Endotoxins are common exogenous pyrogens. Excessive endotoxins in medical devices and injections can lead to serious consequences such as sepsis, septic shock, and even death. Therefore, endotoxin detection plays a crucial role in medical, pharmaceutical, and food sectors. The wide application of Limulus amebocyte lysate (LAL) has led to a sharp decline in the number of horseshoe crabs. Moreover, the LAL assay has limitations such as interbatch variations and difficulty in quantification. The recombinant factor C (rFC) assay is stable between batches, highly sensitive, and capable of quantitation, and thus it can be used as an alternative for the LAL assay. However, the high cost and complex procedures involved in producing recombinant factor C have limited the widespread application of this method. In order to simplify the preparation and reduce the production cost of recombinant factor C, this study focuses on the production of recombinant factor C based on the baculovirus expression system. Multiple measures such as a high-yield and anti-apoptotic vector qBac-IIIG, the optimal signal peptide, and the optimized codon were used to reach the goal of endotoxin detection with cell supernatant. This method simplifies the steps of protein purification. The sensitivity of the supernatant reached 0.05 EU/mL in a 1-L fermentation system, and 500 000 detecting reactions can be supported per liter of fermentation broth. This study increases the yield and activity of recombinant factor C, simplifies the procedures of protein purification, and reduces the cost, laying a foundation for the promotion and application of recombinant factor C in endotoxin detection.
Animals ; Recombinant Proteins/genetics* ; Horseshoe Crabs/chemistry* ; Baculoviridae/metabolism* ; Endotoxins/analysis* ; Protein C/biosynthesis* ; Genetic Vectors/genetics* ; Arthropod Proteins/genetics* ; Enzyme Precursors ; Serine Endopeptidases

BACKGROUND: The health effects of biological aerosols on the respiratory system are unclear. The purpose of this study was to clarify the association of airborne particle, protein, and endotoxin with emergency department visits for asthma in Kyoto City, Japan. METHODS: We collected data on emergency department visits at a hospital in Kyoto from September 2014 to May 2016. Fine (aerodynamic diameter ≤ 2.5 μm) and coarse (≥ 2.5 μm) particles were collected in Kyoto, and protein and endotoxin levels were analyzed. The association of the levels of particles, protein, endotoxin, and meteorological factors (temperature, relative humidity, wind speed, and air pressure) with emergency department visits for asthma was estimated. RESULTS: There were 1 to 15 emergency department visits for asthma per week, and the numbers of visits increased in the autumn and spring, namely many weeks in September, October, and April. Weekly concentration of protein in fine particles was markedly higher than that in coarse particles, and protein concentration in fine particles was high in spring months. Weekly endotoxin concentrations in fine and coarse particles were high in autumn months, including September 2014 and 2015. Even after adjusting for meteorological factors, the concentrations of coarse particles and endotoxin in both particles were significant factors on emergency department visits for asthma. CONCLUSIONS Our results suggest that atmospheric coarse particles and endotoxin are significantly associated with an increased risk of asthma exacerbation.
Adolescent ; Adult ; Aged ; Air Pollutants ; analysis ; Asthma ; epidemiology ; Child ; Emergency Service, Hospital ; statistics & numerical data ; Endotoxins ; analysis ; Female ; Humans ; Japan ; epidemiology ; Male ; Middle Aged ; Particle Size ; Particulate Matter ; analysis ; Proteins ; analysis ; Seasons ; Weather ; Young Adult

