Baseline thrombocytopenia in women with coronary heart disease increases incident acute coronary syndrome: insights from national inpatient database.

There are paucity of data on gender-based differences in the effect of thrombocytopenia and coronary heart disease (CHD) towards development of acute coronary syndrome (ACS). We used National Inpatient Sample (NIS) database of the United States to assess the gender-based differences in the association of thrombocytopenia with CHD and the impact of thrombocytopenia on mortality, length of stay and hospitalization costs on ACS subgroup of CHD. Our analysis found that thrombocytopenia was associated with increased odds of CHD on univariate (odds ratio [OR] 1.31 (95% CI 1.30-1.32) p < 0.001) and multivariate (OR 1.36 (95% CI 1.34-1.38) p < 0.001) analyses. Thrombocytopenic CHD patients had increased odds of developing ACS only in women (OR 1.15, 95% CI 1.12-1.17, p < 0.001). Thrombocytopenia was found to be associated with poor short-term outcome in ACS subgroup of CHD with higher in-hospital mortality (OR 1.64, CI 1.58 to 1.71, p < 0.001), length of stay (3.4 days, CI 3.30-3.52, p < 0.001), and cost of hospitalization ($55,652, CI 53,717-57,587, p < 0.001). Thrombocytopenic women with ACS have greater odds of mortality compared to men. Our study suggests that thrombocytopenia among women with CHD is associated with increased odds of developing ACS. Women with ACS have greater mortality compared to men. Thrombocytopenic ACS patients have worse in-hospital outcome compared to patients with normal platelet count. We demonstrated association only and is not possible to establish causality with our study.

A universal drug delivery catheter for the treatment of infrapopliteal arterial disease using liquid therapy.

OBJECTIVE: The objective of this study was to investigate the safety and feasibility of treating infrapopliteal lesions using a novel drug delivery catheter locally delivering liquid paclitaxel. BACKGROUND: Balloon angioplasty is currently the Gold Standard to treat below-the-knee disease; however, restenosis continues to be a great challenge following these percutaneous revascularization procedures. METHODS: The Occlusion Perfusion Catheter for Optimal Delivery of Paclitaxel for the Prevention of Endovascular Restenosis (COPPER-A) study-Below-the-Knee Cohort was a prospective, nonrandomized, multicenter, feasibility, and safety study that enrolled 35 patients at 11 participating sites. The safety endpoints at 1, 3, and 6 months were freedom from thrombosis, major amputation in the target limb and target limb related death. The efficacy endpoints were primary patency and freedom from clinically driven target lesion revascularization at 6 months. RESULTS: All patients tolerated the procedure well with no reports of adverse procedural events. Thirty-five patients were treated with a mean lesion length of 112 ± 81.2 mm with the lesion length range of 20-286 mm. At 6-month follow-up, primary patency was 89.3% and freedom from clinically driven target lesion revascularization was 96.4%. No patients demonstrated thrombosis, major amputation in the target limb and target limb related death at the 1-, 3- and 6-months follow-up intervals. CONCLUSIONS: The results of this multi-center study demonstrated that infrapopliteal arteries can be safely and effectively treated with liquid paclitaxel using the occlusion perfusion catheter.

Engineering Escherichia coli FAB system using synthetic plant genes for the production of long chain fatty acids.

BACKGROUND: Sustainable production of microbial fatty acids derivatives has the potential to replace petroleum based equivalents in the chemical, cosmetic and pharmaceutical industry. Most fatty acid sources for production oleochemicals are currently plant derived. However, utilization of these crops are associated with land use change and food competition. Microbial oils could be an alternative source of fatty acids, which circumvents the issue with agricultural competition. RESULTS: In this study, we generated a chimeric microbial production system that features aspects of both prokaryotic and eukaryotic fatty acid biosynthetic pathways targeted towards the generation of long chain fatty acids. We redirected the type-II fatty acid biosynthetic pathway of Escherichia coli BL21 (DE3) strain by incorporating two homologues of the beta-ketoacyl-[acyl carrier protein] synthase I and II from the chloroplastic fatty acid biosynthetic pathway of Arabidopsis thaliana. The microbial clones harboring the heterologous pathway yielded 292 mg/g and 220 mg/g DCW for KAS I and KAS II harboring plasmids respectively. Surprisingly, beta-ketoacyl synthases KASI/II isolated from A. thaliana showed compatibility with the FAB pathway in E. coli. CONCLUSION: The efficiency of the heterologous plant enzymes supersedes the overexpression of the native enzyme in the E. coli production system, which leads to cell death in fabF overexpression and fabB deletion mutants. The utilization of our plasmid based system would allow generation of plant like fatty acids in E. coli and their subsequent chemical or enzymatic conversion to high end oleochemical products.

