Total AV Research Articles

An Oral Glucose Load Decreases Postprandial Extracellular Vesicles in Obese Adults with and without Prediabetes.

Although extracellular vesicles (EVs) are a novel biomediator of type 2 diabetes (T2D) and cardiovascular disease (CVD), the effects of hyperglycemia on EVs in humans is unknown. We tested the hypothesis that a 75-g oral glucose tolerance test (OGTT) would promote changes in EVs in relation to CVD risk. Twenty-five obese adults (Age: 52.4 ± 3.2 year, BMI: 32.5 ± 1.2 kg/m2) were screened for normal glucose tolerance (NGT, n = 8) and prediabetes (PD, n = 17) using American Diabetes Association criteria (75 g OGTT and/or HbA1c). Body composition (bioelectrical impedance) and fitness (VO2peak) were measured. Arterial stiffness (augmentation index; AIx) was measured at 0, 60- and 120-min while insulin, glucose, and free fatty acids were evaluated every 30 min during the OGTT to assess CVD risk. Annexin V positive (AV+) and Annexin V negative (AV−) total EVs, platelet EVs (CD31+/CD41+; CD41+), leukocyte EVs (CD45+; CD45+/CD41−), platelet endothelial cell adhesion molecule (PECAM) (CD31+) and endothelial EVs (CD 31+/CD41−; CD105+) were collected at 0 and 120 min. There were no differences in age, BMI, or body fat between NGT and PD (all P > 0.63). Total EVs, AV+ CD31+ (PECAM), and AV+ CD31+/CD41− (endothelial) EVs decreased after the OGTT (P ≤ 0.04). Circulating insulin at 2-h correlated with elevated post-prandial AV− CD45+ (r = 0.48, P = 0.04) while arterial stiffness related to reduced total EVs (r = −0.49, P = 0.03) and AV+ CD41+ (platelet) (r = −0.52, P = 0.02). An oral glucose load lowers post-prandial total, platelet, and endothelial EVs in obese adults with NGT and prediabetes in relation to CVD risk.

Heparin Oligosaccharides Have Antiarrhythmic Effect by Accelerating the Sodium-Calcium Exchanger.

Background: Blockage of the Na+/Ca2+ exchanger (NCX) is used to determine the role of NCX in arrhythmogenesis. Trisulfated heparin disaccharide (TD) and Low Molecular Weight Heparins (LMWHs) can directly interact with the NCX and accelerate its activity.Objective: In this work, we investigated the antiarrhythmic effect of heparin oligosaccharides related to the NCX activity.Methods: The effects of heparin oligosaccharides were tested on the NCX current (patch clamping) and intracellular calcium transient in rat cardiomyocytes. The effects of heparin oligosaccharides were further investigated in arrhythmia induced in isolated rat atria and rats in vivo.Results: The intracellular Ca2+ concentration decreases upon treatment with either enoxaparin or ardeparin. These drugs abolished arrhythmia induction in isolated atria. The NCX antagonist KB-R7943 abolished the enoxaparin or ardeparin antiarrhythmic effects in isolated atria. In the in vivo measurements, injection of TD 15 min both before coronary occlusion or immediately after reperfusion, significantly prevented the occurrence of reperfusion-induced arrhythmias (ventricular arrhythmia and total AV block) and reduced the lethality rate. The patch clamping experiments showed that, mechanistically, TD increases the forward mode NCX current.Conclusion: Together, the data shows that heparin oligosaccharides may constitute a new class of antiarrhythmic drug that acts by accelerating the forward mode NCX under calcium overload.

