4,735 research outputs found
Formal groups arising from formal punctured ribbons
We investigate Picard functor of a formal punctured ribbon. We prove that
under some conditions this functor is representable by a formal group scheme.
Formal punctured ribbons were introduced in arXiv:0708.0985.Comment: 42 pages, minor change
Anti-inflammatory effects of phytocannabinoids and terpenes on inflamed Tregs and Th17 cells in vitro
Aims: Phytocannabinoids and terpenes from Cannabis sativa have demonstrated limited anti-inflammatory and analgesic effects in several inflammatory conditions. In the current study, we test the hypothesis that phytocannabinoids exert immunomodulatory effects in vitro by decreasing inflammatory cytokine expression and activation.Key methods: CD3/CD28 and lipopolysaccharide activated peripheral blood mononuclear cells (PBMCs) from healthy donors (n = 6) were treated with phytocannabinoid compounds and terpenes in vitro. Flow cytometry was used to determine regulatory T cell (Treg) and T helper 17 (Th17) cell responses to treatments. Cell pellets were harvested for qRT-PCR gene expression analysis of cytokines, cell activation markers, and inflammation related receptors. Cell culture supernatants were analysed by ELISA to quantify IL-6, TNF-α and IL-10 secretion.Main findings: In an initial screen of 20 μM cannabinoids and terpenes which were coded to blind investigators, cannabigerol (GL4a), caryophyllene oxide (GL5a) and gamma-terpinene (GL6a) significantly reduced cytotoxicity and gene expression levels of IL6, IL10, TNF, TRPV1, CNR1, HTR1A, FOXP3, RORC and NFKΒ1. Tetrahydrocannabinol (GL7a) suppression of T cell activation was associated with downregulation of RORC and NFKΒ1 gene expression and reduced IL-6 (p < 0.0001) and IL10 (p < 0.01) secretion. Cannabidiol (GL1b) significantly suppressed activation of Tregs (p < 0.05) and Th17 cells (p < 0.05) in a follow-on in vitro dose response study. IL-6 (p < 0.01) and IL-10 (p < 0.01) secretion was significantly reduced with 50 μMcannabidiol.Significance: The study provides the first evidence that cannabidiol and tetrahydrocannabinol suppress extracellular expression of both anti- and pro-inflammatory cytokines in an in vitro PBMC model of inflammation
High-Sensitivity Cardiac Troponin T and Cognitive Decline in Older Adults: Results of the Berlin Aging Study II
Introduction: There is evidence of an association between markers of cardiac injury and cognition in patients with cardiovascular disease. We hypothesized that levels of high-sensitivity cardiac troponin T (hs-cTnT) are associated with cognitive performance and cognitive decline in a population of predominantly healthy older adults. Methods: We included 1,226 predominantly healthy adults >= 60 years from the Berlin Aging Study II. Participants were recruited from the general population of the Berlin metropolitan area from 2009 to 2014. At baseline, participants underwent measurement of hs-cTnT and cognitive testing using the extended Consortium to Establish a Registry for Alzheimer's Disease (CERAD-Plus) battery. In addition, the Digit Symbol Substitution Test (DSST) was performed at baseline and at follow-up (7.3 +/- 1.4 years after the baseline visit). The CERAD test results were summarized into four cognitive domains (processing speed, executive function, visuo-construction, and memory). After summing-up the respective raw scores, we calculated standardized z scores. We performed unadjusted and adjusted linear regression models to assess links between hs-cTnT and cognitive domains. We used linear mixed models to analyze associations between hs-cTnT and cognitive decline according to changes in DSST scores over time. Results: The mean age of study participants at baseline was 68.5 (+/- 3.6) years, 49% were female, and median hs-cTnT levels were 6 ng/L (IQR 4-8 ng/L). We detected no significant association between hs-cTnT and different cognitive domains at baseline after adjustment for age, sex, education, and cardiovascular risk factors. Hs-cTnT was associated with cognitive decline, which remained statistically significant after full adjustment (adjusted beta-coefficient -0.82 (-1.28 to -0.36), p = 0.001). After stratification for sex, the association with hs-cTnT remained statistically significant in men but not in women. Conclusion: Higher hs-cTnT levels in older men are associated with cognitive decline measured with the DSST
Targeting undruggable carbohydrate recognition sites through focused fragment library design
Carbohydrate-protein interactions are key for cell-cell and host-pathogen recognition and
thus, emerged as viable therapeutic targets. However, their hydrophilic nature poses major
limitations to the conventional development of drug-like inhibitors. To address this shortcoming, four fragment libraries were screened to identify metal-binding pharmacophores
