Thrombin, inflammation, and cardiovascular disease: an epidemiologic perspective

Acoustofluidic separation of proteins from platelets in human blood plasma using aptamer-functionalized microparticles

Microfluidic liquid biopsy has emerged as a promising clinical assay for early diagnosis. Herein, we propose acoustofluidic separation of biomarker proteins from platelets in plasma using aptamer-functionalized microparticles. As model proteins, C-reactive protein and thrombin were spiked in human platelet-rich plasma. The target proteins were selectively conjugated with their corresponding aptamer-functionalized microparticles of different sizes, and the particle complexes served as a mobile carrier for the conjugated proteins. The proposed acoustofluidic device was composed of an interdigital transducer (IDT) patterned on a piezoelectric substrate and a disposable polydimethylsiloxane (PDMS) microfluidic chip. The PDMS chip was placed in a tilted arrangement with the IDT to utilize both vertical and horizontal components of surface acoustic wave-induced acoustic radiation force (ARF) for multiplexed assay at high-throughput. The two different-sized particles experienced the ARF at different magnitudes and were separated from platelets in plasma. The IDT on the piezoelectric substrate could be reusable, while the microfluidic chip can be replaceable for repeated assays. The sample processing throughput with the separation efficiency >95% has been improved such that the volumetric flow rate and flow velocity were 1.6 ml/h and 37 mm/s, respectively. For the prevention of platelet activation and protein adsorption to the microchannel, polyethylene oxide solution was introduced as sheath flows and coating on to the walls. We conducted scanning electron microscopy, x-ray photoemission spectroscopy , and sodium dodecyl sulfate- analysis before and after the separation to confirm the protein capture and separation. We expect that the proposed approach will provide new prospects for particle-based liquid biopsy using blood.

Current Therapeutic Approach to Acute Myocardial Infarction in Patients with Congenital Hemophilia

Advances in the treatment of hemophilia have made the life expectancy of hemophiliacs similar to that of the general population. Physicians have begun to face age-related diseases not previously encountered in individuals with hemophilia. Treatment of acute myocardial infarction (AMI) is particularly challenging because the therapeutic strategies influence both the patient's thrombotic and hemorrhagic risk. As progress has been made in the treatment of AMI over the last decade, we performed an in-depth analysis of the available literature, highlighting the latest advances in the therapy of AMI in hemophiliacs. It is generally accepted that after the optimal substitution therapy has been provided, patients with hemophilia should be treated in the same way as those in the general population. New-generation stents that allow short dual antiplatelet therapy and potent P2Y12 receptor inhibitors have begun to be successfully used. At a time when specific recommendations and relevant data are scarce, our study provides up-to-date information to physicians involved in the treatment of AMI in hemophiliacs.

Microfluidic chip grafted with integrin tension sensors for evaluating the effects of flowing shear stress and ROCK inhibitor on platelets

Integrins are key players in platelet adhesion and aggregation. Integrin molecular tensions, the forces transmitted by integrin molecules, are regulated by both mechanical and biochemical cues, and the outside-in and inside-out signaling has been extensively studied. While the mechanical properties of platelets at static status have been studied by atomic force microscopy, traction force microscopy and tension sensors, the biomechanical properties of flowing platelets remain elusive. Herein, we report microfluidic chips grafted with integrin tension sensors for microfluidic-force mapping in platelets. Specifically, the process of integrin α_IIbβ₃ mediating tension transmission and platelet adhesion under low flow rates has been obtained, and the process of platelet clustering at post-stenotic regions has been demonstrated. We found that flowing shear force can postpone the integrin-mediated tension transmission and platelet adhesion. We further evaluated the effect of Y-27632, a ROCK inhibitor that has been proven to reduce integrin-mediated platelet adhesion, at a series of concentrations and demonstrated that microfluidic chips with integrin tension sensors are sensitive to the concentration-dependent effects of Y-27632. Given their low cost and scalable throughput, these chips are ideal technical platforms for biological studies of platelets at flowing status and for platelet inhibitor or potential antiplatelet drug screening.

Investigating the Multi-Faceted Nature of Radiation-Induced Coagulopathies in a Göttingen Minipig Model of Hematopoietic Acute Radiation Syndrome

Coagulopathies are well documented after acute radiation exposure at hematopoietic doses, and radiation-induced bleeding is notably one of the two main causes of mortality in the hematopoietic acute radiation syndrome. Despite this, understanding of the mechanisms by which radiation alters hemostasis and induces bleeding is still lacking. Here, male Göttingen minipigs received hematopoietic doses of 60Co gamma irradiation (total body) and coagulopathies were characterized by assessing bleeding, blood cytopenia, fibrin deposition, changes in hemostatic properties, coagulant/anticoagulant enzyme levels, and markers of inflammation, endothelial dysfunction, and barrier integrity to understand if a relationship exists between bleeding, hemostatic defects, bone marrow aplasia, inflammation, endothelial dysfunction and loss of barrier integrity. Acute radiation exposure induced coagulopathies in the Göttingen minipig model of hematopoietic acute radiation syndrome; instances of bleeding were not dependent upon thrombocytopenia. Neutropenia, alterations in hemostatic parameters and damage to the glycocalyx occurred in all animals irrespective of occurrence of bleeding. Radiation-induced bleeding was concurrent with simultaneous thrombocytopenia, anemia, neutropenia, inflammation, increased heart rate, decreased nitric oxide bioavailability and endothelial dysfunction; bleeding was not observed with the sole occurrence of a single aforementioned parameter in the absence of the others. Alteration of barrier function or clotting proteins was not observed in all cases of bleeding. Additionally, fibrin deposition was observed in the heart and lungs of decedent animals but no evidence of DIC was noted, suggesting a unique pathophysiology of radiation-induced coagulopathies. These findings suggest radiation-induced coagulopathies are the result of simultaneous damage to several key organs and biological functions, including the immune system, the inflammatory response, the bone marrow and the cardiovasculature.

The Effects of Social, Personal, and Behavioral Risk Factors and PM2.5 on Cardio-Metabolic Disparities in a Cohort of Community Health Center Patients

(1) Background: Cardio-metabolic diseases (CMD), including cardiovascular disease, stroke, and diabetes, have numerous common individual and environmental risk factors. Yet, few studies to date have considered how these multiple risk factors together affect CMD disparities between Blacks and Whites. (2) Methods: We linked daily fine particulate matter (PM2.5) measures with survey responses of participants in the Southern Community Cohort Study (SCCS). Generalized linear mixed modeling (GLMM) was used to estimate the relationship between CMD risk and social-demographic characteristics, behavioral and personal risk factors, and exposure levels of PM2.5. (3) Results: The study resulted in four key findings: (1) PM2.5 concentration level was significantly associated with reported CMD, with risk rising by 2.6% for each µg/m3 increase in PM2.5; (2) race did not predict CMD risk when clinical, lifestyle, and environmental risk factors were accounted for; (3) a significant variation of CMD risk was found among participants across states; and (4) multiple personal, clinical, and social-demographic and environmental risk factors played a role in predicting CMD occurrence. (4) Conclusions: Disparities in CMD risk among low social status populations reflect the complex interactions of exposures and cumulative risks for CMD contributed by different personal and environmental factors from natural, built, and social environments.