S142. RESTING STATE NETWORKS ALTERATION IN BIPOLAR DEPRESSION

BackgroundWhile functional MRI and PET studies have shown altered task-related brain activity in bipolar depression, recent studies suggest that such differences might also be found in the resting state (RS). Here we used ICA based analysis to investigate RS fMRI data to compare connectivity of 11 well known networks (Auditory, Cerebellum, DMN, Exectutive Control, Fronto-parietal 1, Fronto-parietal 2, Salience, Sensorimotor, Visual1, Visual2, Visual3 network) between patients with bipolar depression and healthy controls suggesting deficits in related neuropsychological functions.MethodsWe obtained RS fMRI series (3T, 3x3x3mm resolution, 45 slices, TR 2.55s, 210 volumes) in 22 bipolar patients (mean age 38.4a±11.3), on stable medication and 22 matched healthy controls (36.8a±11.7).Subjects were asked to lie in the scanner keeping eyes closed with no further specific instructions. Data were pre-processed; we applied FSL MELODIC (pICA) yielding IC, we used FIX to auto-classify ICA components which represent artifacts and an automated routine to select for each subject the component matching the anatomical definition of resting state networks.SPM12 was used for second level analysis, we used two sample t-test to compare networks functional connectivity between groups.ResultsOur method reliably identified all networks in every controls and patients. We found significant differences in the anatomical pattern of areas. Patients showed decreased functional connectivity in comparison to healthy controls in portions Cerebellum, DMN, Fronto-parietal1, Fronto-parietal2, Visual1, Visual2 and Visual3 networks; in addition, patients showed increased functional connectivity in comparison to healthy controls in portions of Cerebellum Frontoparietal1 networks.The power spectrum of the bipolar patients and healthy control time courses don’t differ significantly in any of the brain networks, but there is a slight difference between the average slope between bipolar and healthy subject, Total Av. Bip = -0.88743 and Total Av. HC = -0.90282.DiscussionWell-known resting state networks were reliable identified from RS fMRI in Bipolar depression patients. The differences in anatomical distribution point to possible alterations in functional connectivity in Bipolar depression, which suggests disruption in cerebellum, DMN, fronto-parietal and visual neuropsychological related activity.

CD142+/CD61+, CD146+ and CD45+ microparticles predict cardiovascular events in high risk patients following a Mediterranean diet supplemented with nuts.

Circulating microparticles (cMPs) are small phospholipid-rich microvesicles shed by activated cells that play a pivotal role in cell signalling related to the pathogenesis of atherothrombosis. We aimed to investigate the prognostic value of cMPs released from different vascular cells for cardiovascular event (CVE) presentation in asymptomatic patients at high cardiovascular risk factors under nutritional and pharmacologic treatment. This is a nested case-control study of 50 patients from the five-year follow-up prospective PREDIMED trial enrolled in the nuts arm of the Mediterranean diet (MedDiet-nuts). We randomly selected 25 patients who had suffered a CVE during follow-up and pair-matched them for sex, age, and classical CV risk factors to 25 patients who remained asymptomatic (no-CVE). Total Annexin V-(AV)+ cMPs and cMPs from cells of the vascular compartment were quantified by flow cytometry at baseline and after one year follow-up. MedDiet-nuts and pharmacological treatment neither modified levels nor source of MP shedding in CVE patients. However, no-CVE patients showed 40-86 % decreased total AV+, PAC-1+/AV+, CD61+/AV+, CD142+/CD61+/AV+, CD62P+/AV+, CD146+/AV+, CD63+/AV+ and CD11a+/AV+ cMPs at one year follow-up (p≤0.046, all). CD142+/CD61+/AV+, CD146+/AV+ and CD45+/AV+ cMPs were decreased in no-CVE patients compared to CVE patients. A ROC-curve clustered model for CD142+/CD61+/AV+, CD45+/AV+ and CD146+/AV+ cMPs predicted a future CVE [p<0.0001, AUC=0.805 (0.672 to 0.938)]. In patients at high CV risk profile treated with a controlled MedDiet supplemented with nuts and receiving up-to-date CV drug treatment, reduced cMPs derived from activated platelets, leukocytes and endothelial cells are predictive of protection against CVE within the next four years.

