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排序方式: 共有202条查询结果,搜索用时 15 毫秒
101.
Shu Wen Wen Raymond Shim Luke Ho Brooke J. Wanrooy Yogitha N. Srikhanta Kathryn Prame Kumar Alyce J. Nicholls SJ. Shen Tara Sepehrizadeh Michael de Veer Velandai K. Srikanth Henry Ma Thanh G. Phan Dena Lyras Connie H. Y. Wong 《Aging cell》2019,18(5)
Bacterial infection a leading cause of death among patients with stroke, with elderly patients often presenting with more debilitating outcomes. The findings from our retrospective study, supported by previous clinical reports, showed that increasing age is an early predictor for developing fatal infectious complications after stroke. However, exactly how and why older individuals are more susceptible to infection after stroke remains unclear. Using a mouse model of transient ischaemic stroke, we demonstrate that older mice (>12 months) present with greater spontaneous bacterial lung infections compared to their younger counterparts (7–10 weeks) after stroke. Importantly, we provide evidence that older poststroke mice exhibited elevated intestinal inflammation and disruption in gut barriers critical in maintaining colonic integrity following stroke, including reduced expression of mucin and tight junction proteins. In addition, our data support the notion that the localized pro‐inflammatory microenvironment driven by increased tumour necrosis factor‐α production in the colon of older mice facilitates the translocation and dissemination of orally inoculated bacteria to the lung following stroke onset. Therefore, findings of this study demonstrate that exacerbated dysfunction of the intestinal barrier in advanced age promotes translocation of gut‐derived bacteria and contributes to the increased risk to poststroke bacterial infection. 相似文献
102.
RG Lockie AB Schultz SJ Callaghan CA Jordan TM Luczo MD Jeffriess 《Biology of sport / Institute of Sport》2015,32(1):41-51
There is little research investigating relationships between the Functional Movement Screen (FMS) and athletic performance in female athletes. This study analyzed the relationships between FMS (deep squat; hurdle step [HS]; in-line lunge [ILL]; shoulder mobility; active straight-leg raise [ASLR]; trunk stability push-up; rotary stability) scores, and performance tests (bilateral and unilateral sit-and-reach [flexibility]; 20-m sprint [linear speed]; 505 with turns from each leg; modified T-test with movement to left and right [change-of-direction speed]; bilateral and unilateral vertical and standing broad jumps; lateral jumps [leg power]). Nine healthy female recreational team sport athletes (age = 22.67 ± 5.12 years; height = 1.66 ± 0.05 m; body mass = 64.22 ± 4.44 kilograms) were screened in the FMS and completed the afore-mentioned tests. Percentage between-leg differences in unilateral sit-and-reach, 505 turns and the jumps, and difference between the T-test conditions, were also calculated. Spearman''s correlations (p ≤ 0.05) examined relationships between the FMS and performance tests. Stepwise multiple regressions (p ≤ 0.05) were conducted for the performance tests to determine FMS predictors. Unilateral sit-and-reach positive correlated with the left-leg ASLR (r = 0.704-0.725). However, higher-scoring HS, ILL, and ASLR related to poorer 505 and T-test performance (r = 0.722-0.829). A higher-scored left-leg ASLR related to a poorer unilateral vertical and standing broad jump, which were the only significant relationships for jump performance. Predictive data tended to confirm the correlations. The results suggest limitations in using the FMS to identify movement deficiencies that could negatively impact athletic performance in female team sport athletes. 相似文献
103.