Facile, Rapid, and Low-Cost Electrophoresis Titration of Thrombin by Aptamer-Linked Magnetic Nanoparticles and a Redox Boundary Chip

An aptamer-linked assay of a target biomarker (e.g., thrombin) is facing the challenges of long-term run, complex performance, and expensive instrument, unfitting clinical diagnosis in resource-limited areas. Herein, a facile chip electrophoresis titration (ET) model was proposed for rapid, portable, and low-cost assay of thrombin via aptamer-linked magnetic nanoparticles (MNPs), redox boundary (RB), and horseradish peroxidase (HRP). In the electrophoresis titration-redox boundary (ET-RB) model, thrombin was chosen as a model biomarker, which could be captured within 15 min by MNP-aptamer 1 and HRP-aptamer 2, forming a sandwich complex of (MNP-aptamer 1)-thrombin-(HRP-aptamer 2). After MNP separation and chromogenic reaction of 3,3',5,5'-tetramethylbenzidine (TMB) within 10 min, an ET-RB run could be completed within 5 min based on the reaction between a 3,3',5,5'-tetramethylbenzidine radical cation (TMB^•+) and l-ascorbic acid in the ET channel. The systemic experiments based on the ET-RB method revealed that the sandwich complex could be formed and the thrombin content could be assayed via an ET-RB chip, demonstrating the developed model and method. In particular, the ET-RB method had the evident merits of simplicity, rapidity (less than 30 min), and low cost as well as portability and visuality, in contrast to the currently used thrombin assay. In addition, the developed method had high selectivity, sensitivity (limit of detection of 0.04 nM), and stability (intraday: 3.26%, interday: 6.07%) as well as good recovery (urine: 97-102%, serum: 94-103%). The developed model and method have potential to the development of a point-of-care testing assay in resource-constrained conditions.

The Effects of Graded Levels of Calorie Restriction: X. Transcriptomic Responses of Epididymal Adipose Tissue

Calorie restriction (CR) leads to a remarkable decrease in adipose tissue mass and increases longevity in many taxa. Since the discovery of leptin, the secretory abilities of adipose tissue have gained prominence in the responses to CR. We quantified transcripts of epididymal white adipose tissue of male C57BL/6 mice exposed to graded levels of CR (0–40% CR) for 3 months. The numbers of differentially expressed genes (DEGs) involved in NF-κB, HIF1-α, and p53 signaling increased with increasing levels of CR. These pathways were all significantly downregulated at 40% CR relative to 12 h ad libitum feeding. In addition, graded CR had a substantial impact on DEGs associated with pathways involved in angiogenesis. Of the 497 genes differentially expressed with graded CR, 155 of these genes included a signal peptide motif. These putative signaling proteins were involved in the response to ketones, TGF-β signaling, negative regulation of insulin secretion, and inflammation. This accords with the previously established effects of graded CR on glucose homeostasis in the same mice. Overall these data suggest reduced levels of adipose tissue under CR may contribute to the protective impact of CR in multiple ways linked to changes in a large population of secreted proteins.

DNA Aptamers in the Diagnosis and Treatment of Human Diseases

Aptamers have a promising role in the field of life science and have been extensively researched for application as analytical tools, therapeutic agents and as vehicles for targeted drug delivery. Compared with RNA aptamers, DNA aptamers have inherent advantages in stability and facility of generation and synthesis. To better understand the specific potential of DNA aptamers, an overview of the progress in the generation and application of DNA aptamers in human disease diagnosis and therapy are presented in this review. Special attention is given to researches that are relatively close to practical application. DNA aptamers are expected to have great potential in the diagnosis and treatment of human diseases.

Preterm birth and future risk of maternal cardiovascular disease - is the association independent of smoking during pregnancy?

BACKGROUND

While the association of preterm birth and the risk of maternal cardiovascular disease (CVD) has been well-documented, most studies were limited by the inability to account for smoking during pregnancy - an important risk factor for both preterm birth and CVD. This study aimed to determine whether the increased future risk of maternal cardiovascular disease (CVD) associated with preterm birth is independent of maternal smoking during pregnancy.

METHODS

A population-based record linkage study of 797,056 women who delivered a singleton infant between 1994 and 2011 in New South Wales, Australia was conducted. Birth records were linked to the mothers' subsequent hospitaliation or death from CVD. Preterm births were categorised as late (35-36 weeks), moderate (33-34 weeks), or extreme (≤32 weeks); and as spontaneous or indicated. Cox proportional hazard regression was used to estimate adjusted hazard ratios (AHR) [95 % CI].

RESULTS

During the study period, 59,563 women (7.5 %) had at least one preterm birth. After adjustment for CVD risk factors other than smoking, AHR [95 % CI] of CVD among women who ever had a preterm birth was 1.78 [1.61-1.96]. Associations were greater for extreme (AHR = 1.98 [1.63-2.42]) and moderate (AHR = 2.06 [1.69-2.51]) than late preterm birth (AHR = 1.63 [1.44-1.85]), for indicated (AHR = 2.04 [1.75-2.38]) than spontaneous preterm birth (AHR = 1.65 [1.47-1.86]), and for having ≥ two (AHR = 2.29[1.75-2.99]) than having one preterm birth (AHR = 1.73[1.57-1.92]). A further adjustment for maternal smoking attenuated, but did not eliminate, the associations. Smoking during pregnancy was also independently associated with maternal CVD risks, with associations being stronger for mothers who smoked during last pregnancy (AHR = 2.07 [1.93-2.23]) than mothers who smoked during a prior pregnancy (AHR = 1.64 [1.41-1.90]).

CONCLUSIONS

Associations of preterm birth and maternal CVD risk are independent of maternal smoking during pregnancy. This underscores the importance of smoking cessation in reducing CVD and suggests that a history of preterm delivery (especially if severe, indicated or recurrent) identifies women who could be targeted for CVD screening and preventative therapies.

Profile of the Immune and Inflammatory Response in Individuals With Prediabetes and Type 2 Diabetes

OBJECTIVE

The inflammatory and immune systems are altered in type 2 diabetes. Here, the aim was to profile the immune and inflammatory response in subjects with prediabetes and diabetes in a large population-representative sample.

RESEARCH DESIGN AND METHODS

In total, 15,010 individuals were analyzed from the population-based Gutenberg Health Study. Glucose status was classified according to HbA1c concentration and history of diagnosis. All samples were analyzed for white blood cells (WBCs), granulocytes, lymphocytes, monocytes, platelets, C-reactive protein (CRP), albumin, fibrinogen, and hematocrit. Interleukin-18 (IL-18), IL-1 receptor antagonist (IL-1RA), and neopterin concentrations were determined in a subcohort.

