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961.
Debra J. Taxman Karen V. Swanson Peter M. Broglie Haitao Wen Elizabeth Holley-Guthrie Max Tze-Han Huang Justin B. Callaway Tim K. Eitas Joseph A. Duncan Jenny P. Y. Ting 《The Journal of biological chemistry》2012,287(39):32791-32799
The interleukin (IL)-1β-processing inflammasome has recently been identified as a target for pathogenic evasion of the inflammatory response by a number of bacteria and viruses. We postulated that the periodontal pathogen, Porphyromonas gingivalis may suppress the inflammasome as a mechanism for its low immunogenicity and pathogenic synergy with other, more highly immunogenic periodontal bacteria. Our results show that P. gingivalis lacks signaling capability for the activation of the inflammasome in mouse macrophages. Furthermore, P. gingivalis can suppress inflammasome activation by another periodontal bacterium, Fusobacterium nucleatum. This repression affects IL-1β processing, as well as other inflammasome-mediated processes, including IL-18 processing and cell death, in both human and mouse macrophages. F. nucleatum activates IL-1β processing through the Nlrp3 inflammasome; however, P. gingivalis repression is not mediated through reduced levels of inflammasome components. P. gingivalis can repress Nlrp3 inflammasome activation by Escherichia coli, and by danger-associated molecular patterns and pattern-associated molecular patterns that mediate activation through endocytosis. However, P. gingivalis does not suppress Nlrp3 inflammasome activation by ATP or nigericin. This suggests that P. gingivalis may preferentially suppress endocytic pathways toward inflammasome activation. To directly test whether P. gingivalis infection affects endocytosis, we assessed the uptake of fluorescent particles in the presence or absence of P. gingivalis. Our results show that P. gingivalis limits both the number of cells taking up beads and the number of beads taken up for bead-positive cells. These results provide a novel mechanism of pathogen-mediated inflammasome inhibition through the suppression of endocytosis. 相似文献
962.
Understanding the factors contributing to expansion of nonnative populations is a critical step toward accurate risk assessment and effective management of biological invasions. Nevertheless, few studies have attempted explicitly to test hypotheses regarding factors driving invasive spread by seeking correlations between patterns of vector movement and patterns of genetic connectivity. Herein, we describe such an attempt for the invasive tunicate Styela clava in the northeastern Pacific. We utilized microsatellite data to estimate gene flow between samples collected throughout the known range of S. clava in the region, and assessed correlation of these estimates with patterns of intracoastal commercial vessel traffic. Our results suggest that recent shipping patterns have contributed to the contemporary distribution of genetic variation. However, the analysis also indicates that other factors—including a complex invasion history and the influence of other vectors—have partially obscured genetic patterns associated with intracoastal population expansion. 相似文献
963.
Chun-Ta Huang Sheng-Yuan Ruan Wei-Yu Liao Yao-Wen Kuo Chi-Ying Lin Yi-Ju Tsai Chao-Chi Ho Chong-Jen Yu 《PloS one》2012,7(11)
Background
The risk of endobronchial ultrasound-guided transbronchial biopsy-related pneumothorax is a major concern and warrants further studies. The aim of our study was to estimate the risk of pneumothorax after this procedure and identify its risk factors.Methods
From 2007 to 2011, 399 patients who underwent endobronchial ultrasound-guided transbronchial biopsy for peripheral lung lesions were included in this study. The variables analyzed included patient factors, lesion factors and procedure factors. Multivariate logistic regression analysis was used to identify independent risk factors for pneumothorax.Results
The incidence of pneumothorax was 3.3% (13/399). Chest tube placement was required for 31% (4/13) of pneumothoraces. Independent risk factors for pneumothorax included pulmonary emphysema (OR, 55.09; 95% CI, 9.37–324.03; p<0.001) and probe position adjacent to the lesion (OR, 17.01; 95% CI, 2.85–101.64; p = 0.002). The number of biopsy specimens, age, sex, history of prior lung surgery and lesion size, location and character did not influence the risk of pneumothorax in our analyses.Conclusions
The risk of pneumothorax after endobronchial ultrasound-guided transbronchial biopsy is low. To further reduce the risk of pneumothorax, every effort should be made to advance the endobronchial ultrasound probe into the bronchus where it is imaged within the target lesion before embarking on transbronchial biopsy. 相似文献964.
965.
Genetic variation among 12 populations of the American chestnut (Castanea dentata) was investigated. Population genetic parameters estimated from allozyme variation suggest that C. dentata at both the population and species level has narrow genetic diversity as compared to other species in the genus. Average expected heterozygosity was relatively low for the population collected in the Black Rock Mountain State Park, Georgia (He = 0.096 +/- 0.035), and high for the population in east central Alabama (He = 0.196 +/- 0.048). Partitioning of the genetic diversity based on 18 isozyme loci showed that ~10% of the allozyme diversity resided among populations. Cluster analysis using unweighted pair-group method using arithmetric averages of Rogers' genetic distance and principal components analysis based on allele frequencies of both isozyme and RAPD loci revealed four groups: the southernmost population, south-central Appalachian populations, north-central Appalachian populations, and northern Appalachian populations. Based on results presented in this study, a conservation strategy and several recommendations related to the backcross breeding aimed at restoring C. dentata are discussed. 相似文献
966.
