bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the Reproducibility of QT Dispersion Measures
Authors: Lund Kaspar , Perkiömäki Juha S. , Brohet Christian , Zaïdi Mohammed , Elming Hanne , Pedersen Christian Torp , Huikuri Heikki V. , Nygaard Hans , Pedersen Anders Kirstein
Published: October 2006

Background: The low reproducibility of the QT dispersion (QTD) method is a major reason why it is not used in clinics. The purpose of this study was to develop QT dispersion parameters with better reproducibility and identification of patients with a high risk of ventricular arrhythmia or death.

Methods and Results: Three institutions using different methods for measuring QT intervals provided QT databases, which included more than 3500 twelve‐lead surface ECGs. The data represented low and high risk subjects from the following groups: the normal population EpiSet (survivors vs dead from cardiovascular causes), acute myocardial infarction patients AmiSet (survivors vs dead) and remote myocardial infarction patients ArrSet (with vs without a history of ventricular arrhythmia). The EpiSet, AmiSet, and the ArrSet contributed with N = 122, 0, and 110 ECGs for reproducibility analysis, and 3244, 446, and 100 ECGs for the analysis of prognostic accuracy. The prognostic accuracy was measured as the area under the Receiver Operator Curve. The QT intervals were divided into six QT pairs; the longest pair consisted of the longest and the shortest QT intervals etc. The QT dispersion trend (QTDT) was defined as the slope of the linear regression of the N longest QT pairs after estimation of missing QT intervals by interpolation of measured QT intervals. The QTMAD and the QTSTD methods were defined as twice the mean absolute deviation and the standard deviation of the N longest QT pairs. The reproducibility was improved by 27% and 19% in the EpiSet and the ArrSet relative to the reproducibility of QTD. The accuracy improved for the EpiSet and the ArrSet and was maintained for the AmiSet.

Conclusions: By using the three longest and the three shortest QT intervals in QTDT, QTMAD, or QTSTD, the reproducibility improved significantly while maintaining or improving the prognostic accuracy compared to QTD.

A.N.E. 2001;6(2):143–152
Normalization of Ventricular Repolarization with Flecainide in Long QT Syndrome Patients with SCN5A:ΔKPQ Mutation
Authors: Windle John R. , Geletka Robin C. , Moss Arthur J. , Zareba Wojciech , Atkins Dianne L.
Published: October 2006

Background:The Long QT Syndrome (LQTS) is a genetic channelopathy with life‐threatening implications. The LQT3 form of this disease is caused by mutations of the SCN5A sodium‐channel gene. A specific mutation, SCN5A:ΔKPQ, is associated with repetitive reopenings of the sodium channel and prolonged inward current. This dominant inward current is manifest on the electrocardiogram as QT prolongation. Flecainide is a potent blocker of the open sodium channel.

Methods and Results:The effect of flecainide on the duration of the QT‐interval and the T‐wave morphology was systematically evaluated in five male patients age 2–64 years having the SCN5A:ΔKPQ mutation. After baseline electrocardiograms were obtained, low‐dose oral flecainide was administered for 48 hours. Serial electrocardiograms and blood flecainide levels were obtained during flecainide therapy. The QTc interval decreased on average by 104 ms, from a baseline value of 565 ± 60 ms to 461 ± 23 ms (P < 0.04) at a mean flecainide level of 0.28 ± 0.08 mg/L, with shortening of the QTonset interval (P < 0.003) and normalization of T‐wave morphology. The effects of flecainide were compared with oral mexiletine in two patients, with flecainide showing greater QTc shortening and more complete normalization of repolarization. No adverse side effects or proarrhythmia were observed with flecainide in this study.

Conclusion:Low‐dose, oral flecainide consistently shortened the QTc interval and normalized the repolarization T‐wave pattern in five LQT3 patients with SCN5A:ΔKPQ mutation. This preliminary study indicates that low‐dose flecainide is a promising therapeutic agent for LQTS patients with the SCN5A:ΔKPQ sodium channel mutation. A.N.E. 2001;6(2):153–158
QT Dispersion and Mortality in the Elderly
Authors: Perkiömäki Juha S. , Sourander Leif B. , Levomäki Lasse , Räihä Ismo J. , Puukka Pauli , Heikki V. Huikuri M.D., F.A.C.C.
Published: October 2006

Background: The prognostic value of QT interval dispersion measured from a standard 12‐lead electrocardiogram (ECG) in the general population is not well established. The purpose of the present study was primarily to assess the value of QT interval dispersion obtained from 12‐lead ECG in the prediction of total, cardiac, stroke, and cancer mortality in the elderly.

Methods: A random population sample of community‐living elderly people (n = 330, age ≧; 65 years, mean 74 ±; 6 years) underwent a comprehensive clinical evaluation, laboratory tests, and 12‐lead ECG recordings.

