220 research outputs found

    New Insights into the Skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea)

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    The skull of the Cretaceous pterosaur Istiodactylus latidens, a historically important species best known for its broad muzzle of interlocking, lancet-shaped teeth, is almost completely known from the broken remains of several individuals, but the length of its jaws remains elusive. Estimates of I. latidens jaw length have been exclusively based on the incomplete skull of NHMUK R3877 and, perhaps erroneously, reconstructed by assuming continuation of its broken skull pieces as preserved in situ. Here, an overlooked jaw fragment of NHMUK R3877 is redescribed and used to revise the skull reconstruction of I. latidens. The new reconstruction suggests a much shorter skull than previously supposed, along with a relatively tall orbital region and proportionally slender maxilla, a feature documented in the early 20th century but ignored by all skull reconstructions of this species. These features indicate that the skull of I. latidens is particularly distinctive amongst istiodactylids and suggests greater disparity between I. latidens and I. sinensis than previously appreciated. A cladistic analysis of istiodactylid pterosaurs incorporating new predicted I. latidens skull metrics suggests Istiodactylidae is constrained to five species (Liaoxipterus brachyognathus, Lonchengpterus zhoai, Nurhachius ignaciobritoi, Istiodactylus latidens and Istiodactylus sinensis) defined by their distinctive dentition, but excludes the putative istiodactylids Haopterus gracilis and Hongshanopterus lacustris. Istiodactylus latidens, I. sinensis and Li. brachyognathus form an unresolved clade of derived istiodactylids, and the similarity of comparable remains of I. sinensis and Li. brachyognathus suggest further work into their taxonomy and classification is required. The new skull model of I. latidens agrees with the scavenging habits proposed for these pterosaurs, with much of their cranial anatomy converging on that of habitually scavenging birds

    Treatment with Natalizumab in Relapsing–Remitting Multiple Sclerosis Patients Induces Changes in Inflammatory Mechanism

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    Natalizumab is a widely accepted drug for the relapsing–remitting subtype of multiple sclerosis (RRMS). The present longitudinal exploratory study in RRMS patients analyzes the effects of natalizumab treatment on the levels of pro-inflammatory and anti-inflammatory cytokine protein levels and also the frequency and suppressor function of regulatory T cells. Flow cytometry was used to determine cytokines and regulatory T cell frequency while regulatory T cell suppressor function was assayed in vitro at different time-points after starting with natalizumab. Results showed serum levels of pro-inflammatory interferon gamma and interleukin (IL)-12p70, as well as anti-inflammatory IL-4 and IL-10, were elevated just a few hours or days after first IV infusion of natalizumab. Interestingly, other cytokines like IL-5 or IL-13 were also elevated while pro-inflammatory IL-17, IL-2, and IL-1β increased only after a long-term treatment, suggesting different immune mechanisms. In contrast, we did not observe any effect of natalizumab treatment on regulatory T cell frequency or activity. In conclusion, these results suggest natalizumab has other immunological effects beyond VLA-4 interaction and inhibition of CNS extravasation, the relevance of which is as yet unknown and warrants further investigation

    Characterization of Changes in Serum Anti-Glycan Antibodies in Crohn's Disease – a Longitudinal Analysis

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    INTRODUCTION: Anti-glycan antibodies are a promising tool for differential diagnosis and disease stratification of patients with Crohn's disease (CD). We longitudinally assessed level and status changes of anti-glycan antibodies over time in individual CD patients as well as determinants of this phenomenon. METHODS: 859 serum samples derived from a cohort of 253 inflammatory bowel disease (IBD) patients (207 CD, 46 ulcerative colitis (UC)) were tested for the presence of anti-laminarin (Anti-L), anti-chitin (Anti-C), anti-chitobioside (ACCA), anti-laminaribioside (ALCA), anti-mannobioside (AMCA) and anti-Saccharomyces cerevisiae (gASCA) antibodies by ELISA. All patients had at least two and up to eleven serum samples taken during the disease course. RESULTS: Median follow-up time for CD was 17.4 months (Interquartile range (IQR) 8.0, 31.6 months) and for UC 10.9 months (IQR 4.9, 21.0 months). In a subgroup of CD subjects marked changes in the overall immune response (quartile sum score) and levels of individual markers were observed over time. The marker status (positive versus negative) remained widely stable. Neither clinical phenotype nor NOD2 genotype was associated with the observed fluctuations. In a longitudinal analysis neither changes in disease activity nor CD behavior led to alterations in the levels of the glycan markers. The ability of the panel to discriminate CD from UC or its association with CD phenotypes remained stable during follow-up. In the serum of UC patients neither significant level nor status changes were observed. CONCLUSIONS: While the levels of anti-glycan antibodies fluctuate in a subgroup of CD patients the antibody status is widely stable over time