Electrocardiography evaluation in type 1 diabetes mellitus, preliminary study

Cardiovascular complication should be evaluated in patient with T1DM. Ventricular instability (QT abnormalities) in Type 1 Diabetes Melitus (T1DM) is a risk factor for mortality. Prolongation of corrected QT interval (QTc) is accurate and the most sensitive test for the autonomic neuropathy whether QT interval dispersion (QTd) in arrhythmia is a predictor for mortality. This study is to evaluate arrhythmia, prolongation of QTc and QTd in T1DM children. Cross sectional study of children diagnosed T1DM in Soetomo Hospital; Surabaya during April 2013 to April 2014 was performed. The ECG was done in all of the patients. Arrhythmia, QTc and QTd were measured and analyzed with Paired t-test. There were 17 patients joint this study. Age was 8 to 15 years. There were 9 girls and 8 boys who suffered from 1 to 7 years of illness. There were 9/17 arrhythmia patients, 2/17 prolonged QTc patients, 4/17 borderline QTc patients, 1/17 with total AV block. The patient with total AV block was diagnosed DMT1 with ketoasidosis and acute pancreatitis. There was 1 patient without prolonged QTc although suffered from five times of DKA. The mean of QTc was 428.5 (SD 27.67) m.sec and QTd was 29.3 (SD 12.79) m.sec. There was significant differences between present of arrhythmia and QTd (P<0.01, 95% CI -35.01 to -20.85) and QTc (P<0.01, 95% CI -442.43 to -411.85). Arrhythmia and prolonged QTc was present in T1DM children under 10 years of illness. No one with prolonged QTd. Every arrhythmia should be taken into account in QTd to predict the mortality.

New ESC guidelines on hypertrophic cardiomyopathy: new insights in invasive treatment?

New ESC guidelines on hypertrophic cardiomyopathy: new insights in invasive treatment?

Digital camera revealed infection with Borrelia burgdorferi as a cause of reversible total AV block in a 42 year old man

Digital camera revealed infection with Borrelia burgdorferi as a cause of reversible total AV block in a 42 year old man

A Bayesian Method for the Extinction

AbstractWe propose a Bayesian method to measure the total Galactic extinction parameters, RV and AV. Validation tests based on the simulated data indicate that the method can achieve the accuracy of around 0.01 mag. We apply this method to the SDSS BHB stars in the northern Galactic cap and find that the derived extinctions are highly consistent with those from Schlegel et al. (1998). It suggests that the Bayesian method is promising for the extinction estimation, even the reddening values are close to the observational errors.

New mutation in prkag2 syndrome and sudden cardiac death

Background: Mutations in PRKAG2 have been described in patients (PT) with familial WPW syndrome and hypertrophic cardiomyopathy (HC). Conduction system disease, embolic stroke and heart failure can happen Tachyarrhythmias are frequent and can cause sudden cardiac death (SCD) and the predictive factors remain unknown. Objective: The purpose of this study is to describe the mechanism of aborted SCD in individuals affected by WPW in association with HC. Methods: A total of 18 (21%) PT selected from an 84-member family cohort were included retrospectively from March 2005 to March 2012 and submitted to ECG, 2D ECHO and 24h Holter. For a genetic analysis, it was collected blood samples (3ml) and used a commercial kit (Gentra System, Puregene), ExoSAP-IT, USB and directly sequenced in both directions using an ABI PRISM Automatic DNA Sequencer in a subgroup of 8 PT. Diagnosis of WPW was based on ECG with a shortened PR interval and a slurred upstroke to the QRS complex (delta wave). Diagnosis of HC was based on ECHO by demonstrating evidence of LVH, asymmetric in distribution, and with any diffuse or segmental pattern of left ventricular [LV] wall thickening ≥ 15 mm. Results: Eleven PT (61%) were female, with a mean age of 27±16. HC was detected in association with WPW in 11 (61.1%) PT, isolated WPW in 6 (33%) PT and HC only in one PT (5.6%). Main clinical findings: TIA (16.7%), spontaneous abortion (16.7%). Palpitations occurred in 12 (67%), chest pain in six (33.3%) and syncope in five (28%). Learning disabilities, retarded growth development were also observed in 3 males (16.7%). Five PT were submitted to pacemaker implantation due to total AV block. Main ECG findings: RBBB morphology (55.5%), LBBB (27.7%), atrial fibrillation (AF) (33.3%), atrial flutter (AFL) (16.7%), atrial tachycardia (11.1%), non-sustained VT (5.5%) and SVT in 12 (67%). ECHO showed generalized and diffuse LVH with septal thickness ≥15 mm and good contractility. Mitral valve insufficiency (50%) and diastolic dysfunction (61.1%). SCD occurred in 4=22% PT. Two PT had SCD at age 37 (♀) and 27 (♂). Three episodes of aborted SCD were documented in two PT with WPW in association with HC due to AF and AFL with anterograde conduction through the accessory pathway Direct sequencing of PRKAG2 revealed a missense mutation in exon 7 of PRKAG2, A869T (K290I).This mutation has not been previously described Conclusion: SCD had a high incidence in this cohort and the documented mechanism was AF and AFL with anterograde conduction through the accessory pathway. A new mutation in PRKAG2 was found in an initial study of subgroup.