Results: By the end of the 10‐year follow‐up, 180 subjects (55%) had died and 150 (45%) were still alive. Heart rate corrected QT (QTc) dispersion had been longer in those who had died than in the survivors (75 ±; 32 ms vs 63 ±; 35 ms, P = 0.01). After adjustment for age and sex in the Cox proportional hazards model, prolonged QTc dispersion (≧; 70 msec) predicted all‐cause mortality (relative risk [RR] 1.38, 95% confidence interval [Cl] 1.02–1.86) and particularly stroke mortality (RR 2.7, 95% Cl 1.29–5.73), but not cardiac (RR 1.38, 95% Cl 0.87–2.18) or cancer (RR 1.51, 95% Cl 0.91–2.50) mortality. After adjustment for age, sex, body mass index, blood pressure, blood glucose and cholesterol concentrations, functional class, history of cerebrovascular disease, diabetes, smoking, previous myocardial infarction, angina pectoris, congestive heart failure, medication, left ventricular hypertrophy on ECG, presence of atrial fibrillation and R‐R interval, increased QTc dispersion still predicted stroke mortality (RR 3.21, 95% Cl 1.09–9.47), but not total mortality or mortality from other causes. The combination of increased QTc dispersion and left ventricular hypertrophy on ECG was a powerful independent predictor of stroke mortality in the present elderly population (RR 16.52, 95% Cl 3.37–80.89). QTcmin (the shortest QTc interval among the 12 leads of ECG) independently predicted total mortality (RR 1.0082, 95% Cl 1.0028–1.0136, P = 0.003), cardiac mortality (RR 1.0191, 95% Cl 1.0102–1.0281, P < 0.0001) and cancer mortality (RR 1.0162, 95% Cl 1.0049–1.0277, P = 0.005).

Conclusions: Increased QTc dispersion yields independent information on the risk of dying from stroke among the elderly and its component, QTcmin, from the other causes of death. A.N.E. 2001; 6(3):183–192
ST Variability during the First 4 Hours of Acute Myocardial Infarction Predicts 1‐Year Mortality
Authors: Johanson Per , Swedberg Karl , Dellborg Mikael
Published: October 2006

Background: Early and complete myocardial reperfusion is the goal when treating a patient with acute myocardial infarction. To achieve this in each individual, an on‐line, accurate, easily handled and preferably noninvasive technique to monitor flow alterations is needed. Recurrent ST‐segment elevation has been shown to reflect cyclic disturbances in perfusion.

Methods: We have retrospectively analyzed ST variability in 102 patients with acute myocardial infarction randomized to 100 mg of rt‐Pa or placebo. Patients were monitored for 24 hours using vectorcardiography.

Results: Patients alive at one year (86%) had significantly less ST variability during the first four hours: 4.3 versus 7.1 episodes, P = 0.007. Patients having six or more ST episodes showed a 31.3% one‐year mortality as compared to no mortality in patients having no ST variability. Furthermore ST variability was reduced by fibrinolysis.

Conclusion: Early ST variability detectable in real time is associated with worse outcome. A.N.E. 2001; 6(3):198–202
A Comparison of the QT and QTc Dispersion Among Patients with Sustained Ventricular Tachyarrhythmias and Different Etiologies of Heart Disease
Authors: Kluger Jeffrey , Giedrimiene Dalia , Michael White C. , Verroneau Joan , Giedrimas Evaldas
Published: October 2006

Objectives: To determine if etiology of heart disease is associated with differences in QT and QTc dispersion among patients with ventricular tachyarrhythmias.

Methods: This study was undertaken in 145 patients undergoing electrophysiological testing for sustained ventricular tachycardia or ventricular fibrillation. Patients were divided into groups based on etiology of heart disease determined by history, ECG, coronary angiography, and echocardiography. The groups included patients with: dilated cardiomyopathy (n = 29), myocardial infarction (n = 90), established coronary artery disease without a myocardial infarction (n = 11), or hypertension induced left ventricular hypertrophy (n = 15). The QT intervals on a 12—lead ECG were determined and Bazett's formula was used to derive the QTc intervals. The QT and QTc dispersion were determined by subtracting the shortest QT(c) interval from the longest on each 12‐lead recording.

Results: The patients with dilated cardiomyopathy had significantly higher QT and QTc dispersion values as compared to any of the other three groups (P < 0.05 for both). No other differences in electrocardiographic variables were found between groups.

Conclusions: In a group of patients with a history of ventricular tachycardia or ventricular fibrillation, QT and QTc dispersion are significantly greater among patients with dilated cardiomyopathy than for patients with a previous myocardial infarction, established coronary artery disease without a myocardial infarction, or hypertensive left ventricular hypertrophy. A.N.E. 2001;6(4):319–322
Holter Recordings with Continuous Marker Annotation to Evaluate Pacemaker Function
Authors: Nowak Bernd , Henry Sophie , Mols Roland , Maertens Steven , Coenen Martin , Meyer Jürgen
Published: October 2006

Background: Pacemaker marker annotations facilitate the interpretation of device behavior in addition to ECG recordings. However, they are only available in conjunction with a programmer. We studied the diagnostic value of a prototype Telemetry Holter Decoder (THD), providing continuous marker annotations on a conventional Holter.

Methods: The study included 20 patients with VDD or DDDR pacemakers. A 24‐hour Holter was performed using the THD. Marker annotations are transmitted from the pacemaker to the THD, which transforms them into analog signals, which are recorded on one of the Holter channels.

Results: During a total recording time of 458 hours, high quality marker annotations were retrieved for every patient. Artefacts disturbed the recordings during 184 min (0.67%). The THD provided information not discernible on the ECG: intermittent atrial undersensing during sinus rhythm (1096 times). Atrial tachycardias, not visible on the ECG, were detected in 2 patients. The activation of tachycardia response algorithms was clearly annotated in 11,516 events. A total of 8875 PVC's occurred, 57.8% of which were classified incorrectly in the event counters as conducted or fusion beats. Atrial far‐field sensing or VA conduction was demonstrated 4294 times. Electromagnetic interferences, not visible on the ECG, could be seen three times.