Hazardous biochemical agents in animal husbandry indoor environments are known to promote the occurrence of various illnesses among workers and animals. The relationship between endotoxin levels in dust collected from chicken farms and various immunological markers was investigated. Peripheral blood was obtained from 20 broiler chickens and 20 laying hens from four different chicken farms in Korea. Concentrations of total or respirable dust in the inside the chicken farm buildings were measured using a polyvinyl chloride membrane filter and mini volume sampler. Endotoxin levels in the dust were determined by the Limulus Amebocyte Lysate Kinetic method. Interferon-gamma production by peripheral blood mononuclear cells stimulated with concanavalin A was significantly lower in broilers or layers from the farms with higher endotoxin concentrations than the chickens from the farms with lower endotoxin levels. An opposite pattern was observed for plasma cortisol concentrations with higher cortisol levels found in chickens from the farms with higher endotoxin levels. When peripheral lymphocytes were examined, the percentage of CD3-Ia+ B cells was lower in layers from farms with higher endotoxin levels than those from locations with lower endotoxin levels. Overall, these results suggest a probable negative association between dust endotoxin levels and cell-mediated immunity in chickens.
Animal Husbandry ; Animals ; Biomarkers/blood ; Chickens/*immunology ; Dust/*analysis ; Endotoxins/*analysis ; *Housing, Animal ; *Immunity, Cellular

OBJECTIVETo investigate the flexibility and mobility of the Bacillus thuringiensis toxin Cry1Aa.

METHODSThe graph theory-based program Constraint Network Analysis and normal mode-based program NMsim were used to analyze the global and local flexibility indices as well as the fluctuation of individual residues in detail.

RESULTSThe decrease in Cry1Aa network rigidity with the increase of temperature was evident. Two phase transition points in which the Cry1Aa structure lost rigidity during the thermal simulation were identified. Two rigid clusters were found in domains I and II. Weak spots were found in C-terminal domain III. Several flexible regions were found in all three domains; the largest residue fluctuation was present in the apical loop2 of domain II.

CONCLUSIONAlthough several flexible regions could be found in all the three domains, the most flexible regions were in the apical loops of domain II.

Bacillus thuringiensis ; Bacterial Proteins ; chemistry ; genetics ; metabolism ; Cluster Analysis ; Computer Simulation ; Endotoxins ; chemistry ; genetics ; metabolism ; Entropy ; Hemolysin Proteins ; chemistry ; genetics ; metabolism ; Models, Structural ; Mutation ; Protein Conformation ; Protein Unfolding ; Software ; Temperature

Endotoxemia ; diagnosis ; Endotoxins ; analysis ; Humans ; Sepsis ; diagnosis

PURPOSE: Since most terminally ill cancer patients die of multiple organ failure, plasma endotoxin concentration levels may be used to predict the life expectancy. This study was performed to evaluate the clinical significance of endotoxin level in plasma as a prognostic factor for survival in patients with terminal cancer. METHODS: This study was conducted with 56 terminally ill cancer patients, above 20 years old, from April 2009 through October 2009. Demographic characteristics, Karnofsky performance status, and survival time were evaluated. We analyzed blood levels of white blood cell hemoglobin, hematocrit, aspartate aminotransferase, alanine aminotransferase, c-reactive protein, total bilirubin and endotoxin in each patient. RESULTS: We considered following variable for univariate analysis: plasma endotoxin level, sex, age, WBC, hemoglobin, hematocrit, AST, ALT, total bilirubin, CRP and severity of pain. Univariate analysis did not show a significant association between plasma endotoxin level and survival time. However, in a multivariate analysis with factors that were found to be significantly associated with survival sex, WBC count and total bilirubin level in univariate analysis, high levels of plasma endotoxin and short survival time were significantly related. CONCLUSION: Plasma endotoxin level could be used as a prognostic factor to predict the life expectancy of terminally ill cancer patients.
Alanine Transaminase ; Aspartate Aminotransferases ; Bilirubin ; C-Reactive Protein ; Endotoxins ; Hematocrit ; Hospice Care ; Humans ; Karnofsky Performance Status ; Leukocytes ; Life Expectancy ; Multiple Organ Failure ; Multivariate Analysis ; Plasma* ; Prognosis ; Terminal Care ; Terminally Ill*