RESULTS

In total, 7,584 men and 7,426 women were analyzed (range 35-74 years), with 1,425 and 1,299 having prediabetes and diabetes, respectively. Biomarkers showed varying dynamics from normoglycemic via subjects with prediabetes to subjects with diabetes: 1) gradual increase (WBCs, granulocytes, monocytes, IL-1RA, IL-18, and fibrinogen), 2) increase with subclinical disease only (lymphocytes and CRP), 3) increase from prediabetes to diabetes only (neopterin), and 4) no variation with glucose status (hematocrit). The strongest relative differences were found for CRP, IL-1RA, and fibrinogen concentrations. Several inflammatory and immune markers were associated with the glucose status independent from cardiovascular risk factors and comorbidities, varied with disease severity and the presence of disease-specific complications in the diabetes subcohort.

CONCLUSIONS

The inflammatory and immune biomarker profile varies with the development and progression of type 2 diabetes. Markers of inflammation and immunity enable differentiation between the early preclinical and clinical phases of the disease, disease complications, and progression.

Pathologies at the nexus of blood coagulation and inflammation: thrombin in hemostasis, cancer, and beyond

Thrombin is the protease involved in blood coagulation. Its deregulation can lead to hemostatic abnormalities, which range from subtle subclinical to serious life-threatening coagulopathies, i.e., during septicemia. Additionally, thrombin plays important roles in many (patho)physiological conditions that reach far beyond its well-established role in stemming blood loss and thrombosis, including embryonic development and angiogenesis but also extending to inflammatory processes, complement activation, and even tumor biology. In this review, we will address thrombin's broad roles in diverse (patho)physiological processes in an integrative way. We will also discuss thrombin as an emerging major target for novel therapies.

The beneficial effects of a direct thrombin inhibitor, dabigatran etexilate, on the development and stability of atherosclerotic lesions in apolipoprotein E-deficient mice : dabigatran etexilate and atherosclerosis

PURPOSE

Dabigatran etexilate (DE) constitutes a novel, direct thrombin inhibitor. Regarding the association of thrombin with atherogenesis, we assessed the effects of DE on the development and stability of atherosclerotic lesions in apolipoprotein-E deficient (ApoE-/-) mice.

MATERIALS-METHODS

Fifty male ApoE-/- mice were randomized to receive western-type diet either supplemented with DE 7.5 mg DE/g chow) (DE-group, n = 25) or matching placebo as control (CO-group, n = 25) for 12 weeks. After this period, all mice underwent carotid artery injury with ferric chloride and the time to thrombotic total occlusion (TTO) was measured. Then, mice were euthanatized and each aortic arch was analyzed for the mean plaque area, the content of macrophages, elastin, collagen, nuclear factor kappaB (NFκB), vascular cell adhesion molecule-1 (VCAM-1), matrix metalloproteinase-9 (MMP-9) and its inhibitor (TIMP-1).

RESULTS

DE-group showed significantly longer TTO compared to CO-group (8.9 ± 2.3 min vs 3.5 ± 1.1 min, p < 0.001) and the mean plaque area was smaller in DE-group than CO-group (441.00 ± 160.01 × 10(3) μm(2) vs 132.12 ± 32.17 × 10(3) μm(2), p < 0.001). Atherosclerotic lesions derived from DE-treated mice showed increased collagen (p = 0.043) and elastin (p = 0.031) content, thicker fibrous caps (p < 0.001) and reduced number of internal elastic lamina ruptures per mm of arterial girth (p < 0.001) when compared to CO-group. Notably, DE treatment seemed to promote plaque stability possibly by reducing concentrations of NFκB, VCAM-1, macrophages and MMP-9 and increasing TIMP-1 within atherosclerotic lesions (p < 0.05).

CONCLUSIONS

DE attenuates arterial thrombosis, reduces lesion size and may promote plaque stability in ApoE-/- mice. The plaque-stabilizing effects of chronic thrombin inhibition might be the result of the favorable modification of inflammatory mechanisms.

Platelet count kinetics following interruption of antiretroviral treatment

OBJECTIVES

To investigate the mechanisms of platelet kinetics in the Strategies for Management of Antiretroviral Therapy (SMART) study that demonstrated excess mortality with CD4 guided episodic antiretroviral therapy (ART) drug conservation compared with continuous treatment viral suppression. Follow-up analyses of stored plasma samples demonstrated increased activation of both inflammatory and coagulation pathways after stopping ART.

DESIGN

SMART patients from sites that determined platelets routinely.

METHODS

Platelet counts were retrospectively collected from 2206 patients from visits at study entry, and during follow-up. D-dimer levels were measured at study entry, month 1, and 2.

RESULTS

Platelet levels decreased in the drug conservation group following randomization, but remained stable in the viral suppression group [median (IQR) decline from study entry to month 4: -24 000/μl (-54 000 to 4000) vs. 3000 (-22 000 to 24 000), respectively, P < 0.0001)] and the rate of developing thrombocytopenia (<100 000/μl) was significantly higher in the drug conservation vs. the viral suppression arm (unadjusted drug conservation/viral suppression [HR (95%CI) = 1.8 (1.2-2.7)]. The decline in platelet count among drug conservation participants on fully suppressive ART correlated with the rise in D-dimer from study entry to either month 1 or 2 (r = -0.41; P = 0.02). Among drug conservation participants who resumed ART 74% recovered to their study entry platelet levels.

CONCLUSION

Interrupting ART increases the risk of thrombocytopenia, but reinitiation of ART typically reverses it. Factors contributing to declines in platelets after interrupting ART may include activation of coagulation pathways or HIV-1 replication itself. The contribution of platelets in HIV-related procoagulant activity requires further study.

Thioredoxin and thioredoxin reductase control tissue factor activity by thiol redox-dependent mechanism

Abnormally enhanced tissue factor (TF) activity is related to increased thrombosis risk in which oxidative stress plays a critical role. Human cytosolic thioredoxin (hTrx1) and thioredoxin reductase (TrxR), also secreted into circulation, have the power to protect against oxidative stress. However, the relationship between hTrx1/TrxR and TF remains unknown. Here we show reversible association of hTrx1 with TF in human serum and plasma samples. The association is dependent on hTrx1-Cys-73 that bridges TF-Cys-209 via a disulfide bond. hTrx1-Cys-73 is absolutely required for hTrx1 to interfere with FVIIa binding to purified and cell-surface TF, consequently suppressing TF-dependent procoagulant activity and proteinase-activated receptor-2 activation. Moreover, hTrx1/TrxR plays an important role in sensing the alterations of NADPH/NADP(+) states and transducing this redox-sensitive signal into changes in TF activity. With NADPH, hTrx1/TrxR readily facilitates the reduction of TF, causing a decrease in TF activity, whereas with NADP(+), hTrx1/TrxR promotes the oxidation of TF, leading to an increase in TF activity. By comparison, TF is more likely to favor the reduction by hTrx1-TrxR-NADPH. This reversible reduction-oxidation reaction occurs in the TF extracellular domain that contains partially opened Cys-49/-57 and Cys-186/-209 disulfide bonds. The cell-surface TF procoagulant activity is significantly increased after hTrx1-knockdown. The response of cell-surface TF procoagulant activity to H(2)O(2) is efficiently suppressed through elevating cellular TrxR activity via selenium supplementation. Our data provide a novel mechanism for redox regulation of TF activity. By modifying Cys residues or regulating Cys redox states in TF extracellular domain, hTrx1/TrxR function as a safeguard against inappropriate TF activity.