Methodological Aspects in the use of Multiple Logistic Regression Analysis

DOI: 10.5935/abc.20130120 Dear Editor, We would like to present a few considerations pursuant to the statistical analysis of the predictors of death in the article by Caluza et al1, even though observing its nature of initial/pilot project. It has not remained clear which variables were included in the initial model and which method was used to select those significant variables in the final adjusted model (backward, forward, full model or variants). By virtue of the fine progression of the patients (in-hospital mortality of 6.8%) and of the relatively small sample size (n = 205), the number of deaths was low (n = 14). That is an excellent clinical result, but it imposes caution upon the logistic regression. The final model has presented six significant variables (perhaps the initial model might have had even more co-variables), with a maximum Events Per Variable (EPV) ratio of 2.3 (14/6). A low ratio of EPV results in an unstable model, with an increase in bias, variability, and overrating of the coefficients of regression and unverisimilar Confidence Intervals (CI)2,3. The worst case scenario4 would exactly be with 2 to 4 EPV, ≤ 30 outcomes, and low prevalence/incidence (< 10%) of the predictors (previous Cerebral Vascular Accident – CVA – [7.8%], Total Atrioventricular Block – total AV block – [6.8%], intra-aortic balloon pump – IABP – [5.8%], and cardiogenic shock [7.3%]). The occluded artery related to the infarction and the zero tissue flow grade (blush) upon the initial injection in the artery related to the infarction were variables inserted in a parallel fashion in the model. Has multi-co-linearity been verified among these? Except in the filling by collaterals, the entire occluded artery will have zero tissue flow grade, resulting in a high redundancy, with a reduction in the reliability of the coefficients of regression and amplification of the standard errors5.

HERSCHELSEARCH FOR O2TOWARD THE ORION BAR

We report the results of a search for molecular oxygen (O2) toward the Orion Bar, a prominent photodissociation region at the southern edge of the HII region created by the luminous Trapezium stars. We observed the spectral region around the frequency of the O2 N_J = 3_3 - 1_2 transition at 487 GHz and the 5_4 - 3_4 transition at 774 GHz using the Heterodyne Instrument for the Far Infrared on the Herschel Space Observatory. Neither line was detected, but the 3sigma upper limits established here translate to a total line-of-sight O2 column density < 1.5 10^16 cm^-2 for an emitting region whose temperature is between 30K and 250 K, or < 1 10^16 cm^-2 if the O2 emitting region is primarily at a temperature of ~< 100 K. Because the Orion Bar is oriented nearly edge-on relative to our line of sight, the observed column density is enhanced by a factor estimated to be between 4 and 20 relative to the face-on value. Our upper limits imply that the face-on O2 column density is less than 4 10^15 cm^-2, a value that is below, and possibly well below, model predictions for gas with a density of 10^4 - 10^5 cm^-3 exposed to a far ultraviolet flux 10^4 times the local value, conditions inferred from previous observations of the Orion Bar. The discrepancy might be resolved if: (1) the adsorption energy of O atoms to ice is greater than 800 K; (2) the total face-on Av of the Bar is less than required for O2 to reach peak abundance; (3) the O2 emission arises within dense clumps with a small beam filling factor; or, (4) the face-on depth into the Bar where O2 reaches its peak abundance, which is density dependent, corresponds to a sky position different from that sampled by our Herschel beams.

