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Objective The objective of this study was to investigate adherence to practice guidelines for antiplatelet and statin use after postoperative myocardial infarction (POMI) and its effect on late mortality following vascular surgery in a multicenter registry. Methods Antiplatelet and statin use was examined in 1749 vascular surgery procedures with POMI within the Vascular Quality Initiative (VQI) from 2005 to 2015. Our primary aim was to assess cardiac medication (CM) use at discharge, defined as (1) single antiplatelet therapy (SAPT; aspirin or P2Y 12 inhibitor) or dual antiplatelet therapy (DAPT; aspirin and P2Y 12 inhibitor) and (2) statin therapy. Long-term mortality in patients with POMI was analyzed on the basis of discharge CM. A proportional hazards model was developed to control for factors associated with mortality. Regional differences in CM use at discharge after POMI were compared. Results Overall discharge CM use after POMI included aspirin (81%), P2Y 12 inhibitor (38%), statin therapy (76%), and combined antiplatelet and statin (74%). At discharge, 26% of patients were not receiving combined antiplatelet and statin therapy. SAPT (50%) was more common than DAPT (35%; P P P = .001). After adjustment for covariates including preoperative medications, treatment with SAPT or DAPT plus statin at discharge was associated with lower late mortality compared with noncombination or no therapy (hazard ratio, 0.72; 95% confidence interval, 0.56-0.93; P = .01). Regional variation in CM at discharge following POMI was also observed with a range of 33% to 100% ( P = .05). Conclusions Within the VQI, regional and procedure-specific variation exists in CM regimen after POMI following vascular surgery. Absence of combined antiplatelet and statin therapy at discharge after POMI was associated with higher late mortality and represents an area for quality improvement in the care of these patients.

Understanding the characteristics of volcanic thermal emissions and how they change with time is important for forecasting and monitoring volcanic activity and potential hazards. Satellite instruments view volcanic thermal features across the globe at various temporal and spatial resolutions. Thermal features that may be a precursor to a major eruption, or indicative of important changes in an on-going eruption can be subtle, making them challenging to reliably identify with satellite instruments. The goal of this study was to explore the limits of the types and magnitudes of thermal anomalies that could be detected using satellite thermal infrared (TIR) data. Specifically, the characterization of sub-pixel thermal features with a wide range of temperatures is considered using ASTER multispectral TIR data. First, theoretical calculations were made to define a “thermal mixing detection threshold” for ASTER, which quantifies the limits of ASTER's ability to resolve sub-pixel thermal mixing over a range of hot target temperatures and % pixel areas. Then, ASTER TIR data were used to model sub-pixel thermal features at the Yellowstone National Park geothermal area (hot spring pools with temperatures from 40 to 90 °C) and at Mount Erebus Volcano, Antarctica (an active lava lake with temperatures from 200 to 800 °C). Finally, various sources of uncertainty in sub-pixel thermal calculations were quantified for these empirical measurements, including pixel resampling, atmospheric correction, and background temperature and emissivity assumptions.

During volcanic eruptions, volcanic ash transport and dispersion models (VATDs) are used to forecast the location and movement of ash clouds over hours to days in order to define hazards to aircraft and to communities downwind. Those models use input parameters, called “eruption source parameters”, such as plume height H, mass eruption rate Ṁ, duration D, and the mass fraction m63 of erupted debris finer than about 4ϕ or 63 μm, which can remain in the cloud for many hours or days. Observational constraints on the value of such parameters are frequently unavailable in the first minutes or hours after an eruption is detected. Moreover, observed plume height may change during an eruption, requiring rapid assignment of new parameters. This paper reports on a group effort to improve the accuracy of source parameters used by VATDs in the early hours of an eruption. We do so by first compiling a list of eruptions for which these parameters are well constrained, and then using these data to review and update previously studied parameter relationships. We find that the existing scatter in plots of H versus Ṁ yields an uncertainty within the 50% confidence interval of plus or minus a factor of four in eruption rate for a given plume height. This scatter is not clearly attributable to biases in measurement techniques or to well-recognized processes such as elutriation from pyroclastic flows. Sparse data on total grain-size distribution suggest that the mass fraction of fine debris m63 could vary by nearly two orders of magnitude between small basaltic eruptions (∼ 0.01) and large silicic ones (> 0.5). We classify eleven eruption types; four types each for different sizes of silicic and mafic eruptions; submarine eruptions; “brief” or Vulcanian eruptions; and eruptions that generate co-ignimbrite or co-pyroclastic flow plumes. For each eruption type we assign source parameters. We then assign a characteristic eruption type to each of the world's ∼ 1500 Holocene volcanoes. These eruption types and associated parameters can be used for ash-cloud modeling in the event of an eruption, when no observational constraints on these parameters are available.

Objective—The purpose of this study was to identify factors that alter expression of FcγRIIa by megakaryocytes.Methods and Results—Effects of selected cytokines and growth factors on megakaryocyte expression of FcγRIIa were assessed with phorbol 12-myristate 13-acetate (PMA)-differentiated human erythroleukemia (HEL) cells and with thrombopoietin-differentiated CD34 stem cells and compared with those obtained with myelocytic cell lines and a monocytic cell lines. Expression of FcγRIIa was quantified with the use of Western blots and real-time reverse transcriptase-polymerase chain reaction. Megakaryocyte differentiation was identified by expression of CD41, CD42, and von Willebrand factor with the use of flow cytometry. Interferon (IFN) γ increased protein expression of FcγRIIa by HEL cells and CD34 stem cells after megakaryocyte differentiation (maximal ≈4-fold,PPConclusions—IFNγ appears to selectively increase expression of FcγRIIa by cells exhibiting characteristics of megakaryocytes. This effect of IFNγ may contribute to greater platelet expression of FcγRIIa in patients with atherosclerotic vascular disease.

Background— More than 80% of patients entering cardiac rehabilitation (CR) are overweight, and >50% have metabolic syndrome. Current CR exercise protocols result in little weight loss and minimal changes in cardiac risk factors. We sought to design an exercise protocol that would lead to greater weight loss and risk factor change. Methods and Results— We performed a randomized controlled clinical trial to evaluate the effect of high-calorie-expenditure exercise (3000- to 3500-kcal/wk exercise-related energy expenditure) compared with standard CR exercise (7 to 800 kcal/wk) on weight loss and risk factors in 74 overweight patients with coronary heart disease. Both groups were counseled for weight loss and taking evidence-based preventive medications. High-calorie-expenditure exercise resulted in double the weight loss (8.2±4 versus 3.7±5 kg; P P P =0.02) than standard CR exercise at 5 months. High-calorie-expenditure exercise reduced insulin resistance, measured with the euglycemic hyperinsulinemic clamp, along with the ratio of total to high-density lipoprotein cholesterol and components of the metabolic syndrome, more than standard CR exercise (each P P Conclusion— High-calorie-expenditure exercise promotes greater weight loss and more favorable cardiometabolic risk profiles than standard CR for overweight coronary patients.

Although chemically defined media have been developed and widely used to study the expression of virulence factors in the model plant pathogen Pseudomonas syringae , it has been difficult to link specific medium components to the induction response. Using a chemostat system, we found that iron is the limiting nutrient for growth in the standard hrp -inducing minimal medium and plays an important role in inducing several virulence-related genes in Pseudomonas syringae pv. tomato DC3000. With various concentrations of iron oxalate, growth was found to follow Monod-type kinetics for low to moderate iron concentrations. Observable toxicity due to iron began at 400 μM Fe 3+ . The kinetics of virulence factor gene induction can be expressed mathematically in terms of supplemented-iron concentration. We conclude that studies of induction of virulence-related genes in P. syringae should control iron levels carefully to reduce variations in the availability of this essential nutrient.