GFP Scaffold-Based Engineering for the Production of Unbranched Very Long Chain Fatty Acids in Escherichia coli With Oleic Acid and Cerulenin Supplementation.

Currently, very long chain fatty acids (VLCFAs) for oleochemical, pharmaceutical, cosmetic, or food applications are extracted from plant or marine organism resources, which is associated with a negative environmental impact. Therefore, there is an industrial demand to develop sustainable, microbial resources. Due to its ease of genetic modification and well-characterized metabolism, Escherichia coli has established itself as a model organism to study and tailor microbial fatty acid biosynthesis using a concerted genetic engineering approach. In this study, we systematically implemented a plant-derived (Arabidopsis thaliana) enzymatic cascade in Escherichia coli to enable unbranched VLCFA biosynthesis. The four Arabidopsis thaliana membrane-bound VLCFA enzymes were expressed using a synthetic expression cassette. To facilitate enzyme solubilization and interaction of the synthetic VLCFA synthase complex, we applied a self-assembly GFP scaffold. In order to initiate VLCFA biosynthesis, external oleic acid and cerulenin were supplemented to cultures. In this context, we detected the generation of arachidic (20:0), cis-11-eicosenoic (20:1) and cis-13-eicosenoic acid (20:1).

A universal drug delivery catheter for the treatment of infrapopliteal arterial disease: Results from the multi-center first-in-human study.

OBJECTIVE: The objective of this study was to assess the feasibility, safety and initial efficacy of paclitaxel administration using a novel drug delivery catheter for the prevention of restenosis in infrapopliteal de novo and restenotic lesions. BACKGROUND: Restenosis continues to be a great challenge after percutaneous revascularization procedures for peripheral arterial disease, particularly for below-the-knee applications. METHODS: A prospective, multicenter first-in-human registry of a novel delivery catheter delivering liquid paclitaxel was conducted in 10 patients. The primary efficacy endpoint at 6 months was freedom from clinically driven target lesion revascularization (CD-TLR) and the primary safety endpoint at 1, 3, and 6 months were thrombosis, major amputation in the target limb and target limb related death. RESULTS: All patients tolerated the procedure well with no reports of adverse procedural events. Twelve (n = 12) lesions in ten patients were treated with a mean lesion length of 83.3 ± 49.2 mm, with the lesion length range of 30mm to 182 mm. At 6-month follow-up, the rate of CD-TLR was 30% (3 of 10 patients). Zero patients (0 out of 10) demonstrated thrombosis, major amputation in the target limb and target limb related death at the 1, 3, and 6 month follow-up intervals. CONCLUSIONS: This first in-human experience obtained in a multicenter study of real-world de novo and restenotic lesions demonstrates a favorable safety and efficacy profile at 6 months. Randomized comparison to current drug coated balloons should be performed to further validate this approach and positive experience.

Phospho-MEK1/2 and uPAR Expression Determine Sensitivity of AML Blasts to a Urokinase-Activated Anthrax Lethal Toxin (PrAgU2/LF).

In this study, we attempt to target both the urokinase plasminogen activator and the mitogen-activated protein kinase pathway in acute myeloid leukemia (AML) cell lines and primary AML blasts using PrAgU2/LF, a urokinase-activated anthrax lethal toxin. PrAgU2/LF was cytotoxic to five out of nine AML cell lines. Cytotoxicity of PrAgU2/LF appeared to be nonapoptotic and was associated with MAPK activation and urokinase activity because all the PrAgU2/LF-sensitive cell lines showed both uPAR expression and high levels of MEK1/2 phosphorylation. Inhibition of uPAR or desensitization of cells to MEK1/2 inhibition blocked toxicity of PrAgU2/LF, indicating requirement for both uPAR expression and MAPK activation for activity. PrAgU2/LF was also cytotoxic to primary blasts from AML patients, with blasts from four out of five patients showing a cytotoxic response to PrAgU2/LF. Cytotoxicity of primary AML blasts was also dependent on uPAR expression and phos-MEK1/2 levels. CD34(+) bone marrow blasts and peripheral blood mononuclear cells lacked uPAR expression and were resistant to PrAgU2/LF, demonstrating the lack of toxicity to normal hematological cells and, therefore, the tumor selectivity of this approach. Dose escalation in mice revealed that the maximal tolerated dose of PrAgU2/LF is at least 5.7-fold higher than that of the wild-type anthrax lethal toxin, PrAg/LF, further demonstrating the increased safety of this molecule. We have shown, in this study, that PrAgU2/LF is a novel, dual-specific molecule for the selective targeting of AML.