(MBPs) as novel scaffolds for inhibition of Ca2+-dependent carbohydrate-protein interactions. Here, we show the effect of MBPs on the clinically relevant lectins DC-SIGN, Langerin,
LecA and LecB. Detailed structural and biochemical investigations revealed the specificity of
MBPs for different Ca2+-dependent lectins. Exploring the structure-activity relationships of
several fragments uncovered the functional groups in the MBPs suitable for modification to
further improve lectin binding and selectivity. Selected inhibitors bound efficiently to DCSIGN-expressing cells. Altogether, the discovery of MBPs as a promising class of Ca2+-
dependent lectin inhibitors creates a foundation for fragment-based ligand design for future
drug discovery campaigns
QSAR models of human data can enrich or replace LLNA testing for human skin sensitization
An example of structural transformation of human skin sensitizers into various non-sensitizers based on interpretation of QSAR models
Alarms about structural alerts
Integrative approach for safety assessment of new chemicals by combining structural alerts and QSAR models
CD169+ Monocyte and Regulatory T Cell Subsets Are Associated with Disease Activity in Rheumatoid Arthritis
Disease activity in rheumatoid arthritis (RA) is influenced by activation of circulating and synovial immune cells. Regulatory T cells (Tregs) and monocytes are key cells that drive inflammation in RA. This study investigated if a relationship exists between disease activity in RA and circulating Treg and monocyte numbers and phenotypes. A potential sialic acid (Sia) mediated link between Tregs and monocytes was also probed in vitro. Peripheral blood mononuclear cells (PBMCs) were isolated from RA patient (n = 62) and healthy control (n = 21) blood using density gradient separation. Flow cytometry was used to count and phenotype Treg and monocyte subsets, and to sort healthy control Tregs for Sia cell culture experiments. The effects of Sia on activated Treg FoxP3 and NFκB expression was assessed by flow cytometry and concentrations of secreted TNFα, IL-10 and IFNγ determined by ELISA. High disease activity RA patients who were unresponsive to disease modifying anti-rheumatic drugs (n = 31), have significantly lower relative numbers (percentages) of CD4(+)CD25(+)CD127(−) Tregs (p < 0.01) and memory CD45RA(−)FoxP3(+) Tregs (p < 0.01), compared to low disease activity responders (n = 24). Relative numbers of non-classical CD169(+) monocytes are associated with disease activity in RA (p = 0.012). Sia reduced Treg expression of FoxP3, NFκB and cytokines in vitro. A strong association has been identified between non-classical CD169(+) monocytes and post-treatment disease activity in RA. This study also indicates that Sia can reduce Treg activation and cytokine release. We postulate that such a reduction could be mediated by interaction with sialyted proteins captured by CD169(+) monocytes
Age and Age-related Diseases: Role of Inflammation Triggers and Cytokines
Cytokine dysregulation is believed to play a key role in the remodeling of the immune system at older age, with evidence pointing to an inability to fine-control systemic inflammation, which seems to be a marker of unsuccessful aging. This reshaping of cytokine expression pattern, with a progressive tendency toward a pro-inflammatory phenotype has been called “inflamm-aging.” Despite research there is no clear understanding about the causes of “inflamm-aging” that underpin most major age-related diseases, including atherosclerosis, diabetes, Alzheimer’s disease, rheumatoid arthritis, cancer, and aging itself. While inflammation is part of the normal repair response for healing, and essential in keeping us safe from bacterial and viral infections and noxious environmental agents, not all inflammation is good. When inflammation becomes prolonged and persists, it can become damaging and destructive. Several common molecular pathways have been identified that are associated with both aging and low-grade inflammation. The age-related change in redox balance, the increase in age-related senescent cells, the senescence-associated secretory phenotype (SASP) and the decline in effective autophagy that can trigger the inflammasome, suggest that it may be possible to delay age-related diseases and aging itself by suppressing pro-inflammatory molecular mechanisms or improving the timely resolution of inflammation. Conversely there may be learning from molecular or genetic pathways from long-lived cohorts who exemplify good quality aging. Here, we will discuss some of the current ideas and highlight molecular pathways that appear to contribute to the immune imbalance and the cytokine dysregulation, which is associated with “inflammageing” or parainflammation. Evidence of these findings will be drawn from research in cardiovascular disease, cancer, neurological inflammation and rheumatoid arthritis
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