Effects Of Endotoxin Research Articles

Changes in the Tissue Barrier after Exposure to Lipopolysaccharide on the Apical Side of Enterocytes and the Follicle-Associated Epithelium in Peyer's Patches of the Rat Intestine.

To study the para- and transcellular permeability of columnar epithelium and follicle-associated epithelium of Peyer's patches in the rat intestine, LPS was applied from the mucosal side to simulate the action of endotoxins from gram-negative bacteria of gut microbiota. LPS did not affect transepithelial resistance or sodium fluorescein permeability, but increased the levels of claudin-3 and claudin-4 in enterocytes, suggesting strengthening of the paracellular intestinal barrier. Transcellular permeability was evaluated by electron microscopy based on the number of vesicular structures in the cytoplasm of different cell types. LPS increased the number of small vesicles in follicle-associated epithelium of Peyers' patches. In columnar epithelial cells, LPS reduced the number of smaller vesicles and increased the number of larger ones. LPS did not damage the tissue barrier, but enhanced transcytosis, which could potentiate the effects of endotoxin on its receptors in the intestinal mucosa.

Lipidomics Analysis of Human HMC3 Microglial Cells in an In Vitro Model of Metabolic Syndrome.

Metabolic endotoxemia (ME) is associated with bacterial lipopolysaccharide (LPS, endotoxin) and increased levels of saturated fatty acids (SFAs) in the bloodstream, causing systemic inflammation. ME usually accompanies obesity and a diet rich in fats, especially SFAs. Numerous studies confirm the effect of ME-related endotoxin on microglial activation. Our study aimed to assess lipid metabolism and immune response in microglia pre-stimulated with TNFα (Tumor Necrosis Factor α) and then with endotoxin and palmitic acid (PA). Using ELISA, we determined cytokines IL-1β, IL-10, IL-13 (interleukin-1β, -10, -13, and TGFβ (Transforming Growth Factor β) in the culture medium from microglial cells stimulated for 24 h with TNFα and then treated with LPS (10 ng/mL) and PA (200 µM) for 24 h. HMC3 (Human Microglial Cells clone 3) cells produced negligible amounts of IL-1β, IL-10, and IL-13 after stimulation but secreted moderate levels of TGFβ. Changes in lipid metabolism accompanied changes in TREM2 (Triggering Receptor Expressed on Myeloid Cells 2) expression. HMC3 stimulation with endotoxin increased TREM2 expression, while PA treatment decreased it. Endotoxin increased ceramide levels, while PA increased triglyceride levels. These results indicated that pre-stimulation of microglia with TNFα significantly affects its interactions with LPS and PA and modulates lipid metabolism, which may lead to microglial activation silencing and neurodegeneration.

A cross-sectional study on occupational hygiene in biowaste plants.

Recycling demands are increasing and new biowaste plants are established. The aim of this study is to obtain knowledge about occupational hygiene in biowaste pretreatment plants. At 6 plants, bioaerosol exposure, hand hygiene, and bioaerosol concentrations in work areas were investigated repeatedly. The total inflammatory potential (TIP) of exposures was measured using the human HL-60 cell line. Exposure to airborne bacteria, bacteria able to grow anaerobic, fungi(37°C), endotoxin, and TIP differed between plants and was lowest in a plant transporting waste in closed pipes compared to plants where waste was delivered on the receiving hall floor. Conversely, high exposures were measured in a plant that also processes compost. All microbial components had an impact on TIP of workers' exposure with main effects of fungi and endotoxin. Seasonality was found for several exposures and TIP, and they were lowest in the winter. Concentrations of bacteria and fungi on workers' hands at the end of the workday were 15 times higher for production than for nonproduction workers. In work areas, the concentrations of airborne fungi were highest in the waste-receiving area. Bacteria (3.2 µm) and anaerobic bacteria (4.0 µm) were present as larger airborne particles than fungi (2.8 µm), and bacteria were largest in the waste-receiving area. The microbial community compositions of exposures and work areas differed between plants and work areas. In conclusion, measures to reduce exposure should focus on the waste-receiving area and on the production workers. Differences in exposures and community compositions were found between seasons, work areas, work groups, and plants.