Potential cardiovascular disease risk markers among HIV-infected women initiating antiretroviral treatment

BACKGROUND

Inflammation and hemostasis perturbation may be involved in vascular complications of HIV infection. We examined atherogenic biomarkers and subclinical atherosclerosis in HIV-infected adults before and after beginning highly active antiretroviral therapy (HAART).

METHODS

In the Women's Interagency HIV Study, 127 HIV-infected women studied pre and post HAART were matched to HIV-uninfected controls. Six semiannual measurements of soluble CD14, tumor necrosis factor (TNF) alfa, soluble interleukin (IL) 2 receptor, IL-6, IL-10, monocyte chemoattractant protein 1, D-dimer, and fibrinogen were obtained. Carotid artery intima-media thickness was measured by B-mode ultrasound.

RESULTS

Relative to HIV-uninfected controls, HAART-naive HIV-infected women had elevated levels of soluble CD14 (1945 vs 1662 ng/mL, Wilcoxon signed rank P < 0.0001), TNF-α (6.3 vs 3.4 pg/mL, P < 0.0001), soluble IL-2 receptor (1587 vs 949 pg/mL, P < 0.0001), IL-10 (3.3 vs 1.9 pg/mL, P < 0.0001), monocyte chemoattractant protein 1 (190 vs 163 pg/mL, P < 0.0001), and D-dimer (0.43 vs 0.31 μg/mL, P < 0.01). Elevated biomarker levels declined after HAART. Although most biomarkers normalized to HIV-uninfected levels, in women on effective HAART, TNF-α levels remained elevated compared with HIV-uninfected women (+0.8 pg/mL, P = 0.0002). Higher post-HAART levels of soluble IL-2 receptor (P = 0.02), IL-6 (P = 0.05), and D-dimer (P = 0.03) were associated with increased carotid artery intima-media thickness.

CONCLUSIONS

Untreated HIV infection is associated with abnormal hemostasis (eg, D-dimer), proatherogenic (eg, TNF-α), and antiatherogenic (eg, IL-10) inflammatory markers. HAART reduces most inflammatory mediators to HIV-uninfected levels. Increased inflammation and hemostasis are associated with subclinical atherosclerosis in recently treated women. These findings have potential implications for long-term risk of cardiovascular disease in HIV-infected patients, even with effective therapy.

Obesity, Inflammation and Acute Myocardial Infarction - Expression of leptin, IL-6 and high sensitivity-CRP in Chennai based population

BACKGROUND

Obesity, characterised by increased fat mass and is currently regarded as a pro-inflammatory state and often associated with increased risk of cardiovascular diseases (CVD) including Myocardial infarction. There is an upregulation of inflammatory markers such as interleukin-6, interleukin-6 receptor and acute phase protein CRP in Acute Myocardial Infarction (AMI) patients but the exact mechanism linking obesity and inflammation is not known. It is of our interest to investigate if serum leptin (ob gene product) is associated with AMI and correlated with inflammatory proteins namely Interleukin-6 (IL-6) and high sensitivity - C reactive protein (hs-CRP).

RESULTS

Serum leptin levels were significantly higher in AMI patients when compared to Non-CVD controls. IL-6 and hs-CRP were also elevated in the AMI group and leptin correlated positively with IL-6 and hs-CRP. Incidentally this is the first report from Chennai based population, India.

CONCLUSIONS

The strong correlation between serum levels of leptin and IL-6 implicates an involvement of leptin in the upregulation of inflammatory cytokines during AMI. We hypothesise that the increase in values of IL-6, hs-CRP and their correlation to leptin in AMI patients could be due to participation of leptin in the signaling cascade after myocardial ischemia.

Are vasomotor symptoms associated with alterations in hemostatic and inflammatory markers? Findings from the Study of Women's Health Across the Nation

OBJECTIVE

Emerging research suggests links between menopausal hot flashes and cardiovascular risk. The mechanisms underlying these associations are unclear due, in part, to the incomplete understanding of the physiology of hot flashes. We aimed to examine the longitudinal associations between hot flashes/night sweats and both inflammatory and hemostatic markers, controlling for cardiovascular risk factors and estradiol concentrations.

METHODS

Participants in the Study of Women's Health Across the Nation (n = 3,199), a longitudinal cohort study, were aged 42 to 52 years at cohort entry. Women completed interviews (hot flashes, night sweats: none, 1-5, and ≥6 d in the past 2 weeks), physical measures (blood pressure, height, weight), and a blood draw (high-sensitivity C-reactive protein, plasminogen activator inhibitor-1, factor VIIc, tissue plasminogen activator antigen [tPA-ag], fibrinogen, glucose, serum estradiol) yearly for 8 years. Hot flashes/night sweats were examined in relation to each inflammatory/hemostatic marker in linear mixed models adjusting for demographic factors, cardiovascular risk factors, and medication use, as well as serum estradiol.

RESULTS

Compared with experiencing no flashes, reporting hot flashes was associated with higher tPA-aglog (hot flashes 1-5 d: percent change, or % change [95% CI], 3.88 [2.22-5.58]; P < 0.0001; ≥6 d: % change [95% CI], 4.11 [1.95-6.32]; P < 0.001) and higher factor VIIclog (hot flashes ≥6 d: % change [95% CI], 2.13 [0.80-3.47]; P < 0.01) in multivariable models. Findings persisted after adjusting for estradiol. Findings for night sweats were similar but attenuated with adjustment.

CONCLUSIONS

Frequent hot flashes were associated with higher factor VIIc and tPA-ag. Hemostatic pathways may be relevant to understanding hot flash physiology and links between hot flashes and cardiovascular risk.

Birth characteristics and subsequent risks of maternal cardiovascular disease: effects of gestational age and fetal growth

BACKGROUND

Prior studies showing an inverse relationship between low birth weight in offspring and maternal risks of cardiovascular diseases (CVD) are limited by lack of information on gestational age and/or insufficient adjustment for confounders.

METHODS AND RESULTS

In a nationwide Swedish study, we included information on 923 686 women and their first singleton births between 1983 and 2005. Cox proportional hazards models were used to study associations between gestational length, fetal growth, and maternal incident hospitalization or death from CVD (coronary heart disease, cerebrovascular events, and heart failure). Multivariable adjusted models accounted for birth year, income, education, country of birth, smoking, diabetes mellitus, hypertension, and preeclampsia. The risk of maternal CVD increased with decreasing gestational age whereas the risk increase related to fetal growth appeared to be restricted to very small-for-gestational-age (SGA) infants. Compared with mothers of non-SGA infants born at term, the hazard ratio of CVD ranged from 1.39 (95% confidence interval 1.22-1.58) to 2.57 (95% confidence interval 1.97-3.34) among mothers to moderately and very preterm infants, respectively. There was a significant interaction between preterm birth and fetal growth with respect to mothers' risk of CVD (P<0.001). Among mothers to very SGA infants, the hazard ratio of CVD ranged from 1.38 (95% confidence interval 1.15-1.65) to 3.40 (95% confidence interval 2.26-5.11) in mothers to term and very preterm infants, respectively.