    Fibrinogen beta variants confer protection against coronary artery disease in a Greek case-control study

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    <p>Abstract</p> <p>Background</p> <p>Although plasma fibrinogen levels are related to cardiovascular risk, data regarding the role of fibrinogen genetic variation in myocardial infarction (MI) or coronary artery disease (CAD) etiology remain inconsistent. The purpose of the present study was to investigate the effect of <it>fibrinogen A (FGA)</it>, <it>fibrinogen B (FGB) </it>and <it>fibrinogen G (FGG) </it>gene SNPs and haplotypes on susceptibility to CAD in a homogeneous Greek population.</p> <p>Methods</p> <p>We genotyped for rs2070022, rs2070016, rs2070006 in <it>FGA </it>gene, the rs7673587, rs1800789, rs1800790, rs1800788, rs1800787, rs4681 and rs4220 in <it>FGB </it>gene and for the rs1118823, rs1800792 and rs2066865 SNPs in <it>FGG </it>gene applying an arrayed primer extension-based genotyping method (APEX-2) in a sample of CAD patients (n = 305) and controls (n = 305). Logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), before and after adjustment for potential confounders.</p> <p>Results</p> <p>None of the <it>FGA </it>and <it>FGG </it>SNPs and <it>FGA, FGB, FGG </it>and <it>FGA-FGG </it>haplotypes was associated with disease occurrence after adjustment. Nevertheless, rs1800787 and rs1800789 SNPs in <it>FGB </it>gene seem to decrease the risk of CAD, even after adjustment for potential confounders (OR = 0.42, 95%CI: 0.19-0.90, p = 0.026 and OR = 0.44, 95%CI:0.21-0.94, p = 0.039, respectively).</p> <p>Conclusions</p> <p><it>FGA </it>and <it>FGG </it>SNPs as well as <it>FGA, FGB, FGG </it>and <it>FGA-FGG </it>haplotypes do not seem to be important contributors to CAD occurrence in our sample. On the contrary, <it>FGB </it>rs1800787 and rs1800789 SNPs seem to confer protection to disease onset lowering the risk by about 50% in homozygotes for the minor alleles.</p

    The multi-societal European consensus on the terminology, diagnosis and management of patients with synchronous colorectal cancer and liver metastases:an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE

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    Background: Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases with a focus on terminology, diagnosis and management. Methods: This project was a multi-organisational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis and management. Statements were refined during an online Delphi process and those with 70% agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising twelve key statements. Results: Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term “early metachronous metastases” applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour with “late metachronous metastases” applied to those detected after 12 months. Disappearing metastases applies to lesions which are no longer detectable on MR scan after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways including systemic chemotherapy, synchronous surgery and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed. Conclusions: The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases.</p

    The multi-societal European consensus on the terminology, diagnosis and management of patients with synchronous colorectal cancer and liver metastases:an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE

    Get PDF
    Background: Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases with a focus on terminology, diagnosis and management. Methods: This project was a multi-organisational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis and management. Statements were refined during an online Delphi process and those with 70% agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising twelve key statements. Results: Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term “early metachronous metastases” applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour with “late metachronous metastases” applied to those detected after 12 months. Disappearing metastases applies to lesions which are no longer detectable on MR scan after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways including systemic chemotherapy, synchronous surgery and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed. Conclusions: The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases

    Temporary reduction in daily global CO2 emissions during the COVID-19 forced confinement

