Endotoxin Measurement Research Articles

Lessons learned from contamination with endotoxin originated from the supplement in the cell culture medium

IntroductionEndotoxin is a typical pyrogen derived from the outer membrane of Gram-negative bacteria. In fabricating cell-based medicinal products, it is necessary to control endotoxin in the process and the products. In the quality control tests of our clinical study, endotoxin concentration in the culture supernatant of autologous oral mucosal epithelial cell sheets exceeded the criterion value. Therefore, endotoxin measurements were conducted to clarify the cause of the endotoxin contamination. MethodsThe reagents used to prepare the culture medium, the unused culture medium, and the culture supernatants were diluted with pure water. Endotoxin concentrations in the diluted samples were measured. ResultsEndotoxin was detected in both the unused culture medium and the culture supernatant of the epithelial cell sheets at higher concentrations than the criterion value. Therefore, endotoxin concentrations in the reagents used to prepare the culture medium were measured and were found to be below the criterion value, except for cholera toxin. On the other hand, three lots of cholera toxin products were used for the measurement, and the endotoxin concentrations were higher than the criterion value. The results indicate that the endotoxin contamination is caused by the cholera toxin product. ConclusionsTo prevent endotoxin contamination in cell-based medicinal products, endotoxin concentrations in reagents used for the fabrication should be measured in the facility conducting clinical research or confirmed by an adequate certificate of analysis from the manufacturers of the reagents.

There is no association between serum endotoxin levels and inflammation in asthma

Backround Endotoxin, in lipopolysaccharide structure (LPS), is the main component of the outer membrane of gram negative bacteria. LPS levels were associated with inflammatory disease. Asthma is a chronic inflammatory disease involving many different cell types and cellular elements. The association between LPS serum levels and the asthma is not well known. The aim of this study was to investigate the association between the LPS serum levels and the severity of asthma, demographic data and laboratory parameters. Methodology The study included 67 patients aged >18 years with a diagnosis of asthma, and 15 healthy volunteers with no history of chronic disease as a control group. The Asthma Control Test (ACT), Respiratory Function Tests (RFTs), fractional exhaled nitric oxide (FeNO), and endotoxin levels were measured and compared between the groups. The endotoxin measurements were performed using the ELISA method. Results The mild-moderate asthma group included 33 patients and the severe asthma group, 34 patients. The endotoxin level was measured as 17.78 (range 3.59 to 304.55) EU/ml in the patient group and 15 (range 4.01 to 74.06) EU/ml in the control group with no statistically significant difference determined between the groups. In the subgroups, the endotoxin level was measured as 15.21 (range 3.69 to 304.55) EU/ml in the mild-moderate group and 14.46 (range 3.59 to 278.86) EU/ml in the severe asthma group with no statistically significant difference determined between the groups. Conclusion The results of this study showed no relationship between serum endotoxin level and asthma or asthma severity.

Effects of Different Container Types on (1→3)-β-D-glucan Recovery.

It has long been known that containers for sample analysis or storage can play a role in endotoxin recovery and have to be taken into account when determining endotoxin concentrations. However, there is little data on the effects of containers regarding (1→3)-β-D-glucan, which plays a role as a contaminant in endotoxin measurements. To determine the effect of the container on (1→3)-β-D-glucan measurements, four different types of containers were investigated at different temperatures and stored for up to 28 days. For short-term storage for 3 h at room temperature, no effect of the container on the (1→3)-β-D-glucan recovery could be observed, but for storage at -20 °C, the results indicate that the storage time and temperature influences (1→3)-β-D-glucan detection. All containers showed a trend of lower recoveries over time, but the polyethylene container showed a significantly lower recovery compared to the other containers. We also showed that freeze/thaw cycles had a strong influence on the recovery of (1→3)-β-D-glucan in polyethylene containers. Our study showed that the container can affect not only the detection of endotoxins but also the detection of (1→3)-β-D-glucans.