Mortal Furosemide-Hypokalemia-Disturbances in Rats NO-System Related Shorten Survival by L-NAME. Therapy Benefit with BPC 157 Peptide More Than With L-Arginine

Background: We focused on NO-system-relations (worsening/amelioration) of furosemide (100 mg/kg intraperitoneally)-diuresis-hypokalemia mortal course in rats and beneficial effect of BPC 157 therapy. Methods: Electrocardiographically 90-150 min post-furosemide application duration of PR, RR, QRS, QT intervals, P, R, S, T waves and its amplitude as well were analysed along with appearance of AV block, ventricular premature beats, ventricular tachycardia. Clinically, skeletal muscle myoclonal activity and lethality at 150 min were also analysed. Results: All NO-system-related agents (alone and/or combined, before/after furosemide) not changed hypokalemia and all averted to some extent furosemide-forced diuresis. NOS-blocker, L-NAME (5 mg/kg intraperitoneally) accelerated mortality, aggravated cardiac and extra-cardiac manifestations, thereby, NO-systemrelated. Prevented hypokalemia-mortality was with NO-precursor L-arginine (100 mg/kg intraperitoneally) and stable gastric pentadecapeptide BPC 157 (10 ug, 10 ng/kg intraperitoneally/intragastrically). Specifically, BPC 157 showed most complete benefit. i. BPC 157 given 15 min before furosemide. All BPC 157 regimens maintained sinus rhythm, had no ventricular premature beats, ventricular tachycardia, AV block, no prolongation of intervals and waves without reduction of amplitude. ii. BPC 157 given 90 min after furosemide (with hypokalemia, 3rd grade AV block and/ or ventricular tachycardia being present). Within 5-10 minutes, BPC 157 regimens normalized P, R, S, T waves, PR, RR, QRS, QT interval duration, R, S, T wave amplitude, total AV block and terminated ventricular tachycardia. Likewise, BPC 157 eliminated skeletal muscle myoclonus. Conclusion: L-NAME/L-arginine was mutual counteraction while BPC 157 completely eliminated L-NAME (arrhythmias, myoclonus, mortality), without an additive benefit when combined with L-arginine. Thus, we showed potentially effective therapeutic interventions for acute hypokalemia.

The dust extinction curves of gamma-ray burst host galaxies

The composition and amount of interstellar dust within gamma-ray burst (GRB) host galaxies is of key importance when addressing selection effects in the GRB redshift distribution, and when studying the properties of their host galaxies. As well as the implications for GRB research, probing the dust within the high-z hosts of GRBs also contributes to our understanding of the conditions of the interstellar medium and star-formation in the distant Universe. Nevertheless, the physical properties of dust within GRB host galaxies continues to be a highly contended issue. In this paper we explore the mean extinction properties of dust within the host galaxies of a sample of 17 GRBs with total host galaxy visual extinction Av<1 (<Av>=0.4), covering a redshift range z=0.7-3.1. We find the average host extinction curve to have an ultraviolet slope comparable to that of the LMC, but with little evidence of a 2175Angs dust extinction feature as observed along Milky Way and LMC sightlines. We cannot at present rule out the presence of a 2175Angs feature, and both the standard SMC and LMC extinction curves also provide good fits to our data. However, we can reject an extinction curve that has a UV slope as flat as the mean Milky Way extinction curve, whilst also having a 2175Angs feature as prominent as seen in the mean Milky Way extinction curve. This is in contrast to the clear detection of a 2175Angs bump and the flatter extinction curves of some more heavily extinguished GRBs (Av>1), which may be indicative of there being a dependence between dust abundance and the wavelength dependence of dust extinction, as has been previously speculated.

Effect of Hydrogen Content on Impact Property of A357 Alloy

The impact specimens with different hydrogen contents were solution treated at 540±3°C for 12h; water quenched at 60-100°C; and aged at 165±1°C for 6h. The impact test was carried out at Roell450 pendulum impact testing machine. The impact test results show that the impact energy has strong relation with the hydrogen content. The total absorption energy increases with the increasing of hydrogen content. The crack propagation energy Avp and present larger proportion than the initial crack energy Avi in the total absorption energy Av. The number of the pinholes increases and the pinholes turn from smaller irregular ones into sub-circular shape ones. The specimen with irregular sub-circular pinholes has larger KI, and has more crack propagation resistance.