The examination of rectoanal mucosa-associated lymphoid tissue (RAMALT) biopsy specimens for the diagnosis of transmissible spongiform encephalopathies has been described in sheep, elk, and small numbers of mule and white-tailed deer. Previous sample numbers have been too small to validate examination of this type of tissue as a viable antemortem diagnostic test. In this study, we examined RAMALT collected postmortem from 76 white-tailed deer removed from a farm in Wisconsin known to be affected by chronic wasting disease (CWD) and from 210 free-ranging white-tailed deer harvested from an area in Wisconsin where the overall prevalence of CWD among the deer was approximately 4 to 6%. The results of immunohistochemical (IHC) staining of the RAMALT sections were compared to the results of IHC staining of sections from the brain stem at the convergence of the dorsal motor nucleus of the vagus nerve, sections of the medial retropharyngeal lymph nodes (RLNs), and sections of tonsil (sections of tonsil only from captive animals were tested). The sensitivities of the IHC staining test with RAMALT sections were 81% for the captive animals and 91% for the free-ranging animals. False-negative results were usually associated with early infection, indicated by a low intensity of immunostaining in the obex and/or a polymorphism at PRNP codon 96. While the RLN remains the tissue of choice for use for the diagnosis of CWD in white-tailed deer, the results of the present study further support the use of RAMALTs collected antemortem as an adjunct to testing of tonsil biopsy specimens and surveillance by necropsy for the screening of farmed deer which have been put at risk through environmental exposure or exposure to deer with CWD.

Platelets are activated in vivo by multiple agonists; however, platelet function testing in vitro has been performed predominantly with only one or two agonists of platelet activation. Greater insight into anticipated effects of antithrombotic regimens should enhance the design of successful clinical trials. To test this concept, we assessed platelet activation induced by multiple agonists and two antithrombotic regimens, unfractionated heparin (UFH) and eptifibatide compared with bivalirudin and cangrelor. Blood samples from 10 patients with coronary artery disease were spiked with pharmacologic concentrations achieved in vivo of either UFH (1.2 U/ml) and eptifibatide (1.7 microg/ml), or with bivalirudin (8 microg/ml) and cangrelor (500 nmol/l). Platelet function was assessed with the use of flow cytometry. Agonists included thrombin (50 nmol/l), adenosine diphosphate (1 micromol/l), the collagen-mimetic convulxin (5 ng/ml), and platelet-activating factor (10 nmol/l). When platelet activation was identified by the surface expression of P-selectin in response to multiple agonists, the combination of bivalirudin and cangrelor suppressed activation more than UFH and eptifibatide. When platelet activation was identified by the activation of glycoprotein IIb-IIIa (PAC-1 binding), the combination of bivalirudin and cangrelor was more effective in suppressing activation in response to thrombin and adenosine diphosphate, whereas UFH and eptifibatide more effectively prevented binding of PAC-1 when platelets were activated with the collagen-mimetic convulxin. In conclusion, bivalirudin and cangrelor suppressed platelet activation in response to diverse agonists in vitro more than UFH and eptifibatide. These results and this approach to selection of promising interventions should be helpful in streamlining the design of clinical trials.

OBJECTIVE To determine whether obesity increases platelet reactivity and thrombin activity in patients with type 2 diabetes plus stable coronary artery disease. RESEARCH DESIGN AND METHODS We assessed platelet reactivity and markers of thrombin generation and activity in 193 patients from nine clinical sites of the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D). Blood taken at the time of enrollment was used for assay of the concentration of prothrombin fragment 1.2 (PT1.2, released when prothrombin is activated) and fibrinopeptide A (FPA, released when fibrinogen is cleaved). Platelet activation was identified with the use of flow cytometry in response to 0, 0.2, and 1 μmol/l adenosine diphosphate (ADP). RESULTS Concentrations of FPA, PT1.2, and platelet activation in the absence of agonist were low. Greater BMI was associated with higher platelet reactivity in response to 1 μm ADP as assessed by surface expression of P-selectin (r = 0.29, P < 0.0001) but not reflected by the binding of fibrinogen to activated glycoprotein IIb-IIIa. BMI was not associated with concentrations of FPA or PT1.2. Platelet reactivity correlated negatively with A1C (P < 0.04), was not related to the concentration of triglycerides in blood, and did not correlate with the concentration of C-reactive peptide. CONCLUSIONS Among patients enrolled in this substudy of BARI 2D, a greater BMI was associated with higher platelet reactivity at the time of enrollment. Our results suggest that obesity and insulin resistance that accompanies obesity may influence platelet reactivity in patients with type 2 diabetes.

Diverse gene products including phytotoxins, pathogen-associated molecular patterns, and type III secreted effectors influence interactions between Pseudomonas syringae strains and plants, with additional yet uncharacterized factors likely contributing as well. Of particular interest are those interactions governing pathogen-host specificity. Comparative genomics of closely related pathogens with different host specificity represents an excellent approach for identification of genes contributing to host-range determination. A draft genome sequence of Pseudomonas syringae pv. tomato T1, which is pathogenic on tomato but nonpathogenic on Arabidopsis thaliana, was obtained for this purpose and compared with the genome of the closely related A. thaliana and tomato model pathogen P. syringae pv. tomato DC3000. Although the overall genetic content of each of the two genomes appears to be highly similar, the repertoire of effectors was found to diverge significantly. Several P. syringae pv. tomato T1 effectors absent from strain DC3000 were confirmed to be translocated into plants, with the well-studied effector AvrRpt2 representing a likely candidate for host-range determination. However, the presence of avrRpt2 was not found sufficient to explain A. thaliana resistance to P. syringae pv. tomato T1, suggesting that other effectors and possibly type III secretion system–independent factors also play a role in this interaction.

Gender-dependent differences in echocardiographic characteristics of the heart have been thought to exist in human subjects, but comparisons have been difficult because of potential confounders such as differential prevalence of occult disease. Little data are available characterizing echocardiographic descriptors in normal experimental animals despite wide use of this modality. Accordingly, we characterized systolic and diastolic criteria of cardiac function echocardiographically in C57BL6 and BalbC age-matched mice to determine whether results in males and females differed. Left ventricular dimensions in absolute terms were lower, transmitral valve A-waves smaller and isovolumic relaxation time greater in females. When dimensional data were normalized for body weight, differences persisted but were directionally opposite. Thus, detection of abnormalities in cardiac function echocardiographically in various strains of mice requires establishing reference values that are gender as well as strain specific. Furthermore, the results suggest that gender-dependent differences are likely to be present in other species, including humans, and accordingly, that normal values should be established separately for males and females.

To determine whether a regimen of aspirin pretreatment, bivalirudin during the procedure and clopidogrel (600 mg) immediately after percutaneous coronary intervention (PCI) was associated with platelet activation during and shortly after (1 and 2 h) PCI, we characterized platelet function in 10 patients with the use of flow cytometry in the absence of agonist and in response to thrombin (10 nM), ADP (1 microM), the collagen-mimetic convulxin (5 ng/ml), and platelet activating factor (10 nM). Activation of platelets in peripheral blood was rare (0.5% of platelets) before, during and after PCI. Platelet reactivity in response to each of the agonists was lower after the PCI compared with that in blood taken before the PCI. Accordingly, platelet activation and platelet reactivity were not increased after elective PCI when patients were treated during the procedure with aspirin and bivalirudin and immediately after the procedure with a 600 mg loading dose of clopidogrel.