105 Workplace Air Standardisation Projects Related to Biological Agents at European Level : Recent History and Perspectives

Abstract As a significant portion of our time is spend in work places, the occupational exposure is of particular interest for maintaining human health. Within the Technical Committee CEN/TC 137 “Assessment of workplace exposure” the working group named WG5 “Biological Agents” is engaged in the standardization of strategies to assess workplace exposure to bioaerosols. The group already exists since the early 2000s in the European Committee of Standardization (CEN) and was reactivated in 2017 to continue on work items of prevailing interest. Between 2018 and 2021 three standards have been revised and newly published: EN 13098 (general guidelines for measurements), EN 14031 (measurement of airborne endotoxins) and EN 14583 (performance of sampling devices). As the COVID-19 pandemic confirmed, the work on bioaerosols is still important and many questions remain open. Recently, the work group drafted three new topics on which normative documents should be prepared in the future: “the measurement of airborne viruses”, “the measurement of airborne mycotoxins” and “the use of biomolecular methods for the measurement of airborne microorganisms”. As it is still a pressing topic, the work on the new preliminary work items has started with the preparation of a standard on virus measurement. The CEN/TC 137/WG5 has maintained its dynamic over the years and is also encouraging pre-normative researches and networking. The work of the group contributes to a unified approach at the European level on the issue of biological risks assessment and makes it possible to disseminate a better awareness of biological risks.

Investigation of the inhibition of bacteria and endotoxin influx by back filtration through dialyzer membranes.

We investigated the usefulness of assays using human neutrophils for radical production as well as endotoxin (ET) measurement and bacterial culture for endotoxin and bacterial influx by back filtration using dialyzers with different membrane pore diameters. Three types of dialyzers made of cellulose triacetate membrane material with different pore size FB-110EG eco, FB-110U eco, and FB-150UHβ eco were used. A circuit to generate back filtration was created. Back filtrate generated by hydraulic head pressure operation was collected. ET and bacteria were examined. Human neutrophils were exposed to back filtrate (experiments using three different membranes) and contaminated solution, and free radical production was measured using LBP-953 (Berthold) to see if there were differences in production. No bacteria were detected and the concentration of endotoxin was below the detection limit in the back filtrate from the three types of membranes and purified water. Free radical production from neutrophils in the contaminated water was highest at 4,405,750 ± 61,244cpm (counts per minute) (mean ± SD) (P < 0.01 vs FB-150UHβ eco, FB-110U-eco, and FB-110EG eco) followed by that in back filtrate via FB-150UHβ eco, FB-110U-eco, FB-110EG eco. Radical production from neutrophils was thereby higher in the back filtrate of dialyzers with larger pore-size membranes. No bacteria were observed and the concentration of ET was below the detection limit in back filtrate from any of the membranes. However, when the reverse filtrate was exposed to neutrophils, radical production increased along with pore size, suggesting the influx of small pyrogens and other pyrogenic substances.

An optical aptasensor for real-time quantification of endotoxin: From ensemble to single-molecule resolution.

Endotoxin is a deadly pyrogen, rendering it crucial to monitor with high accuracy and efficiency. However, current endotoxin detection relies on multistep processes that are labor-intensive, time-consuming, and unsustainable. Here, we report an aptamer-based biosensor for the real-time optical detection of endotoxin. The endotoxin sensor exploits the distance-dependent scattering of gold nanoparticles (AuNPs) coupled to a gold nanofilm. This is enabled by the conformational changes of an endotoxin-specific aptamer upon target binding. The sensor can be used in an ensemble mode and single-particle mode under dark-field illumination. In the ensemble mode, the sensor is coupled with a microspectrometer and exhibits high specificity, reliability (i.e., linear concentration to signal profile in logarithmic scale), and reusability for repeated endotoxin measurements. Individual endotoxins can be detected by monitoring the color of single AuNPs via a color camera, achieving single-molecule resolution. This platform can potentially advance endotoxin detection to safeguard medical, food, and pharmaceutical products.

Clinical relevance of leukocyte-associated endotoxins measured by semi-automatic synthetic luminescent substrate method

A newly developed semi-automatic synthetic luminescence substrate (SALS) method for measuring endotoxin was compared with the existing turbidimetric kinetic assay (TKA) using leukocyte-rich plasma to verify its usefulness. As a result, the endotoxin levels by this method were higher than that by the existing assay in most specimens, and the time required for measurement was much shorter. In addition, the leukocyte-rich plasma endotoxin level minus the plasma endotoxin levels were named leukocyte-associated endotoxin, and these levels per one leukocyte were compared. As a result, those levels were highly correlated with the endotoxin measurement levels of leukocyte-rich plasma. The correlation coefficient of SALS method was superior to the existing TKA method, the endotoxin level by this method may be close to true endotoxin levels.