CONCLUSIONS

Delivery of a preterm or SGA infant is associated with later life maternal hospitalization or death from CVD even after accounting for socioeconomic factors, smoking, and pregnancy-related complications.

Aptamer-functionalized microgel particles for protein detection

Highly sensitive and multiplexed detection of clinically relevant proteins in biologically complex samples is crucial for the advancement of clinical proteomics. In recent years, aptamers have emerged as useful tools for protein analysis due to their specificity and affinity for protein targets as well as their compatibility with particle-based detection systems. In this study, we demonstrate the highly sensitive detection of human α-thrombin on encoded hydrogel microparticles functionalized with an aptamer capture sequence. We use static imaging and microfluidic flow-through analysis techniques to evaluate the detection capabilities of the microgels in sandwich-assay formats that utilize both aptamers and antibodies for the reporting of target-binding events. Buffers and reagent concentrations were optimized to provide maximum reaction efficiency while still maintaining an assay with a simple workflow that can be easily adapted to the multiplexed detection of other clinically relevant proteins. The three-dimensional, nonfouling hydrogel immobilization scaffold used in this work provides three logs of dynamic range, with a limit of detection of 4 pM using a single aptamer capture species and without the need for spacers or signal amplification.

High fibrinogen level is an independent predictor of presence and extent of coronary artery disease among Italian population

Few reports have so far investigated the relationship between fibrinogen levels and the extent of coronary artery disease (CAD) as evaluated by coronary angiography, that is therefore the aim of the current study. We measured fibrinogen in 2,121 consecutive patients undergoing coronary angiography. Patients were divided in 5 groups based on quintiles of fibrinogen levels. Significant CAD was defined as stenosis >50% in at least 1 coronary vessel. We additionally measured carotid intima-media thickness (CIMT) in a subgroup of 359 patients. Patients with elevated fibrinogen were older (P = 0.038), with larger prevalence of diabetes (P = 0.027), female gender (P < 0.0001), hypertension (P < 0.001), chronic renal failure (P < 0.0001), previous CVA (P = 0.036), less often with family history of CAD (P = 0.019) and previous PCI (P < 0.0001), more often presenting with ACS (P < 0.0001), more often on nitrates (P < 0.0001), clopidogrel (P = 0.009) and diuretics (P < 0.0001). Fibrinogen levels were linearly associated with baseline glycaemia (P < 0.017), WBC count (P < 0.0001), creatinine (P < 0.0001), and Platelet count (P < 0.0001) but inversely associated with RBC count (P < 0.0001). Fibrinogen levels were associated with CAD (P = 0.001), especially for extremely high levels (5th percentile, P < 0.0001). At multivariate analysis, after correction for baseline confounding factors, high fibrinogen level (5th percentile) was still associated with the prevalence of CAD (P = 0.034). Furthermore, fibrinogen levels were related with maximal CIMT (r = 0.12; P = 0.01), with larger prevalence of carotid plaques in patients with higher fibrinogen levels (5th quintile) as compared to remaining patients (P = 0.046). This study showed that high fibrinogen level is significantly associated with CAD and carotid atherosclerosis.

Thrombin induces MCP-1 expression through Rho-kinase and subsequent p38MAPK/NF-κB signaling pathway activation in vascular endothelial cells

Thrombin has been shown to increase expression of chemokines such as monocyte chemoattractant protein 1 (MCP-1) in endothelial cells, leading to the development of atherosclerosis. However, the precise mechanism of this induction remains unknown. In the present study, we investigated whether the small G protein RhoA, and its effector, Rho-kinase are involved in MCP-1 induction by thrombin in endothelial cells. Y-27632, a specific Rho-kinase inhibitor, potently inhibited MCP-1 induction by thrombin. Y-27632 significantly decreased the chemotactic activity of thrombin-stimulated supernatants of endothelial cells on monocytes. Importantly, fasudil, a specific Rho-kinase inhibitor, attenuated MCP-1 gene expression in the aorta of db/db mice. Y-27632 attenuated thrombin-mediated phosphorylation of p38MAPK and p65, indicating that Rho-kinase mediates thrombin-induced MCP-1 expression through p38MAPK and NF-κB activation. Our findings demonstrate that the Rho/Rho-kinase signaling pathway plays a critical role in thrombin-mediated MCP-1 expression and function, and suggest that Rho/Rho-kinase may be an important target in the development of new therapeutic strategies for atherosclerosis.

Are inflammatory and coagulation biomarkers related to sleep characteristics in mid-life women?: Study of Women's Health across the Nation sleep study

STUDY OBJECTIVES

Inflammation and pro-coagulation biomarkers may be a link between sleep characteristics and risk for cardiometabolic disorders. We tested the hypothesis that worse sleep characteristics would be associated with C-reactive protein (CRP), fibrinogen, factor VIIc, and plasminogen activator inhibitor (PAI)-1 in a multi-ethnic subsample of mid-life women enrolled in the Study of Women's Health across the Nation.

DESIGN

Cross-sectional.

MEASUREMENTS AND RESULTS

African American, Chinese, and Caucasian women (N=340) participated in 3 days of in-home polysomnographic (PSG) monitoring and had measures of inflammation and coagulation. Regression analyses revealed that each of the biomarkers were associated with indicators of sleep disordered breathing after adjusting for age, duration between sleep study and blood draw, site, menopausal status, ethnicity, residualized body mass index, smoking status, and medications that affect sleep or biomarkers. Among African American women, those who had higher levels of CRP had shorter PSG-sleep duration and those who had higher levels of fibrinogen had less efficient sleep in multivariate models.

CONCLUSIONS

These results suggest that inflammation and pro-coagulation processes may be an important pathway connecting sleep disordered breathing and cardiometabolic disorders in women of these ethnic groups and that inflammation may be a particularly important pathway in African Americans.

Changes in inflammatory and coagulation biomarkers: a randomized comparison of immediate versus deferred antiretroviral therapy in patients with HIV infection

OBJECTIVES

Among a subgroup of participants in the Strategies for Management of Antiretroviral Therapy (SMART) Trial that were naïve to antiretroviral therapy (ART) or off ART (6 months or longer) at study entry, risk of AIDS and serious non-AIDS events were increased for participants who deferred ART compared with those randomized to (re)initiate ART immediately. Our objective was to determine whether ART initiation in this group reduced markers of inflammation and coagulation that have been associated with increased mortality risk in SMART. Changes in these biomarkers have been described after stopping ART, but not after starting ART in SMART.

METHODS

Stored specimens for 254 participants (126 drug conservation [DC] and 128 viral suppression [VS]) who were naïve to ART or off ART (6 months or longer) were analyzed for interleukin-6, high sensitivity C-reactive protein, and D-dimer at baseline and Months 2 and 6.

RESULTS

At Month 6, 62% of the VS group had HIV RNA less than 400 copies/mL and median CD4 count was 190 cells/mm3 higher than for the DC group (590 versus 400 cells/mm3). Compared with DC, the VS group had 32% (95% confidence interval, 19%-43%) lower D-dimer levels at Month 6 (P < 0.001); differences were not significant for high sensitivity C-reactive protein or interleukin-6 levels.

