Signal-dependent splicing of tissue factor pre-mRNA modulates the thrombogenecity of human platelets

Tissue factor (TF) is an essential cofactor for the activation of blood coagulation in vivo. We now report that quiescent human platelets express TF pre-mRNA and, in response to activation, splice this intronic-rich message into mature mRNA. Splicing of TF pre-mRNA is associated with increased TF protein expression, procoagulant activity, and accelerated formation of clots. Pre-mRNA splicing is controlled by Cdc2-like kinase (Clk)1, and interruption of Clk1 signaling prevents TF from accumulating in activated platelets. Elevated intravascular TF has been reported in a variety of prothrombotic diseases, but there is debate as to whether anucleate platelets—the key cellular effector of thrombosis—express TF. Our studies demonstrate that human platelets use Clk1-dependent splicing pathways to generate TF protein in response to cellular activation. We propose that platelet-derived TF contributes to the propagation and stabilization of a thrombus

A Randomized, Controlled Pilot Study of Autologous CD34+ Cell Therapy for Critical Limb Ischemia

Critical limb ischemia (CLI) portends a risk of major amputation of 25-35% within 1 year of diagnosis. Pre-clinical studies provide evidence that intramuscular injection of autologous CD34+ cells improve limb perfusion and reduce amputation risk. In this randomized, double-blind, placebo-controlled pilot study, we evaluated the safety and efficacy of intramuscular injections of autologous CD34+ cells in subjects with moderate or high-risk CLI who were poor or non-candidates for surgical or percutaneous revascularization (ACT34-CLI)

Common femoral artery injury secondary to bicycle handlebar trauma

AbstractBlunt trauma from bicycle handlebars is associated with well-described injuries of the abdominal viscera. These injuries result from the forceful compression of the relatively immobile abdominal organs between the handlebar end and the vertebral bodies. The common femoral artery is also immobile as it passes anterior to the superior pubic ramus, rendering this vessel susceptible to a similar mechanism of injury. We have treated two children who sustained thrombosis of the common femoral artery caused by bicycle handlebar trauma. The lack of familiarity with this uncommon mode of injury may contribute to delayed diagnosis and increased morbidity. We therefore wish to draw attention to this mechanism of injury. (J Vasc Surg 2002;35:589-91.

Vascular Quality Initiative assessment of compliance with Society for Vascular Surgery clinical practice guidelines on the care of patients with abdominal aortic aneurysm.

OBJECTIVE: Professional societies publish clinical practice guidelines to provide evidence-based recommendations to improve care and to reduce practice variation. However, the degree of compliance with the guidelines and its impact on outcomes have not been well defined. This study used the Vascular Quality Initiative (VQI) abdominal aortic aneurysm (AAA) registries to determine current compliance with and impact of recent Society for Vascular Surgery (SVS) AAA guidelines. METHODS: Recommendations from the SVS AAA guidelines were reviewed and assessed as to whether they could be evaluated with current VQI data sets. The degree of compliance with these individual recommendations was calculated by center and correlated with clinical outcomes. Data were analyzed by univariate analysis and mixed effects multivariable logistic regression. Statistical significance was measured at P \u3c .05. RESULTS: Of the 111 SVS recommendations, 10 could be evaluated using VQI registries. The mean center-specific compliance rate ranged from 40% (smoking cessation 2 weeks before open AAA [OAAA] repair) to 99% (preservation of flow to one internal iliac artery during endovascular aneurysm repair [EVAR]). Some recommendations were associated with improved outcomes (eg, cell salvage for OAAA repair and antibiotic prophylaxis), whereas others were not (eg, EVAR at a center with \u3e10 cases per year or door-to-intervention timeAAA). With multivariable analysis, compliance with preservation of flow to the internal iliac artery decreased major adverse cardiac events in EVAR and marginally decreased in-hospital and 1-year mortality in OAAA repair. Antibiotic administration decreased surgical site infection, major adverse cardiac events, and in-hospital mortality and marginally decreased respiratory complications and 1-year mortality in EVAR. Cell salvage for OAAA repair decreased 1-year mortality. Tobacco cessation before EVAR or OAAA repair decreased respiratory complications and 1-year mortality. CONCLUSIONS: The VQI registry is a valuable tool that can be used to measure compliance with SVS AAA guidelines. Compliance with recommendations was associated with improved outcomes and should be encouraged for providers. Participation in the VQI registry provides an objective assessment of performance and compliance with guidelines. VQI provider and center reports may be used as a focus for quality improvement efforts