Conclusion: Recording of continuous high‐quality marker annotation on a conventional Holter is feasible. The THD provides important information on device behavior, even in patients assumed to have regular device function, and shows to be clearly superior to ECG interpretation alone. Such data can be used for improved programming, troubleshooting and for the validation of new algorithms. A.N.E. 2002;7(1):22–28
Prognostic Value of Continuous ST‐Segment Monitoring in Patients with Non‐ST‐Segment Elevation Acute Coronary Syndromes
Authors: Aguiar Carlos , Ferreira Jorge , Seabra‐Gomes Ricardo
Published: October 2006

Background: Patients with non‐ST‐segment elevation acute coronary syndromes constitute a heterogeneous group concerning prognosis. The 12‐lead ECG at rest is recommended for early risk stratification but is unable to reflect the dynamic nature of myocardial ischemia and coronary thrombosis. This study investigated whether continuous ST‐segment monitoring provides early prognostic information in such patients.

Methods: We prospectively studied 183 patients admitted due to chest pain at rest suggestive of an acute coronary syndrome. ST‐segment monitoring was performed continuously for 24 hours from admission. Cardiac‐specific troponin I levels were determined on admission and every 6 hours for the first 24 hours. The endpoint was defined as death or nonfatal myocardial infarction, whichever occurred first by 30 days follow‐up.

Results: ST episodes, defined as transient ST deviations of at least 0.1 mV, were detected in 50 patients 27.3%) and associated with worse 30‐day outcome: 22.0% endpoint rate compared to 6.8% for patients without ST episodes (P = 0.003). In a multivariate analysis, the presence of ST episodes hazard ratio, 3.07; 95% Cl, 1.26 to 7.46; P = 0.014) and peak troponin I levels > 0.2 μg/L (hazard ratio, 2.65; 95% Cl, 1.01 to 6.95; P = 0.048) were independent predictors of prognosis. The combination of ST‐segment monitoring and peak troponin I identified patients at low (2.5%, n = 79), intermediate (14.5%, n = 76), and high (25.0%, n = 28) risk for the 30‐day endpoint.

Conclusions: In patients with non‐ST‐segment elevation acute coronary syndromes, continuous ST‐segment monitoring provides on‐line early prognostic information, in addition to troponin I levels. A.N.E. 2002;7(1):29–39
Value of the Corrected QT Interval Dispersion Obtained Exercise Electrocardiography in Determining Remote Vessel Disease in Patients with Healed Q‐Wave Myocardial Infarction
Authors: Altunkeser Bülent B. , Ozdemir Kurtuluş , Özdil Hüseyin , Gök Hasan , Aydin Mustafa
Published: October 2006

Background: QT and corrected QT dispersion (QTD, QTcD) obtained by using the standard 12‐lead ECG is a marker of nonhomogenous ventricular repolarization. QTD obtained from exercise ECG increases the diagnostic reliability of ST‐segment changes. The aim of this study was to investigate the diagnostic accuracy of the QTD and QTcD obtained by a 12‐lead ECG during the peak exercise in determining remote vessel disease in patients with healed Q‐wave MI.

Methods: Eighty patients with healed Q‐wave Ml (mean age 54 ± 8 years; 71 men, 9 women; 29 anterior; 51 inferior Ml) who underwent exercise stress testing and coronary angiography were included in this study. Patients were divided into two groups, with (group I) and without (group II) remote vessel coronary artery disease. During peak exercise, sensitivity, specificity, negative and positive predictive value of the ST‐segment depression, and QTcD were compared between both groups. Moreover, the resting and peak exercise ECG parameters were compared between group I and group II.

Results: In coronary angiography, remote vessel disease was detected in 48 patients (group I). In determining remote vessel disease, the sensitivity, specificity, and the negative and positive predictive values of the peak exercise QTcD ≧ 70 ms were significantly higher than those of the peak exercise ST‐segment depression (81%, 63%, 69%, and 76% vs 71%, 53%, 55%, and 69%, respectively; P < 0.01 for all comparisons). In group I, QTD and QTcD were significantly higher in patients with anterior wall Ml than those with inferior wall Ml both during the resting and peak exercise ECG. In group II, the resting QTD and QTcD were significantly higher in patients with anterior wall MI than those with inferior wall MI. In patients with anterior wall MI and inferior wall Ml, QTD and QTcD significantly increased with exercise in group I.

Conclusion: In patients with healed Q‐wave Ml, the value of QTcD ≧ 70 ms increases the diagnostic: accuracy of the exercise stress testing in determining remote vessel disease. A.N.E. 2002;7(3):228–233
Computer‐Based Analysis of Dynamic QT Changes: Toward High Precision and Individual Rate Correction
Authors: Dota Corina , Skallefell Bo , Edvardsson Nils , Fager Gunnar
Published: October 2006

Background: New strategies are needed to improve the results of automatic measurement of the various parts of the ECG signal and their dynamic changes.

Methods: The EClysis software processes digitally‐recorded ECGs from up to 12 leads at 500 Hz, using strictly defined algorithms to detect the PQRSTU points and to measure ECG intervals and amplitudes. Calculations are made on the averaged curve of each sampling period (beat group) or as means ± SD for beat groups, after being analyzed at the individual beat level in each lead. Resulting data sets can be exported for further statistical analyses. Using QT and R‐R measured on beat level, an individual correction for the R‐R dependence can be performed.

