117 research outputs found
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Impact of specific functional groups in flavonoids on the modulation of platelet activation
Flavonoids exert innumerable beneficial effects on cardiovascular health including the
reduction of platelet activation, and thereby, thrombosis. Hence, flavonoids are deemed to be a
molecular template for the design of novel therapeutic agents for various diseases including
thrombotic conditions. However, the structure-activity relationships of flavonoids with platelets is
not fully understood. Therefore, this study aims to advance the current knowledge on structure-activity
relationships of flavonoids through a systematic analysis of structurally-related flavones.
Here, we investigated a panel of 16 synthetic flavones containing hydroxy or methoxy groups at
C-7,8 positions on the A-ring, with a phenyl group or its bioisosteres as the B-ring, along with
their thio analogues possessing a sulfur molecule at the 4th carbon position of the C-ring. The
antiplatelet efficacies of these compounds were analysed using human isolated platelets upon
activation with cross-linked collagen-related peptide by optical aggregometry. The results
demonstrate that the hydroxyl groups in flavonoids are important for optimum platelet inhibitory
activities. In addition, the 4-C=O and B ring phenyl groups are less critical for the antiplatelet
activity of these flavonoids. This structure-activity relationships of flavonoids upon the
modulation of platelet function may guide the design, optimisation and development of flavonoid
scaffolds as antiplatelet agents
Transient Increase in Cyclic AMP Localized to Macrophage Phagosomes
Cyclic AMP (cAMP) regulates many biological processes and cellular functions. The importance of spatially localized intracellular gradients of cAMP is increasingly appreciated. Previous work in macrophages has shown that cAMP is produced during phagocytosis and that elevated cAMP levels suppress host defense functions, including generation of proinflammatory mediators, phagocytosis and killing. However, the spatial and kinetic characteristics of cAMP generation in phagocytosing macrophages have yet to be examined. Using a Förster resonance energy transfer (FRET)-based cAMP biosensor, we measured the generation of cAMP in live macrophages. We detected no difference in bulk intracellular cAMP levels between resting cells and cells actively phagocytosing IgG-opsonized particles. However, analysis with the biosensor revealed a rapid decrease in FRET signal corresponding to a transient burst of cAMP production localized to the forming phagosome. cAMP levels returned to baseline after the particle was internalized. These studies indicate that localized increases in cAMP accompany phagosome formation and provide a framework for a more complete understanding of how cAMP regulates macrophage host defense functions
Non-Raft AC2 Defines a cAMP Signaling Compartment That Selectively Regulates IL-6 Expression in Airway Smooth Muscle Cells
Adenylyl cyclase (AC) isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions. Most cell types express multiple AC isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses in human bronchial smooth muscle cells (BSMC). Overexpression of AC2, AC3, or AC6 had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes. These data show that different AC isoforms can differentially regulate gene expression. Most notable, overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production by BSMC was induced by Fsk and select G protein-coupled receptor (GPCR) agonists, though IL-6 levels did not directly correlate with global cAMP levels. Treatment with PKA selective 6-Bnz-cAMP or Epac selective 8-CPT-2Me-cAMP cAMP analogs revealed a predominant role for PKA in cAMP-mediated induction of IL-6. IL-6 promoter mutations demonstrated that AP-1 and CRE transcription sites were required for Fsk to stimulate IL-6 expression. Our present study defines an AC2 cAMP signaling compartment that specifically regulates IL-6 expression in BSMC via Epac and PKA and demonstrates that other AC isoforms are excluded from this pool
Fatal Human Rabies due to Duvenhage Virus from a Bat in Kenya: Failure of Treatment with Coma-Induction, Ketamine, and Antiviral Drugs
Antemortem diagnosis of human rabies in a veterinarian infected when handling a herbivore in Minas Gerais, Brazil
ISSN exercise & sport nutrition review: research & recommendations
Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients
The digestion of protein and carbohydrate by the stream detritivore, Tipula abdominalis (Diptera, Tipulidae)
The digestive system of larvae of Tipula abdominalis (Diptera, Tipulidae), a stream detritivore, is poorly adapted for the digestion of the major polysaccharides in its diet, but well adapted for the digestion of protein. These crane fly larvae are unable to digest the major cell wall polysaccharides of higher plants, i.e., cellulose, hemicellulose and pectin. The only polysaccharides toward which the midguts of T. abdominalis exhibited any activity were α-amylose and laminarin, indicating that polysaccharide digestion is restricted to α-1,4-and β-1,3-glucans. The most concentrated source of these two classes of carbohydrates in submerged leaf litter would be associated fungal tissue. The midgut of T. abdominalis is strongly alkaline throughout, with a maximum pH near 11.5 in a narrow zone near the midpoint. Proteolytic activity in the midgut is extraordinarily high, and the pH optimum for midgut proteolytic activity is above 11. We conclude that the high alkalinity and high proteolytic activity observed in T. abdominalis larvae are manifestations of a highly efficient protein-digesting system, a system of crucial importance to a nitrogen-limited organism which must derive its nitrogen from a resource in which much of the limited nitrogen present is in a “bound” form in complexes of proteins with lignins and polyphenols.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47733/1/442_2004_Article_BF00346265.pd
Post-automation
Tremendous research, policy, and investment is directed towards a new wave of automation in modern societies. Most notable within discourse for the Fourth Industrial Revolution, but also in radical ideas for Fully Automated Luxury Communism, automation appears essential to the future. Advocates claim it will renew capital accumulation, boost labour productivity, and extend managerial control in sustainable systems of production and consumption. Noting criticism about future essentialism in this automation advocacy, this essay will turn to innovations in marginal industrious spaces within industrial societies. Here people are hacking, subverting and appropriating ostensibly automating technologies for purposes of creativity, collaboration, and care. Social capabilities in post-automation are being cultivated. Perhaps greater attention to the politics implied in post-automation can help open our futures to more democratic deliberation
Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls
Background The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea. Methods We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up. Findings We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01–1.03), male (1.54, 1.16–2.04), neither obese nor severely obese (1.82, 1.06–3.13 and 4.19, 2.14–8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09–2.22) or cardiovascular disease (1.33, 1.00–1.79), and shorter hospital admission (1.01 per day, 1.00–1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission). Interpretation Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19. Funding PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care. COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders
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