Mitigating lipopolysaccharide-induced impairment in human dental pulp stem cells with tideglusib-doped nanoparticles: Enhancing osteogenic differentiation and mineralization

ObjectiveDrug-loaded non-resorbable polymeric nanoparticles (NPs) are proposed as an adjunctive treatment for pulp regenerative strategies. The present in vitro investigation aimed to evaluate the effectiveness of tideglusib-doped nanoparticles (TDg-NPs) in mitigating the adverse effects of bacterial lipopolysaccharide endotoxin (LPS) on the viability, morphology, migration, differentiation and mineralization potential of human dental pulp stem cells (hDPSCs). MethodsCell viability, proliferation, and differentiation were assessed using a MTT assay, cell migration evaluation, cell cytoskeleton staining analysis, Alizarin Red S staining and expression of the odontogenic related genes by a real-time quantitative polymerase chain reaction (RT-qPCR) were also performed. Cells were tested both with and without stimulation with LPS at various time points. One-way ANOVA and Tukey's test were employed for statistical analysis (p < 0.05). ResultsAdequate cell viability was encountered in all groups and at every tested time point (24, 48, 72 and 168 h), without differences among the groups (p > 0.05). The analysis of cell cytoskeleton showed nuclear alteration in cultures with undoped NPs after LPS stimulation. These cells exhibited an in blue diffuse and multifocal appearance. Some nuclei looked fragmented and condensed. hDPSCs after LPS stimulation but in the presence of TDg-NPs exhibited less nuclei changes. LPS induced down-regulation of Alkaline phosphatase, Osteonectin and Collagen1 gene markers, after 21d. LPS half-reduced the cells production of calcium deposits in all groups (p < 0.05), except in the group with TDg-NPs (decrease about 10 %). SignificanceLPS induced lower mineral deposition and cytoskeletal disorganization in hDPSCs. These effects were counteracted by TDg-NPs, enhancing osteogenic differentiation and mineralization.

Metabolic Endotoxemia: From the Gut to Neurodegeneration.

Metabolic endotoxemia is a severe health problem for residents in developed countries who follow a Western diet, disrupting intestinal microbiota and the whole organism's homeostasis. Although the effect of endotoxin on the human immune system is well known, its long-term impact on the human body, lasting many months or even years, is unknown. This is due to the difficulty of conducting in vitro and in vivo studies on the prolonged effect of endotoxin on the central nervous system. In this article, based on the available literature, we traced the path of endotoxin from the intestines to the blood through the intestinal epithelium and factors promoting the development of metabolic endotoxemia. The presence of endotoxin in the bloodstream and the inflammation it induces may contribute to lowering the blood-brain barrier, potentially allowing its penetration into the central nervous system; although, the theory is still controversial. Microglia, guarding the central nervous system, are the first line of defense and respond to endotoxin with activation, which may contribute to the development of neurodegenerative diseases. We traced the pro-inflammatory role of endotoxin in neurodegenerative diseases and its impact on the epigenetic regulation of microglial phenotypes.

Characterization of airborne endotoxin in personal exposure to fine particulate matter (PM2.5) and bioreactivity for elderly residents in Hong Kong

The heavy metals and bioreactivity properties of endotoxin in personal exposure to fine particulate matter (PM2.5) were characterized in the analysis. The average personal exposure concentrations to PM2.5 were ranged from 6.8 to 96.6 μg/m3. The mean personal PM2.5 concentrations in spring, summer, autumn, and winter were 32.1±15.8, 22.4±11.8, 35.3±11.9, and 50.2±19.9 μg/m3, respectively. There were 85 % of study targets exceeded the World Health Organization (WHO) PM2.5 threshold (24 hours). The mean endotoxin concentrations ranged from 1.086 ± 0.384–1.912 ± 0.419 EU/m3, with a geometric mean (GM) varied from 1.034 to 1.869. The concentration of iron (Fe) (0.008–1.16 μg/m3) was one of the most abundant transition metals in the samples that could affect endotoxin toxicity under Toll-Like Receptor 4 (TLR4) stimulation. In summer, the interleukin 6 (IL-6) levels showed statistically significant differences compared to other seasons. Spearman correlation analysis showed endotoxin concentrations were positively correlated with chromium (Cr) and nickel (Ni), implying possible roles as nutrients and further transport via adhering to the surface of fine inorganic particles. Mixed-effects model analysis demonstrated that Tumor necrosis factor-α (TNF-α) production was positively associated with endotoxin concentration and Cr as a combined exposure factor. The Cr contained the highest combined effect (0.205–0.262), suggesting that Cr can potentially exacerbate the effect of endotoxin on inflammation and oxidative stress. The findings will be useful for practical policies for mitigating air pollution to protect the public health of the citizens.