CONCLUSIONS

In this randomized comparison of immediate versus delayed ART initiation, D-dimer, but not interleukin-6 and high sensitivity C-reactive protein, declined significantly after starting ART. Further studies are needed to determine whether improvements in D-dimer are associated with reduced risk of clinical disease and whether adjunct treatments used in combination with ART can reduce inflammation among individuals with HIV infection.

Prothrombin fragments in cardiovascular disease

Prothrombin fragment 1+2 (F1+2), which comes from in vivo cleavage of prothrombin by factor Xa, is considered to be useful for diagnosis of thrombosis. Recognition of the central role of thrombosis in the pathogenesis ofcardiovascular disease has prompted growing interest in the association o F1+2 with cardiovascular clinical syndromes. Increased F1+2 levels have reported in venous thromboembolism, inflammation, cancer, sepsis, acute coronary syndromes, stroke, peripheral arterial disease, atrial fibrillation and during the postoperative period. However, a clear relationship with the appearance of thrombosis has not always been consistently demonstrated. Besides its potential prognostic and diagnostic value, it could also be usefu in assessing the impact of various therapies. However, it should be kept in mind that measurement of hemostasis activation markers has several important biological and methodological disadvantages. Activation markers reflect the presence of thrombosis in any vascular bed, so they are not specific. Furthermore, elevations occur not only in the presence of overt thrombosis but also during the hypercoagulable state. The cutoff level to be used for the definition of elevations is still largely unknown due to the use of different analytical methods, none of which have been standardized until know. Finally, the prognostic value of F1+2 and other markers of coagulation activation remains to be fully defined in future studies.

Fibrinogen and left ventricular myocardial systolic function: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Increasing evidence suggests that elevated plasma fibrinogen is associated with incident heart failure. However, the underlying pathophysiological mechanisms have not been well elucidated.

METHODS

We examined the relationship between plasma fibrinogen level and peak systolic midwall circumferential strain (Ecc) at the base, mid cavity, and apex of the left ventricle measured by magnetic resonance imaging myocardial tagging in 1096 participants without clinical cardiovascular disease enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA).

RESULTS

After adjustment for demographics, established risk factors and body mass index, elevated fibrinogen was independently associated with reductions in absolute Ecc indicative of impaired systolic function in all regions (all P < or = .015). The relationships were consistently significant upon further adjustment for measures of atherosclerosis (all P < .024) and were modestly attenuated with regional heterogeneity after additional adjustment for other inflammatory biomarker and N-terminal pro-brain natriuretic peptide. In this fully-adjusted model, every 1-SD (74 mg/dL) increment in plasma fibrinogen was independently associated with a reduction in left ventricular absolute Ecc of 0.29% (95% CI 0.03%-0.59%, P = .048) at the base, 0.22% (95% CI 0.006%-0.43%, P = .044) at mid cavity, 0.20% (95% CI = -0.035% to 0.43%, P = .097) at the apex, and 0.24% (95% CI = 0.05%-0.43%, P = .015) overall.

CONCLUSIONS

Among asymptomatic individuals without clinical cardiovascular disease, elevated fibrinogen is independently associated with impaired myocardial systolic function. These findings support roles of inflammation, procoagulation, and hyperviscosity underlying hyperfibrinogenemia in the pathogenesis of incipient myocardial dysfunction.

Detection of Non-Nucleic Acid Targets with an Unmodified Aptamer and a Fluorogenic Competitor

Aptamers are oligonucleotides that can bind to various non-nucleic acid targets, ranging from proteins to small molecules, with a specificity and affinity comparable to that of antibodies. Most aptamer-based detection strategies require modification on the aptamer, which could lead to a significant loss in its affinity and specificity to the target. Here we reported a generic strategy to design aptamer-based optical probes. An unmodified aptamer specific to the target and a fluorogenic competitor complementary to the aptamer are utilized for target recognition and signal generation, respectively. The competitor is a hairpin oligonucleotide with a fluorophore attached on one end and a quencher attached on the other. When no target is present, the competitor binds to the aptamer. However, when the target is introduced, the competitor will be displaced from the aptamer by the target, thus resulting in a target-specific decrease in fluorescence signal. Successful application of this strategy to different types of targets (small molecules and proteins) as well as different types of aptamers (DNA and RNA) has been demonstrated. Furthermore, a thermodynamics-based prediction model was established to further rationalize the optimization process. Due to its rapidness and simplicity, this aptamer-based detection strategy holds great promise in high throughput applications.

Metabolic factors and microinflammatory state promote kidney injury in type 2 diabetes mellitus patients

OBJECTIVE

This study examined the associations among the factors of metabolic syndrome, microinflammatory state, and kidney injury in type 2 diabetes mellitus patients.

METHODS

A retrospective study was conducted on 914 type 2 diabetes mellitus patients from January 2007 to May 2008. We observed the prevalence of chronic kidney disease in different groups of type 2 diabetes mellitus patients, and analyzed the association between metabolic syndrome and chronic kidney disease. We chose 84 cases randomly from this cohort to test their inflammatory biomarkers including tumor necrosis factor alpha, interleukin-6, and C-reactive protein to study the relationship to chronic kidney disease.

RESULTS

The prevalence of chronic kidney disease was 39.17% (358 patients), and patients with metabolic factors had a significantly higher prevalence of chronic kidney disease than without metabolic factors (40.90% vs. 17.65%, p < 0.01). The metabolic factors and microinflammatory biomarkers were significantly higher in patients with chronic kidney disease. Patients who had more abnormal metabolic factors also had higher levels of microinflammatory biomarkers, as well as higher risk of chronic kidney disease. Multiple logistic regression analyses revealed that systolic blood pressure, serum triglyceride, low density lipoprotein, age, and duration of diabetes were independent risk factors of chronic kidney disease in type 2 diabetes mellitus patients.

CONCLUSIONS

The abnormality of metabolic factors in type 2 diabetes mellitus had a close relationship to the microinflammatory state and chronic kidney disease. Hypertension and hyperlipidemia were independent factors of chronic kidney disease in type 2 diabetes mellitus.

Duffy antigen receptor for chemokines (Darc) polymorphism regulates circulating concentrations of monocyte chemoattractant protein-1 and other inflammatory mediators

To identify the genetic basis of circulating concentrations of monocyte chemoattractant protein-1 (MCP-1), we conducted genome-wide association analyses for MCP-1 in 3 independent cohorts (n = 9598). The strongest association was for serum MCP-1 with a nonsynonymous polymorphism, rs12075 (Asp42Gly) in DARC, the gene for Duffy antigen receptor for chemokines, a known vascular reservoir of proinflammatory cytokines (minor allele frequency, 45.6%; P < 1.0 * 10(-323)). This association was supported by family-based genetic linkage at a locus encompassing the DARC gene (genome-wide P = 8.0 * 10(-13)). Asp42Gly accounted for approximately 20% of the variability in serum MCP-1 concentrations and also was associated with serum concentrations of interleukin-8 and RANTES. While exploring a lack of association between this polymorphism and EDTA plasma MCP-1 concentrations (P = .82), we determined that both clotting and exogenous heparan sulfate (unfractionated heparin) released substantial amounts of MCP-1 from Darc. Quantitative immunoflow cytometry failed to identify meaningful Asp42Gly-associated differences in Darc expression, suggesting that a functional change is responsible for the differential cytokine binding. We conclude that Asp42Gly is a major regulator of erythrocyte Darc-mediated cytokine binding and thereby the circulating concentrations of several proinflammatory cytokines. We have also identified for the first time 2 mechanisms for the release of reservoir chemokines with possible clinical implications.