Early exposure to farm dust in an allergic airway inflammation rabbit model: Does it affect bronchial and cough hyperresponsiveness?

Over the past 50 years, the prevalence of allergic respiratory diseases has been increasing. The Hygiene hypothesis explains this progression by the decrease in the bio-diversity of early microbial exposure. This study aims to evaluate the effect of early-life farm exposure on airway hyperresponsiveness and cough hypersensitivity in an allergic airway inflammation rabbit model. A specific environment was applied to pregnant rabbits and their offspring until six weeks after birth. Rabbits were housed in a pathogen-free zone for the control group and a calf barn for the farm group. At the end of the specific environmental exposure, both groups were then housed in a conventional zone and then sensitized to ovalbumin. Ten days after sensitization, the rabbit pups received ovalbumin aerosols to provoke airway inflammation. Sensitization to ovalbumin was assessed by specific IgE assay. Cough sensitivity was assessed by mechanical stimulation of the trachea, and bronchial reactivity was assessed by methacholine challenge. The farm environment was characterized by endotoxin measurement. A total of 38 rabbit pups were included (18 in the farm group). Endotoxin levels in the farm environment varied from 30 to 1854 EU.m-3. There was no significant difference in specific IgE values to ovalbumin (p = 0.826) between the two groups. The mechanical threshold to elicit a cough did not differ between the two groups (p = 0.492). There was no difference in the number of cough (p = 0.270) or the intensity of ventilatory responses (p = 0.735). After adjusting for age and weight, there was no difference in respiratory resistance before and after methacholine challenge. Early exposure to the calf barn did not affect cough sensitivity or bronchial reactivity in ovalbumin-sensitized rabbits. These results suggest that not all farm environments protect against asthma and atopy. Continuous exposure to several sources of microbial diversity is probably needed.

Asphyxia-Induced Bacterial Translocation in an Animal Experimental Model in Neonatal Piglets.

The term "bacterial translocation" (BT) refers to the migration of bacteria or their products from the gastrointestinal tract to tissues located outside it, and may occur after intestinal ischemia-reperfusion injury. The term "endotoxin" is synonymous, and is used interchangeably with the term lipopolysaccharide (LPS). LPS, a component of Gram-negative gut bacteria, is a potent microbial virulence factor, that can trigger production of pro-inflammatory mediators, causing localized and systemic inflammation. The aim of this study is to investigate if neonatal asphyxia provokes BT and an increased concentration of LPS in an animal model of asphyxia in piglets. Twenty-one (21) newborn male Landrace/Large White piglets, 1-4 days old, were randomly allocated into three groups, Control (A), Asphyxia (B) and Asphyxia-Cardiopulmonary Resuscitation (CPR) (C). All animals were instrumented, anesthetized and underwent hemodynamic monitoring. In Group A, the animals were euthanized. In Group B, the endotracheal tube was occluded to cause asphyxia leading to cardiopulmonary arrest. In Group C, the animals were resuscitated after asphyxia and further monitored for 30'. Bacterial translocation was assessed by the measurement of endotoxin in blood from the portal vein and the aorta, and also by the measurement of endotoxin in mesenteric lymph nodes (MLNs) at euthanasia. The results are given as median (IQR) with LPS concentration in EU/mL. BT was observed in all groups with minimum LPS concentration in the MLN and maximum concentration in the portal vein. LPS levels in the MLNs were higher in the Group B: 6.38 EU/mL (2.69-9.34) compared to the other groups (Group A: 2.1 EU/mL (1.08-2.52), Group C: 1.66 EU/mL (1.51-2.48), p = 0.012). The aorta to MLNs LPS difference (%) was lower in Group B: 0.13% (0.04-1.17), compared to Group A: 5.08% (2.2-10.7), and Group C: 3.42% (1.5-5.1)) (p = 0.042). The same was detected for portal to MLNs LPS difference (%) which was lower in Group B: 0.94% (0.5-3) compared to Group A: 4.9% (4-15), and Group C: 3.85% (1.5-5.1)) (p = 0.044). Neonatal asphyxia can provoke ΒΤ and increased LPS concentration in blood and tissue located outside the gastrointestinal system.