Effects of the combined exposure to chemicals and unusual working hours.

Both exposure to occupational chemicals and to unusual working hours have well documented effects on health. Determination of occupational exposure limits is, however, usually based on chemical-only exposure and assumes an 8-h workday, 5 days/week and a 40-h work week. A significant proportion of the workforce is exposed to chemicals while working in other work schedules. This review thus aimed to synthesize and evaluate the scientific support for a combined effect of unusual working hours and chemical exposure and, if possible, give recommendations for OEL adjustments to account for unusual working hours. The search for articles was made as part of the preparation of a report for the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals. In this report, unusual working hours were categorized as shift work or extended (>8h) working hours. Inclusion criteria were observational studies in the English language published up to November 2021 in peer-reviewed journals, with explicit metrics of exposure (chemicals and unusual working hours) and of health outcome, and which explicitly tested the association between exposure and outcome. Search engines of seven databases were used. Of the initially 15 400 identified papers, 9 studies published between 1985 and 2021 met the inclusion criteria, 7 of which showed significant associations. Results from a few of the studies, i.e. regarding effects of dust and endotoxin on lung function, effects of acetone on sleep quality and tiredness, effects of carbon disulphide on coronary artery disease and effects of chemicals on spontaneous abortion, suggested more pronounced effects during night shifts compared to during day shifts. The reviewed data is considered insufficient to conclude on recommendations for OEL adjustment for shift work. Suggested areas of future studies are mentioned. Further studies about the effects of the combined exposure to unusual working hours and chemical exposure are essential for risk assessment, and for recommendation of potential OEL adjustments. What is important about this paper? Effects of chemical agents at the workplace may depend not only on exposure level and duration but also on the time of exposure in relation to the circadian rhythm. This study reviewed the scientific support for a combined effect of unusual working hours and chemical exposure and revealed an obvious need for additional studies regarding the complex interplay of the two different exposures with respect to adverse health effects.

185 Maternal live yeast supplementation protects newly weaned piglets against lipopolysaccharide challenge by regulating immune-associated milk proteins

Abstract Sow milk serves as a crucial source of nutritional, immunological, and growth-promoting components for the piglets. Our previous studies established that maternal live yeast (LY) supplementation altered the expression of antioxidant and immune-regulatory genes in the intestinal mucosa of suckling piglets. The current study aimed to investigate the effects of maternal LY supplementation during late gestation and lactation on milk proteomic profile in dams and health of offspring under lipopolysaccharide (LPS) challenge. On d 77 of gestation, 40 sows were allocated to 2 dietary treatments: without (CON) or with LY supplementation at 0.05% of diet during gestation and 0.1% during lactation. Milk samples were collected on d 0, 10, and 18 post-partum (n = 6), respectively. Within 24 h postweaning, piglets from the CON and LY groups were intraperitoneally injected with sterile saline or LPS [25 μg/kg body weight (BW)] and divided into four groups (n = 8): 1) saline + CON (CS), 2) saline + LY (YS), 3) LPS + CON (CLPS), and 4) LPS + LY (YLPS). Data were analyzed in a 2 × 2 factorial arrangement with main effects of maternal diet and immunological challenge. Rectal temperature was measured hourly for 4 h post-injection after which piglets were euthanized. Results showed that LPS increased concentrations of serum tumor necrosis factor (TNF) -α and interlekin (IL) -10 (P &amp;lt; 0.05) and tended to increase IL-8 in the ileal mucosa of piglets (P &amp;lt; 0.10). At 3 h post-injection, YLPS piglets tended to have a lower rectal temperature than CLPS piglets (P &amp;lt; 0.10). YLPS piglets also had decreased protein levels of TNF-α in the ileal mucosa (P &amp;lt; 0.05), with a tendency for greater protein abundance of E-cadherin but decreased mRNA abundance of catalase (P &amp;lt; 0.10) in the jejunal mucosa at 4 h post-injection (P &amp;lt; 0.05). In addition, YLPS piglets had less mRNA abundance of TLR2 and TLR4 in the liver than CLPS piglets (P &amp;lt; 0.05). With shotgun proteomics analysis, we found that milk of LY sows had more abundant proteins associated with immunity, including immunoglobulin and complement protein (Ig-like and C1q domain-containing proteins) on d 0 and d 10. Insulin-like growth factor binding protein (IGFBP) 5 was also more abundant in the d 0 milk of LY sows, whereas prostaglandin synthase was greater in d 10 and d 18 milk of CON sows. Additionally, pathway analysis showed that proteins identified in the milk of CON sows have roles in neutrophil degranulation and IL-12 signaling and production, whereas pathways associated with regulation of complement system, IGF and DHCR24 signaling, were enriched in the milk of LY sows. These results suggest that maternal LY supplementation could protect newly weaned piglets from bacteria endotoxin effect by suppressing inflammatory response, improving expression of tight junction proteins in offspring, and altering immune-associated proteins in sow milk.

