Bacterial endotoxin (lipopolysaccharide) binds to the surface of gold nanoparticles,interferes with biocorona formation and induces human monocyte inflammatory activation

Nanoparticles (NPs) are easily contaminated by bacterial endotoxin (lipopolysaccharide [LPS]). The presence of LPS can be responsible for many immune/inflammatory effects attributed to NPs. In this study, we examined the effects of LPS adsorption on the NP surface on the formation of a biocorona in biological fluids and on the subsequent inflammation-inducing activity of NPs. Different gold (Au) NPs with sizes ranging from 10 to 80?nm and with different surface functionalization (sodium citrate, lipoic acid, and branched polyethyleneimine (BPEI), or polyethylene glycol (PEG)) were exposed to E. coli LPS under different conditions. The binding capacity of LPS to the surface of AuNPs was dose- and time-dependent. LPS attached to sodium citrate and lipoic acid coatings, but did not adhere to BPEI- or PEG-coated NPs. By computational simulation, the binding of LPS to AuNPs seems to follow the Langmuir absorption isotherm. The presence of LPS on AuNP surface interfered and caused a decrease in the formation of the expected biomolecular corona upon incubation in human plasma. LPS-coated AuNPs, but not the LPS-free NPs, induced significant inflammatory responses in vitro. Notably, while free LPS did also induce an anti-inflammatory response, LPS bound to NPs appeared unable to do so. In conclusion, the unintentional adsorption of LPS onto the NP surface can affect the biocorona formation and the inflammatory properties of NPs. Thus, for an accurate interpretation of NP interactions with cells, it is extremely important to be able to distinguish the intrinsic NP biological effects from those caused by biologically active contaminants such as endotoxin.     

无肠坏死腹股沟嵌顿疝腹膜前间隙Ⅰ期修补可行性的临床观察

目的探讨无肠坏死腹股沟嵌顿疝腹膜前间隙行Ⅰ期修补的可行性。方法对无坏死肠嵌顿疝30例(肠嵌顿组)、网膜嵌顿疝18例(网膜嵌顿组)及择期行腹股沟疝修补术30例(对照组),采用腹膜前间隙补片修补术,检测3组术前D-乳酸、内毒素水平及术前、术后第3天白细胞及中性粒细胞计数;观察嵌顿疝患者局部疝囊内渗液细菌培养及术后并发症情况。结果 3组术前血浆D-乳酸[分别为(11.7550±3.0391)mg/L,(12.8453±3.0457)mg/L.,(11.9056±2.6754)mg/L]及内毒素[分别为(0.5623±0.0893)EU/ml,(0.6137±0.0725)EU/ml,(0.5861±0.0820)EU/ml]比较,差异有统计学意义(P0.05);嵌顿疝患者疝囊囊液细菌培养均为阴性;肠嵌顿组及网膜嵌顿组术前出现白细胞及中性粒细胞增高[分别为(9.22±1.471)×10~9/L、(6.03±1.403)×10~9/L,和(8.87±1.711)×10~9/L、(6.26±1.364)×10~9/L],与对照组[(6.00±1.054)×10~9/L)、(3.67±0.783)×10~9/L]比较,差异有统计学意义(P0.05),但肠嵌顿组及网膜嵌顿组之间比较差异无统计学意义。术后第3天肠嵌顿组及网膜嵌顿组白细胞及中性粒细胞均下降至正常水平[分别为(5.67±1.052)×10~9/L、(3.663±0.557)×10~9/L,(5.53±0.684)×10~9/L、(3.600±0.555)×10~9/L],与对照组比较[(5.23±1.028)×10~9/L、(3.36±0.544)×10~9/L],差异无统计学意义。结论对于腹股沟嵌顿疝,需要采取个体化治疗,如果术中发现为网膜嵌顿或肠管嵌顿但尚未发生肠坏死者,Ⅰ期行腹膜前间隙修补术是安全有效的。     

Toll-like receptor interactions: tolerance of MyD88-dependent cytokines but enhancement of MyD88-independent interferon-beta production

Toll-like receptors (TLRs) signal through two main pathways: a myeloid differentiation factor (MyD)88-dependent pathway that acts via nuclear factor kappaB (NF-kappaB) to induce proinflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) and a MyD88-independent pathway that acts via type I interferons to increase the expression of interferon-inducible genes. Repeated signalling through TLR4 and a number of other TLRs has been reported to result in a reduction in the subsequent proinflammatory cytokine response, a phenomenon known as TLR tolerance. In this study we have shown that, whilst NF-kappaB activation and production of TNF-alpha and interleukin-12 by murine RAW264.7 and J774.2 cells in response to stimulation by TLR4, -5, -7 or -9, was reduced by prior stimulation with TLR4, -5, -7 or -9 ligands, the primary stimulation of TLR3, which does not use the MyD88 pathway, did not reduce the TNF-alpha or interleukin-12 responses to subsequent TLR stimulation. The response to TLR3 stimulation was not diminished by prior TLR ligand exposure. Furthermore, the production of interferon-beta (IFN-beta) following stimulation of TLR3 or -4, which is MyD88-independent, was increased by prior activation of TLR4, -5, -7 or -9. In contrast, TLR9 ligand-induced IFN-beta production, which is MyD88-dependent, was tolerized by prior TLR stimulation. These results are consistent with differential regulation of MyD88-dependent and MyD88-independent cytokine production following serial activation of TLRs.     