Results: EClysis assigns PQRSTU points and intervals in a sensitive and highly reproducible manner, with coefficients of variation in ECG intervals corresponding to ca. 2 ms in the simulated ECG. In the normal ECG, the CVs are 2% for QRS, 0.8% for QT, and almost 6% for PQ intervals. EClysis highlights the increase in QT intervals and the decrease of T‐wave amplitudes during almokalant infusion versus placebo. Using the observed linear or exponential relationships to adjust QT for R‐R dependence in healthy subjects, one can eliminate this dependence almost completely by individualized correction.

Conclusions: The EClysis system provides a precise and reproducible method to analyze ECGs. A.N.E. 2002;7(4):289–301
Late Potential Analysis: Is a Mathematically‐Derived X, Y, Z Lead System Comparable to a True Orthogonal X, Y, Z Lead System?
Authors: Cron Thomas A. , Zellweger Michael J. , Buser Peter T. , Pfisterer Matthias E. , Osswald Stefan
Published: October 2006

Background: Analysis of ventricular late potentials (LP) with signal‐averaged ECG (SAECG) using three bipolar, orthogonal X,Y, Z leads is a validated method of risk‐stratification in patients prone to ventricular tachycardia. The aim of‐this study was to validate a ECG system, which allows LP analysis using X,Y, Z leads mathematically derived from the standard 12‐lead ECG.

Methods and Results: In 36 patients (age 56 ± 12 years, coronary artery disease 71 %, LVEF 46 ± 14%) with known or suspected ventricular tachyarrhythmia, two consecutive SAECGs were recorded, one with mathematically derived and another one with true X,Y, Z leads. Time domain measurements with these different lead systems were compared using linear regression analysis and “Bland‐Altman” plots. Correlation was good (r = 0.92) for the filtered QRS complex duration, but poor for the terminal QRS amplitude (RMS) and duration (LAS) criteria (r = 0.66 and 0.61, respectively; P < 0.0001). Defining LPS as present if at least two of the three time domain criteria were abnormal, the result matched in 28 (78%), but differed in 8 (22%) patients.

Conclusion: SAECG using X,Y, Z leads mathematically derived from the standard 12‐lead ECG compared to true bipolar X,Y, Z leads show a close correlation in filtered QRS duration, but can differ considerably in the other time domain measurements, resulting in different interpretation of LP analysis in 22%. Therefore, SAECG registration should currently be performed with true X,Y, Z leads, until the accuracy of other approaches is validated. A.N.E. 2002;7(4):302–306
QT Interval in Patients with Unstable Angina and Non‐Q Wave Myocardial Infarction
Authors: Rukshin Vladimir , Monakier Daniel , Olshtain‐Pops Karen , Balkin Jonathan , Tzivoni Dan
Published: October 2006

Background: Non‐Q wave mvocardial infarction (NQMI) and unstable angina (UAP) have similar clinical presentations and similar ST‐T changes on the electrocardiogram. The purpose of this study was to assess whether changes in QT interval might help differentiating between these entities.

Methods: The QT intervals of 52 patients hospitalized with NQMI were compared to those of 52 patients hospitalized for UAP. All patients had repeated ECG for at least 4 days.

Results: Maximal QTc in patients with NQMI was significantly longer than in patients with UAP (475 vs 439 ms, P < 0.0001). QTc on the admission ECG was 450 ms in patients with NQMI compared to 417 ms in UAP P < 0.005). QTc > 460 ms was present in 48% patients with NQMI and in 19% of UAP patients. Maximal QT prolongation was observed within 36 hours of admission with return to normal within 96 hours. QT dispersion was within normal range, being longer in patients with NQMI than patients with UAP (55 vs 43 ms, P < 0.003). QT prolongation was not associated with increased frequency of arrhythmia. The cause of QT prolongation in NQMI may be related to the damage of subendocardial layer exposing the M cells layer which markedly prolong action potential duration.

Conclusion: Transient QT prolongation is observed in about half of patients with NQMI. These ECG changes may help differentiating between patients with NQMI and UAP already on admission. A.N.E. 2002;7(4):343–348
Morphology Transformation of Nanoscale Magnesium Hydroxide: from Nanosheets to Nanodisks
Authors: Jia Baoping , Gao Lian
Published: October 2006

Nanoscale Mg(OH)2 with different morphologies, from nanosheets, nanosquares, and nanodisks, have been successfully synthesized via a simple hydrothermal reaction of Mg(CH3COO)2 and sodium hydroxide in the presence of citrate. Direct observation of transformation from nanosheets to nanodisks indicates clearly the growth of a Mg(OH)2 nanocrystal. The structure and morphology of the resultant Mg(OH)2 nanostructures were characterized by X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HRTEM), and selected area electron diffraction patterns (SAED). A possible formation mechanism of the Mg(OH)2 nanostructures is proposed based on the oriented aggregation mechanism.
PLZT Phases Near Lead Zirconate: 2. Determination by Capacitance and Polarization
Authors: Breval Else , Wang Chiping , Dougherty Joseph P. , Yilmazbayhan Aylin , Gachigi Kamau W. A. , Stewart Michael , Duva Frank , Crespi Ann
Published: October 2006

