188 research outputs found
Oleacein and foam cell formation in human monocyte-derived macrophages: a potential strategy against early and advanced atherosclerotic lesions
Background: Oleacein is a secoiridoid group polyphenol found mostly in Olea europea L. and Ligustrum vulgare L. (Oleaceae). The aim of the present study was to investigate a potential role of oleacein in prevention of the foam cell formation. Materials and Methods: Oleacein was isolated from Ligustrum vulgare leaves. Human monocyte-derived macrophages were obtained from monocytes cultured with Granulocyte-macrophage colony-stimulating factor (GM-CSF)Then, cells were incubated with 20 M or 50 M of oleacein and with oxidized low-density lipoprotein (oxLDL) (50 g/mL). Visualization of lipid deposition within macrophages was carried out using Oil-Red-O. Expression of CD36, Scavenger receptor A1 (SRA1) and Lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) was determined by Reverse transcription polymerase chain reaction (RT-PCR) and by flow cytometry. Apoptosis was determined by flow cytometry using Annexin V assay. STAT3 and Acyl-coenzyme A:cholesterol acyltransferase type 1 (ACAT1)levels were determined by ELISA. P-STAT3, P-JAK1, P-JAK2 expressions were determined by Western blot (WB). Results: Oleacein in dose-dependent manner significantly reduced lipid deposits in macrophages as well as their expression of selected scavenger receptors. The highest decrease of expression was found for CD36 and SRA1 receptors, from above 20% to more than 75% compared to oxLDL and the lowest for LOX-1 receptor, from approx. 8% to approx. 25% compared to oxLDL-stimulated macrophages. Oleacein significantly reduced (2.5-fold) early apoptosis of oxLDL-stimulated macrophages. Moreover, oleacein significantly increased the protein expression of JAK/STAT3 pathway and had no effect on ACAT1 level. Conclusions: Our study demonstrates, for the first time, that oleacein inhibits foam cell formation in human monocyte-derived macrophages and thus can be a valuable tool in the prevention of early and advanced atherosclerotic lesions
Denture-related stomatitis is associated with endothelial dysfunction
Oral inflammation, such as periodontitis, can lead to endothelial dysfunction, accelerated atherosclerosis, and vascular dysfunction. The relationship between vascular dysfunction and other common forms of oral infections such as denture-related stomatitis (DRS) is unknown. Similar risk factors predispose to both conditions including smoking, diabetes, age, and obesity. Accordingly, we aimed to investigate endothelial function and major vascular disease risk factors in 44 consecutive patients with dentures with clinical and microbiological features of DRS (n = 20) and without DRS (n = 24). While there was a tendency for higher occurrence of diabetes and smoking, groups did not differ significantly in respect to major vascular disease risk factors. Groups did not differ in main ambulatory blood pressure, total cholesterol, or even CRP. Importantly, flow mediated dilatation (FMD) was significantly lower in DRS than in non-DRS subjects, while nitroglycerin induced vasorelaxation (NMD) or intima-media thickness (IMT) was similar. Interestingly, while triglyceride levels were normal in both groups, they were higher in DRS subjects, although they did not correlate with either FMD or NMD. Conclusions. Denture related stomatitis is associated with endothelial dysfunction in elderly patients with dentures. This is in part related to the fact that diabetes and smoking increase risk of both DRS and cardiovascular disease
Laser-produced plasma EUV source based on tin-rich, thin-layer targets
In this paper a new approach to a laser-produced plasma EUV source based on a tin target is presented. A thin layer of pure tin and composite layers consisting of Sn with Si, SiO and LiF are investigated. The target composed of several thin layers produces less debris than the other targets and provides a conversion efficiency (CE) in the 13.5-nm +/- 1% band at least comparable to the CE for the pure tin slab target. The largest CE was observed for the target composed of a mixture of Sn and LiF, due to the fact that lithium, similarly to tin, is a strong emitter at 13.5 nm
Supplementation of standard antibiotic therapy with oral probiotics for bacterial vaginosis and aerobic vaginitis : a randomised, double-blind, placebo-controlled trial
BACKGROUND: This multicentre, randomised, double-blind, placebo-controlled trial was performed to determine whether the use of oral probiotic preparation (prOVag®) containing three Lactobacillus strains together with standard metronidazole treatment and also targeted antibiotic treatment (following the failure of metronidazole therapy) could reduce the recurrence rates of bacterial vaginosis (BV) and aerobic vaginitis (AV). METHODS: Patients at private gynaecological clinics in Poland with histories of recurrent BV/AV and current symptoms were randomly allocated to receive metronidazole and probiotic or placebo, and assessed monthly on visits II and III-V. The total number of study visits was 5–6 (I, II, II bis – if applicable, III, IV, V). One probiotic or placebo capsule was administered with metronidazole/targeted antibiotic twice daily for 10 days; during follow up, patients took one capsule daily for 10 days perimenstrually. Clinical examination and vaginal swabbing were performed at each visit. Primary outcomes were clinical or microbiological BV/AV recurrence and probiotic safety. Secondary outcomes were vaginal pH, Nugent score, and