Bacterial DNA Induces the <Emphasis Type="Italic">Complement</Emphasis> System Activation in Serum and Ascitic Fluid from Patients with Advanced Cirrhosis

Translocation of intestinal bacteria to ascitic fluid is, probably, the first step in the development of spontaneous bacterial peritonitis in patients with cirrhosis. Proteins of the complement system are soluble mediators implicated in the host immune response to bacterial infections and its activation has been traditionally considered to be an endotoxin-induced phenomenon. The aim of this study was to compare the modulation of these proteins in response to the presence of bacterial DNA and/or endotoxin in patients with advanced cirrhosis and ascites in different clinical conditions. Groups I and II consisted of patients without/with bacterial DNA. Group III included patients with spontaneous bacterial peritonitis and Group IV with patients receiving norfloxacin as secondary long-term prophylaxis of spontaneous bacterial peritonitis. Serum and ascitic fluid levels of endotoxin and truncated residues of the complement system were measured by ELISA. The complement system is triggered in response to bacterial DNA, as evidenced by significantly increased levels of C3b, membrane attack complex, and C5a in patients from Groups II and III compared with patients without bacterial DNA (Group I) and those receiving norfloxacin (Group IV). Gram classification did not further differentiate the immune response between patients within groups II and III, even though endotoxin levels were, as expected, significantly higher in patients with bacterial DNA from gram-negative microorganisms. The complement protein activation observed in patients with bacterial DNA in blood and ascitic fluid is indistinguishable from that observed in patients with spontaneous bacterial peritonitis and may occur in an endotoxin-independent manner.     

Environmental determinants of atopic eczema phenotypes in relation to asthma and atopic sensitization

BACKGROUND: There is still uncertainty about the determinants of atopic eczema (AE). To explain the heterogeneity of the disease, different phenotypes of AE have been suggested. METHODS: The cross-sectional PARSIFAL study included 14 893 school-age children of farmers or children attending Steiner schools and their respective reference groups. A detailed questionnaire was completed, and house dust was collected for the measurement of endotoxin and glucans. Atopic sensitization was defined by allergen-specific IgE levels in the serum. RESULTS: In multivariate analyses, helping with haying was the only variable related to a farming environment having a consistent inverse association with both current symptoms and a doctor's diagnosis of AE [aOR = 0.65 (95% CI: 0.46-0.93) and 0.73 (0.51-1.05)], respectively. Severe lower respiratory tract infections (LRTI) in the first 2 years of life and usage of antibiotics ever were found to be positively related only to asthma-associated AE, whereas the effect of LRTI on AE without asthma had an opposite effect. Levels of beta(1-->3)-glucans in mattress dust were inversely related to a doctor's diagnosis of asthma-associated AE [aOR = 0.75 (0.57-0.98)], and endotoxin levels to current symptoms of asthma-associated AE [aOR = 0.73 (0.57-0.94)]. CONCLUSIONS: The analyses of the PARSIFAL study revealed two different phenotypes of AE, depending on the association with asthma and wheezing ever. With regard to the hygiene hypothesis, help with haying, exposure to beta(1-->3)-glucans and endotoxin were found to be inversely associated with the AE phenotype associated with asthma and wheezing.     

Personal exposure of dairy workers to dust,endotoxin, muramic acid,ergosterol, and ammonia on large-scale dairies in the high plains Western United States

Dairy workers experience a high degree of bioaerosol exposure, composed of an array of biological and chemical constituents, which have been tied to adverse health effects. A better understanding of the variation in the magnitude and composition of exposures by task is needed to inform worker protection strategies. To characterize the levels and types of exposures, 115 dairy workers grouped into three task categories on nine farms in the high plains Western United States underwent personal monitoring for inhalable dust, endotoxin, 3-hydroxy fatty acids (3-OHFA), muramic acid, ergosterol, and ammonia through one work shift. Eighty-nine percent of dairy workers were exposed to endotoxin at concentrations exceeding the recommended exposure guidelines (adjusted for a long work shift). The proportion of workers with exposures exceeding recommended guidelines was lower for inhalable dust (12%), and ammonia (1%). Ergosterol exposures were only measurable on 28% of samples, primarily among medical workers and feed handlers. Milking parlor workers were exposed to significantly higher inhalable dust, endotoxin, 3-OHFA, ammonia, and muramic acid concentrations compared to workers performing other tasks. Development of large modern dairies has successfully made progress in reducing worker exposures and lung disease prevalence. However, exposure to endotoxin, dust, and ammonia continues to present a significant risk to worker health on North American dairies, especially for workers in milking parlors. This study was among the first to concurrently evaluate occupational exposure to assayable endotoxin (lipid A), 3-hydroxy fatty acids or 3-OHFA (a chemical measure of cell bound and noncell-bound endotoxins), muramic acid, ergosterol, and ammonia among workers on Western U.S. dairies. There remains a need for cost-effective, culturally acceptable intervention strategies integrated in OHS Risk Management and production systems to further optimize worker health and farm productivity.     

