674 research outputs found
Boosting Adaptive Immunity: A New Role for PAFR Antagonists.
We have previously shown that the Platelet-Activating Factor Receptor (PAFR) engagement in murine macrophages and dendritic cells (DCs) promotes a tolerogenic phenotype reversed by PAFR-antagonists treatment in vitro. Here, we investigated whether a PAFR antagonist would modulate the immune response in vivo. Mice were subcutaneously injected with OVA or OVA with PAFR-antagonist WEB2170 on days 0 and 7. On day 14, OVA-specific IgG2a and IgG1 were measured in the serum. The presence of WEB2170 during immunization significantly increased IgG2a without affecting IgG1 levels. When WEB2170 was added to OVA in complete Freund's adjuvant, enhanced IgG2a but not IgG1 production was also observed, and CD4+ FoxP3+ T cell frequency in the spleen was reduced compared to mice immunized without the antagonist. Similar results were observed in PAFR-deficient mice, along with increased Tbet mRNA expression in the spleen. Additionally, bone marrow-derived DCs loaded with OVA were transferred into naïve mice and their splenocytes were co-cultured with fresh OVA-loaded DCs. CD4(+) T cell proliferation was higher in the group transferred with DCs treated with the PAFR-antagonist. We propose that the activation of PAFR by ligands present in the site of immunization is able to fine-tune the adaptive immune response
Two Generations of Hexagonal CaAl_2Si_2O_8 (Dmisteinbergite) in the Type B2 FUN CAI STP-1
Dmisteinbergite (dmist) is a metastable hexag-onal form of CaAl_2Si_2O_8, with space group of P6_3/mcm, a = 5.10Å and c = 14.72Å [1]. First occurrence of meteoritic dmist has been reported in the Allende Type B2 FUN CAI STP-1 [2], where it appears to have crystallized from a ^(16)O-rich (Δ^(17)O ~ −25‰) silicate melt via rapid cooling [3]. Here we report on an-other textural occurrence of dmist in STP-1 - ^(16)O-poor (Δ^(17)O ~ −2‰) fine-grained crystals in alteration zone of the inclusion
Association of serum immunoglobulin G (IgG) levels against two periodontal pathogens and prothrombotic state: a clinical pilot study
<p>Abstract</p> <p>Objective</p> <p>Periodontitis is associated with cardiovascular diseases (CVD). In our previous studies a prothrombotic state has been observed in periodontitis, which contributes to the risk of CVD. The aim of this study was to investigate whether serum IgG levels against <it>Aggregatibacter actinomycetemcomitans (Aa) </it>and <it>Porphyromonas gingivalis (Pg) </it>in periodontitis were associated with a prothrombotic state.</p> <p>Materials and methods</p> <p>Patients with moderate (n = 38) and severe periodontitis (n = 30) and controls (n = 24) were recruited. We explored correlations between serum anti-<it>Aa </it>and anti-<it>Pg </it>IgG and plasma levels of markers of prothrombotic state (von Willebrand Factor [vWF], prothrombin fragment 1+2 [F1+2], plasminogen activator inhibitor-1 [PAI-1] and D-dimer). Multivariate analyses were performed considering several major potential contributing factors.</p> <p>Results</p> <p>Periodontitis patients showed higher anti-<it>Aa </it>IgG (<it>p </it>= 0.015) than controls but not for <it>Pg </it>(<it>p </it>= 0.320). In periodontitis patients, body mass index and anti-<it>Aa </it>IgG showed a positive correlation with vWF (β = 0.297, <it>p </it>= 0.010 and β = 0.248, <it>p </it>= 0.033 respectively).</p> <p>Conclusions</p> <p>In periodontitis, infection with <it>Aa </it>together with other well accepted risk factors for CVD, may play a role in increasing the risk for prothrombotic state.</p
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Checklist of marine and estuarine fishes from the Alaska–Yukon Border, Beaufort Sea, to Cabo San Lucas, Mexico
This paper is a checklist of the fishes that have been documented, through both published and unpublished sources, in marine and estuarine waters, and out 200 miles, from the United States-Canadian border on the Beaufort Sea to Cabo San Lucas, Mexico. A minimum of 241 families and 1,644 species are known within this range, including both native and nonnative species. For each of these species, we include maximum size, geographic and depth ranges, whether it is native or nonnative, as well as a brief mention of any taxonomic issues
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Spatial Distribution, Temporal Changes, and Knowledge Gaps in Basking Shark (Cetorhinus maximus) Sightings in the California Current Ecosystem