CD28(-)CD8(+) T cells do not contain unique clonotypes and are therefore dispensable

Highly differentiated CD28(-) effector T cells which accumulate in a variety of diseases and also with increasing age contribute to inflammatory processes, limit immunological space and diversity, and are associated with immunological dysfunction and reduced responses to vaccination. Elimination of CD28(-) T cells has been suggested as a measure for immunological rejuvenation but may lead to the loss of important T cell specificities. Using T cells specific for the immunodominant CMV-derived epitope NLVPMVATV as a model, we show that the same clonotypes are present in CD8(+)CD28(+) naïve/early memory and CD8(+)CD28(-) effector T cells. Therefore, CD28(-) cells do not seem to contain clones which are not present in the residual population. The elimination of effector T cells would not lead to the loss of important specificities, as relevant clonotypes could be recruited and propagated from naïve or early memory T cell subsets in the case of exposure to pathogen.

The coagulation and protein C pathways in patients with sleep apnea

Patients with obstructive sleep apnea (OSA) have a high frequency of cardiovascular diseases and hypercoagulability is believed to be involved in the mechanism of those vascular events. We evaluated whether there is a dysfunction in the protein C anticoagulant pathway in patients with obstructive sleep apnea. Two hundred ninety-three patients were enrolled. To confirm the diagnosis of OSA, all-night polysomnography, including determination of SpO(2), was carried out. The apnea-hypopnea index (AHI) was used for judging the presence of sleep-breathing disorder. The plasma levels of the thrombin-antithrombin complex were higher in patients with AHI > 5 than in those without OSA, defined as AHI < 5. However, there was no statistically significant difference in the plasma level of either activated protein C/alpha-antitrypsin complex or soluble thrombomodulin between patients with AHI > 5 and those with AHI < 5. The results of this study showed for the first time that markers of the protein C anticoagulant pathway are not affected in patients with OSA and that the protein C pathway is probably not involved in the mechanism of hypercoagulability in subjects with sleep-disordered breathing.

Common coding variants of the HNF1A gene are associated with multiple cardiovascular risk phenotypes in community-based samples of younger and older European-American adults: the Coronary Artery Risk Development in Young Adults Study and The Cardiovascular Health Study

BACKGROUND

The transcription factor hepatocyte nuclear factor (HNF)-1 alpha regulates the activity of a number of genes involved in innate immunity, blood coagulation, lipid and glucose transport and metabolism, and cellular detoxification. Common polymorphisms of the HNF-1 alpha gene (HNF1A) were recently associated with plasma C-reactive protein and gamma-glutamyl transferase concentration in middle-aged to older European Americans (EA).

METHODS AND RESULTS

We assessed whether common variants of HNF1A are associated with C-reactive protein, gamma-glutamyl transferase, and other atherosclerotic and metabolic risk factors, in the large, population-based Coronary Artery Risk Development in Young Adults Study of healthy young EA (n=2154) and African American (AA; n=2083) adults. The minor alleles of Ile27Leu (rs1169288) and Ser486Asn (rs2464196) were associated with 0.10 to 0.15 standard deviation units lower C-reactive protein and gamma-glutamyl transferase levels in EA. The same HNF1A coding variants were associated with higher low-density lipoprotein cholesterol, apolipoprotein B, creatinine, and fibrinogen in EA. We replicated the associations between HNF1A coding variants and C-reactive protein, fibrinogen, low-density lipoprotein cholesterol, and renal function in a second population-based sample of EA adults 65 years and older from the Cardiovascular Health Study. The HNF1A Ser486Asn and/or Ile27Leu variants were also associated with increased risk of subclinical coronary atherosclerosis in Coronary Artery Risk Development in Young Adults and with incident coronary heart disease in Cardiovascular Health Study. The Ile27Leu and Ser486Asn variants were 3-fold less common in AA than in EA. There was little evidence of association between HNF1A genotype and atherosclerosis-related phenotypes in AA.

CONCLUSIONS

Common polymorphisms of HNF1A seem to influence multiple phenotypes related to cardiovascular risk in the general population of younger and older EA adults.

Association of aortic valve sclerosis with thrombin generation in hypertensive patients

Aortic valve sclerosis (AVS) may predispose to a prothrombotic state, as AVS is predictor of cardiovascular events in hypertensive populations. Thrombin exerts non-thrombotic effects such as vessel tone regulation, progression of atherosclerosis and stimulation of atrial natriuretic peptide (ANP) secretion. We hypothesized that hypertensive patients with AVS may have a persistently activated thrombin generation. We studied 234 asymptomatic never-treated hypertensive patients (73 of them with AVS). Prothrombin F1+2 (F1+2), as a marker of thrombin generation and fibrin D-dimer, as a marker of thrombus formation, ANP and brain natriuretic peptide (BNP) were measured. Presence of AVS, aortic jet velocity and left ventricular diameter at diastole were determined by echocardiography. Glomerular filtration rate was estimated using the Modification of Diet in Renal Disease formula. F1+2 (median and interquartile range (IQR) = 1.05, 0.87-1.38 nM vs. 0.93, 0.72-1.16) and ANP (22, 14-37 pg ml(-1) vs. 17, 11-25) levels were greater, and glomerular filtration rate values (65+/-9 ml min(-1)/1.73 m2 vs. 68+/-11) were lower in hypertensive patients with AVS than in those without AVS. F1+2 (odds ratio, 95% CI = 2.94, 1.07-8.6) was independently associated with AVS after being adjusted for age, gender and the variables of cardiorenal functions measured. After 6 months of treatment using valsartan, F1+2 levels remained elevated in hypertensive patients with AVS (1.14, 0.83-1.42 nM vs. 1.07, 0.84-1.5, n=19), but decreased in those without AVS (1.01, 0.85-1.31 vs. 0.8, 0.84-1.78, n=27). Thrombin generation was associated with AVS in untreated hypertensive patients, and this association was persistent after blood-pressure-lowering treatment using valsartan.

Elevated fibrinogen levels and subsequent subclinical atherosclerosis: the CARDIA Study

OBJECTIVE

To determine whether elevated levels of hemostatic factors are associated with the subsequent development of subclinical cardiovascular disease.

METHODS

Fibrinogen, factors VII (FVII) and VIII (FVIII), and von Willebrand factor (vWF) were measured in 1396 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Coronary artery calcification (CAC) and carotid intimal/medial thickness (CIMT) were determined 13 years later. The adjusted prevalence of CAC and mean CIMT across the quartiles of each hemostatic factor was computed for the total sample and for each race and gender group.

