Members of the marine Roseobacter lineage have been characterized as ecological generalists, suggesting that there will be challenges in assigning well-delineated ecological roles and biogeochemical functions to the taxon. To address this issue, genome sequences of 32 Roseobacter isolates were analyzed for patterns in genome characteristics, gene inventory, and individual gene/ pathway distribution using three predictive frameworks: phylogenetic relatedness, lifestyle strategy and environmental origin of the isolate. For the first framework, a phylogeny containing five deeply branching clades was obtained from a concatenation of 70 conserved single-copy genes. Somewhat surprisingly, phylogenetic tree topology was not the best model for organizing genome characteristics or distribution patterns of individual genes/pathways, although it provided some predictive power. The lifestyle framework, established by grouping isolates according to evidence for heterotrophy, photoheterotrophy or autotrophy, explained more of the gene repertoire in this lineage. The environment framework had a weak predictive power for the overall genome content of each strain, but explained the distribution of several individual genes/pathways, including those related to phosphorus acquisition, chemotaxis and aromatic compound degradation. Unassembled sequences in the Global Ocean Sampling metagenomic data independently verified this global-scale geographical signal in some Roseobacter genes. The primary findings emerging from this comparative genome analysis are that members of the lineage cannot be easily collapsed into just a few ecologically differentiated clusters (that is, there are almost as many clusters as isolates); the strongest framework for predicting genome content is trophic strategy, but no single framework gives robust predictions; and previously unknown homologs to genes for H 2 oxidation, proteorhodopsin-based phototrophy, xanthorhodpsin-based phototrophy, and CO 2 fixation by Form IC ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) expand the possible mechanisms for energy and carbon acquisition in this remarkably versatile bacterial lineage.
Recently, it has been recognized that the cannabinoid receptor CB 2 may play a functionally relevant role in the central nervous system (CNS). This role is mediated primarily through microglia, a resident population of cells in the CNS that is morphologically, phenotypically, and functionally related to macrophages. These cells also express the cannabinoid receptor CB 1 . The CB 1 receptor (CB1R) is constitutively expressed at low levels while the CB 2 receptor (CB2R) is expressed at higher levels and is modulated in relation to cell activation state. The relatively high levels of the CB2R correspond with microglia being in 'responsive' and 'primed' states, suggesting the existence of a 'window' of functional relevance during which activation of the CB2R modulates microglial activities. Signature activities of 'responsive' and 'primed' microglia are chemotaxis and antigen processing, respectively. The endocannabinoid 2-arachidonylglycerol has been reported to stimulate a chemotactic response from these cells through the CB2R. In contrast, we have shown in vivo and in vitro that the exogenous cannabinoids delta-9-tetrahydrocannabinol and CP55940 inhibit the chemotactic response of microglia to Acanthamoeba culbertsoni, an opportunistic pathogen that is the causative agent of Granulomatous Amoebic Encephalitis, through activation of the CB2R. It is postulated that these exogenous cannabinoids superimpose an inhibitory effect on pro-chemotactic endocannabinoids that are elicited in response to Acanthamoeba. Furthermore, the collective results suggest that the CB2R plays a critical immune functional role in the CNS.
Cocoa is a major source of these flavanols. However, research on the potential anti-obesity and anti-diabetic health benefits of cocoa flavanols is lacking in the literature. Furthermore, the effect that the size of these flavanols has on the extent of its beneficial properties is also unclear. The objective of this study was to evaluate the dietary effects of cocoa flavanols on the onset of obesity, insulin resistance and impaired glucose tolerance and to determine the impact that the size of these compounds has on the magnitude of this effect. Cocoa extract was fractionated into a monomer-, an oligomer-, and a polymer-rich fraction. Six groups (n=9) of C57BL/6J mice were fed either a control low-fat diet, a control high-fat diet, or a high-fat diet supplemented with 25 mg/kg*BW of cocoa extract or one of the three cocoa fractions. After 12 weeks on these diets, the oligomer-rich fraction proved to be most effective in preventing weight gain, fat mass accumulation, elevated fasting blood glucose and impaired glucose tolerance in diet-induced obese mice. This is the first long-term feeding study to examine the relative activities of cocoa constituents on diet-induced obesity and insulin resistance.iii Acknowledgements
ObjectiveTo explore the clinical efficacy and safety of subcutaneous (SC) rozanolixizumab, an anti-neonatal Fc receptor humanized monoclonal antibody, in patients with generalized myasthenia gravis (gMG).MethodsIn this phase 2a, randomized, double-blind, placebo-controlled, 2-period, multicenter trial (NCT03052751), patients were randomized (1:1) in period 1 (days 1–29) to 3 once-weekly (Q1W) SC infusions of rozanolixizumab 7 mg/kg or placebo. In period 2 (days 29–43), patients were re-randomized to either rozanolixizumab 7 mg/kg or 4 mg/kg (3 Q1W SC infusions), followed by an observation period (days 44–99). Primary endpoint: change from baseline to day 29 in Quantitative Myasthenia Gravis (QMG) score. Secondary endpoints: change from baseline to day 29 in MG-Activities of Daily Living (MG-ADL) and MG-Composite (MGC) scores; safety.ResultsForty-three patients were randomized (rozanolixizumab: 21 patients; placebo: 22 [period 1]). Least squares (LS) mean change from baseline to day 29 for rozanolixizumab vs placebo: QMG (LS mean: −1.8 vs −1.2; difference: −0.7; 95% UCL: 0.8; p = 0.221; not statistically significant), MG-ADL (LS mean: −1.8 vs −0.4; difference: −1.4; 95% UCL: −0.4), and MGC (LS mean: −3.1 vs −1.2; difference: −1.8; 95% UCL: 0.4) scores. Efficacy measures continued to improve with rozanolixizumab 7 mg/kg in period 2. The most common adverse event in period 1 was headache (rozanolixizumab: 57%; placebo: 14%).ConclusionWhile change from baseline in QMG was not statistically significant, the data overall suggest rozanolixizumab may provide clinical benefit in patients with gMG and was generally well tolerated. Phase 3 evaluation is ongoing (NCT03971422).Classification of evidenceThis study provides class I evidence that for patients with gMG, rozanolixizumab is well tolerated, but did not significantly improve QMG score.
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