Among the largest fish species, the basking shark (Cetorhinus maximus) is found circumglobally in temperate and tropical waters. Though historical documents have recorded their presence in the California Current Ecosystem (CCE), basking sharks are now only rarely observed in this part of their range. We compiled recent and historical data from systematic surveys (1962–1997) and other sources (1973–2018) to (i) examine temporal patterns of basking shark sightings in the CCE, and (ii) determine the spatial, temporal, and environmental drivers that have affected basking shark presence and distribution here for the last 50 years. We first calculated variation in basking shark sightings and school size over time. We then generated species distribution models using the systematic survey data and evaluated the performance of these models against the more recent non-systematic sightings data. The sightings records indicated that the number of shark sightings was variable across years, but the number and probability of sightings declined in the mid-1980s. The systematic survey data showed up to nearly 4,000 sharks sighted per year until the 1990s, after which there were no sightings reported. In parallel, there was more than a 50% decline in school size from the 1960s to the 1980s (57.2 to 24.0 individuals per group). During the subsequent decades in the non-systematic data (>1990), less than 60 sharks were sighted per year. There were no schools larger than 10 reported, and the mean school size in the last decade (2010s) was 3.53 individuals per group. Low sea surface temperature and high chlorophyll a concentration increased sightings probability, and prevailing climatic oscillations (El Nino-Southern Oscillation index, North Pacific Gyre Oscillation, Pacific Decadal Oscillation) were also correlated with basking shark presence. Lastly, we observed a significant shift in the seasonality of sightings, from the fall and spring during the systematic survey period to the summer months after the 2000s. We conclude by offering suggestions for future research and conservation efforts; specifically, coordinating the documentation of fisheries mortalities and sightings throughout the Pacific basin would facilitate more robust population estimates and identify sources of mortality. Additionally, monitoring shark fin markets and developing region-specific genetic markers would help ensure that convention on international trade in endangered species (CITES) regulations are being followed
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Trophic guilds of marine predators in the California Current Large Marine Ecosystem
Quantifying trophic relationships of marine species is fundamental to the construction and performance of ecosystem models, development of effective ecosystem-based fisheries management strategies, and support of trait-based approaches to ecological risk assessment. Accounting for food web dynamics in taxonomically diverse ecosystems, such as the California Current Large Marine Ecosystem (CCLME), is especially challenging because of the sheer number of trophic linkages and their inherent variability. Consequently, analyses that can inform the most appropriate means of aggregating species or other taxonomic groups into assemblages or guilds are critical to reducing system complexity for modeling and management, particularly when data are limited. To provide a methodological approach that is globally applicable in such cases, we define trophic guilds within biogeographic regions of the CCLME, compare results among these regions, and discuss ecological and management implications. Within each biogeographic region, predator guilds were clearly demarcated by foraging habitat (benthic, nearshore pelagic, offshore pelagic), scale of foraging movements, and trophic position. Furthermore, trophic guilds were distinctive for each region, with species composition and the noted ecological characteristics largely driving guild structure. Predator species that are reliant on continental slope and offshore foraging habitat, such as adult Pacific Hake, have diets that are representative of these areas and are similar throughout the CCLME. Generally, larger, more mobile predators that typically feed in deeper offshore waters, including swordfish, sea lions, and sharks clustered together in multiple bioregions along the coast; all reliant primarily on fishes and squids. Throughout bioregions, groundfishes preyed on benthic invertebrates (e.g., decapods, amphipods, polychaetes), while shelf-oriented pelagic predators, including smaller salmon, preyed on pelagic invertebrates (e.g., euphausiids, copepods, gelatinous zooplankton). A large number of forage taxa that are well represented in this study have dynamics largely dependent on oceanographic conditions at a regional scale (e.g., decapods), basin scale (e.g., copepods), or a combination of both (e.g., euphausiids, Northern Anchovy). Such distinctions indicate that spatial and temporal scales of coherence of predators and prey also must be considered in development of ecosystem models and evaluation of management strategies. Our study quantifies the spatial coherence of predator guilds integrated over decades within and across bioregions of the CCLME, providing an improved understanding of regional ecosystem functioning. The analytical approach we developed may be easily extended to address similar ecological and ecosystem based fisheries management priorities in other marine regions
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