Effect of sugammadex on QT/QTc interval prolongation when combined with QTc-prolonging sevoflurane or propofol anaesthesia.

BACKGROUND: We evaluated the potential for QT/corrected QT (QTc) interval prolongation after sugammadex given with propofol or sevoflurane anaesthesia. METHODS: This was a two-factorial, randomized, parallel-group study in 132 healthy subjects. Anaesthesia was maintained with sevoflurane or propofol. At ~20 min following sevoflurane/propofol initiation, sugammadex 4 mg/kg or placebo was administered. Neuromuscular blocking agents were not administered. Electrocardiograms were recorded regularly. The primary variable was the time-matched mean difference in the Fridericia-corrected QT interval (QTcF) change from baseline for sugammadex versus placebo when combined with propofol or sevoflurane. No relevant QTcF prolongation was concluded if the upper one-sided 95 % confidence interval (CI) was below the 10 ms margin of regulatory non-inferiority, up to 30 min post-study drug. Blood samples were taken for pharmacokinetic analysis. An exploratory analysis evaluated potential QT/QTc effects of neostigmine 50 µg/kg/glycopyrrolate 10 µg/kg in combination with propofol. RESULTS: The estimated mean QTcF differences between sugammadex and placebo ranged from -2.4 to 0.6 ms when combined with either anaesthetic. The largest upper one-sided 95 % CI for the mean QTcF difference between sugammadex and placebo was 2 ms, occurring 2 min post-dosing. Propofol and sevoflurane resulted in mean QTcF increases exceeding 10 and 30 ms, respectively. On top of these prolongations, the effect of sugammadex was negligible at all timepoints. The mean peak sugammadex concentration was 66.5 µg/mL, with exposure similar in the sevoflurane/propofol groups. The mean QTcF changes from baseline following neostigmine/glycopyrrolate in 10 healthy subjects ranged between -1.4 and 3.6 ms. CONCLUSION: Sugammadex 4 mg/kg does not cause clinically relevant QTc interval prolongation versus placebo when combined with propofol or sevoflurane.

Accumulation of myeloperoxidase-positive neutrophils in atherosclerotic lesions in LDLR-/- mice.

OBJECTIVE: Atherosclerosis is a chronic inflammatory disease in which the immune system plays an important role. Neutrophils have not been thoroughly studied in the context of atherogenesis. Here, we investigated neutrophils in the development of murine atherosclerotic lesions. METHODS AND RESULTS: LDLR-/- mice were given a high-fat diet for different time periods and subsequently atherosclerotic lesions were studied by immunohistochemistry. Staining with anti-Ly-6G monoclonal antibody, a specific marker for neutrophils, revealed a marked accumulation of neutrophils during atherosclerosis development. Neutrophils were observed in the lesion, attached to the cap, and in the arterial adventitia. In addition, at some sites, neutrophil accumulation colocalized with endothelial E-selectin expression. Immunofluorescence double staining with anti-myeloperoxidase and anti-Ly-6G antibodies demonstrated the presence of myeloperoxidase in atherosclerotic lesions and its colocalization with neutrophils. After introducing the high-fat diet, levels of circulating myeloperoxidase in plasma strongly increased, with a peak at 6 weeks and a subsequent decrease to almost normal levels after 16 weeks of diet. CONCLUSIONS: We here demonstrate for the first time the presence of neutrophils and myeloperoxidase in murine atherosclerotic lesions. As a major cell type in inflammatory responses the neutrophil may also be an important mediator in the development of atherosclerosis.

Polycyclic aromatic hydrocarbons induce an inflammatory atherosclerotic plaque phenotype irrespective of their DNA binding properties.

Although it has been demonstrated that carcinogenic environmental polycyclic aromatic hydrocarbons (PAHs) cause progression of atherosclerosis, the underlying mechanism remains unclear. In the present study, we aimed to investigate whether DNA binding events are critically involved in the progression of PAH-mediated atherogenesis. Apolipoprotein E knockout mice were orally (24 wk, once/wk) exposed to 5 mg/kg benzo[a]pyrene (B[a]P), or its nonmutagenic, noncarcinogenic structural isoform benzo[e]pyrene (B[e]P). 32P-postlabeling of lung tissue confirmed the presence of promutagenic PAH-DNA adducts in B[a]P-exposed animals, whereas in B[e]P-exposed and vehicle control animals, these adducts were undetectable. Morphometrical analysis showed that both B[a]P and B[e]P caused an increase in plaque size, whereas location or number of plaques was unaffected. Immunohistochemistry revealed no differences in oxidative DNA damage (8-OHdG) or apoptosis in the plaques. Also plasma lipoprotein levels remained unchanged after PAH-exposure. However, T lymphocytes were increased > or =2-fold in the plaques of B[a]P- and B[e]P-exposed animals. Additionally, B[a]P and to a lesser extent B[e]P exposure resulted in increased TGFbeta protein levels in the plaques, that was mainly localized in the plaque macrophages. In vitro studies using the murine macrophage like RAW264.7 cells showed that inhibition of TGFbeta resulted in decreased tumor necrosis factor (TNF) alpha release, suggesting that enhanced TGFbeta expression in the plaque macrophages contributes to the proinflammatory effects in the vessel wall. In general, this inflammatory reaction in the plaques appeared to be a local response since peripheral blood cell composition (T cells, B cells, granulocytes, and macrophages) was not changed upon PAH exposure. In conclusion, we showed that both B[a]P and B[e]P cause progression of atherosclerosis, irrespective of their DNA binding properties. Moreover, our data revealed a possible novel mechanism of PAH-mediated atherogenesis, which likely involves a TGFbeta-mediated local inflammatory reaction in the vessel wall.

Transforming growth factor-beta mediates balance between inflammation and fibrosis during plaque progression.

The transition from stable to rupture-prone and ruptured atherosclerotic plaques involves many processes, including an altered balance between inflammation and fibrosis. An important mediator of both is transforming growth factor (TGF)-beta, and a pivotal role for TGF-beta in atherogenesis has been postulated. Here, we determine the in vivo effects of TGF-beta inhibition on plaque progression and phenotype in atherosclerosis. Recombinant soluble TGF-beta receptor II (TGFbetaRII:Fc), which inhibits TGF-beta signaling, was injected in apolipoprotein E-deficient mice for 12 weeks (50 microg, twice a week intraperitoneally) as early treatment (treatment age 5 to 17 weeks) and delayed treatment (age 17 to 29 weeks). In the early treatment group, inhibition of TGF-beta signaling treatment resulted in a prominent increase in CD3- and CD45-positive cells in atherosclerotic lesions. Most profound effects were found in the delayed treatment group. Plaque area decreased 37.5% after TGFbetaRII:Fc treatment. Moreover, plaque morphology changed into an inflammatory phenotype that was low in fibrosis: lipid cores were 64.6% larger, and inflammatory cell content had increased 2.7-fold. The amount of fibrosis decreased 49.6%, and intraplaque hemorrhages and iron and fibrin deposition were observed frequently. TGFbetaRII:Fc treatment did not result in systemic effects. These results reveal a pivotal role for TGF-beta in the maintenance of the balance between inflammation and fibrosis in atherosclerotic plaques.