Expression pattern of NLRP3 and its related cytokines in the lung and brain of avian influenza virus H9N2 infected BALB/c mice

Background

H9N2 avian influenza virus (AIV) becomes the focus for its ability of transmission to mammals and as a donor to provide internal genes to form the new epidemic lethal influenza viruses. Residue 627 in PB2 has been proven the virulence factor of H9N2 avian influenza virus in mice, but the detailed data for inflammation difference between H9N2 virus strains with site 627 mutation is still unclear. The inflammasome NLRP3 is recently reported as the cellular machinery responsible for activation of inflammatory processes and plays an important role during the development of inflammation caused by influenza virus infection.

Methods

In this study, we investigated the expression pattern of NLRP3 and its related cytokines of IL-1β and TNF-α in BALB/c mice infected by H9N2 AIV strains with only a site 627 difference at both mRNA and protein levels at different time points.

Results

The results showed that the expression level of NLRP3, IL-1β and TNF-α changed in the lung and brain of BALB/c mice after infection by V_K627 and rV_K627E. The immunohistological results showed that the positive cells of NLRP3, IL-1β and TNF-α altered the positive levels of original cells in tissues and infiltrated inflammatory cells which caused by H9N2 infection.

Conclusions

Our results provided the basic data at differences in expression pattern of NLRP3 and its related cytokines in BALB/c mice infected by H9N2 influenza viruses with only a site 627 difference. This implied that NLRP3 inflammasome plays a role in host response to influenza virus infection and determines the outcome of clinical manifestation and pathological injury. This will explain the variable of pathological presentation in tissues and enhance research on inflammation process of the AIV H9N2 infection.

     

Oral Administration of Polymyxin B Modulates the Activity of Lipooligosaccharide E. coli B against Lung Metastases in Murine Tumor Models

Introduction

Polymyxin B (PmB) belongs to the group of cyclic peptide antibiotics, which neutralize the activity of LPS by binding to lipid A. The aim of this study was to analyze the effect of PmB on the biological activity of lipooligosaccharide (LOS E. coli B,rough form of LPS) in vitro and in experimental metastasis models.

Results

Cultures of murine macrophage J774A.1 cells and murine bone marrow-derived dendritic cells (BM-DC) stimulated in vitro with LOS and supplemented with PmB demonstrated a decrease in inflammatory cytokine production (IL-6, IL-10, TNF-α) and down-regulation of CD40, CD80, CD86 and MHC class II molecule expression. Additionally, PmB suspended in drinking water was given to the C57BL/6 mice seven or five days prior to the intravenous injection of B16 or LLC cells and intraperitoneal application of LOS. This strategy of PmB administration was continued throughout the duration of the experiments (29 or 21 days). In B16 model, statistically significant decrease in the number of metastases in mice treated with PmB and LOS (p<0.01) was found on the 14th day of the experiments, whereas the most intensive changes in surface-antigen expression and ex vivo production of IL-6, IL-1β and TNF-α by peritoneal cells were observed 7 days earlier. By contrast, antigen expression and ex vivo production of IL-6, IL-10, IFN-γ by splenocytes remained relatively high and stable. Statistically significant decrease in LLC metastases number was observed after the application of LOS (p<0.01) and in the group of mice preconditioned by PmB and subsequently treated with LOS (LOS + PmB, p<0.01).

Conclusions

In conclusion, prolonged in vivo application of PmB was not able to neutralize the LOS-induced immune cell activity but its presence in the organism of treated mice was important in modulation of the LOS-mediated response against the development of metastases.     

Epidemiology and Outcome of Severe Sepsis and Septic Shock in Intensive Care Units in Mainland China

Introduction

Information about sepsis in mainland China remains scarce and incomplete. The purpose of this study was to describe the epidemiology and outcome of severe sepsis and septic shock in mixed ICU in mainland China, as well as the independent predictors of mortality.

Methods

We performed a 2-month prospective, observational cohort study in 22 closed multi-disciplinary intensive care units (ICUs). All admissions into those ICUs during the study period were screened and patients with severe sepsis or septic shock were included.