Lactobacillus counts in the vaginal microbiota. Safety analysis was performed in 578 (probiotic, n = 285; placebo, n = 293) 18–50-year-old women who were randomised. RESULTS: BV/AV was confirmed microbiologically in 241 (probiotic, n = 118; placebo, n = 123) participants, who continued the trial. Data from 154 (probiotic, n = 73; placebo, n = 81) participants who completed the study were analysed to determine the efficacy of prOVag. Additional analyses included 37 (probiotic, n = 22; placebo, n = 15) participants who received targeted antibiotics and probiotics or placebo. prOVag lengthened the time to clinical relapse of BV/AV symptoms up to 51 % (p < 0.05) compared with placebo; AV relapse was delayed by up to 76 % (p < 0.05). Probiotic use also reduced and maintained low vaginal pH and Nugent score, and increased vaginal Lactobacillus counts following standard treatment. CONCLUSION: This study demonstrated that oral probiotics lengthened remission in patients with recurrent BV/AV and improved clinical and microbiological parameters. TRIAL REGISTRATION: NCT01993524; 20 November 2013. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12905-015-0246-6) contains supplementary material, which is available to authorized users
Periodontitis as an inflammatory trigger in hypertension: from basic immunology to clinical implications
Hypertension and periodontitis are both highly prevalent co-morbidities worldwide, and their occurrence increases with age. Multiple observational epidemiological studies have shown that periodontitis is associated with an increased cardiovascular disease (CVD) occurrence. Large systematic reviews and metanalyses further show that periodontitis increases the risk of hypertension and is associated with increased systolic and diastolic blood pressure. Genetic and clinical evidence, utilizing mendelian randomization and randomized clinical trials, support the causal role of periodontitis in hypertension. The mechanisms of this link remain unclear. Critical components of immune and inflammatory pathogenesis of periodontitis considerably overlap with immune mechanisms of hypertension. Clinical studies support that both C-reactive protein (CRP) levels and white blood cell counts (WBC) mediate the relationship between periodontal disease and high blood pressure. In particular, activation of Th1, Th17, T regulatory cells, and proinflammatory monocytes has been shown to be essential in both conditions. Immunosenescent dysregulated CD28null T cells have been implicated, along with key effector cytokines such as interleukin 6 (IL-6), TNF-alpha (TNF-α), interferon-gamma (IFN-γ), and interleukin 17 (IL-17). A better understanding of the relationships between hypertension and periodontitis is essential not only for possible utilization of this knowledge for a non-pharmacological approach to improving blood pressure control. It may also provide valuable pathogenetic clues linking inflammation and hypertension, which has become particularly relevant in the light of links between hypertension and autoimmune disorders or, more recently, COVID-19
Resonant third harmonic generation of KrF laser in Ar gas
Investigations of emission of harmonics from argon gas jet irradiated by 700 fs, 5 mJ pulses from a KrF laser are presented. Harmonics conversion was optimized by varying the experimental geometry and the nozzle size. For the collection of the harmonic radiation silicon and solar-blind diamond semiconductor detectors equipped with charge preamplifiers were applied. The possibility of using a single-crystal CVD diamond detector for separate measurement of the 3rd harmonic in the presence of a strong pumping radiation was explored. Our experiments show that the earlier suggested 0.7% conversion efficiency can really be obtained, but only in the case when phase matching is optimized with an elongated gas target length corresponding to the length of coherence
Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension
Recent studies have emphasized the role of perivascular inflammation in cardiovascular disease. We studied mechanisms of perivascular leukocyte infiltration in angiotensin II (Ang II)-induced hypertension and their links to vascular dysfunction. Chronic Ang II infusion in mice increased immune cell content of T cells (255 ± 130 to 1664 ± 349 cells/mg; P < 0.01), M1 and M2 macrophages, and dendritic cells in perivascular adipose tissue. In particular, the content of T lymphocytes bearing CC chemokine receptor (CCR) 1, CCR3, and CCR5 receptors for RANTES chemokine was increased by Ang II (CCR1, 15.6 ± 1.5% vs. 31 ± 5%; P < 0.01). Hypertension was associated with an increase in perivascular adipose tissue expression of the chemokine RANTES (relative quantification, 1.2 ± 0.2 vs. 3.5 ± 1.1; P < 0.05), which induced T-cell chemotaxis and vascular accumulation of T cells expressing the chemokine receptors CCR1, CCR3, and CCR5. Mechanistically, RANTES−/− knockout protected against vascular leukocyte, and in particular T lymphocyte infiltration (26 ± 5% in wild type Ang II vs. 15 ± 4% in RANTES−/−), which was associated with protection from endothelial dysfunction induced by Ang II. This effect was linked with diminished infiltration of IFN-γ-producing CD8+ and double-negative CD3+CD4−CD8− T cells in perivascular space and reduced vascular oxidative stress while FoxP3+ T-regulatory cells were unaltered. IFN-γ ex vivo caused significant endothelial dysfunction, which was reduced by superoxide anion scavenging. In a human cohort, a significant inverse correlation was observed between circulating RANTES levels as a biomarker and vascular function measured as flow-mediated dilatation (R = −0.3, P < 0.01) or endothelial injury marker von Willebrand factor (R = +0.3; P < 0.01). Thus, chemokine RANTES is important in the regulation of vascular dysfunction through modulation of perivascular inflammation.—Mikolajczyk, T. P., Nosalski, R., Szczepaniak, P., Budzyn, K., Osmenda, G., Skiba, D., Sagan, A., Wu, J., Vinh, A., Marvar, P. J., Guzik, B., Podolec, J., Drummond, G., Lob, H. E., Harrison, D. G., Guzik, T. J. Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension
Pseudomonas aeruginosa biofilm is a potent inducer of phagocyte hyperinflammation
OBJECTIVE: Pseudomonas aeruginosa effectively facilitate resistance to phagocyte killing by biofilm formation. However, the cross talk between biofilm components and phagocytes is still unclear. We hypothesize that a biofilm provides a concentrated extracellular source of LPS, DNA and exopolysaccharides (EPS), which polarize neighbouring phagocytes into an adverse hyperinflammatory state of activation. METHODS: We measured the release of a panel of mediators produced in vitro by murine neutrophils and macrophages exposed to various biofilm components of P. aeruginosa cultures. RESULTS: We found that conditioned media from a high biofilm-producing strain of P. aeruginosa, PAR5, accumulated high concentrations of extracellular bacterial LPS, DNA and EPS by 72 h. These conditioned media induced phagocytes to release a hyperinflammatory pattern of mediators, with enhanced levels of TNF-α, IL-6, IL12p40, PGE2 and NO. Moreover, the phagocytes also upregulated COX-2 and iNOS with no influence on the expression of arginase-1. CONCLUSIONS: Phagocytes exposed to biofilm microenvironment, called by us biofilm-associated neutrophils/macrophages (BANs/BAMs), display secretory properties similar to that of N1/M1-type phagocytes. These results suggest that in vivo high concentrations of LPS and DNA, trapped in biofilm by EPS, might convert infiltrating phagocytes into cells responsible for tissue injury without direct contact with bacteria and phagocytosis
The Gaia alerted fading of the FUor-type star Gaia21elv
FU Orionis objects (FUors) are eruptive young stars, which exhibit outbursts
that last from decades to a century. Due to the duration of their outbursts,
and to the fact that only about two dozens of such sources are known,
information on the end of their outbursts is limited. Here we analyse follow-up
photometry and spectroscopy of Gaia21elv, a young stellar object, which had a
several decades long outburst. It was reported as a Gaia science alert due to
its recent fading by more than a magnitude. To study the fading of the source
and look for signatures characteristic of FUors, we have obtained follow-up
near infrared (NIR) spectra using Gemini South/IGRINS, and both optical and NIR
spectra using VLT/X-SHOOTER. The spectra at both epochs show typical FUor
signatures, such as a triangular shaped -band continuum, absorption-line
dominated spectrum, and P Cygni profiles. In addition to the typical FUor
signatures, [OI], [FeII], and [SII] were detected, suggesting the presence of a
jet or disk wind. Fitting the spectral energy distributions with an accretion
disc model suggests a decrease of the accretion rate between the brightest and
faintest states. The rapid fading of the source in 2021 was most likely
dominated by an increase of circumstellar extinction. The spectroscopy
presented here confirms that Gaia21elv is a classical FUor, the third such
object discovered among the Gaia science alerts.Comment: Accepted to MNRA
Catalogue of BRITE-Constellation targets I. Fields 1 to 14 (November 2013 - April 2016)
The BRIght Target Explorer (BRITE) mission collects photometric time series
in two passbands aiming to investigate stellar structure and evolution. Since
their launches in the years 2013 and 2014, the constellation of five BRITE
nano-satellites has observed a total of more than 700 individual bright stars
in 64 fields. Some targets have been observed multiple times. Thus, the total
time base of the data sets acquired for those stars can be as long as nine
years. Our aim is to provide a complete description of ready-to-use BRITE data,
to show the scientific potential of the BRITE-Constellation data by identifying
the most interesting targets, and to demonstrate and encourage how scientists
can use these data in their research. We apply a decorrelation process to the
automatically reduced BRITE-Constellation data to correct for instrumental
effects. We perform a statistical analysis of the light curves obtained for the
300 stars observed in the first 14 fields during the first ~2.5 years of the
mission. We also perform cross-identification with the International Variable
Star Index. We present the data obtained by the BRITE-Constellation mission in
the first 14 fields it observed from November 2013 to April 2016. We also
describe the properties of the data for these fields and the 300 stars observed
in them. Using these data, we detected variability in 64% of the presented
sample of stars. Sixty-four stars or 21.3% of the sample have not yet been
identified as variable in the literature and their data have not been analysed
in detail. They can therefore provide valuable scientific material for further
research. All data are made publicly available through the BRITE Public Data
Archive and the Canadian Astronomy Data Centre.Comment: accepted by Astronomy & Astrophysics, 13 pages main text, 22 pages of
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