3D Mapping for Guide RF Ablation of Accessory Pathways Close Proximity of Atrioventricular Node and His Bundle

Anteroseptal and parahisian accessory pathway (AP) in the vicinity of the atrioventricular node (AVN) and the bundle of His, are associated with a high risk of complete atrioventricular block (AVB) during transcatheter radiofrequency ablation (RFA). Electro anatomical 3D mapping may be applied to avoid AVN and His bundle and reduce radiation exposure. We report 2 cases of AP that close proximity to AVN and His bundle using 3D EnSite NavX system. The first case was 35 year old lady with anteroseptal AP that conduct biderectonally. The AP was 16 mm away from His bundle. Both antegrade and retrograde conduction could be abolished with RF energy by of 3D mapping guidance. The procedure time was 65 minutes and the fluoroscopy time was 18 minutes. The second case was 22 year-old man with parahissian AP that only antegrade conduction. The distance between AP and His was about 3–4 mm. The AP could be successfully ablated using 3D mapping guide. The procedure time was 95 minutes and the fluoroscopy time was 20 minutes. In conclusion: RFA for patients with AP that close proximity to AV node and His bundle using 3D mapping guide is a feasible and effective radical therapy. This technique may reduce the risk of total AV block and radiation exposure.

Percutaneous transluminal septal myocardial ablation (PTSMA) of hypertrophic cardiomyopathy: Indonesian initial experience

Aim Percutaneous transluminal septal myocardial ablation (PTSMA), a non-surgical intervention to treat hypertrophic cardiomyopathy (HCM), has been a standard treatment in developed countries. However, this procedure not yet systematically performed in Indonesia. This case series aim to study feasibility, safety and efficacy of PTSMA in National Cardiovascular Center Harapan Kita, Jakarta. Methods Three HCM patients (2 male) with dynamic left ventricle outflow tract (LVOT) pressure gradient of higher than 30 mmHg underwent PTSMA. Left ventricle apex pressure was measured using multipurpose catheter and aortic pressure was measured by means of left coronary guiding catheter simultaneously. Target vessel is confirmed by myocardial echocardiography contrast. Two ml absolute alcohol delivered to the target vessel by means over the wire balloon. Immediate pressure gradient changed 10 minute after alcohol administration was recorded. Continuous ECG monitoring is attemted along the procedure. Results All subject demonstrated more than 50% LVOT pressure gradient reduction. One subject experienced transient total AV block and right bundle branch block which completely recovered 6 hours after procedure. In one patient, target vessel must be changed as it gives perfusion to extensive area of right ventricle. Conclusion PTSMA guided with myocardial echocardiography contrast is feasible, safe and effective to reduce LVOT pressure gradient in HCM patient. (Med J Indones 2009;19:164-71)

PP-118 COMPARISON OF TWO PATIENTS WITH MITRAL STENOSIS WHICH DO NOT HAVE DIAGNOSIS UP TO ADVANGED AGE

Objective: Abnormalities in the origin, number and distribution of the coronary arteries are common in the tetralogy of Fallot (TOF). The most common abnormality is origin of left anterior descending artery and large conal branches, both arising from the right coronary artery. The important of these anomalous vessels depends on their course across the infundibulum. Echocardiographic examinations are able to offer enough information for surgeon about origin and distribution of coronary arteries and prevention of its possible damage during the surgical correction of anomaly. Aim of presentation is presenting our results in echocardiographic examination of coronary artery in children with TOF. Methods: Cross sectional echocardiography examination. Results: During the period 23. December 1999. to 22. December 2009. in our Clinic were diagnosed 83 children with TOF. In most of them (73 children -87.9%) we found normal position of coronary arteries with small conal branch. In 6 cases (7.22%) we found normal position of coronary arteries with large conal branch. During the surgery in two children conal branch has been damaged and they developed total AV block. That was reason for pacemaker implantation. In two children (2.4%) left anterior descending artery and circumflexa has origin form the right coronary artery; in one child we founded dual left anterior descending artery. Conclusions: Our results in echocardiography presentation of the coronary artery in children with tetralogy of Fallot are similar with other studies and solely diagnostic methods (invasive examination, MRI) for the diagnosis of coronary artery anatomy are not necessary.