The entire genome of E. amylovora, strain Ea273, was sequenced at the Sanger Institute. A manuscript reporting the total sequence and its annotation is in preparation by authors in three locations. The genome of Ea273 is ca. 3.8 mbp, which is small compared with other enterobacteria including non-pathogenic E. coli K-12, and it shows signs of erosion due to many pseudogenes and "lost" genes. It also has a limited number of homologs with proteins associated with the type three secretion system (T3SS) of other sequenced Gram-negative plant pathogens. Analysis of a preliminary annotation identified several potential novel virulence factors, including two novel T3SS islands. The genome sequence can be accessed at http://www.sanger.ac.uk/Projects/E- amylovora/. The preliminary annotation and 0sequence can be accessed on request and registration at: https://asap.ahabs.wisc.edu/asap/logon.php. The ASAP database, maintained at the University of Wisconsin, Madison, is an extensive compendium of information relative to microbial genomes, along with tools that facilitate comparisons of the genome of Ea273 with that of other sequenced bacteria. To increase the value of the genome to the fire blight community and others, additional biological annotation is solicited. Curation of the genome will be done both at UW-Madison by Nicole Perna and at Cornell by Ana Maria Bocsanczy. In the following few years, we hope that the genome sequence will facilitate greater understanding of fire blight at both the molecular genetic and practical disease control levels.

Summary Bacteria that survive under variable conditions possess an assortment of genetic regulators to meet these challenges. The group IV or extracytoplasmic function (ECF) sigma factors regulate gene expression in response to specific environmental signals by altering the promoter specificity of RNA polymerase. We have undertaken a study of PvdS, a group IV sigma factor encoded by Pseudomonas syringae pv. tomato DC3000 (DC3000), a plant pathogen that is likely to encounter variations in nutrient availability as well as plant host defences. The gene encoding PvdS was previously identified by sequence similarity to the Pseudomonas aeruginosa orthologue, which directs transcription of genes encoding the biosynthesis of pyoverdine, a siderophore involved in iron acquisition, and is responsible for the characteristic fluorescence of the pseudomonads. We identified 15 promoters regulated by PvdS in DC3000 and characterized the promoter motif using computational analysis. Mutagenesis of conserved nucleotides within the motif interfered with promoter function and the degree of the effect was different depending on which region of the motif was mutated. Hidden Markov models constructed from alignments of sequence motifs extracted from DC3000 and PAO1 were used to query genomes of DC3000 and other fluorescent pseudomonads for similar motifs. We conclude that the role of PvdS as a regulator of pyoverdine synthesis is conserved among the fluorescent pseudomonads, but the promoters recognized by PvdS orthologues may differ subtly from species to species.

Obesity promotes the development and progression of coronary heart disease (CHD), in part, through its association with hyperlipidemia, hypertension, clotting abnormalities and insulin resistance. We assessed whether these relationships persist in patients with established CHD treated with evidence-based preventive pharmacologic therapies.We performed a cross-sectional study of 74 adults with CHD and a body mass index (BMI) of27 kg m(-2) (mean 32+/-4). The mean age of subjects was 64+/-9 years (range 44-84 years).Obesity measures included weight, BMI, waist, fat mass, intra-abdominal fat and subcutaneous fat. Risk factor measures included insulin sensitivity, fasting insulin level, lipid profiles, blood pressure, C-reactive protein (hs-CRP), plasminogen activator inhibitor (PAI-1) and platelet reactivity. Medication use included aspirin (99%), statin (84%), beta-blocker (71%), ACE inhibitor or blocker (37%) and clopidogrel (28%).There was no direct relationship between obesity parameters and risk factor measures of lipid concentrations, blood pressure, clotting abnormalities or platelet reactivity except for a modest relationship between visceral fat and hs-CRP (r=0.30, P=0.02). However, increased BMI, waist circumference, fat mass, total abdominal fat and abdominal subcutaneous fat all correlated with insulin sensitivity (r-values -0.30 to -0.45, P-values 0.01 to0.001) and insulin concentrations. Insulin sensitivity, in turn, was the best predictor of PAI-1, triglycerides, high-density lipoprotein (HDL) levels, cholesterol/HDL levels (all P0.01) and platelet reactivity (R=0.34, P=0.02).Use of preventive pharmacologic therapies obviated the expected relationship between adiposity and CHD risk factors. However, a residual effect of insulin resistance is left untreated. Total adiposity and central adiposity were strong predictors of insulin sensitivity, which in turn predicted cardiac risk factors such as lipid concentrations, PAI-1 and platelet reactivity. Thus, while evidence-based pharmacologic treatments may diminish the statistical relationship between obesity and many cardiac risk factors, adiposity negatively impacts CHD risk by reducing tissue insulin sensitivity.

Objectives We consider the conundrum suggested by myocardial hibernation and late restoration of function despite the absence of a substantial lateral peri-infarction border zone with respect to oxygenation, and suggest a pivotal role for apoptosis and its attenuation in salvaging jeopardized myocardium. Methods Selective pertinent literature is reviewed, and some recent observations indicating difficulties in identifying and quantifying apoptosis microscopically are summarized. Results Apoptosis seems to occur primarily after reperfusion following ischemia rather than persistent ischemia leading to necrosis. Refinements of markers of its presence are needed in vitro for use ultimately in vivo and should be pivotal in defining the extent to which tissue-protective interventions can salvage myocardium in the context of a fixed magnitude and duration of ischemia. Conclusion Apoptosis is strongly implicated in the overall demise of jeopardized myocardium. Its attenuation seems likely to be potentially beneficial. Validation of this hypothesis will require progress in identification, delineation, and assessment of the extent of apoptosis in the threatened heart.

SummaryPlasminogen activator inhibitor type-1 (PAI-1), an inhibitor of plasminogen activators, inhibits formation of plasmin and plasmin-mediated proteolysis. Apoptosis,or programmed cell death, is a potentially important phenomenon in mediating overall cell death. This review focuses on the influence of PAI-1 on apoptosis. Greater expression of PAI-1 has been associated with increased survival of cells and resistance to apoptosis. PAI-1 appears to influence apoptosis by decreasing cell adhesion (anoikis) as well as its effect on intracellular signaling. Mechanisms by which PAI-1 may render a cell resistant to apoptosis include its ability to inhibit generation of plasmin,its ability to inhibit caspase 3, and its ability to inhibit cell adhesion mediated by vitronectin. Inhibition of caspase 3 by PAI-1 may divert intracellular signalling from induction of apoptosis to induction of proliferation.