The phases of PLZT, (Pb,La)(Zr,Ti)O3, or L/Z/T for L<12 and T<10 were detected via determination of capacitance at varying temperatures at 0 field and via polarization at varying fields at room temperature and at selected elevated temperatures. It was possible to determine two different orthorhombic phases, and three rhombohedral (hexagonal) phases, one of which only exists at elevated temperatures. Two sets of phase diagrams were constructed with the phases as a function of temperature, and electric field, respectively. Temperature/field phase diagrams for 0/100/0, 2.95/5, and 4/95/5 were also constructed. A comparison was made between room‐temperature and 0 field PLZT phase diagrams determined via X‐ray diffraction, capacitance, and polarization.
Microstructure and Electrical Properties of MnO‐Doped (Na0.5Bi0.5)0.92Ba0.08TiO3 Lead‐Free Piezoceramics
Authors: Zhu Mankang , Liu Liying , Hou Yudong , Wang Hao , Yan Hui
Published: October 2006

Microstructure and electrical properties of manganese oxide (MnO)‐doped (Na0.5Bi0.5)0.92Ba0.08TiO3 (NBBT) piezoceramics were investigated in this work. X‐ray diffraction analysis shows that the suitable substitution of Mn ion into the B site induces the lattice distortion of perovskite NBBT: the solution limit is at 0.3 wt% MnO. Besides, it is observed that the sintering properties can be improved by adding a small amount of MnO, thus increasing the grain size and the relative density. Further, the temperature dependence of the dielectric permittivity of NBBT ceramics indicates that the MnO addition reconstructs the disorder array destroyed by joining BaTiO3 in the Na0.5Bi0.5TiO3 system due to the sizable radius of the B‐site cations. Combining these effects of MnO addition, the optimal electrical properties were acquired for NBBT ceramic with addition of 0.30 wt% MnO. The excellent electrical properties of MnO‐doped NBBT ceramics indicate its promising application in large displacement actuators.
Effect of exogenous administration of melatonin and growth hormone on pro‐antioxidant functions of the liver in aging male rats
Authors: Kireev R. A. , Tresguerres A. C. F. , Castillo C. , Salazar V. , Ariznavarreta C. , Vara E. , Tresguerres J. A. F.
Published: October 2006

Abstract: Aging is accompanied by changes in the morphology and physiology of organs and tissues, such as the liver. This process might be due to the accumulation of oxidative damage induced by reactive oxygen (ROS) and reactive nitrogen species (RNS). Hepatocytes are very rich in mitochondria and have a high respiratory rate, so they are exposed to large amounts of ROS and permanent oxidative stress. Twenty‐four male Wistar rats of 22 months of age were divided into three groups. One group remained untreated and acted as the control group. The second was treated with growth hormone (GH) (2 mg/kg/d sc) and the third was submitted to treatment wit 1 mg/kg/d of melatonin in the drinking water. A group of 2‐months‐old male rats was used as young controls. After 10 wk of treatment the rats were killed by decapitation, and the liver was dissected and homogenized. Mitochondrial, cytosolic and microsomal fractions were obtained and cytochromeC, glutathione peroxidase, s‐transferase and nitric oxide (NO) were measured. Aging induced a significant increase in mitochondrial nitric oxide. An increase in cytochromeCin the cytosolic fraction and a reduction in the mitochondrial fraction with age was also observed. Both GH and melatonin treatments significantly reduced the enhanced measures and increased the reduced values. A reduction in glutathione peroxidase and glutathione S‐transferase was found in old control rats when compared with the group of young animals. Treatment for 2.5 months of old rats with GH and melatonin were able to increase the enzymes reaching values similar to those found in young animals. In conclusion, GH and melatonin treatment seems to have beneficial effects against age‐induced damage in the liver.
A ‘pure’ chemoattractant formylpeptide analogue triggers a specific signalling pathway in human neutrophil chemotaxis
Authors: Spisani Susanna , Falzarano Sofia , Traniello Serena , Nalli Marianna , Selvatici Rita
Published: October 2006

As it has not yet been established whether the second messengers involved in the neutrophil response have identical or specific signalling requirements for each physiological function, protein kinase C (PKC) isoforms and mitogen activated protein kinases (MAPKs) were studied in human chemotaxis triggered by the full agonist for‐Met‐Leu‐Phe‐OMe (fMLP‐OMe) and the ‘pure’ chemoattractant for‐Thp‐Leu‐Ain‐OMe [Thp1,Ain3] analogue. Experiments were performed in the presence or absence of extracellular Ca2+, known to be an important modulator of second messengers. Our data demonstrate that specific PKC β1 translocation and p38 MAPK phosphorylation are strongly associated with the chemotactic response of the neutrophils triggered by both peptides, while Ca2+ is not necessary for chemotaxis to occur. PKC and MAPK inhibitors were used in Western blotting assays and in cell locomotion experiments to investigate if the MAPK signalling pathway was controlled by PKC activation. The most important finding emerging from this study is that PKC and MAPK activate the chemotactic function of human neutrophils by two independent pathways.
Protective effect of active oxygen scavengers on protein degradation and photochemical function in photosystem I submembrane fractions during light stress
Authors: Rajagopal Subramanyam , Joly David , Gauthier Alain , Beauregard Marc , Carpentier Robert
Published: October 2006