RECOVERING STELLAR POPULATION PROPERTIES AND REDSHIFTS FROM BROADBAND PHOTOMETRY OF SIMULATED GALAXIES: LESSONS FOR SED MODELING

We present a detailed analysis of our ability to determine stellar masses, ages, reddening and extinction values, and star formation rates of high-redshift galaxies by modeling broad-band SEDs with stellar population synthesis. In order to do so, we computed synthetic optical-to-NIR SEDs for model galaxies taken from hydrodynamical merger simulations placed at redshifts 1.5 < z < 3. Viewed under different angles and during different evolutionary phases, the simulations represent a wide variety of galaxy types (disks, mergers, spheroids). We show that simulated galaxies span a wide range in SEDs and color, comparable to these of observed galaxies. In all star-forming phases, dust attenuation has a large effect on colors, SEDs, and fluxes. The broad-band SEDs were then fed to a standard SED modeling procedure and resulting stellar population parameters were compared to their true values. Disk galaxies generally show a decent median correspondence between the true and estimated mass and age, but suffer from large uncertainties. During the merger itself, we find larger offsets (e.g., log M_recovered - log M_true = -0.13^{+0.10}_{-0.14}). E(B-V) values are generally recovered well, but the estimated total visual absorption Av is consistently too low, increasingly so for larger optical depths. Since the largest optical depths occur during the phases of most intense star formation, it is for the highest SFRs that we find the largest underestimates. The masses, ages, E(B-V), Av, and SFR of merger remnants (spheroids) are very well reproduced. We discuss possible biases in SED modeling results caused by mismatch between the true and template star formation history, dust distribution, metallicity variations and AGN contribution.

Circulating Microparticles, Plasma Protein C and Free Protein S Levels in Children with Sickle Cell Anemia.