The eruption of Mount St. Helens from 2004 to 2006 has comprised extrusion of solid lava spines whose growth patterns were shaped by a large space south of the 1980-86 dome that was occupied by the unique combination of glacial ice, concealed subglacial slopes, the crater walls, and relics of previous spines. The eruption beginning September 2004 can be divided (as of April 2006) into five phases: (1) pre-dome deformation and phreatic activity, (2) initial extrusion of spines, (3) recumbent spine growth and repeated breakup, (4) southward extrusion across previous dome debris, and (5) normal faulting of the phase 4 dome to form a depression, a shift to westward extrusion and overthrusting of earlier phase 5 products. Overall, steady spine extrusion gradually slowed from 6 m 3 /s in November 2004 to 0.6 m 3 /s in February 2006. Thermal camera data show that phase 1 activity included low-temperature thermal features, such as fumaroles, fractures, and ground warming related to rapid uplift, as well as deformation in the south moat of the crater. The relatively cold (

A helicopter-mounted thermal imaging radiometer documented the explosive vent-clearing and effusive phases of the eruption of Mount St. Helens in 2004. A gyrostabilized gimbal controlled by a crew member housed the radiometer and an optical video camera attached to the nose of the helicopter. Since October 1, 2004, the system has provided thermal and video observations of dome growth. Flights conducted as frequently as twice daily during the initial month of the eruption monitored rapid changes in the crater and 1980-86 lava dome. Thermal monitoring decreased to several times per week once dome extrusion began. The thermal imaging system provided unique observations, including timely recognition that the early explosive phase was phreatic, location of structures controlling thermal emissions and active faults, detection of increased heat flow prior to the extrusion of lava, and recognition of new lava extrusion. The first spines, 1 and 2, were hotter when they emerged (maximum temperature 700-730°C) than subsequent spines insulated by as much as several meters of fault gouge. Temperature of gouge-covered spines was about 200°C where they emerged from the vent, and it decreased rapidly with distance from the vent. The hottest parts of these spines were as high as 500-730°C in fractured and broken-up regions. Such temperature variation needs to be accounted for in the retrieval of eruption parameters using satellite-based techniques, as such features are smaller than pixels in satellite images.

This article focuses on lessons learned from clinical trials of antiplatelet therapies-in particular, that the degree of inhibition of ex vivo platelet aggregation does not necessarily directly translate into clinical efficacy. As an example, the case of the oral platelet glycoprotein IIb/IIIa inhibitors is presented, in which despite consistent evidence of substantial inhibition of platelet aggregation, this class of drugs provided no clinical benefit in Phase III trials and, in fact, was harmful. Several hypotheses for these unexpected findings have been proposed, but none has been confirmed. The connection between ex vivo inhibition of platelet aggregation and clinical benefit of platelet P2Y(12) antagonists is also not straightforward and is currently being tested in large clinical trials. A link between inflammatory status and clinical benefit from antiplatelet agents continues to emerge and highlights the fact that biomarkers beyond ex vivo platelet aggregation may predict the clinical benefit of antiplatelet agents that can reduce platelet activation (i.e., aspirin and thienopyridines). Results of past and ongoing trials hold valuable clues to determining the appropriate targets for maximizing antiplatelet efficacy, but the current lack of a proven ex vivo assay that correlates with clinical outcomes hampers clinical investigation, drug development programs, and clinical practice.

Previous studies have shown that anticoagulants alter platelet reactivity and the apparent effects of antiplatelet agents. This study was conducted to identify the impact of methods of preparation of blood samples on an assay of platelet function and the effects of antiplatelet agents. The activation of platelets was identified with the use of flow cytometry in response to thrombin (1 and 10 nmol/L), adenosine diphosphate (0.2 and 1 micromol/L), platelet activating factor (1 nmol/L), and convulxin (1 and 10 ng/ml). Antiplatelet effects were assessed after the addition in vitro of tirofiban (50 ng/ml) and cangrelor (10 nmol/L). Results were compared in whole blood and platelet-rich plasma (PRP) anticoagulated with corn trypsin inhibitor (32 microg/ml, a specific inhibitor of factor XIIa). The fraction of young platelets was quantified with thiazole orange, which identifies ribonucleic acid. The activation of platelets was consistently less in PRP compared with whole blood. Activation in PRP was 23 +/- 15% that in whole blood for thrombin, 65 +/- 26% for adenosine diphosphate, 40 +/- 20% for platelet activating factor, and 49 +/- 25% for convulxin (p0.01 for each comparison). The fraction of young platelets in PRP was 39 +/- 11% that in whole blood (p0.001). The effects of antiplatelet agents varied with agonist and antiplatelet agent but were generally greater in PRP compared with whole blood (p0.05). In conclusion, platelet reactivity is lower and the effects of antiplatelet agents are greater and potentially misleading in PRP compared with whole blood. The accuracy of platelet function testing may be improved by performance in whole blood.

Medical pharmacological therapy typically targets a single process or agent. Examples include the selection of a specific antibiotic to suppress growth or viability of a specific bacterium, administration of a specific hormone to obviate a specific endocrinologic deficiency, and utilization of a specific chemotherapeutic agent selected to annihilate neoplastic cells of a specific type. By contrast, the use of anticoagulants and antiplatelet drugs deviates from this general principle because of several considerations: (1) inevitable interactions that link activation of platelets and activation of the coagulation cascade; (2) the effect of commonly used antithrombotics (eg, heparin and warfarin) on multiple factors in the coagulation cascade; and (3) profound amplification of a prothrombotic state of >5 orders of magnitude associated with activation. Accordingly, the concentration in blood of an antithrombotic agent that is sufficient to completely suppress its target under basal conditions may be totally insufficient in such suppression when the thrombotic system is activated. Conversely, if a concentration is sufficient to suppress the target under conditions of activation of the thrombotic system, a hemorrhagic diathesis may be induced under basal conditions. Thus, even when a patient has a single condition to be targeted with antithrombotic measures, the considerations that govern therapy are complex. Numerous positive and negative feedback loops in the prothrombotic process1 confer additional complexity. Important examples of positive loops include activation of coagulation factor (F) V and FVIII by thrombin with consequent augmentation of activation of generation of FXa through what has been called the intrinsic pathway, activation of FIX by the tissue factor/VIIa complex, and activation of FXI and consequently FIX by thrombin. Examples of negative feedback loops include inactivation of FVa and FVIIIa by activated protein C formed by the thrombin/thrombomodulin complex, inhibition of the tissue factor FVIIa complex by tissue factor pathway inhibitor, and inhibition …

We sought to delineate mechanisms through which the lack of plasminogen activator inhibitor (PAI)-1 in the heart affects remodeling of the heart early after myocardial infarction (MI). MI was induced by coronary occlusion in 10-weeks old PAI-1 knockout (KO) and control mice. Three days after MI, systolic and diastolic function was assessed with high-resolution echocardiography, infarct size was determined biochemically and histologically and accumulation of acute inflammatory cells in zones of infarction was characterized by immunocytochemistry. PAI-1 KO mice exhibited markedly thickened diastolic left ventricular anterior walls (1.38 +/- 0.38 mm vs. 0.77 +/- 0.13 SD), more profound depression of global and regional cardiac function (19 vs. 22% fractional shortening), and greater evidence of diastolic dysfunction (average E wave amplitude = 568 vs. 675 mm/s) all of which were significant. Markedly greater extent of infarction was demonstrated biochemically and histologically in knockout mice compared with controls (76 vs. 29% of the left ventricle, P0.05) associated with striking hemorrhage and intense inflammation. Fibrosis normalized for infarct size was markedly reduced (0.006 vs. 0.022 microg hydroxyproline/mg dry weight). Thus, lack of PAI-1 in the heart exerted deleterious effects mediated, at least in part by increased inflammation and hemorrhage and attenuating of fibrosis.