PD32-10 KIDNEY STONE ENDOTOXIN CONCENTRATION CORRELATES WITH POST-OPERATIVE SEPSIS FOLLOWING PERCUTANEOUS NEPHROLITHOTOMY

You have accessJournal of UrologyCME1 May 2022PD32-10 KIDNEY STONE ENDOTOXIN CONCENTRATION CORRELATES WITH POST-OPERATIVE SEPSIS FOLLOWING PERCUTANEOUS NEPHROLITHOTOMY David T. Tzou, Farhan Anwar, Ava C. Wong, David T. Harris, Thomas Chi, and Gayatri Vedantam David T. TzouDavid T. Tzou More articles by this author , Farhan AnwarFarhan Anwar More articles by this author , Ava C. WongAva C. Wong More articles by this author , David T. HarrisDavid T. Harris More articles by this author , Thomas ChiThomas Chi More articles by this author , and Gayatri VedantamGayatri Vedantam More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002583.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Patients with infected kidney stones are at risk for post-operative sepsis following surgical removal of their calculi. Of all the surgical approaches, percutaneous nephrolithotomy (PCNL) remains associated with the highest risk for experiencing post-operative SIRS (severe inflammatory response syndrome). Accurate prediction of patients at risk for SIRS after surgery would be of clinical value. While previous studies have demonstrated infected kidney stones contain variable levels of endotoxin concentrations, these were limited in their rigor and ability to correlate stone immunobiology with important clinical outcomes. The aim of this study was to quantitate endotoxin levels amongst PCNL patients who experienced and did not experience SIRS. METHODS: Between October 2020 and June 2021, urine & stone specimens from consecutive stone patients were prospectively collected as part of the Registry for Stones of the Kidneys and Ureter (ReSKU) at the University of Arizona. Clinical data including stone analyses and post-operative outcomes have been tracked. Equal weights of stones were uniformly broken using an easy-to-replicate ‘beat-beating’ homogenization approach, allowing for consistent measurement of stone endotoxin using a Pierce™ LAL Chromogenic Endotoxin Quantification Kit (ThermoFisher, Waltham, MA). Endotoxin levels from stones removed during PCNL were compared between patients who experienced and did not experience SIRS. Independent T-test was used to determine statistical significance. RESULTS: Endotoxin levels amongst 4 patients with infection calculi who experienced SIRS were compared to 16 patients who did not experience SIRS – 8 of which had infection calculi and 8 had non-infection calculi (Figure 1). In the SIRS group, the mean Endotoxin concentration was 1.084 endotoxin units (EU)/ml compared to 0.476 EU/ml in the non-SIRS group (p<0.01). CONCLUSIONS: Higher kidney stone bacterial endotoxin concentrations are present in patients who experienced SIRS after percutaneous stone removal compared to those who did not. Whether exceeding a threshold endotoxin level corresponds to patients experiencing SIRS warrants future study. Source of Funding: P30DK081943 – SUBK00015084 - NIH/NIDDK; University of Arizona Health Sciences Career Development Award © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e550 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information David T. Tzou More articles by this author Farhan Anwar More articles by this author Ava C. Wong More articles by this author David T. Harris More articles by this author Thomas Chi More articles by this author Gayatri Vedantam More articles by this author Expand All Advertisement PDF DownloadLoading ...

Effects of systemic inflammation due to hepatic ischemia-reperfusion injury upon lean or obese visceral adipose tissue.

ABSTRACTPurpose:To evaluate how the induction of liver damage by ischemia and reperfusion affects the adipose tissue of lean and obese mice.Methods:Lean and diet-induced obese mice were subjected to liver ischemia (30 min) followed by 6 h of reperfusion. The vascular stromal fraction of visceral adipose tissue was analyzed by cytometry, and gene expression was evaluated by an Array assay and by RT-qPCR. Intestinal permeability was assessed by oral administration of fluorescein isothiocyanate (FITC)-dextran and endotoxemia by serum endotoxin measurements using a limulus amebocyte lysate assay.Results:It was found that, after liver ischemia and reperfusion, there is an infiltration of neutrophils, monocytes, and lymphocytes, as well as an increase in the gene expression that encode cytokines, chemokines and their receptors in the visceral adipose tissue of lean mice. This inflammatory response was associated with the presence of endotoxemia in lean mice. However, these changes were not observed in the visceral adipose tissue of obese mice.Conclusions:Liver ischemia and reperfusion induce an acute inflammatory response in adipose tissue of lean mice characterized by an intense chemokine induction and leukocyte infiltration; however, inflammatory alterations are already present at baseline in the obese adipose tissue and liver ischemia and reperfusion do not injure further.