The protective role of reactive oxygen scavengers against photodamage was studied in isolated photosystem (PS) I submembrane fractions illuminated (2000 µE·m−2·s−1) for various periods at 4 °C. The photochemical activity of the submembrane fractions measured as P700 photooxidation was significantly protected in the presence of histidine or n‐propyl gallate. Chlorophyll photobleaching resulting in a decrease of absorbance and fluorescence, and a blue‐shift of both absorbance and fluorescence maximum in the red region, was also greatly delayed in the presence of these scavengers. Western blot analysis revealed the light harvesting antenna complexes of PSI, Lhca2 and Lhca1, were more susceptible to strong light when compared to Lhca3 and Lhca4. The reaction‐center proteins PsaB, PsaC, and PsaE were most sensitive to strong illumination while other polypeptides were less affected. Addition of histidine or n‐propyl gallate lead to significant protection of reaction‐center proteins as well as Lhca against strong illumination. Circular dichroism (CD) spectra revealed that the α‐helix content decreased with increasing period of light exposure, whereas β‐strands, turns, and unordered structure increased. This unfolding was prevented with the addition of histidine or n‐propyl gallate even after 10 h of strong illumination. Catalase or superoxide dismutase could not minimize the alteration of PSI photochemical activity and structure due to photodamage. The specific action of histidine and n‐propyl gallate indicates that 1O2 was the main form of reactive oxygen species responsible for strong light‐induced damage in PSI submembrane fractions.
Regulation of the human leukocyte‐derived arginine aminopeptidase endoplasmic reticulum‐aminopeptidase 2 gene by interferon‐γ
Authors: Tanioka Toshihiro , Hattori Akira , Mizutani Shigehiko , Tsujimoto Masafumi
Published: October 2006

The leukocyte‐derived arginine aminopeptidase (L‐RAP) is the second aminopeptidase localized in the endoplasmic reticulum (ER) processing antigenic peptides presented to major histocompatibility complex (MHC) class I molecules. In this study, the genomic organization of the gene encoding human L‐RAP was determined and the regulatory mechanism of its expression was elucidated. The entire genomic structure of the L‐RAP gene is similar to both placental leucine aminopeptidase (P‐LAP) and adipocyte‐derived leucine aminopeptidase (A‐LAP) genes, confirming the close relationship of these three enzymes. Interferon (IFN)‐γ up‐regulates the expression of the L‐RAP gene. Deletion and site‐directed mutagenic analyses of the 5′‐flanking region of the L‐RAP gene and electrophoretic mobility shift assay indicated that while interferon regulatory factor (IRF)‐2 is important in the basal condition, IRF‐1 is the primary regulator of IFN‐γ‐mediated augmentation of the gene expression. In addition, PU.1, a member of the E26 transformation‐specific family of transcription factors, also plays a role in the regulation of gene expression. The maximum expression of the gene was achieved by coexpression of IRF‐1 and PU.1 in HEK293 cells and IRF‐2 suppressed the IRF‐1‐mediated enhancement of gene expression, suggesting that IFN‐γ‐induced L‐RAP gene expression is cooperatively regulated by IRFs and PU.1 transcription factors.
Determination of the metal ion dependence and substrate specificity of a hydratase involved in the degradation pathway of biphenyl/chlorobiphenyl
Authors: Wang Pan , Seah Stephen Y. K.
Published: October 2006

BphH is a divalent metal ion‐dependent hydratase that catalyzes the formation of 2‐keto‐4‐hydroxypentanoate from 2‐hydroxypent‐2,4‐dienoate (HPDA). This reaction lies on the catabolic pathway of numerous aromatics, including the significant environmental pollutant, polychlorinated biphenyls (PCBs). BphH from the PCB degrading bacterium, Burkholderia xenoverans LB400, was overexpressed and purified to homogeneity. Atomic absorption spectroscopy and Scatchard analysis reveal that only one divalent metal ion is bound to each enzyme subunit. The enzyme exhibits the highest activity when Mg2+ was used as cofactor. Other divalent cations activate the enzyme in the following order of effectiveness: Mg2+ > Mn2+ > Co2+ > Zn2+ > Ca2+. This differs from the metal activation profile of the homologous hydratase, MhpD. UV‐visible spectroscopy of the Co2+–BphH complex indicates that the divalent metal ion is hexa‐coordinated in the enzyme. The nature of the metal ion affected only the kcat and not the Km values in the BphH hydration of HPDA, suggesting that cation has a catalytic rather than just a substrate binding role. BphH is able to transform alternative substrates substituted with methyl‐ and chlorine groups at the 5‐position of HPDA. The specificity constants (kcat/Km) for 5‐methyl and 5‐chloro substrates are, however, lowered by eight‐ and 67‐fold compared with the unsubstituted substrate. Significantly, kcat for the chloro‐substituted substrate is eightfold lower compared with the methyl‐substituted substrate, showing that electron withdrawing substituent at the 5‐position of the substrate has a negative influence on enzyme catalysis.
Characterization of promoter 3 of the human thromboxane A2 receptor gene
Authors: Coyle Adrian T. , Kinsella B. Therese
Published: October 2006