Background: Assessment of the likelihood of platelet activation (i.e. platelet reactivity) identifies patients at high and low risk of subsequent thrombotic events. Turbidometric platelet aggregation has been used to assess platelet function for more than 4 decades. We have developed a method to assess individual components of platelet activation with the use of flow cytometry that is performed in minimally altered whole blood. Aims: To compare assessment of platelet reactivity determined with the use of aggregometry and flow cytometry. Material and Methods: Twenty adult patients with atherosclerotic vascular disease were included in this study. Blood from each patient was used to determine turbidometric platelet aggregation and to assess platelet activation by flow cytometry. ADP was used as the agonist. Values are means ± SEM. Comparison was performed with the use of Student’s t test and correlation was assessed with the use of Pearson’s correlation analysis. Results: Both maximal aggregation and the slope of aggregation correlate with the percentage of platelets that bound fibrinogen in response to 0.2 μM ADP. The best correlation was seen between the slope of aggregation induced by 0.2 or 1 μM ADP and the percentage of platelets that bound fibrinogen in response to 0.2 μM ADP (for 0.2 μM r = 0.62, p = 0.038; for 1 μM r = 0.71, p = 0.025). Conclusion: The binding of fibrinogen to activated platelets assessed with the use of flow cytometry correlates best with the slope of turbidometric aggregation and appears to reflect the propensity of platelets to activate.

A plant's ability to maintain or improve its yield under limiting conditions, such as nutrient deficiency or drought, can be strongly influenced by root system architecture (RSA), the three-dimensional distribution of the different root types in the soil. The ability to image, track and quantify these root system attributes in a dynamic fashion is a useful tool in assessing desirable genetic and physiological root traits. Recent advances in imaging technology and phenotyping software have resulted in substantive progress in describing and quantifying RSA. We have designed a hydroponic growth system which retains the three-dimensional RSA of the plant root system, while allowing for aeration, solution replenishment and the imposition of nutrient treatments, as well as high-quality imaging of the root system. The simplicity and flexibility of the system allows for modifications tailored to the RSA of different crop species and improved throughput. This paper details the recent improvements and innovations in our root growth and imaging system which allows for greater image sensitivity (detection of fine roots and other root details), higher efficiency, and a broad array of growing conditions for plants that more closely mimic those found under field conditions.

Cangrelor is the first parenteral antagonist of the platelet P2Y12 receptor. This direct-acting antagonist of the platelet P2Y12 receptor should be considered an adjunct to a percutaneous coronary intervention in patients who have not been adequately pretreated with platelet P2Y12 receptor antagonists at the time of the procedure. The use of cangrelor requires transition to an oral platelet P2Y12 receptor antagonist. Transition strategies have been developed on the basis of pharmacologic characteristics of platelet P2Y12 receptor antagonists, results of pharmacodynamic studies, and results from clinical trials. Cangrelor blocks the binding to the platelet P2Y12 receptor of the active metabolite of the thienopyridines, clopidogrel and prasugrel. The active metabolite of thienopyridines is present in blood for a short interval after administration. For this reason, clopidogrel should be administered after cangrelor is stopped. Prasugrel can be administered at the end of the cangrelor infusion or up to 30 min before cangrelor is stopped. Ticagrelor is also a reversible direct-acting antagonist of the platelet P2Y12 receptor. Because there is no interaction between ticagrelor and cangrelor, ticagrelor can be administered before or during the infusion of cangrelor.

To determine whether initiation of clopidogrel before discontinuation of cangrelor would impact on the recovery of platelet reactivity.The active metabolite of clopidogrel cannot bind to P2Y12 when cangrelor occupies the receptor. Pharmacodynamic studies have shown that this interaction is avoided when clopidogrel is given at the end of the cangrelor infusion. We found that antiplatelet effects of another thienopyridine, prasugrel, were apparent when prasugrel was administered 0.5 hour before cangrelor was stopped.Platelet function studies (light transmission aggregometry, VerifyNow, and flow cytometry) were performed on blood from patients with stable coronary artery disease who were taking aspirin when a loading dose of clopidogrel (600 mg) was given during a cangrelor infusion (0.5 and 1 hour before cangrelor was stopped). Results were compared with those obtained when clopidogrel was given immediately after cangrelor was stopped.Administration of clopidogrel 0.5 and 1 hour before discontinuation of the cangrelor infusion did not prevent recovery of platelet reactivity more effectively than administration at the end of the infusion.Our results support the previously established strategy of administering clopidogrel immediately after discontinuation of cangrelor. Earlier administration increases the recovery of platelet function.

During explosive eruptions, airborne particles collide and stick together, accelerating the fallout of volcanic ash and climate-forcing aerosols. This aggregation process remains a major source of uncertainty both in ash dispersal forecasting and interpretation of eruptions from the geological record. Here we illuminate the mechanisms and timescales of particle aggregation from a well-characterized ‘wet' eruption. The 2009 eruption of Redoubt Volcano, Alaska, incorporated water from the surface (in this case, a glacier), which is a common occurrence during explosive volcanism worldwide. Observations from C-band weather radar, fall deposits and numerical modelling demonstrate that hail-forming processes in the eruption plume triggered aggregation of ∼95% of the fine ash and stripped much of the erupted mass out of the atmosphere within 30 min. Based on these findings, we propose a mechanism of hail-like ash aggregation that contributes to the anomalously rapid fallout of fine ash and occurrence of concentrically layered aggregates in volcanic deposits., The behaviour of airborne fine ash during explosive volcanic eruptions is poorly understood. Here, the authors study hail formation during an eruption, proposing a mechanism of particle aggregation that leads to the fallout of fine ash and the occurrence of concentrically layered aggregates in volcanic deposits

Background.Research has shown less aggressive treatment and poorer control of cardiovascular disease (CVD) risk factors in women than men.Methods.We analyzed sex differences in pharmacotherapy strategies and attainment of goals for hemoglobin A1c (HbA1c), blood pressure (BP), and low density lipoprotein cholesterol (LDL-C) in patients with type 2 diabetes and established coronary artery disease enrolled into the BARI 2D trial.Results.Similar numbers of drugs were prescribed in both women and men. Women were less frequent on metformin or sulfonylurea and more likely to take insulin and to be on higher doses of hydroxymethylglutaryl-CoA reductase inhibitors (statins) than men. After adjusting for baseline differences and treatment prescribed, women were less likely to achieve goals for HbA1c (OR = 0.71, 95% CI 0.57, 0.88) and LDL-C (OR = 0.64, 95% CI 0.53, 0.78). More antihypertensives were prescribed to women, and yet BP ≤ 130/80 mmHg did not differ by sex.Conclusions.Women entering the BARI 2D trial were as aggressively treated with drugs as men. Despite equivalent treatment, women less frequently met targets for HbA1c and LDL-C. Our findings suggest that there may be sex differences in response to drug therapies used to treat diabetes, hypertension, and hyperlipidemia.