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    Government policies during the COVID-19 pandemic have drastically altered patterns of energy demand around the world. Many international borders were closed and populations were confined to their homes, which reduced transport and changed consumption patterns. Here we compile government policies and activity data to estimate the decrease in CO2 emissions during forced confinements. Daily global CO2 emissions decreased by –17% (–11 to –25% for ±1σ) by early April 2020 compared with the mean 2019 levels, just under half from changes in surface transport. At their peak, emissions in individual countries decreased by –26% on average. The impact on 2020 annual emissions depends on the duration of the confinement, with a low estimate of –4% (–2 to –7%) if prepandemic conditions return by mid-June, and a high estimate of –7% (–3 to –13%) if some restrictions remain worldwide until the end of 2020. Government actions and economic incentives postcrisis will likely influence the global CO2 emissions path for decades

    Effects of acute tryptophan depletion on executive function in healthy male volunteers

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    BACKGROUND: Neurocognitive impairment is frequently described in a number of psychiatric disorders and may be a direct consequence of serotonergic dysfunction. As impairments in executive functions are some of the most frequently described, the purpose of this study was to examine the performance of normal volunteers on a range of executive tasks following a transient reduction of central serotonin (5-HT) levels using the method of acute tryptophan depletion (ATD). METHODS: Fifteen healthy male subjects participated in a within-subject, double-blind, counterbalanced crossover study. ATD was induced by ingestion of a 100 g amino-acid drink. Executive function was evaluated using the Wisconsin Card Sorting Test, Stroop, Verbal Fluency and Trail Making. Visual analogue scales were administered to assess mood. RESULTS: Plasma free and total tryptophan concentrations were significantly reduced by the depleting drink (P < 0.001). ATD selectively improved motor speed/ attention on the Trails A test (P = 0.027), with no effect on subjective ratings of mood. Interaction effects between drink and the order of drink administration were observed on most neurocognitive tests. CONCLUSIONS: The improvement in simple motor speed/ attention following ATD is in keeping with the ascribed role of 5-HT in the cortex, however performance on tests of executive function is not robustly altered. The presence of interaction effects on most tasks suggests that subtle changes may occur but are masked, possibly by simple learning effects, in the context of a crossover design. This has implications for the design of future studies, particularly those examining executive functions

    Alanine Racemase Mutants of Burkholderia pseudomallei and Burkholderia mallei and Use of Alanine Racemase as a Non-Antibiotic-Based Selectable Marker

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    Burkholderia pseudomallei and Burkholderia mallei are category B select agents and must be studied under BSL3 containment in the United States. They are typically resistant to multiple antibiotics, and the antibiotics used to treat B. pseudomallei or B. mallei infections may not be used as selective agents with the corresponding Burkholderia species. Here, we investigated alanine racemase deficient mutants of B. pseudomallei and B. mallei for development of non-antibiotic-based genetic selection methods and for attenuation of virulence. The genome of B. pseudomallei K96243 has two annotated alanine racemase genes (bpsl2179 and bpss0711), and B. mallei ATCC 23344 has one (bma1575). Each of these genes encodes a functional enzyme that can complement the alanine racemase deficiency of Escherichia coli strain ALA1. Herein, we show that B. pseudomallei with in-frame deletions in both bpsl2179 and bpss0711, or B. mallei with an in-frame deletion in bma1575, requires exogenous d-alanine for growth. Introduction of bpsl2179 on a multicopy plasmid into alanine racemase deficient variants of either Burkholderia species eliminated the requirement for d-alanine. During log phase growth without d-alanine, the viable counts of alanine racemase deficient mutants of B. pseudomallei and B. mallei decreased within 2 hours by about 1000-fold and 10-fold, respectively, and no viable bacteria were present at 24 hours. We constructed several genetic tools with bpsl2179 as a selectable genetic marker, and we used them without any antibiotic selection to construct an in-frame ΔflgK mutant in the alanine racemase deficient variant of B. pseudomallei K96243. In murine peritoneal macrophages, wild type B. mallei ATCC 23344 was killed much more rapidly than wild type B. pseudomallei K96243. In addition, the alanine racemase deficient mutant of B. pseudomallei K96243 exhibited attenuation versus its isogenic parental strain with respect to growth and survival in murine peritoneal macrophages
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