Microparticles (MP) originate from blebbing and shedding from cell membrane surfaces in physiological and pathological conditions. Increased levels are generated by a number of mechanisms including platelet activation, vascular endothelial damage, thrombin activity, C5b-9 activation, and PF4-heparin-antibody interaction. Increased circulating MP have been described in patients with sickle cell anemia (SCA). Elevated monocyte-derived MP expressing tissue factor have been reported in patients in crisis. The lack of a standardised method for MP quantification remains problematic. We measured MP (numbers and functional markers), protein C and free protein S, in a large cohort of pediatric patients to investigate the role of MP in SCA and their relation to protein C and free protein S plasma levels. One hundred and eleven children of sub-Saharan African ethnicity with SCA (hemoglobin (Hb) SS) were studied: 51 without previous history of crisis in steady state (mean age 5.3 years); 15 in crisis (9 chest crises, 6 other, mean age 5.4 years); 30 on hydroxyurea (mean age 7.2 years); 15 on transfusion therapy (mean age 6.5 years); 17 children of sub-Saharan African ethnicity of similar age (mean age 4.6 years) were used as control group (Hb AA). MP were analyzed by flow cytometry, according to Biró et al ( J Thromb Haemost. 2004; 2(10):1842–51), using Annexin V and antibodies against, CD61, CD42a, CD62P (P-selectin), CD235a, CD14, CD142 (tissue factor), CD201 (endothelial protein C receptor or EPCR), CD62E (E-selectin), CD36 (thrombospondin or TSP-1), CD47 (TSP-1 receptor), CD31 PECAM (platelet-endothelial cellular adhesion marker), CD144 (VE-cadherin). Protein C (chromogenic) and free protein S (latex based assay) were measured in all subjects. Correlation was measured by Pearson Rank test, and comparisons between groups were analyzed by Mann-Whitney test. Total MP AV were lower in crisis (1.26 × 106/ml; 0.56–2.44 × 106) and steady state (1.35 × 106/ml; 0.71– 3.0 × 106) compared to transfusion (4.33 × 106/ml; 1.6–9.2 × 106p<0.01). Protein C levels were significantly lower in crisis (median 0.52 IU/ml; interquartile range 0.43–0.62) compared to all other groups: HbAA (0.72 IU/ml; 0.66–0.82, p<0.001); hydroxyurea (0.67 IU/ml; 0.58–0.77, p<0.001); steady state (0.63 IU/ml; 0.54–0.70, p<0.05) and transfusion (0.60 IU/ml; 0.54–0.70, p<0.05). In addition levels were significantly reduced in steady state (0.63 IU/ml; 0.54–0.70) compared to HbAA (0.72 IU/ml; 0.66–0.80, p<0.01). Protein S levels were significantly higher in HbAA (0.85 IU/ml; 0.72–0.97) compared with crisis (0.49 IU/ml; 0.42–0.64, p<0.001), hydroxyurea (0.65 IU/ml; 0.56–0.74, p<0.01), and transfusion (0.59 IU/ml; 0.47–0.71, p<0.01). There was also a significant difference in crisis patients compared to steady state (0.49 IU/ml; 0.42–0.64 v 0.68 IU/ml; 0.58–0.79, p<0.05). There was high correlation (R>0.9, p<0.05) between total numbers of Annexin V positive MP (MP AV) and platelet MP expressing non-activation platelet markers. There was a lower correlation between MP AV and MP CD62P (R=0.73, p<0.05) (platelet activation marker), and also a lower correlation between percentage of MP expressing CD201 (%MP CD201) and %MP CD14 (R=0.627, p<0.001). %MP CD201 was higher in crisis (11.6%) compared to HbAA (3.2%, p<0.05); %MP CD144 was higher in crisis (7.6%) compared to transfusion (2.1%, p<0.05); %CD14 (0.77%) was higher in crisis compared to transfusion (0.0%, p<0.05) and steady state (0.0%, p<0.01); MP CD14 was detectable in a higher number of samples (92%) in crisis compared to the rest (40%); %MP CD235a was higher in crisis (17.9%) compared to transfusion (8.9%), hydroxurea (8.7%) and steady state (9.9%, p<0.05); %CD62E did not differ significantly across the groups and CD142 was undetectable. These studies indicate that there are significantly lower levels of protein C and free protein S in children with sickle cell crisis. In addition there are significantly lower numbers of circulating platelet MP in steady state and crisis patients; however in crisis a significantly higher percentage of MP express markers of endothelial and vascular damage, and of red cell origin. Among these are composite hybrid microparticles expressing markers of more than one cell type, probably brought about by severe vascular stress and close contact of various circulating cell types with vascular endothelium.

Left bundle branch–Purkinje system in patients with bundle branch reentrant tachycardia: Lessons from catheter ablation and electroanatomic mapping

The mechanism of bundle branch reentrant tachycardia has been described, and ablation of the right bundle branch (RBB) is a curative approach. The purpose of this study was to evaluate the left bundle branch (LBB)-Purkinje system during sinus rhythm and to test the feasibility of ablating the LBB in patients with bundle branch reentrant tachycardia. Thirteen consecutive male patients (age 62 +/- 12 years) with sustained bundle branch reentrant tachycardia were included in the study. Surface ECG before ablation showed left bundle branch block (LBBB) in 10 patients and a narrow QRS in 3 patients. Bundle branch reentrant tachycardia with LBBB morphology was inducible in all cases. Ablation of the RBB resulted in right bundle branch block (RBBB) on surface ECG in 8 of 9 patients and total AV block with preserved retrograde conduction over the LBB in 1 of 9 patients. In 4 patients with LBBB during sinus rhythm, electroanatomic mapping showed (1) absent conduction through the anterior fascicle of the LBB and (2) anterograde slow conduction through the posterior fascicle of the LBB with (3) left ventricular activation by transseptal conduction due to conduction block between the distal Purkinje and the local ventricle in 2 of 4 patients. The LBB was successfully ablated in these 4 patients. During mean follow-up of 48 +/- 29 months, 3 patients died, but bundle branch reentrant tachycardia did not recur in any patient. In patients with LBBB and bundle branch reentrant tachycardia, anterograde slow conduction over the LBB is present. Ablation of the LBB is feasible and may be an alternative approach for bundle branch reentrant tachycardia. Patients with normal heart and bundle branch reentrant tachycardia have a good prognosis and may not require further intervention.