Coronary artery calcification may play a significant role in the pathophysiology of plaque progression and healing. We hypothesized that osteoprotegerin, an inhibitor of osteoclastogenesis, may participate in the calcification of coronary plaques or the response to injury after coronary stenting. A prospective registry was performed in 2004. Blood samples from 100 patients undergoing percutaneous coronary intervention (PCI) were obtained before PCI and 24 h after PCI. The concentrations of osteoprotegerin (OPG), C-reactive protein, interleukin-6, and soluble CD40 ligand (sCD40L) were determined by ELISA. Quantitative coronary angiography was performed to define the presence of culprit lesion calcification (CLC). Comparisons among markers of inflammation and tertiles of OPG were stratified with respect to CLC. Patients with CLC (n = 28) compared with no CLC (n = 71) were older (P

Pseudomonas syringae pv. tomato DC3000 is a pathogen of tomato and Arabidopsis that translocates virulence effector proteins into host cells via a type III secretion system (T3SS). Many effector-encoding hypersensitive response and pathogenicity (Hrp) outer protein (hop) genes have been identified previously in DC3000 using bioinformatic methods based on Hrp promoter sequences and characteristic N-terminal amino acid patterns that are associated with T3SS substrates. To approach completion of the Hop/effector inventory in DC3000, 44 additional candidates were tested by the Bordetella pertussis calmodulin-dependent adenylate cyclase (Cya) translocation reporter assay; 10 of the high-probability candidates were confirmed as T3SS substrates. Several previously predicted hop genes were tested for their ability to be expressed in an HrpL-dependent manner in culture or to be expressed in planta. The data indicate that DC3000 harbors 53 hop/avr genes and pseudogenes (encoding both injected effectors and T3SS substrates that probably are released to the apoplast); 33 of these genes are likely functional in DC3000, 12 are nonfunctional members of valid Hop families, and 8 are less certain regarding their production at functional levels. Growth of DC3000 in tomato and Arabidopsis Col-0 was not impaired by constitutive expression of repaired versions of two hops that were disrupted naturally by transposable elements or of hop genes that are naturally cryptic. In summary, DC3000 carries a complex mixture of active and inactive hop genes, and the hop genes in P. syringae can be identified efficiently by bioinformatic methods; however, a precise inventory of the subset of Hops that are important in pathogenesis awaits more knowledge based on mutant phenotypes and functions within plants.

Pseudomonas syringae strains translocate large and distinct collections of effector proteins into plant cells via the type III secretion system (T3SS). Mutations in T3SS-encoding hrp genes are unable to elicit the hypersensitive response or pathogenesis in nonhost and host plants, respectively. Mutations in individual effectors lack strong phenotypes, which has impeded their discovery. P. syringae effectors are designated Hop (Hrp outer protein) or Avr (avirulence) proteins. Some Hop proteins are considered to be extracellular T3SS helpers acting at the plant-bacterium interface. Identification of complete sets of effectors and related proteins has been enabled by the application of bioinformatic and high-throughput experimental techniques to the complete genome sequences of three model strains: P. syringae pv. tomato DC3000, P. syringae pv. phaseolicola 1448A, and P. syringae pv. syringae B728a. Several recent papers, including three in this issue of Molecular Plant-Microbe Interactions, address the effector inventories of these strains. These studies establish that active effector genes in P. syringae are expressed by the HrpL alternative sigma factor and can be predicted on the basis of cis Hrp promoter sequences and N-terminal amino-acid patterns. Among the three strains analyzed, P. syringae pv. tomato DC3000 has the largest effector inventory and P. syringae pv. syringae B728a has the smallest. Each strain has several effector genes that appear inactive. Only five of the 46 effector families that are represented in these three strains have an active member in all of the strains. Web-based community resources for managing and sharing growing information on these complex effector arsenals should help future efforts to understand how effectors promote P. syringae virulence.

Heart failure is associated with advanced age and insulin resistance and is thought to be exacerbated by cardiac fibrosis. Plasminogen activator inhibitor type-1 (PAI-1) has been strongly implicated as a determinant of fibrosis in diverse organs and tissues. Its concentration is increased in blood, and its expression is increased in vessel walls in association with insulin resistance. Accordingly, we sought to determine whether expression of PAI-1 in the heart increases as a function of age of 10 week old and 20 week old normal and insulin resistant transgenic mice thereby potentially predisposing to heart failure. Results obtained indicate that PAI-1 content increases significantly in the heart as a function of age by more than 60%. The increases are much greater than those that can be accounted for by the modest, and statistically insignificant increases in the concentrations of PAI-1 in plasma that were observed to occur as a function of age as well. Thus, PAI-1 increases in the heart is a function of age, occurs in insulin resistant and non-insulin resistant mice, and may contribute to fibrosis predisposing to heart failure associated with advanced age, particularly when insulin resistance is present.

Objectives The effects of antithrombotic agents on the activation of platelets by thrombin were determined in blood from patients (n=12) with symptomatic coronary artery disease. Methods Blood obtained immediately before cardiac catheterization was incubated in vitro with therapeutic concentrations of unfractionated heparin (1.2 and 2.0 U/ml) alone and in combination with eptifibatide (unfractionated heparin 1.2 U/ml + eptifibatide, 1.7 μg/ml) or bivalirudin (8 and 14 μg/ml). An activated clotting time was determined. Platelet activation was induced with thrombin (0, 5,15, and 40 U/ml) and assessed with the use of flow cytometry. Fibrin polymerization was prevented by the peptide Gly-Pro-Arg-Pro. The activation of glycoprotein llb-llla and surface expression of P-selectin were identified with antibodies (PAC-1 and anti-CD62). Results The activated clotting time was 258±13 s with 1.2 U/ml unfractionated heparin alone, 396±8 s with unfractionated heparin + eptifibatide, and 348 ± 9 s with 8 μg/ml bivalirudin. The binding of PAC-1 (reflecting the potential to aggregate) was decreased most effectively by bivalirudin (percentage of platelets binding PAC-1 in response to 15 U/ml thrombin - unfractionated heparin =54±7%, unfractionated heparin + eptifibatide = 12±4%, bivalirudin=1 ±0.3% of platelets, P

Objective— Proliferation of vascular smooth muscle cells (VSMCs) contributes to restenosis after coronary intervention. We have shown previously that increased expression of plasminogen activator inhibitor type 1 (PAI-1) limits VSMC apoptosis. Because apoptosis and proliferation appear to be linked, we sought to determine whether increased PAI-1 would affect VSMC proliferation. Methods and Results— VSMCs were explanted from control and transgenic mice (SM22-PAI + ) in which VSMC expression of PAI-1 was increased. Increased growth of SM22-PAI + -VSMCs (2.3±0.4-fold) reflected, at least partially, increased proliferation. Greater expression of FLICE-like inhibitory protein (FLIP; 2.7-fold) and its cleaved active form were seen in SM22-PAI + -VSMCs. The balance between caspase-8 and FLIP favored proliferation in SM22-PAI + -VSMCs. Increased expression of NF-κB and activation of extracellular signal-regulated kinase (ERK) were demonstrated in SM22-PAI + -VSMCs (fold=NF-κB=2.2±0.1, fold=phosphorylated-ERK=1.6±0.1). Results were confirmed when expression of PAI-1 was increased by transfection. Inhibition of NF-κB and ERK attenuated proliferation in SM22-PAI + -VSMCs. Increased expression of PAI-1 promoted proliferation when VSMCs were exposed to tumor necrosis factor (TNF). Conclusions— Increased expression of PAI-1 is associated with greater activity of FLIP that promotes VSMC proliferation through NF-κB and ERK. Thus, when vascular wall expression of PAI-1 is increased, restenosis after coronary intervention is likely to be potentiated by greater proliferation of VSMC and resistance to apoptosis.