Results

A total of 484 patients, 37.3 per 100 ICU admissions were diagnosed with severe sepsis (n = 365) or septic shock (n = 119) according to clinical criteria and included into this study. The most frequent sites of infection were the lung and abdomen. The overall ICU and hospital mortality rates were 28.7% (n = 139) and 33.5% (n = 162), respectively. In multivariate analyses, APACHE II score (odds ratio[OR], 1.068; 95% confidential interval[CI], 1.027–1.109), presence of ARDS (OR, 2.676; 95%CI, 1.691–4.235), bloodstream infection (OR, 2.520; 95%CI, 1.142–5.564) and comorbidity of cancer (OR, 2.246; 95%CI, 1.141–4.420) were significantly associated with mortality.

Conclusions

Our results indicated that severe sepsis and septic shock were common complications in ICU patients and with high mortality in China, and can be of help to know more about severe sepsis and septic shock in China and to improve characterization and risk stratification in these patients.     

Albumin versus Other Fluids for Fluid Resuscitation in Patients with Sepsis: A Meta-Analysis

Background

Early fluid resuscitation is vital to patients with sepsis. However, the choice of fluid has been a hot topic of discussion. The objective of this study was to evaluate whether the use of albumin-containing fluids for resuscitation in patients with sepsis was associated with a decreased mortality rate.

Methods

We systematically searched PubMed, EMBASE and Cochrane library for eligible randomized controlled trials (RCTs) up to March 2014. The selection of eligible studies, assessment of methodological quality, and extraction of all relevant data were conducted by two authors independently.

Results

In total, 15 RCTs were eligible for analysis. After pooling the data, we found there was no significant effect of albumin-containing fluids on mortality in patients with sepsis of any severity (RR: 0.94, 95% CI: 0.87, 1.02 and RD: –0.01, 95% CI: –0.03, 0.01). The results were robust to subgroup analyses, sensitivity analyses and trial sequential analyses.

Conclusion

The present meta-analysis did not demonstrate significant advantage of using albumin-containing fluids for resuscitation in patients with sepsis of any severity. Given the cost-effectiveness of using albumin, crystalloids should be the first choice for fluid resuscitation in septic patients.     

Endothelial dysfunction is induced by proinflammatory oxidant hypochlorous acid

The myeloperoxidase (MPO)-derived oxidant hypochlorous acid (HOCl) plays a role in tissue injury under inflammatory conditions. The present study tests the hypothesis that HOCl decreases nitric oxide (NO) bioavailability in the vasculature of Sprague-Dawley rats. Aortic ring segments were pretreated with HOCl (1-50 microM) followed by extensive washing. Endothelium-dependent relaxation was then assessed by cumulative addition of acetylcholine (ACh) or the calcium ionophore A23187. HOCl treatment significantly impaired both ACh- and A23187-mediated relaxation. In contrast, endothelium-independent relaxation induced by sodium nitroprusside was unaffected. The inhibitory effect of HOCl on ACh-induced relaxation was reversed by exposure of ring segments to L-arginine but not D-arginine. In cellular studies, HOCl did not alter endothelial NO synthase (NOS III) protein or activity, but inhibited formation of the NO metabolites nitrate (NO3(-) and nitrite (NO2(-). The reduction in total NO metabolite production in bovine aortic endothelial cells was also reversed by addition of L-arginine. These data suggest that HOCl induces endothelial dysfunction via modification of L-arginine.     

稻属三种植物叶片下表皮的形态比较

稻属有20多种,其中3种和其他物种明显不同.Oryza eichingeri被认为在亚洲和非洲间断分布;O. officinalis和O punctata被证明同时含有二倍体和四倍体.为了识别种内微形态差异,利用光镜和扫描电镜,对这3个物种的成熟叶片下表皮进行了观察.结果表明,O. eichingeri的叶脉长细胞乳突形状在种内是不一致的,除了斯里兰卡地理宗具有的瘤状乳突外,乌千达地理宗还具有长条状的乳突;同样,种内多样性也存在于O. officinalis和O.punctata内,特别存在于它们不同倍性的细胞型间.在D officinalis中,四倍体有粒状气孔器外围乳突和脉带表皮毛较少,二倍体细胞型具有三角形拱状排列的气孔器外围乳突和较密集的脉带表皮毛;而在O. punctata中,和四倍体相比,二倍体具有小的长细胞表面乳突和低密度分布的气孔.这些稳定的差异为3种植物的种内鉴定和分类修订提供了新的证据.     