Improved bioluminescence-based endotoxin measurement method using a salt-resistant luciferase mutant

Endotoxin is a component of the cell wall of gram-negative bacteria and causes fever and shock symptoms upon entering the bloodstream. We previously demonstrated that the bioluminescence-based Limulus amebocyte lysate test is highly sensitive and rapid for measuring endotoxin. However, as the firefly luciferase reaction is inhibited in the presence of sodium chloride, the endotoxin detection method did not meet the validation guidelines under medical dialysis conditions (range of 75–125% of the measured values tested in water). Here, we used a salt-resistant luciferase mutant, which met the criteria for validation of endotoxin measurement.

Endotoxin measurements in the PM10 fraction of ambient air/Endotoxinmessungen in der PM10-Fraktion der Außenluft

As part of the outer cell wall of gram-negative bacteria endotoxins can be found ubiquitous in nature. So far most studies on airborne endotoxins focussed on occupational environments. In Germany IFA-Arbeitsmappe 9450 gives recommendations for sampling and analysis of endotoxins at workplaces. However, apart from background measurements for workplace evaluations, there are currently no guidelines in Germany for endotoxin measurements at environmental settings. Therefore, the aim of this study was to test whether PM10 sampling on filters with a high volume sampler and determination of endotoxin concentration via LAL assay are suitable methods for a new guideline for measurement of endotoxin concentration in ambient air. Over the course of one year endotoxin concentration was investigated at three different rural sampling spots. Annual median endotoxin concentration over all samples was 0.143 EU/m3. Between different sampling spots no significant differences in endotoxin concentrations were observed, yet endotoxin concentration in ambient air showed an obvious seasonal course. The applied methods have proven suitable for the analysis of endotoxins in the outdoor air, although further standardization is needed before implementation in a guideline.

The Antibacterial Potential of Honeydew Honey Produced by Stingless Bee (Heterotrigona itama) against Antibiotic Resistant Bacteria.

Scientific studies about the antibacterial effects of honeydew honey produced by the stingless bee are very limited. In this study, the antibacterial activities of 46 blossom and honeydew honeys produced by both honey bees and stingless bees were evaluated and compared. All bacterial isolates showed varying degrees of susceptibility to blossom and honeydew honeys produced by the honey bee (Apis cerana) and stingless bee (Heterotrigona itama and Geniotrigona thoracica) in agar-well diffusion. All stingless bee honeys managed to inhibit all the isolates but only four out of 23 honey bee honeys achieved that. In comparison with Staphylococcus aureus, Escherichia coli was found to be more susceptible to the antibacterial effects of honey. Bactericidal effects of stingless bee honeys on E. coli were determined with the measurement of endotoxins released due to cell lysis. Based on the outcomes, the greatest antibacterial effects were observed in honeydew honey produced by H. itama. Scanning electron microscopic images revealed the morphological alteration and destruction of E. coli due to the action of this honey. The combination of this honey with antibiotics showed synergistic inhibitory effects on E. coli clinical isolates. This study revealed that honeydew honey produced by H. itama stingless bee has promising antibacterial activity against pathogenic bacteria, including antibiotic resistant strains.

Endotoxin, Food Allergen Sensitization, and Food Allergy: A Complementary Epidemiologic and Experimental Study

A Tsuang, A Grishin, G Grishina. Allergy. 2020;75(3):625–635 The epidemiologic aspect of the study aimed to describe the association between exposure to house dust endotoxin and sensitization to food allergens, while the experimental component compared the measurement of cytokines secreted from peripheral blood mononuclear cells (PBMCs) after stimulation with endotoxin in allergic and nonallergic children. 6963 participants, ages 1 to 84 years, from the 2005–2006 NHANES were included in the epidemiologic study. Twenty-one children (ages 1–19 years) from pediatric clinics at the Mount Sinai Health System with food allergy to either egg, milk or peanut, and healthy controls were included in the experimental study. Dust endotoxin measurement in the household was …