Human recombinant arginase I(Co)-PEG5000 [HuArgI(Co)-PEG5000]-induced arginine depletion is selectively cytotoxic to human acute myeloid leukemia cells.

In this study, we target arginine auxotrophy of AML cell lines using human arginase I cobalt-PEG5000. HuArgI(Co)-PEG5000 was cytotoxic to all AML cell lines tested. Mononuclear cells and CD34(+) blasts were not sensitive demonstrating the selectivity of HuArgI(Co)-PEG5000-induced arginine deprivation. Addition of L-citrulline led to the rescue of five cell lines. The four cell lines that were not rescued by L-citrulline did not express argininosuccinate synthetase-1, indicating complete arginine auxotrophy. Inhibition of autophagy increased cell sensitivity to HuArgI(Co)-PEG5000 demonstrating the protective role of autophagy following arginine deprivation. We have shown that AML can be selectively targeted using HuArgI(Co)-PEG5000-induced arginine depletion.

Cytotoxicity of anthrax lethal toxin to human acute myeloid leukemia cells is nonapoptotic and dependent on extracellular signal-regulated kinase 1/2 activity.

In this study, we attempt to target the mitogen-activated protein kinase (MAPK) pathway in acute myeloid leukemia (AML) cells using a recombinant anthrax lethal toxin (LeTx). LeTx consists of protective antigen (PrAg) and lethal factor (LF). PrAg binds cells, is cleaved by furin, oligomerizes, binds three to four molecules of LF, and undergoes endocytosis, releasing LF into the cytosol. LF cleaves MAPK kinases, inhibiting the MAPK pathway. We tested potency of LeTx on a panel of 11 human AML cell lines. Seven cell lines showed cytotoxic responses to LeTx. Cytotoxicity of LeTx was mimicked by the specific mitogen-activated protein/extracellular signal-regulated kinase kinase 1/2 (MEK1/2) inhibitor U0126, indicating that LeTx-induced cell death is mediated through the MEK1/2-extracellular signal-regulated kinase (ERK1/2) branch of the MAPK pathway. The four LeTx-resistant cell lines were sensitive to the phosphatidylinositol 3-kinase inhibitor LY294002. Co-treatment of AML cells with both LeTx and LY294002 did not lead to increased sensitivity, showing a lack of additive/synergistic effects when both pathways are inhibited. Flow cytometry analysis of MAPK pathway activation revealed the presence of phospho-ERK1/2 only in LeTx-sensitive cells. Staining for Annexin V/propidium iodide and active caspases showed an increase in double-positive cells and the absence of caspase activation following treatment, indicating that LeTx-induced cell death is caspase-independent and nonapoptotic. We have shown that a majority of AML cell lines are sensitive to the LF-mediated inhibition of the MAPK pathway. Furthermore, we have demonstrated that LeTx-induced cytotoxicity in AML cells is nonapoptotic and dependent on phospho-ERK1/2 levels.

Defining the optimal degree of heparin anticoagulation for peripheral vascular interventions: insight from a large, regional, multicenter registry.