OBJECTIVE: To evaluate the mid-term prognostic value of procalcitonin (PCT), endotoxin and common inflammatory markers combining the model for end-stage liver disease (MELD) score in patients with chronic severe hepatitis. METHODS: A total of 124 chronic severe hepatitis patients were enrolled, who were hospitalized in the Department of Infectious Diseases, Xiangya Hospital, Central South University from May 2011 to December 2011. Indexes of inflammation, liver and kidney function tests and MELD were determined within 24 h after the admission, and blood samples were collected for measurement of endotoxin , procalcitonin (PCT), and C-reactin protein (CRP). The outcome was confirmed after discharge follow-up at the end of the 3rd month. According to the outcome, the 124 patients were divided into a survival group (n=58) and a death group(n=66). RESULTS: 1) Of the 124 patients, 66 died and 58 survived, with statistical difference in age, MELD score, white blood cell (WBC), polymorphonuclear (PMN), CRP and PCT by single factor analysis between the 2 groups(P<0.05). Binary logistic regression analysis indicated that age, MELD scores and PCT were highly correlated with the outcome (OR=1.07, 1.42 and 1.02 respectively, P<0.05), which could be used to predict the 3 month mid-term mortality of chronic severe hepatitis. 2)There was significant correlation between the MELD scores and the mid-term mortality. Age was positively correlated with the MELD score, and Pearson's correlation coefficient was 0.21 (P<0.05). PCT was also positively correlated with the MELD, and Spearman's correlation coefficient was 0.54 (P<0.01). 3)According to the receiver operation characteristic (ROC) curve analysis , the area under the curve (AUC) of MELD score and PCT were 0.91 and 0.77 respectively, higher than those of other indexes (P<0.01). When the MELD score was up to 30.09 or higher, the predicted mortality risk among these tested patients was the highest(82.26%). The mortality risk predicted by PCT combining MELD score and PCT alone was lower than by MELD score alone (75.00%), but the specificity of MELD score combining PCT was 100%, and the positive prediction value was 1.00. CONCLUSION Endotoxin and common inflammatory markers (WBC, PMN, and CRP) are not reliable indicators to predict the prognosis in patients with chronic-severe hepatitis. MELD score is significantly correlated with the outcome of mid-term chronic severe hepatitis, PCT and age are both positively correlated with the MELD score. PCT and age combining MELD score can be used to predict the 3 month mid-term mortality of chronic severe hepatitis. MELD score has better prognostic value than PCT. MELD score combining PCT can improve the specificity of prediction.
Adult ; Age Factors ; C-Reactive Protein ; metabolism ; Calcitonin ; blood ; Calcitonin Gene-Related Peptide ; End Stage Liver Disease ; diagnosis ; mortality ; Endotoxins ; blood ; Female ; Hepatitis, Chronic ; diagnosis ; mortality ; Humans ; Male ; Middle Aged ; Predictive Value of Tests ; Prognosis ; Protein Precursors ; blood ; ROC Curve ; Severity of Illness Index ; Survival Analysis

To investigate the relationship between uncoupling protein 2 (UCP2) expression and the damage caused by oxygen free radicals in acute liver failure rat models. Thirty-five male Sprague-Dawley rats were randomly divided into two groups: the control group (15 rats) and liver failure group (20 rats). The rats were injected intraperitoneally with thioacetamide (TAA) to induce models of acute liver failure. The levels of endotoxin (ET) were detected by double antibody sandwich enzyme-linked immunosorbent assay. The expression of liver UCP2 mRNA was detected by reverse transcription polymerase chain reaction. The superoxide dismutase (SOD) and malonaldehyde (MDA) were detected by spectrophotometry. The expression of UCP2 protein was observed by immunohistochemistry. The data of the two groups were compared using Mann-Whitney U test or ANOVA. The expression of UCP2 mRNA in liver failure group was higher as compared to the control group (P value is less than 0.01); the level of MDA and endotoxin of liver failure group were higher than that of the control group (P value is less than 0.01). SOD of the liver failure group was lower (P value is less than 0.01). There was a certain correlation between UCP2 mRNA expression and ET, SOD and MDA (r = 0.952, -0.667, 0. 634 respectively, P value is less than 0.05 or 0.01). UCP2 is highly expressed in the livers of liver failure rats. A certain correlation perhaps existed between the expression of UCP2 mRNA and the serous SOD, MDA and ET.
Animals ; Endotoxins ; analysis ; Ion Channels ; metabolism ; Liver ; metabolism ; Liver Failure, Acute ; metabolism ; Male ; Malondialdehyde ; analysis ; Mitochondrial Proteins ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; adverse effects ; Superoxide Dismutase ; analysis ; Uncoupling Protein 2