wnt proteins (wnts) promote both differentiation of midbrain dopaminergic cells and self-renewal of haematopoietic stem cells. Mouse embryonic stem (ES) cells can be maintained and self-renew on mouse feeder cell layers or in media containing leukemia inhibitory factor (LIF). However, the effects of wnts on ES cells self-renewal and differentiation are not clearly understood. In the present study, we found that conditioned medium prepared from L cells expressing wnt3a can replace feeder cell layers and medium containing LIF in maintaining ES cells in the proliferation without differentiation (self-renewal) state. By contrast, conditioned medium from NIH3T3 cells expressing wnt11 did not. Alkaline phosphatase staining and compact colony formation were used as criteria of cells being in the undifferentiated state. ES cells maintained in medium conditioned by Wnt3a expressing cells underwent freezing and thawing while maintaining properties seen with LIF maintained ES cells. Purified wnt3a did not maintain self-renewal of ES cells for prolonged intervals. Thus, other factors in the medium conditioned by wnt3a expressing cells may have contributed to maintenance of ES cells in a self-renewal state. Pluripotency of ES cells was determined with the use of embryoid bodies in vitro. PD98059, a MEK specific inhibitor, promoted the growth of undifferentiated ES cells maintained in conditioned medium from wnt3a expressing cells. By contrast, the P38 MAPK inhibitor SB230580 did not, suggesting a role for the MEK pathway in self-renewal and differentiation of ES cells maintained in the wnt3a cell conditioned medium. Thus, our results show that conditioned medium from wnt3a but not wnt11 expressing cells can maintain ES cells in self-renewal and in a pluripotent state.

Introduction Platelet–leukocyte aggregates have been implicated in atherogenesis. This study was designed to determine the influence in vivo of a direct thrombin inhibitor, bivalirudin, compared with unfractionated heparin (UFH) plus the GP IIb–IIIa inhibitor eptifibatide (E) on platelet reactivity, the formation of platelet–leukocyte aggregates, and leukocyte activation. Materials and methods Blood was taken before and after percutaneous coronary intervention (PCI) from 60 patients randomized to UFH + E (n = 26) or bivalirudin (n = 34). Platelet function and the formation in vivo of platelet–monocyte aggregates (PMA) and platelet–neutrophil aggregates (PNA) were assessed with the use of flow cytometry. Myeloperoxidase (MPO) elaborated during leukocyte activation was measured by ELISA. Results Compared with those treated with bivalirudin, patients treated with UFH + E exhibited a 45% decrease in the capacity of platelets to bind fibrinogen (p = 0.006) but a 2-fold increase in platelet surface expression of P-selectin (p = 0.04) in samples taken from the coronary ostium before PCI. Platelet–leukocyte aggregation in vivo was greater (PMA = 2-fold, p = 0.04; PNA = 3-fold, p = 0.006) with UFH + E as was the concentration in blood of MPO (1.5-fold, p = 0.007). Conclusions Increased platelet surface expression of P-selectin, augmented platelet–leukocyte aggregation in vivo, and consequent activation of leukocytes was seen before PCI in blood from patients treated with UFH + E compared with bivalirudin. Benefits associated with decreased platelet aggregation when PCI is performed with UFH plus GP IIb–IIIa inhibition may be partially offset by increased platelet–leukocyte aggregation.

Insulin resistance that accompanies obesity, hypertension, polycystic ovary syndrome, and the early phases of type 2 diabetes is characterized by a prothrombotic state. The prothrombotic state is a reflection of the direct effects of hyperinsulinemia and associated metabolic abnormalities (postprandial hyperglycemia, increased free fatty acids, and hypertriglyceridemia) on platelets, coagulation, and fibrinolysis. Therapies that improve insulin sensitivity and thereby decrease insulin resistance, hyperinsulinemia, and metabolic abnormalities decrease the prothrombotic state.

It has been speculated that a shift of the throwing arc commonly develops in athletes who perform overhead activities, resulting in greater external rotation and decreased internal rotation caused by anterior capsular laxity and posterior capsular contracture, respectively. Osseous adaptation in the form of increased humeral and glenoid retroversion may provide a protective function in the asymptomatic athlete but cannot explain the pathological changes seen in the shoulder of the throwing athlete. Therefore, the objective of the present study was to examine the biomechanical effects of capsular changes in a cadaveric model.Ten cadaveric shoulders were tested with a custom shoulder-testing device. Humeral rotational range of motion, the position of the humerus in maximum external rotation, and glenohumeral translations in the anterior, posterior, superior, and inferior directions were measured with the shoulder in 90 degrees of abduction. Translations were measured with the humerus secured in 90 degrees of external rotation. To simulate anterior laxity due to posterior capsular contracture, the capsule was nondestructively stretched 30% beyond maximum external rotation with the shoulder in 90 degrees of abduction. This was followed by the creation of a 10-mm posterior capsular contracture. Rotational, humeral shift, and translational tests were performed for the intact normal shoulder, after anterior capsular stretching, and after simulated posterior capsular contracture.Nondestructive capsular stretching resulted in a significant increase in external rotation (average increase, 18.2 degrees 2.1 degrees ; p0.001), and subsequent simulated posterior capsular contracture resulted in a significant decrease in internal rotation (average decrease, 8.8 degrees +/- 2.3 degrees ; p = 0.02). There also was a significant increase in anterior translation with the application of a 20-N anterior translational force after nondestructive capsular stretching (average increase, 1.7 +/- 0.3 mm, p = 0.0006). The humeral head translated posteroinferiorly when the humerus was rotated from neutral to maximum external rotation. This did not change significantly in association with anterior capsular stretching. Following simulated posterior capsular contracture, there was a trend toward a more posterosuperior position of the humeral head with the humerus in maximum external rotation in comparison with the position in the stretched conditions, although these differences were not significant.A posterior capsular contracture with decreased internal rotation does not allow the humerus to externally rotate into its normal posteroinferior position in the cocking phase of throwing. Instead, the humeral head is forced posterosuperiorly, which may explain the etiology of Type-II superior labrum anterior-to-posterior lesions in overhead athletes.

Diabetes is strongly associated with coronary, cerebral and peripheral arterial disease, as well as with microangiopathy. In those with diabetes, the extent of macrovascular disease increases and atherosclerotic plaques are more prone to rupture. Both hormonal abnormalities (insulin resistance that is typically present for many years before the onset of type 2 diabetes) and metabolic abnormalities contribute. Multi-targeted intensive therapy is imperative; however, unfortunately it is underutilized. Functional and structural derangements contribute to impaired arterial and ventricular compliance predisposing to congestive heart failure that is increasingly recognized to be a cause of morbidity and mortality in patients with diabetes.

This research investigated how individuals classify and distinguish among stigmatized groups. In Study 1, participants sorted 54 stigmas based on perceived similarity and then provided evaluations. Cluster analysis revealed 7 stigma clusters, including physical disability, mental disability, economically disadvantaged, social deviants, physical appearance, sexual identity, and racial identity. Multidimensional scaling showed that the stigmas differed on dimensions of social undesirability, controllability, and general pity. In Study 2, participants provided evaluation ratings of stigmas across 6 situations. Results confirmed the validity of the 7-cluster solution.