967.
Three new oplopane sesquiterpenes, knorringianalarins D – F ( 1 – 3 , respectively), and five known analogues ( 4 – 8 , respectively), were isolated from the roots and rhizomes of Ligularia knorringiana. The structures of three new compounds were identified as 4‐acetoxy‐11α,12‐epoxy‐2β‐hydroxy‐3β‐(2‐methylbutyryloxy)‐9α‐(4‐methylsenecioyloxy)oplop‐10(14)‐ene ( 1 ), 3β,4‐diacetoxy‐9α‐(4‐acetoxy‐4‐methylsenecioyloxy)‐11α,12‐epoxy‐8α‐(2‐methylbutyryloxy)oplop‐10(14)‐ene ( 2 ), and (1R,5R,6R,7R,9R)‐5,9,11‐trihydroxy‐4,15‐dinoroplop‐10(14)‐en‐3‐one ( 3 ) based on spectroscopic methods including 1D‐ and 2D‐NMR, mass spectrometry, and CD spectroscopy techniques. All compounds were evaluated for their anti‐complementary activity on the classical pathway of the complement system in vitro. Among which, three oplopane sesquiterpenes ( 3 , 7 , and 8 ) exhibited better anti‐complementary effects with CH50 values ranging from 0.33 to 0.89 mm , which are plausible candidates for developing potent anti‐complementary agents. 相似文献
968.
Variation in Phenolic Content,Profile, and Antioxidant Activity of Seeds among Different Paeonia ostii Cultivated Populations in China 下载免费PDF全文
The purpose of this study was to analyze the phenolic profiles of seeds from fifteen Paeonia ostii cultivated populations in China and identify their relationship with antioxidant activities and associated environmental factors. Thirteen individual phenolic compounds were quantitatively determined by HPLC, and (+)‐catechin was the most abundant phenolic compound in the seeds. Correlation analysis showed that phenolics were the most effective antioxidant compound class by evaluating DPPH, ABTS, and hydroxyl radical scavenging activities as well as ferric reducing antioxidant power. Latitude and annual rainfall had significant effects on the contents of many phenolic compounds, and elevation was only significantly correlated with gallic acid content. Within fifteen P. ostii cultivated populations, the seeds of Tongling population exhibited the highest phenolic contents and strongest antioxidant activities. These results suggest that Tongling population has a relatively high utilization value and a potential for sources of natural antioxidants. 相似文献
969.
Collagen peptides modulate the metabolism of extracellular matrix by human dermal fibroblasts derived from sun‐protected and sun‐exposed body sites 下载免费PDF全文
Vivian Zague Jonatas Bussador do Amaral Paula Rezende Teixeira Evandro Luis de Oliveira Niero Camila Lauand Glaucia Maria Machado‐Santelli 《Cell biology international》2018,42(1):95-104
Clinical data published in recent years have demonstrated positive effects of collagen hydrolysate (CH) on skin aging clinical signs. CH use as food supplement has a long history; however, few studies have addressed the underlying purpose of CH on the cellular and molecular biology of skin cells that could elucidate clinical improvement findings. Wide diversity of characteristics has been reported for dermal fibroblasts derived from different body sites and it is unknown whether collagen peptides could modulate differently cells from chronological aged and photoaged skin areas. This study investigated the influence of CH on the extracellular matrix metabolism and proliferation of human dermal fibroblasts (HDFs) derived from chronological aged (sun‐protected) and photoaged (sun‐exposed) body sites. CH treatment did not affect cellular proliferation of either cell cultures, but notably modulated cell metabolism in monolayer model, increasing the content of dermal matrix precursor and main protein, procollagen I and collagen I, respectively. These effects were confirmed in the human dermal equivalent model. The increase in collagen content in the cultures was attributed to stimulation of biosynthesis and decreased collagen I metabolism through inhibition of metalloproteinase activity (MMP) 1 and 2. Modulation of CH in dermal metabolism did not differ between cells derived from sun‐protected and sun‐exposed areas, although lower concentrations of CH seemed to be enough to stimulate sun‐exposed‐derived HDFs, suggesting more pronounced effect in these cells. This study contributes to understanding the biological effects of CH on skin cells and viability of its use as a functional ingredient in food supplements. 相似文献
970.
Viral infections can play direct or indirect roles in the etiology of the bovine mastitis. Mx dynamin-like GTPase 2 (MX2) gene is a main effector of the antiviral innate immune defense mediated by type I interferon (IFN I), which was demonstrated to confer positive antiviral responses to many viruses. Given the importance of the MX2 in modulating the host immune response, MX2 gene may be a suitable candidate gene for studying disease resistance in dairy cattle. Here, we scanned the sequence variation of the MX2 gene in Chinese indigenous cattle breeds. Twenty-three previously reported SNPs were identified. To further analyze the effects of SNPs detected on mastitis disease, analysis of two SNPs (g.787527 C?>?T and g.787610 T?>?C) from 297 Chinese Holstein cows revealed a significant association with somatic cell score (SCS). Although functional studies are necessary to ascertain whether these two SNPs are causal polymorphisms or merely in linkage with the true causal SNPs, implementation of these two SNPs as genetic markers in the dairy industry may be beneficial in selecting individuals with lower SCS. 相似文献