OBJECTIVESTo identify significantly differentially expression genes of steroid-induced femoral head necrosis (SINFH) of rats by gene chip, and to find out the potential factors and molecular mechanisms that oxidative stress originate or strengthen the SINFH.

METHODSTwenty Wistar rats were divided into experimental group and control group randomly. E. coli endotoxin was given to all rats at a dose of 20 µg/kg body weight by daily i.p. for two times. Then methylprednisolone (40 mg/kg) or saline was daily injected into the left gluteus muscle of the rats in experimental group and control group respectively. Six weeks later, the mRNA was extracted from the femoral head of rats in every group, and the cDNA were obtained by inverse transcript, then carried out microarray detection. The quantitative RT-PCR was used to confirm the result of microarray, and the differentially expressed genes were analyzed for the functional annotation by gene ontology (GO).

RESULTSCompared to the control group, 190 genes in the experimental group were differentially expressed, with 52 up-regulated and 138 down-regulated. Of these genes, 102 are known (have deposited in GeneBank), while 88 of them are unknown. The known genes can be divided into several families according to their biological functions, such as: oxidative stress, apoptosis, signal transduction, angiogenesis, extracellular matrix, lipid metabolism, and gene transcription related genes. The results of quantitative RT-PCR are consistent with gene-chip results.

CONCLUSIONSThe occurrence of SINFH is a complicated process affected by multiple factors and signaling pathways. Our findings indicate that many genes which are involved in different signaling pathways were differentially expressed between SINFH rats and normal rats.

Animals ; Endotoxins ; toxicity ; Female ; Femur Head Necrosis ; chemically induced ; genetics ; Gene Expression ; Genomics ; Male ; Oligonucleotide Array Sequence Analysis ; Prednisolone ; adverse effects ; Rats ; Rats, Wistar

OBJECTIVEBy using RAW 264.7 macrophage cell line, we studied the dose-effect relationship of endotoxin induced RAW 264.7 cells to release TNF-alpha, and then detected the content of endotoxin in 8 kinds of injections, so that we can investigate the feasibility and the interference factors of the novel test.

METHODBy using endotoxin of different concentrations to induce RAW 264. 7 cells to release TNF-a, we drew the curve of dose-effect relationship between endotoxin and generated TNF-alpha. Then we detected the content of TNF-alpha in yuxingcao, shuanghuanglian, qingkailing, gegensu, xiangdan, qianrongmei and jiangxianmei injections and shuanghuanglian powder injection, and calculated their content of endotoxin.

RESULTThe endotoxin could induce the cells to release TNF-alpha in a good dose-dependent manner, even at a very low concentration. In the range of maximum available dilution multiple, the content of endotoxin in the rest 7 kinds of injections was less than 1.0 EU x mL(-1) except qingkailing injection of two batch.

CONCLUSIONCytokine revulsion has the advantage of wide detection range, high sensitivity, simple operation, and the detected endotoxin is of bioactivity. This method provides another technical mean for pyrogen test of injections.

Animals ; Biological Assay ; methods ; Cell Line ; Drug Contamination ; Drugs, Chinese Herbal ; analysis ; Endotoxins ; adverse effects ; analysis ; Macrophages ; drug effects ; immunology ; Mice ; Tumor Necrosis Factor-alpha ; analysis ; immunology