Background This prospective study evaluated the early increase in markers of inflammation after coronary stenting, and the predictors of early rise. Elevation of markers of inflammation after percutaneous coronary intervention correlates with an increased risk of adverse events. The role of soluble CD40 ligand (sCD40L) as a potential initiator of inflammation after stenting has not been described. Methods Seventy-five patients were treated with heparin alone (n=25), or randomized to adjuvant treatment with eptifibatide (n=26) or abciximab (n=24) during stenting. Systemic blood was obtained before coronary stenting and at 10 min after stenting. C-reactive protein (CRP), interleukin (IL)-6, IL-1 receptor antagonist and sCD40L were determined by enzyme liberated immunosorbent assay. Results sCD40L exhibited the greatest relative rise (35%, P=0.01 compared to concentrations before intervention) in the first 10 min after stenting. In a logistic regression model, an early increase in the concentration of sCD40L was predicted by baseline laboratory values (white blood count and sCD40L level before stenting) and procedural characteristics (number of stents and glycoprotein IIb-IIIa inhibitor assignment). Conclusions In conclusion, a systemic inflammatory response is detectable 10 min after coronary stent placement. The early increase in sCD40L suggests a possible role for this marker in the initiation of inflammation after coronary stenting.

This article will review the development of glycoprotein IIb-IIIa antagonists, with particular emphasis on the characteristics and pharmacodynamic studies of each agent that is available for clinical use. Abciximab is a Fab fragment of the 7E3 antibody that has high affinity and a slow rate of dissociation from glycoprotein IIb-IIIa. In contrast, the small molecules eptifibatide and tirofiban, have a much more rapid rate of dissociation, with an off time of 10 to 15 s. Accordingly, the circulating pool of abciximab is predominantly associated with platelets, whereas maintenance of a consistent concentration of tirofiban and eptifibatide in the blood is critical in order to achieve and sustain their inhibitory effects. The affinity of abciximab and tirofiban for glycoprotein IIb-IIIa are substantially greater than that of eptifibatide, necessitating maintenance of greater molar concentrations of eptifibatide in blood in order to achieve effective inhibition of the binding of fibrinogen to the activated conformer of glycoprotein IIb-IIIa.

Diabetes and the metabolic syndrome, including insulin resistance, that underlies it are hyper-coagulable states. Increased platelet reactivity,augmented activity of the coagulation system,and impaired fibrinolysis are characteristic and understood to a remarkable extent. In aggregate,these derangements contribute to accelerated atherosclerosis, premature coronary artery dis-ease, and a profound toll from both.

The extent of luminal involvement of atherosclerotic vascular disease and platelet reactivity portend subsequent cardiovascular events. This study was designed to determine whether platelet reactivity correlates with the extent of the territorial distribution of vascular disease. Blood was obtained from 130 patients who had known atherosclerotic vascular disease categorized as being in > or =1 of the following territories: coronary artery disease (CAD; n = 89), cerebrovascular disease (n = 36), and peripheral arterial disease (n = 61). Platelet reactivity, i.e., the activation of platelets in response to a low concentration of adenosine diphosphate (0.2 micromol/L), was measured using flow cytometry. Patients with vascular disease in >1 territory compared with those with disease in only 1 territory had greater platelet reactivity with respect to P-selectin expression (p = 0.01). The percentages of platelets expressing P-selectin (mean +/- SD) were 6.4 +/- 4.2 in patients who had involvement of 1 territory (n = 88), 10.0 +/- 6.8 in those who had involvement of 2 territories (n = 28), and 10.1 +/- 9.9 in those who had involvement of 3 territories (n = 14). Patients who had CAD and diabetes mellitus had greater P-selectin expression than did those who had CAD without diabetes (p

Background. Increased platelet reactivity presages adverse cardiac events. Because both haemodialysis and unfractionated heparin (UFH) can increase platelet reactivity, we compared platelet reactivity during haemodialysis when patients were anticoagulated with UFH or enoxaparin. Methods. Patients (n ¼ 20) underwent consecutive haemodialysis sessions with either UFH or enoxaparin in a random order. Blood was taken from the arterial end of the haemodialysis circuit at the initiation of haemodialysis before anticoagulation. Subsequently, blood was taken during dialysis from the venous end of the circuit 10 min after treatment with UFH or enoxaparin. Platelet reactivity was assessed with the use of flow cytometry by determining the capacity of platelets to bind fibrinogen and the surface expression of P-selectin in response to adenosine diphosphate (ADP, 0 and 0.2mM). Results were compared with the use of two-way repeated measure ANOVA. Results. Platelet reactivity in arterial blood obtained at the beginning of dialysis prior to patients being treated with either UFH [0.2mM ADP-induced capacity to bind fibrinogen ¼ 28±15% (SD)] or enoxaparin (30±18%) was similar (P ¼ 0.15). In contrast, platelet reactivity was less after treatment with enoxaparin compared with UFH (P ¼ 0.006). The 0.2mM ADPinduced capacity to bind fibrinogen in venous blood obtained 10 min after anticoagulation was 34±11% after treatment with UFH and 22±11% after treatment with enoxaparin. Conclusions. Anticoagulation with enoxaparin during haemodialysis is associated with less platelet reactivity compared with UFH. Accordingly, enoxaparin use may contribute to a lesser risk of cardiac events in patients with end-stage renal disease treated with haemodialysis.

Acute coronary syndromes are generally precipitated by rupture of lipid-laden, relatively acellular, vulnerable atherosclerotic plaques with thin fibrous caps. We investigated whether a high-fat diet alters insulin sensitivity and whether insulin sensitizers (troglitazone and rosiglitazone) alter the composition of otherwise lipidladen atherosclerotic plaques in mice deficient in apolipoprotein E (ApoE). ApoE-knockout mice were fed a high-fat (n=30) or standard chow (n=10) diet for two weeks. Thereafter, those fed the high-fat diet were treated with troglitazone (n=10), rosiglitazone (n=10) or no drug (n=10) for 16 weeks beginning at 8 weeks of age. Carbohydrate metabolism was assessed with intraperitoneal glucose tolerance tests and insulin tolerance tests. Plaque composition was characterised with confocal laser scanning microscopy. The high-fat diet induced insulin resistance in the absence of weight gain. Compared with control animals on the high-fat diet, animals given troglitazone (400 mg/kg/day) or rosiglitazone (4 mg/kg/day) had significantly less area under the curve (AUC) for insulin ( p

Blood taken from the coronary artery ostium reflects biochemical changes indicative of thrombosis in the culprit vessel. We sought to determine whether inflammation is manifested by increased concentrations of selected markers in ostial blood sampled from a culprit coronary artery proximal to an atherosclerotic plaque. The concentrations of C-reactive protein (CRP), interleukin (IL)-6, IL-1 receptor antagonist, and soluble CD40 ligand (sCD40L) were measured in blood drawn from 75 patients before percutaneous coronary intervention from the femoral artery and from a guide catheter after engagement of the culprit coronary artery. Results were compared using Student's t tests. An acute coronary syndrome was present in 88% of patients. The concentrations of CRP and IL-6 were similar in coronary ostial and peripheral blood. Concentrations of IL-1 receptor antagonist were consistently greater in coronary arterial compared with peripheral arterial blood (peripheral 545 +/- 378 vs coronary 595 +/- 388 pg/ml, p = 0.003). Concentrations of sCD40L were also greater in the coronary compared with peripheral blood (peripheral 0.80 +/- 0.46 vs coronary 2.12 +/- 2.77 ng/ml, p0.0001). The increased concentration of IL-1 receptor antagonist and sCD40L in blood drawn from the culprit coronary artery compared with that taken from the peripheral artery suggests that these cytokines contribute directly to inflammation in response to coronary intervention and may potentiate a systemic inflammatory state.