Involvement of heart-gut axis in endocannabinoid CB1R signaling following alcohol binge

Introduction: Binge alcohol drinking is linked to an increasing number of emergency room visits and rising healthcare costs. We have recently shown that binge alcohol drinking is associated with the activation of cannabinoid receptor type-1 (CB1R) signaling, aggravating binge alcohol-induced cardiovascular dysfunction. The endogenous CB1R agonist, anandamide (AEA), can form in response to various stimuli including increased levels of circulating endotoxins derived from intestinal Gram-negative bacteria. Besides, increased levels of serum endotoxins can also provoke the activation of innate immune cells. However, it is still unclear if how AEA is formed in the cardiovascular system. Here, we studied the effect of intestinal Gram-negative bacteria-derived endotoxins on myocardial CB1R activation and aimed to identify the cellular source of AEA after alcohol binge. Methods: 8-12 week old C57BL/6J mice were orally administered a single ethanol binge at a dose of 5g/kg body weight, with or without prior treatment with non-absorbable antibiotics. Circulating endotoxins were assessed following alcohol binge. Intestinal-barrier permeability was assayed by using FITC-Dextran administration. Myocardial tissue endocannabinoid levels were measured by LC/MS. Immunostaining approaches were applied to determine the rate of oxidative stress in the myocardium. Left ventricle performance was assessed by using a pressure-volume catheterization approach. Tissue perfusion was also evaluated by laser speckle contrast imaging. Results: Alcohol gavage was associated with a time-dependent increase of serum endotoxins peaking 3h after intoxication. Selective intestinal decontamination significantly improved the gut barrier function following alcohol gavage which was concomitant with the decreased myocardial oxidative stress. Simultaneously, reduced levels of myocardial AEA and cardiovascular performance improvement were observed. Conclusion: Our findings underscore the potential role of Gram-negative flora derived substances in the modulation of cardiovascular endocannabinoid AEA levels following alcohol binge drinking, impacting cardiac function and oxidative stress. Supported by Intramural Research Program of NIH/NIAAA; R00AA028300, LSUHSC start-up funds. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The immunostimulatory activity of sea spray aerosols: bacteria and endotoxins activate TLR4, TLR2/6, NF-κB and IRF in human cells

Frequent exposure to sea spray aerosols (SSA) containing marine microorganisms and bioactive compounds may influence human health. However, little is known about potential immunostimulation by SSA exposure. This study focuses on the effects of marine bacteria and endotoxins in SSA on several receptors and transcription factors known to play a key role in the human innate immune system. SSA samples were collected in the field (Ostend, Belgium) or generated in the lab using a marine aerosol reference tank (MART). Samples were characterized by their sodium contents, total bacterial counts, and endotoxin concentrations. Human reporter cells were exposed to SSA to investigate the activation of toll-like receptor 4 (TLR4) in HEK-Blue hTLR4 cells and TLR2/6 in HEK-Blue hTLR2/6 cells, as well as the activation of nuclear factor kappa B (NF-κB) and interferon regulatory factors (IRF) in THP1-Dual monocytes. These responses were then correlated to the total bacterial counts and endotoxin concentrations to explore dose-effect relationships. Field SSA contained from 3.0 × 103 to 6.0 × 105 bacteria/m3 air (averaging 2.0 ± 1.9 × 105 bacteria/m3 air) and an endotoxin concentration ranging from 7 to 1217 EU/m3 air (averaging 389 ± 434 EU/m3 air). In contrast, MART SSA exhibited elevated levels of total bacterial count (from 2.0 × 105 to 2.4 × 106, averaging 7.3 ± 5.5 × 105 cells/m3 air) and endotoxin concentration from 536 to 2191 (averaging 1310 ± 513 EU/m3 air). SSA samples differentially activated TLR4, TLR2/6, NF-κB and IRF. These immune responses correlated dose-dependently with the total bacterial counts, endotoxin levels, or both. This study sheds light on the immunostimulatory potential of SSA and its underlying mechanisms, highlighting the need for further research to deepen our understanding of the health implications of SSA exposure.

