22 research outputs found

    Geometric invariant theory of syzygies, with applications to moduli spaces

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    We define syzygy points of projective schemes, and introduce a program of studying their GIT stability. Then we describe two cases where we have managed to make some progress in this program, that of polarized K3 surfaces of odd genus, and of genus six canonical curves. Applications of our results include effectivity statements for divisor classes on the moduli space of odd genus K3 surfaces, and a new construction in the Hassett-Keel program for the moduli space of genus six curves.Comment: v1: 23 pages, submitted to the Proceedings of the Abel Symposium 2017, v2: final version, corrects a sign error and resulting divisor class calculations on the moduli space of K3 surfaces in Section 5, other minor changes, In: Christophersen J., Ranestad K. (eds) Geometry of Moduli. Abelsymposium 2017. Abel Symposia, vol 14. Springer, Cha

    Acute Modulation of Toll-Like Receptors by Insulin

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    OBJECTIVE—Low-dose insulin infusion has been shown to exert a prompt and powerful anti-inflammatory effect. Toll-like receptors (TLRs) are major determinants of the inflammatory response to viral and bacterial pathogens. We have now hypothesized that low-dose insulin infusion in obese type 2 diabetic patients suppresses TLR expression

    Evidence for metabolic endotoxemia in obese and diabetic Gambian women.

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    OBJECTIVE: Emerging evidence from animal models suggests that translocation of bacterial debris across a leaky gut may trigger low-grade inflammation, which in turn drives insulin resistance. The current study set out to investigate this phenomenon, termed 'metabolic endotoxemia', in Gambian women. METHODS: In a cross-sectional study, we recruited 93 age-matched middle-aged urban Gambian women into three groups: lean (body mass index (BMI): 18.5-22.9 kg m(-2)), obese non-diabetic (BMI: 30.0 kg m(-2)) and obese diabetic (BMI: 30.0 kg m(-2) and attending a diabetic clinic). We measured serum bacterial lipopolysaccharide (LPS) and endotoxin-core IgM and IgG antibodies (EndoCAb) as measures of endotoxin exposure and interleukin-6 (IL-6) as a marker of inflammation. RESULTS: Inflammation (IL-6) was independently and positively associated with both obesity and diabetes (F=12.7, P<0.001). LPS levels were highest in the obese-diabetic group compared with the other two groups (F=4.4, P<0.02). IgM EndoCAb (but not total IgM) was highly significantly reduced in the obese (55% of lean value) and obese diabetic women (30% of lean; F=21.7, P<0.0001 for trend) compared with lean women. CONCLUSION: These data support the hypothesis that gut-derived inflammatory products are associated with obesity and diabetes. Confirmation of these findings and elucidation of the role of the microbiota, gut damage and the pathways for translocation of bacterial debris, could open new avenues for prevention and treatment of type 2 diabetes

    Metabolic endotoxaemia in childhood obesity

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    BACKGROUND: Childhood obesity is associated with chronic low-grade inflammation considered as a precursor to metabolic disease; however, the underlying mechanisms for this remain unclear. Studies in adults have implicated gut derived gram-negative bacterial fragments known as lipopolysaccharide or endotoxin, activating the inflammatory response, whilst the importance in childhood obesity is unclear. The aim of this research is to understand the relationship between circulating endotoxin in childhood obesity, and its’ association with inflammatory and cardiovascular (CV) injury biomarkers. METHODS: Fasted blood was obtained from children with varying degrees of obesity (age: 13.9 ± 2.3Yr; BMI: 35.1 ± 5.2 Kg/m(2); n = 60). Multiplex CVD biomarker immunoassays were used to determine systemic levels of inflammatory and vascular injury biomarkers, such as tumour necrosis factor-α (TNF-α), interleukin (IL-) 1β, 6, 8 and 10, plasminogen activator inhibitor-1 (PAI-1), soluble intercellular adhesion molecule type-1 (sICAM-1), matrix metalloproteinase-9 (MMP-9), myeloperoxidase (MPO) and vascular endothelial growth factor (VEGF) as well as endotoxin levels. RESULTS: Endotoxin levels demonstrated a significant and positive correlation with the markers for inflammation, vascular injury and atherogenesis (TNF-α: r(2) = 0.077, p < 0.05; PAI-1: r(2) = 0.215, p < 0.01; sICAM-1: r(2) = 0.159, p < 0.01; MMP-9: r(2) = 0.159, p < 0.01; MPO: r(2) = 0.07, p < 0.05; VEGF: r(2) = 0.161, p < 0.01). Males demonstrated significantly higher circulating endotoxin than females (Males: 9.63 ± 5.34 EU/ml; p = 0.004; Females: 5.56 ± 4.06 EU/ml; n = 60) in these BMI and age-matched cohorts. CONCLUSION: The present study demonstrates for the first time a significant association between circulating endotoxin and biomarkers of metabolic risk in children as young as 11 years. Thus, endotoxin-mediated sub-clinical inflammation during childhood obesity may be a key contributor to T2DM and CVD development later in life
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