PERIPHERAL BLOOD ENDOTOXIN LEVELS ARE NOT ASSOCIATED WITH SMALL INTESTINAL BACTERIAL OVERGROWTH IN NONALCOHOLIC FATTY LIVER DISEASE WITHOUT CIRRHOSIS.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver disease worldwide. Approximately 20% of individuals with NAFLD develop nonalcoholic steatohepatitis (NASH), which is associated with increased risk of cirrhosis, portal hypertension, and hepatocellular carcinoma. Intestinal microflora, including small intestinal bacterial overgrowth (SIBO), appear to play an important role in the pathogenesis of the disease, as demonstrated in several clinical and experimental studies, by altering intestinal permeability and allowing bacterial endotoxins to enter the circulation. To determine the relationship between SIBO and endotoxin serum levels with clinical, laboratory, and histopathological aspects of NAFLD and the relationship between SIBO and endotoxin serum levels before and after antibiotic therapy. Adult patients with a histological diagnosis of NAFLD, without cirrhosis were included. A comprehensive biochemistry panel, lactulose breath test (for diagnosis of SIBO), and serum endotoxin measurement (chromogenic LAL assay) were performed. SIBO was treated with metronidazole 250 mg q8h for 10 days and refractory cases were given ciprofloxacin 500 mg q12h for 10 days. Overall, 42 patients with a histopathological diagnosis of NAFLD were examined. The prevalence of SIBO was 26.2%. Comparison of demographic and biochemical parameters between patients with SIBO and those without SIBO revealed no statistically significant differences, except for use of proton pump inhibitors, which was significantly more frequent in patients with positive breath testing. The presence of SIBO was also associated with greater severity of hepatocellular ballooning on liver biopsy. Although the sample, as a whole, have elevated circulating endotoxin levels, we found no significant differences in this parameter between the groups with and without SIBO. Endotoxin values before and after antibiotic treatment did not differ, even on paired analysis, suggesting absence of any relationship between these factors. Serum endotoxin levels were inversely correlated with HDL levels, and directly correlated with triglyceride levels. Serum endotoxin levels did not differ between patients with and without SIBO, nor did these levels change after antibacterial therapy, virtually ruling out the possibility that elevated endotoxinemia in non-cirrhotic patients with NAFLD is associated with SIBO. Presence of SIBO was associated with greater severity of ballooning degeneration on liver biopsy, but not with a significantly higher prevalence of NASH. Additional studies are needed to evaluate the reproducibility and importance of this finding in patients with NAFLD and SIBO.

Occupational endotoxin exposure and health effects.

Lipopolysaccharide (LPS), also termed endotoxin, is an integral structural component of the outer membrane of Gram-negative bacteria and has been a focus of bioaerosol research for many years. Endotoxin is nearly ubiquitous in the environment; however, exposure at specific workplaces, such as waste collecting, livestock farming, agriculture, the textile industry has been associated with adverse health effects. The aim of this review is to summarize studies published in the last 10years on endotoxin measurement and health effects due to endotoxin in occupational settings. The search was mainly performed using MEDLINE (Pubmed), focusing on publications related to the determination of endotoxin, inhalative occupational endotoxin exposure, and health effects. The review shows that despite the well-established methods available to measure endotoxin, a global comparison of studies still remains difficult because the details of sampling strategies and exposure assessment are variable and depend on the specific workplace situation. Thus, health-based threshold limit values still cannot be derived on the basis of available data. Since endotoxin is only one component in a heterogeneous bioaerosol mixture, the question remains open on how to evaluate and record the additional effects of the other components. In particular, there is a lack of intervention studies investigating the effectiveness of protective measures with respect to health outcome. In addition, the studies selected in this review show a wide range of endotoxin exposure, even within one industry or sector. The level of exposure seems to depend more on the specific task performed and the way it was performed rather than on the profession or industry itself. The identification of hot spots of exposure, as well as methods of communication on hazards and possible protective measures, seem to remain important tasks in occupational health protection.

Assessment of Post-Resuscitation Intestinal Injury and Timing of Bacterial Translocation in Swine Anaesthetized With Propofol-Based Total Intravenous Anaesthesia.