BACKGROUND: The optimal degree of heparin anticoagulation for peripheral vascular interventions (PVIs) has not been defined. We sought to correlate total heparin dose and peak procedural activated clotting time (ACT) with postprocedural outcomes in patients undergoing PVI. METHODS AND RESULTS: We studied 4743 patients who received heparin during PVIs in a regional, multicenter registry. From those, 1246 had recorded peak procedural ACT with the same point-of-care device. Periprocedural and in-hospital outcomes were compared between patients who received a total heparin dose <60 U/kg (n=2161) and ≥60 U/kg (n=2582). Similarly, outcomes were evaluated between groups with a peak procedural ACT <250 seconds (n=855) and ≥250 seconds (n=391). Technical and procedural success as well as intraprocedural thrombotic events did not differ between groups. Patients with heparin dose ≥60 U/kg had a higher rate of postprocedural hemoglobin drop ≥3 g/dL (7.09% versus 5.09%, respectively, P=0.004) and a higher transfusion rate compared with those with heparin dose <60 U/kg (4.92% versus 3.15%, respectively, P=0.002). In multivariate analysis, independent predictors of bleeding requiring transfusion were total heparin dose ≥60 U/kg, ACT ≥250 seconds, female sex, age ≥70 years, prior anemia, prior heart failure, low creatinine clearance, hybrid vascular surgery, rest pain, and below-knee intervention. In propensity-matched, risk-adjusted models and after hierarchical modeling, total heparin dose ≥60 U/kg and ACT ≥250 seconds remained strong predictors of post-PVI drop in hemoglobin ≥3 g/dL or transfusion. CONCLUSIONS: During PVI, higher total heparin dose (≥60 U/kg) and peak ACT ≥250 seconds were predictors of postprocedural transfusion. The high technical and procedural success in all groups suggests that use of weight-based heparin dosing with a target ACT <250 seconds in PVI may minimize the bleeding risk without compromising procedural success or increasing thromboembolic complications.

Protected carotid stenting in high-risk patients: results of the SpideRX arm of the carotid revascularization with ev3 arterial technology evolution trial.

PURPOSE: A prospective nonrandomized multicenter registry of 160 patients with severe carotid stenosis and high-risk features for carotid endarterectomy was conducted during the 3-month period from March to May 2005. METHODS: Carotid artery stenting (CAS) was performed with the SpideRX™ Embolic Protection System (ev3, Inc., Plymouth, MN, USA) as part of an investigational device exemption from the Food and Drug Administration. RESULTS: The primary end-point of major adverse cardiac and cerebrovascular events at 30 days after CAS was observed in nine patients (5.6%), including death in four patients (2.5%), nonfatal stroke in five patients (3.1%), and nonfatal myocardial infarction in one patient (0.6%). A secondary end-point of technical success (defined as successful deployment of all devices, filter retrieval, and final diameter stenosis <50%) was achieved in 156 of 160 patients (97.5%). The only independent predictor of death or stroke at 30 days was baseline stenosis severity (P < 0.05). CONCLUSION: CAS with distal embolic protection using the SpideRX™ Embolic Protection System is a reasonable alternative for revascularization of some high-risk patients with severe carotid stenosis.

Development of a multicenter peripheral arterial interventional database: the PVD-QI2.

BACKGROUND: The number of peripheral vascular intervention (PVI) procedures performed is steadily increasing in the United States. PVD-QI 2 is a prospective, multicenter observational study designed to improve the quality of care for patients undergoing PVI and to better understand the effectiveness and appropriateness of PVI in improving outcomes of peripheral arterial disease. The registry aims to elucidate which comorbid conditions and procedure-related variables are associated with beneficial or adverse outcomes after vascular interventions. METHODS: Five centers are currently prospectively collecting data on consecutive PVIs performed at their institutions and will include patients with both claudication and critical limb ischemia. A common data collection form and a standard set of definitions were developed during several planning meetings. Information on patient demographics, clinical history, comorbid conditions, treatment approaches, and in hospital outcomes are being collected. Patients will be followed up at 30 days, 6 months, and 1 year after each procedure to identify recurrent vascular events, medication use, lifestyle modifications (regular exercise, dietary modification), self-reported walking scores, and mortality. Data validity will be assured through review of data form accuracy by a trained nurse, by automatic database diagnostic routines, and by site visits that include review of angiography suite logs and randomly selected charts. CONCLUSIONS: The development of a quality-controlled PVI registry requires the commitment and collaboration of clinician-investigators and hospital systems devoted to understanding factors that contribute to quality outcomes. Central to achievement of this goal is the creation of a careful diagnostic and data quality assessment system. This registry will provide important clinical insights into patient demographic and clinical characteristics, procedural characteristics, and current practice patterns that foster or impede achievement of long-term quality-based clinical outcomes for patients with peripheral arterial disease.