Jules D. P. Valentin Herv Straub Franziska Pietsch Marion Lemare Christian H. Ahrens Frank Schreiber Jeremy S. Webb Henny C. van der Mei Qun Ren 《The ISME journal》2022,16(4):1176
Pseudomonas aeruginosa biofilms exhibit an intrinsic resistance to antibiotics and constitute a considerable clinical threat. In cystic fibrosis, a common feature of biofilms formed by P. aeruginosa in the airway is the occurrence of mutants deficient in flagellar motility. This study investigates the impact of flagellum deletion on the structure and antibiotic tolerance of P. aeruginosa biofilms, and highlights a role for the flagellum in adaptation and cell survival during biofilm development. Mutations in the flagellar hook protein FlgE influence greatly P. aeruginosa biofilm structuring and antibiotic tolerance. Phenotypic analysis of the flgE knockout mutant compared to the wild type (WT) reveal increased fitness under planktonic conditions, reduced initial adhesion but enhanced formation of microcolony aggregates in a microfluidic environment, and decreased expression of genes involved in exopolysaccharide formation. Biofilm cells of the flgE knock-out mutant display enhanced tolerance towards multiple antibiotics, whereas its planktonic cells show similar resistance to the WT. Confocal microscopy of biofilms demonstrates that gentamicin does not affect the viability of cells located in the inner part of the flgE knock-out mutant biofilms due to reduced penetration. These findings suggest that deficiency in flagellar proteins like FlgE in biofilms and in cystic fibrosis infections represent phenotypic and evolutionary adaptations that alter the structure of P. aeruginosa biofilms conferring increased antibiotic tolerance.Subject terms: Microbiology, Diseases 相似文献
104.
The aim of this study was to investigate the hepatocellular site of reactive oxygen species generation during acute ethanol metabolism. Reactive oxygen species production was detected using the 2',7'-dichlorofluorescein fluorescence assay and cell injury was determined by lactate dehydrogenase release. Incubation with 1 and 10 mM ethanol increased the production of reactive oxygen species by 72% and 151%, respectively, which was associated with mild decreases in cell viability. Antimycin, a mitochondrial complex III inhibitor, elicited a 17-fold increase in the levels of reactive oxygen species and markedly decreased hepatocyte viability and ATP levels. Ethanol increased reactive oxygen species production and the cytosolic NADH/NAD+ ratio in antimycin-treated cells. Rotenone, a mitochondrial complex I inhibitor that allows electron flow through the flavin mononucleotide (FMN), but prevents electron flow to complex III, significantly increased reactive oxygen species production in untreated cells, but decreased reactive oxygen species production in antimycin plus ethanol-treated cells. Diphenyliodonium, a mitochondrial complex I inhibitor that inhibits electron flow through FMN, attenuated reactive oxygen species generation in all groups. Fructose prevented cytotoxicity in all treatment groups. Though they do not eliminate the participation of other intracellular compartments, these results indicate that the NADH dehydrogenase complex, as well as complex III of mitochondria, are involved in ethanol-related production of reactive oxygen species. 相似文献
105.
106.
Negative Feedback Loop of Wnt Signaling through Upregulation of Conductin/Axin2 in Colorectal and Liver Tumors 总被引:16,自引:0,他引:16
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Barbara Lustig Boris Jerchow Martin Sachs Sigrid Weiler Torsten Pietsch Uwe Karsten Marc van de Wetering Hans Clevers Peter M. Schlag Walter Birchmeier Jürgen Behrens 《Molecular and cellular biology》2002,22(4):1184-1193
Activation of Wnt signaling through beta-catenin/TCF complexes is a key event in the development of various tumors, in particular colorectal and liver tumors. Wnt signaling is controlled by the negative regulator conductin/axin2/axil, which induces degradation of beta-catenin by functional interaction with the tumor suppressor APC and the serine/threonine kinase GSK3beta. Here we show that conductin is upregulated in human tumors that are induced by beta-catenin/Wnt signaling, i.e., high levels of conductin protein and mRNA were found in colorectal and liver tumors but not in the corresponding normal tissues. In various other tumor types, conductin levels did not differ between tumor and normal tissue. Upregulation of conductin was also observed in the APC-deficient intestinal tumors of Min mice. Inhibition of Wnt signaling by a dominant-negative mutant of TCF downregulated conductin but not the related protein, axin, in DLD1 colorectal tumor cells. Conversely, activation of Wnt signaling by Wnt-1 or dishevelled increased conductin levels in MDA MB 231 and Neuro2A cells, respectively. In time course experiments, stabilization of beta-catenin preceded the upregulation of conductin by Wnt-1. These results demonstrate that conductin is a target of the Wnt signaling pathway. Upregulation of conductin may constitute a negative feedback loop that controls Wnt signaling activity. 相似文献
107.
Inko Nimmrich Waltraut Friedl Roland Kruse Stephan Pietsch Sebastian Hentsch Rainer Deuter Günther Winde O. Müller 《Human genetics》1997,100(3-4):345-349
The Min (multiple intestinal neoplasia) mouse with a germline mutation in the adenomatous polyposis coli gene serves as an animal
model for familial adenomatous polyposis coli (FAP). The number and age at onset of colorectal adenomas varies in the offspring
of Min mice crossed with other strains. The murine gene for the secretory phospholipase A2 (PLA2G2A) was found to be the main candidate for these variations. To test the hypothesis of a correlation between PLA2G2A gene alterations and human tumor development, we screened 14 patients with FAP and 20 patients with sporadic colorectal cancer
for germline and somatic PLA2G2A gene mutations. None of the individuals with FAP showed PLA2G2A germline alterations. However, a germline mutation was observed in one patient with an apparently sporadic colorectal tumor;
the wildtype allele was somatically lost in the tumor of this patient.
Received: 12 February 1997 / Accepted: 9 May 1997 相似文献
108.
Jessica Pietsch Richard Kussian Albert Sickmann Johann Bauer Gerhard Weber Mikkel Nissum Kriss Westphal Marcel Egli Jirka Grosse Johann Schönberger Robert Wildgruber Manfred Infanger Daniela Grimm 《Proteomics》2010,10(5):904-913
Using antibody‐related methods, we recently found that human thyroid cells express various proteins differently depending on whether they are cultured under normal gravity (1g) or simulated microgravity (s‐μg). In this study, we performed proteome analysis in order to identify more gravity‐sensitive thyroid proteins. Cells cultured under 1g or s‐μg conditions were sonicated. Proteins released into the supernatant and those remaining in the cell fragments were fractionated by free‐flow IEF. The fractions obtained were further separated by SDS‐gel electrophoresis. Selected gel pieces were excised and their proteins were determined by MS. A total of 235 different proteins were found. Out of 235 proteins, 37 appeared to be first identifications in human thyroid cells. Comparing SDS gel lanes of equally numbered free‐flow IEF fractions revealed similar patterns with a number of identical bands if proteins of a distinct cell line had been applied, irrespective of whether the cells had been cultured under 1g or s‐μg. Most of the identical band pairs contained identical proteins. However, the concentrations of some types of proteins were different within the two pieces of gel. Proteins that concentrated differently in such pieces of gel are considered as candidates for further investigations of gravitational sensitivity. 相似文献
109.
A. Pietsch C. Weber M. Goretzki P. C. Weber R. L. Lorenz 《Cell biochemistry and function》1995,13(3):211-216
CD36, a multifunctional adhesion receptor e.g. for thrombospondin and collagen, as well as a scavenger receptor for oxidized low density lipoprotein, is expressed e.g. on platelets and monocytes. By this dual role it might be involved in early steps of atherosclerosis like the recruitment of monocytes and formation of foam cells. We therefore studied the effects of n-3 fatty acids on CD36 expression in human monocytic cells. Incorporation of eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3) into cellular phospholipids resulted in a significant reduction of CD36 expression at the mRNA and protein level, whereas arachidonic acid (AA, C20: 4n-6) and linoleic acid (LA, C18:2n-6) tended to increase CD36 expression compared to the control. This specific down-regulation of CD36 by n-3 fatty acids in cells involved in the initiation and progression of atherogenesis and inflammation, represents a further mechanism that may contribute to the beneficial effects of n-3 polyunsaturated fatty acids (PUFA) in these disorders. 相似文献
110.
P Pietsch 《Cytobios》1991,66(264):41-61
After systemic treatment with retinoic acid (RA), Ambystoma opacum and A. punctatum larvae regenerated forelimbs with a wide variety of skeletal and gross anatomical abnormalities. Yet the musculatures within the RA-treated limb regenerates were normal even in instances where the cartilages were deformed beyond recognition as components of the limb skeleton. RA is known to induce reduplication of limb structures, sometimes entire segments. When the latter condition occurred in the present study, the corresponding replicates exhibited limb musculatures which were perfect down to minute details, yet of opposite bilateral symmetry. The results attest, firstly, to the independence of myogenesis and chondrogenesis during limb regeneration. Secondly, RA treatment unmasked an otherwise hidden potential within postembryonic salamander limb tissue for the morphogenesis of the contralateral musculature. 相似文献