Tryptase activates PKB in inflammatory reaction in ECV304 cells

Tryptase is involved in proteinase-activated receptor-2 (PAR-2) mediated up-regulation of IL-8 expression. The present report showed the effects of tryptase on gene expression and activation, including up-regulation IL-8 expression. The expression of mRNA for NF-kappaB first increased at 1 h after tryptase-treatment (1 ng/ml) and reached the plateau after 4 h. The NF-kappaB mRNA increased by 3-fold (n = 3, P < 0.05), AP-1 by 2-fold (n = 3, P < 0.05), and PKB by 10-fold (n = 3, P < 0.05). However, tryptase-treatment did not affect the expression of JNK and p38 MAPK when compared with control cells at mRNA level. Furthermore, in addition to increasing phosphorylation of p38 MAPK, tryptase-treatment also increased phosphorylation of PKB by 2-fold at 15 min following the treatment. The up-regulation and phosphorylation of PKB by tryptase could be abolished by either phosphoinositol-3-kinase (PI3K) inhibitor (LY294002) at 10 microM or antisense PKB cDNA transfection. The up-regulation of NF-kappaB expression could be inhibited by LY294002 and antisense PKB cDNA. These results indicate that tryptase can activate PI3K-PKB pathway and enhance IL-8 expression.     

Treatment of hypoxic-ischemic encephalopathy in mouse by transplantation of embryonic stem cell-derived cells

A 7-day-old hypoxic-ischemic encephalopathy (HIE) mouse model was used to study the effect of transplantation of embryonic stem (ES) cell-derived cells on the HIE. After the inducement in vitro, the ES cell-derived cells expressed Nestin and MAP-2, rather than GFAP mRNA. After transplantation, ES cell-derived cells can survive, migrate into the injury site, and specifically differentiate into neurons, showing improvement of the learning ability and memory of the HIE mouse at 8 months post-transplantation. The non-grafted HIE mouse brain showed typical pathological changes in the hippocampus and cerebral cortex, where the number of neurons was reduced, while in the cell graft group, number of the neurons increased in the same regions. Although further study is necessary to elucidate the precise mechanisms responsible for this functional recovery, we believe that ES cells have advantages for use as a donor source in HIE.     

Allelopathy of diterpenoids on three species of soil ciliates

Allelopathy of diterpenoids extracted from plants of the genus Robdosia on three common species of soil ciliates, Colpoda inflata, Colpoda cucullus and Euplotes muscicola, was studied by acute toxicity test, sub-lethal effect test and morphological observation. Acute toxicity test showed that there was remarkable toxicity of the diterpenoids on the individuals of the three soil ciliate species, and there was close correlation between toxicity and concentration of the diterpenoids. 12 h-LC₅₀ values of the diterpenoids on the individuals of C. inflata, C. cucullus and E. muscicola were 161.40 mg L^?1, 94.80 mg L^?1 and 83.70 mg L^?1 respectively, and 24 h-LC₅₀ values were 114.90 mg L^?1, 92.30 mg L^?1and 65.80 mg L^?1 separately. Sub-lethal effect test of soil ciliates suggested that there existed significant inhibition of the diterpenoids on population growth of the three ciliates with dose-dependant relationships, population density and growth rate of the test group was obviously lower than that of the control group. Morphological observation indicated that diterpenoids affected the body shapes of the three ciliates and made them shorter and thicker, and the higher the concentration of diterpenoids, the greater the affection. The results are of great significance for understanding the functions of ciliates and their relationships to other organisms, and for the application of allelopathy in biological pest control in the soil ecosystems.