ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThe complement system is implicated in the pathogenesis of atherosclerosis. Complement has been shown to activate endothelial cells (ECs) by inducing a proinflammatory response. Physiological levels of shear stress exert potent antiatherosclerotic effects. Therefore, we investigated whether shear stress antagonizes the effects of complement on ECs.Methods and ResultsIncubation of ECs with nonlytic concentrations of complement serum (CS: 0.2 U/mL for 6 hours) resulted in an upregulation of interleukin-8 (IL-8) (165±12%) and monocyte chemoattractant protein-1 (MCP-1) mRNA expression (267±34%). Preexposure of ECs for 18 hours with laminar shear stress (15 dyne/cm2) abrogated CS-induced IL-8 release to 106±10% (P<0.001) and reduced CS-induced MCP-1 expression (170±31%;P<0.05). To examine the mechanism of the protective effect of shear stress, expression of the complement-inhibitory protein clusterin was analyzed under shear exposure. Shear stress increased clusterin mRNA (225±76%, 6 hours) and protein expression (164±22%, 18 hours). Specific inhibition of clusterin by transfection with antisense oligonucleotides reversed the protective effect of shear stress on CS-induced MCP-1 and IL-8 upregulation (P<0.05 versus sense-transfected cells). Moreover, clusterin overexpression inhibited CS-induced EC activation.ConclusionsShear stress abrogates the complement-induced proinflammatory response of ECs by upregulation of the complement-inhibitory protein clusterin. Upregulation of clusterin may contribute to the potent antiatherosclerotic effects of shear stress by preventing endothelial activation through the complement cascade.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundA shortage of donor organs and increased numbers of deaths of patients on the waiting list for cardiac transplantation make mechanical circulatory support for a bridge to transplantation a standard clinical procedure. Continuous-flow rotary blood pumps offer exciting new perspectives.Methods and ResultsTwo male patients (ages 44 and 65 years) suffering from end-stage left heart failure were implanted with a DeBakey VAD axial-flow pump for use as a bridge to transplant. In the initial postoperative period, the mean pump flow was 3.9±0.5 L/min, which equals a mean cardiac index (CI) of 2.3±0.2 L · min−1· m−2. In both patients, the early postoperative phase was characterized by a completely nonpulsatile flow profile. However, with the recovery of heart function 8 to 12 days after implantation, increasing pulse pressures became evident, and net flow rose to 4.5±0.6 L/min, causing an increase of mean CI up to 2.7±0.2 L · min−1· m−2. Patients were mobilized and put through regular physical training. Hemolysis stayed in the physiological range and increased only slightly from 2.1±0.8 mg/dL before surgery to 3.3±1.8 mg/dL 6 weeks after implantation.ConclusionsThe first clinical implants of the DeBakey VAD axial-flow pump have demonstrated the device to be a promising measure of bridge-to-transplant mechanical support.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundAlthough several early trials indicate treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The objective of this report is to document angiographic and clinical outcome 3 years after treatment of restenotic stented coronary arteries with catheter-based192Ir.Methods and ResultsA double-blind, randomized trial compared192Ir with placebo sources in patients with previous restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to192Ir and 29 to placebo. At 3-year follow-up, target-lesion revascularization was significantly lower in the192Ir group (15.4% versus 48.3%;P<0.01). The dichotomous restenosis rate at 3-year follow-up was also significantly lower in192Ir patients (33% versus 64%;P<0.05). In a subgroup of patients with 3-year angiographic follow-up not subjected to target-lesion revascularization by the 6-month angiogram, the mean minimal luminal diameter between 6 months and 3 years decreased from 2.49±0.81 to 2.12±0.73 mm in192Ir patients but was unchanged in placebo patients.ConclusionsThe early clinical benefits observed after treatment of coronary restenosis with192Ir appear durable at late follow-up. Angiographic restenosis continues to be significantly reduced in192Ir-treated patients, but a small amount of late loss was observed between the 6-month and 3-year follow-up time points. No events occurred in the192Ir group to suggest major untoward effects of vascular radiotherapy. At 3-year follow-up, vascular radiotherapy continues to be a promising new treatment for restenosis.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID