renal function (non-HRS group were included in the study. Their general data, causes of liver cirrhosis, infection rates and types, Child-Pugh classification, systemic inflammatory response syndrome (SIRS score, and mean arterial pressure (MAP were recorded; blood samples were collected to evaluate liver and renal function and measure serum electrolyte, PCT, and ET-1 levels. The clinical data and laboratory parameters were compared between the two groups. Categorical data were analyzed by chi-square test; comparison of normally distributed continuous data between the two groups was made by independent-samples t test, and comparison of non-normally distributed continuous data between the two groups was made by Wilcoxon rank sum test. ResultsThe infection rate of HRS group (75.0% was significantly higher than that of non-HRS group (28.4% (χ2=11.91, P＜0.05. The PCT and ET-1 levels and SIRS score of HRS group ［8.72 (3.14, 31.68 ng/L, 13.04±2.82 pg/ml, and 2.1±1.1］ were significantly higher than those of non-HRS group ［0.11 (0.04, 0.45 ng/L, 5.76±1.68 pg/ml, and 0.6±0.6］ (P＜0.05. In addition, the HRS group had significantly higher serum urea, creatine, cystatin C, and K levels than the non-HRS group (P＜0.05, while the HRS group had significantly lower Na and Cl levels than the non-HRS group (P＜0.05. There were no significant differences in ALT and AST levels between the two groups (P＞005. ConclusionEndotoxin causes elevated expression of ET-1, and ET-1 induces renal perfusion deficiency by

Permeability, zonulin production, and enteropathy in dermatitis herpetiformis.

Science.gov (United States)

Smecuol, Edgardo; Sugai, Emilia; Niveloni, Sonia; Vázquez, Horacio; Pedreira, Silvia; Mazure, Roberto; Moreno, María Laura; Label, Marcelo; Mauriño, Eduardo; Fasano, Alessio; Meddings, Jon; Bai, Julio César

2005-04-01

Dermatitis herpetiformis (DH) is characterized by variable degrees of enteropathy and increased intestinal permeability. Zonulin, a regulator of tight junctions, seems to play a key role in the altered intestinal permeability that characterizes the early phase of celiac disease. Our aim was to assess both intestinal permeability and serum zonulin levels in a group of patients with DH having variable grades of enteropathy. We studied 18 DH patients diagnosed on the basis of characteristic immunoglobulin (Ig)A granular deposits in the dermal papillae of noninvolved skin. Results were compared with those of classic celiac patients, patients with linear IgA dermatosis, and healthy controls. According to Marsh's classification, 5 patients had no evidence of enteropathy (type 0), 4 patients had type II, 2 patients had type IIIb damage, and 7 patients had a more severe lesion (type IIIc). Intestinal permeability (lactulose/mannitol ratio [lac/man]) was abnormal in all patients with DH. Patients with more severe enteropathy had significantly greater permeability ( P zonulin concentration (enzyme-linked immunosorbent assay) for patients with DH was 2.1 +/- .3 ng/mg with 14 of 16 (87.5%) patients having abnormally increased values. In contrast, patients with linear IgA dermatosis had normal histology, normal intestinal permeability, and negative celiac serology. Increased intestinal permeability and zonulin up-regulation are common and concomitant findings among patients with DH, likely involved in pathogenesis. Increased permeability can be observed even in patients with no evidence of histologic damage in biopsy specimens. Patients with linear IgA dermatosis appear to be a distinct population with no evidence of gluten sensitivity.

Jerusalem artichokes stimulate growth of broiler chickens and protect them against endotoxins and potential cecal pathogens.

Science.gov (United States)

Kleessen, Brigitta; Elsayed, N A A E; Loehren, U; Schroedl, W; Krueger, Monika

2003-11-01

Control of intestinal pathogens during the earliest phases of broiler production may be the best strategy for the reduction of human pathogens on processed broiler carcasses. The recent ban on antibiotics in poultry feed has served to focus much attention on alternative methods of controlling the gastrointestinal microflora. A field trial was conducted to evaluate the effect of the fructan-rich Jerusalem artichoke, or topinambur (administered as 0.5% topinambur syrup in drinking water), on cultural numbers of selected cecal bacteria (total aerobes, Enterobacteriaceae, Bdellovibrio spp., and Clostridium perfringens) and levels of bacterial endotoxins as well as on body weights and relative weights of organs (the pancreas and the bursa of Fabricius) of chickens in the first 35 days of life (with weekly investigations being conducted). One-day-old broiler chickens (Ross 308) were randomly assigned to experimental (with topinambur) and control (without topinambur) groups. They were allowed free access to a standard broiler diet without growth-promoting antibiotics. Topinambur treatment resulted in a significant increase (P broilers than for control birds at the ages of 14, 21, 28, and 35 days. These results indicate that a small amount of topinambur in broilers' drinking water has a beneficial effect on growth performance, reduces bacterial endotoxin levels, and suppresses potential pathogens in broilers' ceca.

Exercise and IL-6 infusion inhibit endotoxin-induced TNF-alpha production in humans

DEFF Research Database (Denmark)

Starkie, Rebecca; Ostrowski, Sisse Rye; Jauffred, Sune

2003-01-01

and atherosclerosis. To test this hypothesis, we performed three experiments in which eight healthy males either rested (CON), rode a bicycle for 3 h (EX), or were infused with recombinant human IL-6 (rhIL-6) for 3 h while they rested. After 2.5 h, the volunteers received a bolus of Escherichia coli...... exercise and rhIL-6 infusion at physiological concentrations inhibit endotoxin-induced TNF-alpha production in humans. Hence, these data provide the first experimental evidence that physical activity mediates antiinflammatory activity and suggest that the mechanism include IL-6, which is produced...