Exploring the Gut-Mitochondrial Axis: p66Shc Adapter Protein and Its Implications for Metabolic Disorders.

This review investigates the multifaceted role of the p66Shc adaptor protein and the gut microbiota in regulating mitochondrial function and oxidative stress, and their collective impact on the pathogenesis of chronic diseases. The study delves into the molecular mechanisms by which p66Shc influences cellular stress responses through Rac1 activation, Forkhead-type transcription factors inactivation, and mitochondria-mediated apoptosis, alongside modulatory effects of gut microbiota-derived metabolites and endotoxins. Employing an integrative approach, the review synthesizes findings from a broad array of studies, including molecular biology techniques and analyses of microbial metabolites' impacts on host cellular pathways. The results underscore a complex interplay between microbial metabolites, p66Shc activation, and mitochondrial dysfunction, highlighting the significance of the gut microbiome in influencing disease outcomes through oxidative stress pathways. Conclusively, the review posits that targeting the gut microbiota-p66Shc-mitochondrial axis could offer novel therapeutic strategies for mitigating the development and progression of metabolic diseases. This underscores the potential of dietary interventions and microbiota modulation in managing oxidative stress and inflammation, pivotal factors in chronic disease etiology.

Abstract A016: Reprogramming of immune-enhancing neutrophils by subclinical low-dose endotoxin for the treatment of cancer

Abstract Despite the recent resurgence of the pioneering concept of “Coley’s toxin” in ushering in anti-cancer immune therapies highlight by check-point inhibitors and CAR-T approaches, fundamental mechanisms responsible for the immune-enhancing efficacy of innate low-dose “Coley’s toxin” remain poorly understood. This study aims to reveal the novel reprogramming of immune-enhancing neutrophils by super-low dose endotoxin conducive for innate immunity-based anti-cancer therapies. We perform scRNAseq analyses and reveal that neutrophils trained by super-low dose endotoxin (SL-LPS) adopt a unique immune-enhancing cluster characterized by CD177loCD11BloCD80hiCD40hi. Transfusion of SL-LPS trained neutrophils into recipient mice with AOM/DSS-inducing colorectal tumors exhibit potent efficacy in reducing tumor burden. SL-LPS trained neutrophils show relieved suppression of adaptive T cells as compared to un-trained neutrophils in vivo and in vitro. Mechanistically, SL-LPS enables the generation of immune-enhancing neutrophils through activating STAT5 and reducing innate suppressor IRAK-M. Herein, we present evidence revealing the key principle that underlying the immune-enhancing effects of super-low dose endotoxin, unrevealing the long-held mystery of low-dose “Coley’s toxin” in generically boosting host anti-tumor defense. Our mechanistic and translational observations not only reveal fundamental mechanisms for re-programming immune-enhancing neutrophils, but also provide a proof-of-principle in developing innate neutrophil-based anti-tumor therapeutics. Citation Format: Yao Zhang, Liwu Li. Reprogramming of immune-enhancing neutrophils by subclinical low-dose endotoxin for the treatment of cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A016.

Immune challenge affects reproductive behaviour in the guppy (Poecilia reticulata).

Immunocompetence and reproduction are among the most important determinants of fitness. However, energetic and metabolic constraints create conflict between these two life-history traits. While many studies have explored the relationship between immune activity and reproductive fitness in birds and mammals inoculated with bacterial endotoxin, very few have focused on fish. Fish have been neglected in this area due, in part, to the claim that they are largely resistant to the immune effects of endotoxins. However, the present study suggests that they are susceptible to significant effects with respect to reproductive behaviour. Here, we examined the reproductive behaviour of male guppies following exposure to bacterial lipopolysaccharides (LPS) in comparison to that of male guppies in a control treatment. Additionally, we investigated the responses of females to these males. We show that although immune challenge does not suppress general activity in male guppies, it significantly reduces mating effort. While females showed no difference in general activity as a function of male treatments, they did exhibit reduced group cohesion in the presence of LPS-exposed males. We discuss this in the context of sickness behaviours, social avoidance of immune-challenged individuals and the effects of mounting an immune response on reproductive behaviour.