Introduction and objectivesBacterial translocation (BT) is the passage of viable bacteria or endotoxins from the gastrointestinal lumen to extra-luminal tissues and is usually observed after intestinal ischaemia-reperfusion injury. The aim of this study was to investigate post-resuscitation BT after cardiac arrest and resuscitation in a swine anaesthetized with propofol-based total intravenous anaesthesia.Materials and methodsEighteen female Landrace/Large White piglets were randomly divided into control (CON), cardiac arrest (CA) and cardiac arrest-cardiopulmonary resuscitation (CA-CPR) groups. In the CON group, the animals were only monitored for two hours. In the CA group, the animals were not resuscitated and underwent necropsy immediately after cardiac arrest. In the CA-CPR group, the animals were resuscitated until the return of spontaneous circulation (ROSC) and were monitored for two hours. The animals of the CON and CA-CPR groups underwent necropsy 24 hours later. Bacterial translocation was assessed by blood and tissue cultures and endotoxin measurement in the portal and systemic circulation. Malondialdehyde content calculation and histological analysis of the intestine were performed in order to estimate ischemia and reperfusion (I/R) tissue damage.Results Malondialdehyde content, an indicator of oxidative stress, was significantly higher in the CA-CPR group compared to the CA in homogenized ileum (p=0.016). Malondialdehyde content in homogenized colon revealed significantly higher levels in the CA-CPR group compared to the CON (p=0.004) and the CA group (p=0.016). We found significantly higher levels of portal endotoxin in the CA-CPR group compared to the CON (p=0.026) and the CA group (p=0.026). The number of positive mesenteric lymph nodes cultures for E. coli was greater in the CA-CPR group, followed by the CA and CON groups, although the difference was not significant (67%, 33%, and 33%, respectively; p=0.407).ConclusionsMalondialdehyde content and portal endotoxin levels do not increase during the cardiac arrest interval, but only after CPR and ROSC. Although the number of positive MLNs cultures was greater in the CA-CPR animals, no statistically significant differences were observed between the three groups due to the short monitoring period.

House dust endotoxin, asthma and allergic sensitization through childhood into adolescence.

BackgroundHouse dust endotoxin may have beneficial effects on allergic sensitization and asthma in children. Evidence is scarce for adolescents and most studies so far have been cross‐sectional and limited to a single exposure measurement.ObjectiveWe assessed associations of house dust endotoxin with asthma and allergic sensitization from birth to age 17 years longitudinally taking into account exposure early in life and at primary school age.MethodsWe used data of 854 participants of the prospective Dutch PIAMA birth cohort study with house dust endotoxin measurements at 3 months and/or 5‐6 years and data on asthma and/or allergic sensitization from at least one of 11 follow‐ups until age 17. We assessed overall and age‐specific associations of the prevalence of asthma and sensitization with mattress and living room floor dust concentrations (per gram of dust) and loads (per m2 of sampling surface).ResultsHigher living room floor dust endotoxin concentrations at 3 months were associated with lower odds of asthma until age 4 [odds ratio (95% confidence interval) ranging from 0.70 (0.51‐0.97) at age 1 to 0.76 (0.57‐1.00) at age 3 per interquartile range increase], but not thereafter in children of allergic mothers. Higher living room floor dust endotoxin at 5‐6 years was associated with higher odds of sensitization at 8‐16 years [eg odds ratio (95% confidence interval) 1.70 (1.17‐2.47) per interquartile range increase in endotoxin load].Conclusions and clinical relevanceHouse dust endotoxin may have beneficial effects on asthma in preschool children of allergic mothers, which do not persist into adolescence. Beneficial associations with allergic sensitization could not be confirmed.

A dextran-based warming method for preparing leukocyte-rich plasma and its clinical application for endotoxin assay.

We devised a method using dextran for obtaining leukocyte-rich plasma (LRP) to measure endotoxin in blood. In order to find the optimal temperature for obtaining LRP, the measurement results were examined using samples prepared at 37 and 0°C. Sample separation time of LRP was significantly shorter at 37°C than at 0°C. Endotoxin measurement values showed a strong correlation between the two groups but many of the LRPs made at 37°C had measurements above those of the LRPs prepared at 0°C. The diagnostic accuracy for gram-negative bacterial infection was superior for LRP prepared at 37°C, with sensitivity and specificity of 96.8 and 100%, respectively.