RESULTS

The age-, race-, and gender-adjusted prevalences of CAC with increasing quartiles of fibrinogen were 14.4%, 15.2%, 20.0%, and 29.1% (p<0.001 for trend). This trend persisted after further adjustment for body mass index (BMI), smoking, educational level, center, systolic blood pressure (BP), diabetes, antihypertensive medication use, total and high-density lipoprotein (HDL) cholesterol, and CRP. A similar trend was observed for CIMT (age-, race- and gender-adjusted, p<0.001; multivariable-adjusted, p=0.014). Further analyses of race and gender subgroups showed that increasing quartiles of fibrinogen were associated with CAC and CIMT in all subgroups except black men. The prevalence of CAC was not associated with increasing quartiles of FVII, FVIII, or vWF, suggesting they may be less involved in plaque progression.

CONCLUSION

An elevated fibrinogen concentration in persons aged 25-37 is independently associated with subclinical cardiovascular disease in the subsequent decade.

Metabolic syndrome traits in long-term survivors of pediatric sarcoma

PURPOSE

The metabolic syndrome (MS), a cluster of central obesity, dyslipidemia, hyperglycemia, and hypertension, conveys an increased risk of type 2 diabetes and cardiovascular disease. This cross-sectional study investigated the prevalence of metabolic syndrome traits (MST) in long-term survivors of pediatric sarcoma (SARC) who received multi-modality therapy (MMT).

METHODS

Thirty-two SARC survivors (predominantly Ewings; median age 36.5; median age at MMT 15) underwent body composition, activity, and psychosocial analysis. Serum endocrine and inflammatory parameters and urine beta(2)-microglobulin (B2M) were evaluated. The prevalence of MST was compared to age- and gender-matched U.S. population data.

RESULTS

SARC survivors were more likely to have two or more MST (OR 2.38 95% CI: [1.14, 5.04]). Analysis of individual MST demonstrated higher prevalence of hypertension (OR 2.61 95% CI: [1.20, 5.59]), hypertriglyceridemia (OR 3.63 95% CI: [1.75, 7.60]), and male visceral abdominal obesity (20-39 years old OR 4.63 95% CI: [0.91, 21.63], 40-59 years old OR infinity). Survivors 18-39 years old had a higher prevalence of the MS (OR 4.29 95% CI: [1.50, 11.21]), defined as three or more MST. Plasminogen activator inhibitory activity (P = 0.016) and B2M (P = 0.027) increased with increasing numbers of MST. In males, total testosterone declined (P = 0.0027) as the number of MST increased. Average (P = 0.014) and maximum (P = 0.021) activity levels decreased as the number of MST increased.

CONCLUSION

After a median follow up of 17 years, adult SARC survivors of MMT had an increased prevalence of MST, especially those less than 40 years old. The development of MST in this population was associated with decreased testosterone and activity levels.

Elevated Risk of Thrombosis in Neonates Undergoing Initial Palliative Cardiac Surgery

BACKGROUND

Thrombotic events cause significant morbidity and mortality in children who undergo surgery for complex congenital cardiac disease. We prospectively evaluated the incidence of thrombosis and examined preoperative and postoperative laboratory tests of coagulation and inflammation in neonates experiencing initial surgical palliation for variations of single ventricle physiology.

METHODS

Neonates (<30 days) requiring initial surgical palliation were studied. All subjects received aspirin from postoperative day 1 onward. Thromboses were diagnosed by serial transthoracic echocardiograms, vascular imaging, and interstage cardiac catheterizations according to predefined criteria.

RESULTS

Twenty-two neonates, age 1 to 11 days (mean 4 +/- 2.5) were studied. Follow-up ranged from three hours to 18 months (median, 212 days). Eight infants died. Four of the 14 subjects who survived (28%), and one of the eight who died (12.5%), had evidence of thrombosis identified over a range of four hours to nine months postoperatively (median 14 days). When compared with reference values established in healthy children, preoperative subject hematocrit (Hct), platelet count, factors II, V, VII, VIII, and X, antithrombin, protein C, and soluble CD40 ligand measures were significantly lower, and the prothrombin time and partial thromboplastin time were significantly higher. Postoperative C reactive protein (CRP) was significantly higher, and Hct and platelet count significantly lower, than preoperative values. Thrombotic events were significantly related to high preoperative CRP (p = 0.02).

CONCLUSION

Thrombotic complications occur frequently in neonates undergoing initial palliative surgery, suggesting that aspirin therapy alone may constitute inadequate protection. Elevated preoperative CRP appears to be associated with increased thrombotic risk.

Accelerated atherogenesis and neointima formation in heparin cofactor II deficient mice

Heparin cofactor II (HCII) is a plasma protein that inhibits thrombin when bound to dermatan sulfate or heparin. HCII-deficient mice are viable and fertile but rapidly develop thrombosis of the carotid artery after endothelial injury. We now report the effects of HCII deficiency on atherogenesis and neointima formation. HCII-null or wild-type mice, both on an apolipoprotein E-null background, were fed an atherogenic diet for 12 weeks. HCII-null mice developed plaque areas in the aortic arch approximately 64% larger than wild-type mice despite having similar plasma lipid and glucose levels. Neointima formation was induced by mechanical dilation of the common carotid artery. Thrombin activity, determined by hirudin binding or chromogenic substrate hydrolysis within 1 hour after injury, was higher in the arterial walls of HCII-null mice than in wild-type mice. After 3 weeks, the median neointimal area was 2- to 3-fold greater in HCII-null than in wild-type mice. Dermatan sulfate administered intravenously within 48 hours after injury inhibited neointima formation in wild-type mice but had no effect in HCII-null mice. Heparin did not inhibit neointima formation. We conclude that HCII deficiency promotes atherogenesis and neointima formation and that treatment with dermatan sulfate reduces neointima formation in an HCII-dependent manner.

G protein-coupled receptor Ca2+-linked mitochondrial reactive oxygen species are essential for endothelial/leukocyte adherence

Receptor-mediated signaling is commonly associated with multiple functions, including the production of reactive oxygen species. However, whether mitochondrion-derived superoxide (mROS) contributes directly to physiological signaling is controversial. Here we demonstrate a previously unknown mechanism in which physiologic Ca(2+)-evoked mROS production plays a pivotal role in endothelial cell (EC) activation and leukocyte firm adhesion. G protein-coupled receptor (GPCR) and tyrosine kinase-mediated inositol 1,4,5-trisphosphate-dependent mitochondrial Ca(2+) uptake resulted in NADPH oxidase-independent mROS production. However, GPCR-linked mROS production did not alter mitochondrial function or trigger cell death but rather contributed to activation of NF-kappaB and leukocyte adhesion via the EC induction of intercellular adhesion molecule 1. Dismutation of mROS by manganese superoxide dismutase overexpression and a cell-permeative superoxide dismutase mimetic ablated NF-kappaB transcriptional activity and facilitated leukocyte detachment from the endothelium under simulated circulation following GPCR- but not cytokine-induced activation. These results demonstrate that mROS is the downstream effector molecule that translates receptor-mediated Ca(2+) signals into proinflammatory signaling and leukocyte/EC firm adhesion.