Background-Simvastatin, a 3-hydroxy-methylglutaryl coenzyme A reductase inhibitor, has been shown to lower serum cholesterol levels in clinical use. Moreover, statins exert beneficial effects in vascular diseases by inhibition of leukocyte rolling, adherence, and transmigration. The aim of this study was to determine if pretreatment with simvastatin attenuates Staphylococcus aureus ␣-toxin-induced increase in leukocyte-endothelial interactions during exotoxemia. Methods and Results-The effects of simvastatin on leukocyte-endothelial cell interactions were observed by intravital microscopy in the rat mesenteric microcirculation. Simvastatin (50 or 100 g/kg) was administered 18 hours before the study. Activation of microcirculation was induced by bolus administration of 40 g/kg S aureus ␣-toxin. Exotoxemia resulted in a significant and time-dependent increase in leukocyte rolling, adherence, and transmigration of leukocytes as well as P-selectin expression on the intestinal vascular endothelium. Pretreatment with simvastatin significantly inhibited exotoxin-induced leukocyte rolling from 71Ϯ10 to 14Ϯ4.7 cells/min (PϽ0.01) and adherence from 14Ϯ3.5 to 0.4Ϯ0.2 cells (PϽ0.01). In addition, simvastatin pretreatment significantly inhibited transmigration of leukocytes from 10.5Ϯ1.2 to 4.2Ϯ0.9 (PϽ0.05) cells. Immunohistochemical detection of endothelial cell adhesion molecule P-selectin showed a 50% decrease in endothelial cell surface expression after simvastatin treatment. Furthermore, simvastatin treatment resulted in enhanced expression of endothelial cell NO synthase III in the intestinal microcirculation. Conclusions-These results demonstrate that simvastatin interferes with exotoxin-induced leukocyte-endothelial cell interactions, which may be relevant in various infectious diseases. Statin treatment may offer a new therapeutic strategy for these clinical conditions.
Early diagnosis of primary pulmonary artery sarcomas can be improved by computed tomography and magnetic resonance scanning. Radical surgical resection probably presents the only chance for cure. The role of neoadjuvant or adjuvant treatment modalities has to be defined. Pulmonary artery sarcoma need not necessarily be a fatal diagnosis.
Polytetrafluoroethylene (PTFE), a frequently utilized polymer for the fabrication of synthetic vascular grafts, was surface-modified by means of a wet-chemical process. The inherently non-cell-adhesive polymer does not support cellular attachment, a prerequisite for the endothelialization of luminal surface grafts in small diameter applications. To impart the material with cell-adhesive properties a treatment with sodium-naphthalene provided a basis for the subsequent immobilization of the adhesion promoting RGD-peptide using a hydroxy- and amine-reactive crosslinker. Successful conjugation was shown with cell culture experiments which demonstrated excellent endothelial cell growth on the modified surfaces.
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