一种难溶性原料药细菌内毒素检查方法的建立

摘 要 目的：建立原料药HSSYO 001 3S细菌内毒素检查方法。方法: 以二甲亚砜（DMSO）溶解HSSYO 001 3S,用适量细菌内毒素检查用水（BET水）稀释后,离心取上清液,按中国药典2015年版四部通则11431检查凝胶法,对HSSYO 001 3S进行细菌内毒素检查的方法学研究。结果:HSSYO 001 3S加助溶剂并以BET水稀释至1 mg·m^-1 ,经离心后取上清液稀释4倍及以上时对鲎试剂凝集反应无干扰作用。结论:HSSYO 001 3S可采用细菌内毒素检查法控制其质量。     

注射用磷酸特地唑胺细菌内毒素检查

目的：注射用磷酸特地唑胺用于特定的敏感细菌引起的成人急性细菌性皮肤和皮肤结构感染,于2014年6月20日,被美国FDA批准磷酸特地唑胺上市,临床研究也进入了临床II期,用于严重革兰氏阳性菌感染的治疗。该药尚未在中国上市。未被中国药典2015年版收录,没有与之相关的质量标准,所以需要尽快制定药品的检验标准,已完善医药市场对药物的质量要求与监管。方法：参照中国药典2015年版二部,拟定的质量标准并对细菌内毒素检查的方法学进行了验证。结果：拟定本品的细菌内毒素限值为1.5EU/mg,当采用灵敏度为0.5EU/ml的鲎试剂,样品浓度为含磷酸特地唑胺4mg/ml时,对内毒素与鲎试剂的反应无干扰。结论：当采用两个鲎试剂生产厂家的试剂对样品进行干扰试验,灵敏度为0.5EU/ml,样品浓度为含磷酸特地唑胺4mg/ml时,对内毒素与鲎试剂的反应无干扰。此限值为可靠限值。此浓度为本品的最大无干扰浓度。     

Occupational exposure to textile dust and lung cancer risk: Results from the ICARE Study

Background

To investigate the association of lung cancer with occupational exposure to textile dust and specifically to cotton dust in the population‐based case‐control study ICARE.

Methods

Lifelong occupational history of 2926 cases and 3555 controls was collected using standardized questionnaires, with specific questions for textile dust exposure. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using unconditional logistic regression models controlling for confounding factors including smoking and asbestos exposure.

Results

An inverse association between textile dust exposure and lung cancer was found among workers exposed ≥5% of their work time (OR = 0.80, 95%CI = 0.58‐1.09), more pronounced for distant exposures (40+ years; up to a 56% reduced risk, statistically significant). The OR of lung cancer was significantly decreased among workers exposed to cotton fibers (OR = 0.70, 95%CI = 0.48‐0.97).

Conclusions

Our results provide some evidence of a decreased risk of lung cancer associated with exposure to textile dust, particularly cotton.

     

烫伤延迟复苏后肠上皮细胞凋亡诱导肠道内毒素和细菌移位

目的 :探讨烫伤延迟复苏后肠上皮细胞凋亡对肠道内毒素和细菌移位的影响。方法 :Wistar大鼠 110只 ,30 %总体表面积 ( STBA) 度烫伤 ,立即或伤后 6 h进行复苏。观察伤后肠上皮细胞凋亡率 ( ap% )变化 ,并测定了门静脉和体循环内毒素及肠系膜淋巴结 ( ML N)细菌移位率和移位量变化。结果 :电泳、原位末端标记( TU NEL )法和电镜均观察到伤后肠上皮凋亡梯形带和凋亡阳性细胞增多。延迟复苏组肠上皮细胞凋亡发生早且更严重 ;其门静脉内毒素水平及 ML N细菌移位量均显著高于立即复苏组 ( P<0 .0 1) ;门静脉内毒素变化与肠黏膜 ap%成显著正相关 (烫伤后立即复苏组 r=0 .936 ,P<0 .0 1;烫伤后延迟复苏组 r=0 .899,P<0 .0 5 )。结论 :烫伤后延迟复苏使肠黏膜上皮发生病理性凋亡 ,可能导致肠道细菌和内毒素移位增加。