The TPα and TPβ isoforms of the human thromboxane A2 receptor (TP) arise by differential splicing but are under the transcriptional control of two distinct promoters, termed Prm1 and Prm3, respectively (Coyle et al. 2002 Eur J Biochem269, 4058–4073). The aim of the current study was to determine the key factors regulating TPβ expression by functionally characterizing Prm3, identifying the core promoter and the cis‐acting elements regulating basal Prm3 activity. Hence, the ability of Prm3 and a series of Prm3 deleted/mutated subfragments to direct reporter gene expression in human erythroleukemia 92.1.7 and human embryonic kidney 293 cells was investigated. It was established that nucleotides −118 to +1 are critical for core Prm3 activity in both cell types. Furthermore, three distinct regulatory regions comprising of an upstream repressor sequence, located between −404 to −320, and two positive regulatory regions required for efficient basal gene expression, located between −154 to −106 and −50 to +1, were identified within the core Prm3. Deletion and site‐directed mutagenesis of consensus Oct‐1/2 and AP‐1 elements within the latter −154 to −106 and −50 to +1 regions, respectively, substantially reduced Prm3 activity while mutation of both elements abolished Prm3 activity. Electromobility shift and supershift assays confirmed the specificity of nuclear factor binding to the latter Oct‐1/2 and AP‐1 elements. Moreover, herein it was established that the core AP‐1 element mediates phorbol myristic acid‐induction of Prm3 activity hence providing a mechanistic explanation of phorbol ester up‐regulation of TPβ mRNA expression.
The superflares of soft γ-ray repeaters: giant quakes in solid quark stars?
Authors: Xu R. X. , Tao D. J. , Yang Y.
Published: October 2006

Three supergiant flares from soft γ-ray repeaters are observed, with typical released energy of ∼1044–47 erg. A conventional model (i.e. the magnetar model) for such events is catastrophic magnetism-powered instability through a magnetohydrodynamic process, in which a significant part of the short–hard γ-ray bursts could also be the result of magnetars. Based on various observational features (e.g. precession, glitches, thermal photon emission) and the underlying theory of strong interaction (quantum chromodynamics), it cannot yet be ruled out that pulsar-like stars might be actually solid quark stars. Strain energy develops during the life of a solid star, and starquakes could occur when stellar stresses reach a critical value, with a huge amount of energy released. An alternative model for supergiant flares of soft γ-ray repeaters is presented, in which the energy release during a starquake of a solid quark star is calculated. Numerical results for spherically asymmetric solid stars show that the gravitational energy released during a giant quake could be as high as 1048 erg if the tangential pressure is slightly higher than the radial one. Difficulties in magnetar models may be overcome if anomalous X-ray pulsars/soft γ-ray repeaters are accreting solid quark stars with mass ∼1–2 M⊙.
The Family International: A Case Study in the Management of Change in New Religious Movements
Authors: Shepherd Gary , Shepherd Gordon
Published: October 2006

This paper focuses on The Family International – a group that since its inception in the late 1960s (when it was known as The Children of God) has provoked intense public controversy and considerable social science attention as a result. Sociologists of religion have found it to be a particularly useful case study for contributing detailed insights as to how new religious movements (NRMs) may survive (and more rarely, flourish). NRM survival and possible success are viewed as occurring through certain adaptive changes and developments by the group in response to social environments that are often hostile to the groups’ existence. We summarize portions of our own research to show how The Family International has coped with a number of problems common to most NRMs, but often in quite unique ways that expand sociological understanding of how religious adaptation processes may occur and what forms they may assume. A particular focus of our research has been on The Family's unique expansion of both personal and corporate prophecy to facilitate its functioning.
The Tabernacle and the Temple in Ancient Israel
Authors: Homan Michael M.
Published: October 2006

According to the Bible, the Tabernacle, a portable and ornate tent shrine, served as the terrestrial home for ancient Israel's deity from its construction at Mount Sinai under the supervision of Moses until it was replaced by Solomon's Temple. Solomon built his Temple in Jerusalem on the summit of Mount Moriah, and this served as God's home for approximately four hundred years. The Babylonians destroyed the Temple in 586 BCE. Zerubbabel oversaw the building of a Second Temple in 520 BCE. This building underwent extensive renovations by Herod in 19 BCE, and the Jerusalem Temple was finally destroyed in 70 CE by the Romans. Many of the most famous events in the Bible and history take place at the Tabernacle and Jerusalem Temple, as they were the most important structures in ancient Israel. For the past two millennia they have been the focus of more attention than any other buildings in antiquity.
Fast Variability of TeraElectron Volt γ Rays from the Radio Galaxy M87
Authors: Aharonian F. , Akhperjanian A. G. , Bazer-Bachi A. R. , Beilicke M. , Benbow W. , Berge D. , Bernlöhr K. , Boisson C. , Bolz O. , Borrel V. , Braun I. , Brown A. M. , Bühler R. , Büsching I. , Carrigan S. , Chadwick P. M. , Chounet L.-M. , Coignet G. , Cornils R. , Costamante L. , Degrange B. , Dickinson H. J. , Djannati-Ataï A. , Drury L. O'C. , Dubus G. , Egberts K. , Emmanoulopoulos D. , Espigat P. , Feinstein F. , Ferrero E. , Fiasson A. , Fontaine G. , Funk Seb. , Funk S. , Füßling M. , Gallant Y. A. , Giebels B. , Glicenstein J. F. , Goret P. , Hadjichristidis C. , Hauser D. , Hauser M. , Heinzelmann G. , Henri G. , Hermann G. , Hinton J. A. , Hoffmann A. , Hofmann W. , Holleran M. , Hoppe S. , Horns D. , Jacholkowska A. , de Jager O. C. , Kendziorra E. , Kerschhaggl M. , Khélifi B. , Komin Nu. , Konopelko A. , Kosack K. , Lamanna G. , Latham I. J. , Le Gallou R. , Lemière A. , Lemoine-Goumard M. , Lenain J.-P. , Lohse T. , Martin J. M. , Martineau-Huynh O. , Marcowith A. , Masterson C. , Maurin G. , McComb T. J. L. , Moulin E. , de Naurois M. , Nedbal D. , Nolan S. J. , Noutsos A. , Orford K. J. , Osborne J. L. , Ouchrif M. , Panter M. , Pelletier G. , Pita S. , Pühlhofer G. , Punch M. , Ranchon S. , Raubenheimer B. C. , Raue M. , Rayner S. M. , Reimer A. , Ripken J. , Rob L. , Rolland L. , Rosier-Lees S. , Rowell G. , Sahakian V. , Santangelo A. , Saugé L. , Schlenker S. , Schlickeiser R. , Schröder R. , Schwanke U. , Schwarzburg S. , Schwemmer S. , Shalchi A. , Sol H. , Spangler D. , Spanier F. , Steenkamp R. , Stegmann C. , Superina G. , Tam P. H. , Tavernet J.-P. , Terrier R. , Tluczykont M. , van Eldik C. , Vasileiadis G. , Venter C. , Vialle J. P. , Vincent P. , Völk H. J. , Wagner S. J. , Ward M.
Published: October 2006