A Comparative Proteomic Analysis to Explore the Influencing Factors on Endometritis Using LC-MS/MS.

The inflammatory system activated by uterine infection is associated with decreased fertility. Diseases can be detected in advance by identifying biomarkers of several uterine diseases. Escherichia coli is one of the most frequent bacteria that is involved in pathogenic processes in dairy goats. The purpose of this study was to investigate the effect of endotoxin on protein expression in goat endometrial epithelial cells. In this study, the LC-MS/MS approach was employed to investigate the proteome profile of goat endometrial epithelial cells. A total of 1180 proteins were identified in the goat Endometrial Epithelial Cells and LPS-treated goat Endometrial Epithelial Cell groups, of which, 313 differentially expressed proteins were accurately screened. The proteomic results were independently verified by WB, TEM and IF techniques, and the same conclusion was obtained. To conclude, this model is suitable for the further study of infertility caused by endometrial damage caused by endotoxin. These findings may provide useful information for the prevention and treatment of endometritis.

Establishing Heterologous Production of Microcins J25 and Y in Bacillus subtilis

Microcin J25 (MccJ25) and microcin Y (MccY) are lasso peptides and considered potential alternatives to antibiotics and harmful preservatives. The combination of these two microcins can provide a wide antimicrobial spectrum against food-borne Salmonella. Currently, MccJ25 and MccY are produced using Escherichia coli expression systems; however, the entire production process is accompanied by negative effects from endotoxins. In this study, we identified Bacillus subtilis as a suitable host for MccJ25 and MccY production. High-level production of microcins was achieved by promoter optimization, host strain selection, and recombinant expression. The engineered strains produced maximum yields of 2.827 μM MccJ25 and 1.481 μM MccY. This is the first study to demonstrate the expression of MccJ25 and MccY in B. subtilis, and it offers a few engineered strains that are without antibiotic resistance markers, inducer-free, sporulation-deficient, and free of the negative effects of endotoxins for antibacterial therapy and food preservation.

LPS Administration during Fertilization Affects Epigenetic Inheritance during Embryonic Development.

Intrauterine inflammation can cause infertility by disrupting reproductive function. The pathogenesis underlying this process may primarily involve endotoxins from lipopolysaccharides (LPS), which are produced by Gram-negative bacteria. However, the long-term effects of endotoxins in mammalian pregnancy following LPS exposure during fertilization have not been clarified. In this study, we performed experiments to analyze the influence of LPS on early embryonic development and fetal development in mice. Mice uteruses were examined for the expression of genes related to the inflammatory response. The expression of Il-1β and Il-6 increased following the administration of 200 and 1000 µg/kg LPS. Exposure to LPS using in vitro fertilization (IVF) significantly decreased the embryonic developmental rate. A concentration of 100 µg/kg LPS significantly increased the placental weight and fetal crown -rump length (CRL), whereas a concentration of 200 µg/kg LPS significantly decreased the placenta weight and fetal weight in vivo. These findings indicate that maternal LPS during fertilization affects fetal development until the late stage of pregnancy. Thus, maternal endotoxins may affect epigenetic inheritance during embryonic development from the early to late stages of pregnancy.

ACETAMINOPHEN ATTENUATES PULMONARY VASCULAR RESISTANCE AND PULMONARY ARTERIAL PRESSURE AND INHIBITS CARDIOVASCULAR COLLAPSE IN A PORCINE MODEL OF ENDOTOXEMIA.

Acetaminophen (paracetamol) is often used in critically ill patients with fever and pain; however, little is known about the effects of acetaminophen on cardiovascular function during systemic inflammation. Here, we investigated the effect of acetaminophen on changes in the systemic and pulmonary circulation induced by endotoxin (0.5 μg/kg per hour) in anesthetized pigs. Endotoxin infusion led to a rapid increase in pulmonary artery pressure and pulmonary vascular resistance index. Acetaminophen delayed and attenuated this increase. Furthermore, acetaminophen reduced tachycardia and decreased stroke volume, accompanied by systemic inflammation, without affecting inflammatory parameters such as white blood cell count and TNF-α in blood. As a proof of concept, we injected a high dose of endotoxin (100 μg), which induced rapid cardiovascular collapse in pigs. Pigs treated with acetaminophen survived with no obvious hemodynamic instability during the 50-min observation period. In conclusion, acetaminophen attenuates the effects of endotoxin on pulmonary circulation in anesthetized pigs. This may play a role in severe systemic inflammation.

Design of AgNPs doped chitosan/sodium lignin sulfonate/polypyrrole films with antibacterial and endotoxin adsorption functions

There is an urgent need to develop materials to prevent bacterial infection and the deleterious effects of endotoxins. In this study, we introduce a one-step electrodeposition method to prepare films composed of chitosan/Ag/polypyrrole and layer-by-layer self-assembly to introduce lignin sulphonate (LS) to obtain chitosan/Ag/polypyrrole/LS films. Antibacterial effects against both E. coli and S. aureus are shown by bacterial growth profiles and observation of bacteriostatic zones. Meanwhile, the addition of self-assembled LS improved the antibacterial effect of the film. For E. coli, the inhibition zone diameter was 0.93 cm, while for S. aureus, the inhibition zone diameter was 0.72 cm. Rapid and efficient endotoxin adsorption effects were shown whereby the electrostatic interactions between chitosan and endotoxin molecules played a major role. After adsorption for 1 h, in initial concentration of 1 EU/mL endotoxin solution, the adsorption efficiency could reach up to 85 %, while in initial concentration of 5 EU/mL endotoxin solution, the adsorption efficiency could reach up to 87.6 %. The results suggest chitosan/Ag/polypyrrole/LS films for their capability as a new type of antibacterial film with intrinsic endotoxin adsorption activity.

Characterization of Trypsin-like Serine Proteases from Tachypleus tridentatus Amebocyte Lysate and its Potential for Endotoxin Detection

Background: Serine Proteases in the Tachypleus Amoebocyte Lysate (TAL) from horseshoe crab, Tachpleus tridentatus have many applications in biomedical industries. The sensitivity of these enzymes is a crucial factor for such usages. Until today, the catalytic behavioural and biochemical stability of these enzymes has not been properly addressed. This report aimed to characterize the physicochemical properties of serine proteases to determine their kinetic reactions and to determine the potential utilization of the enzymes for endotoxin detection. Methods: The purification process of protease from crude TAL was performed using a two-phase filtration unit by affinity and gel columns and the molecular weights of the enzyme fraction from crude, affinity and gel filtration columns were determined. The Azocasein, Aldolase and transaldolase assays were used for the determination of the enzyme Catalysis. The chromogenic assay was carried out to determine the bacterial endotoxin effects using a standard endotoxin from strain Escherichia coli 0113: H10 as a positive control. The absorbance was measured at 405 nm. The enzyme activity was determined using the constructed p-nitroanilide standard curve. Result: A 72 kDa trypsin-like enzyme was purified at fraction-14 (F14) gel filtration and identified as transaldolase. The purified-F14 hydrolysed trypsin substrate, Ná-Benzoyl-L-Arginine-p-nitroanilide at higher activity than chymotrypsin. In conclusion, the purified enzyme showed a great potential for enhancing the TAL sensitivity.

Hyaluronic acid hydrolysis using vacuum ultraviolet TiO2 photocatalysis combined with an oxygen nanobubble system

Advanced technologies for producing high-quality low molecular weight hyaluronic acid (LMW-HA) are required from the perspective of cost-efficiency and biosafety. Here, we report a new LMW-HA production system from high molecular weight HA (HMW-HA) using vacuum ultraviolet TiO2 photocatalysis with an oxygen nanobubble system (VUV-TP-NB). The VUV-TP-NB treatment for 3 h resulted in a satisfactory LMW-HA (approximately 50 kDa measured by GPC) yield with a low endotoxin level. Further, there were no inherent structural changes in the LMW-HA during the oxidative degradation process. Compared with conventional acid and enzyme hydrolysis methods, VUV-TP-NB showed similar degradation degree with viscosity though reduced process time by at least 8-fold. In terms of endotoxin and antioxidant effects, degradation using VUV-TP-NB demonstrated the lowest endotoxin level (0.21 EU/mL) and highest radical scavenging activity. This nanobubble-based photocatalysis system can thus be used to produce biosafe LMW-HA cost-effectively for food, medical, and cosmetics applications.