The detection of fast variations of the tera–electron volt (TeV) (10
12
eV) γ-ray flux, on time scales of days, from the nearby radio galaxy M87 is reported. These variations are about 10 times as fast as those observed in any other wave band and imply a very compact emission region with a dimension similar to the Schwarzschild radius of the central black hole. We thus can exclude several other sites and processes of the γ-ray production. The observations confirm that TeV γ rays are emitted by extragalactic sources other than blazars, where jets are not relativistically beamed toward the observer.
A Genome-Wide Association Study Identifies
IL23R
as an Inflammatory Bowel Disease Gene
Authors: Duerr Richard H. , Taylor Kent D. , Brant Steven R. , Rioux John D. , Silverberg Mark S. , Daly Mark J. , Steinhart A. Hillary , Abraham Clara , Regueiro Miguel , Griffiths Anne , Dassopoulos Themistocles , Bitton Alain , Yang Huiying , Targan Stephan , Datta Lisa Wu , Kistner Emily O. , Schumm L. Philip , Lee Annette T. , Gregersen Peter K. , Barmada M. Michael , Rotter Jerome I. , Nicolae Dan L. , Cho Judy H.
Published: October 2006

The inflammatory bowel diseases Crohn's disease and ulcerative colitis are common, chronic disorders that cause abdominal pain, diarrhea, and gastrointestinal bleeding. To identify genetic factors that might contribute to these disorders, we performed a genome-wide association study. We found a highly significant association between Crohn's disease and the
IL23R
gene on chromosome 1p31, which encodes a subunit of the receptor for the proinflammatory cytokine interleukin-23. An uncommon coding variant (rs11209026, c.1142G>A, p.Arg381Gln) confers strong protection against Crohn's disease, and additional noncoding
IL23R
variants are independently associated. Replication studies confirmed
IL23R
associations in independent cohorts of patients with Crohn's disease or ulcerative colitis. These results and previous studies on the proinflammatory role of IL-23 prioritize this signaling pathway as a therapeutic target in inflammatory bowel disease.
Outburst of Jupiter's Synchrotron Radiation after the Impact of Comet Shoemaker-Levy 9
Authors: de Pater Imke , Heiles C. , Wong M. , Maddalena R. J. , Bird M. K . , Funke O. , Neidhoefer J. , Price R. M. , Kesteven M. , Calabretta M. , Klein M. J. , Gulkis S. , Bolton S. J. , Foster R. S. , Sukumar S. , Strom R. G. , LePoole R. S. , Spoelstra T. , Robison M. , Hunstead R. W. , Campbell-Wilson D. , Ye T. , Dulk G. , Leblanc Y. , Galopeau P. , Gerard E. , Lecacheux A.
Published: October 2006

Jupiter's nonthermal microwave emission, as measured by a global network of 11 radio telescopes, increased dramatically during the Shoemaker-Levy 9 impacts. The increase was wavelength-dependent, varying from ∼10 percent at 70 to 90 centimeters to ∼45 percent at 6 and 36 centimeters. The radio spectrum hardened (flattened toward shorter wavelengths) considerably during the week of impacts and continued to harden afterward. After the week of cometary impacts, the flux density began to subside at all wavelengths and was still declining 3 months later. Very Large Array and Australia Telescope images of the brightness distribution showed the enhancement to be localized in longitude and concentrated near the magnetic equator. The evidence therefore suggests that the increase in flux density was caused by a change in the resident particle population, for example, through an energization or spatial redistribution of the emitting particles.
Prospects for Larger or More Frequent Earthquakes in the Los Angeles Metropolitan Region
Authors: Dolan James F. , Sieh Kerry , Rockwell Thomas K. , Yeats Robert S. , Shaw John , Suppe John , Huftile Gary J. , Gath Eldon M.
Published: October 2006

Far too few moderate earthquakes have occurred within the Los Angeles, California, metropolitan region during the 200-year-long historic period to account for observed strain accumulation, indicating that the historic era represents either a lull between clusters of moderate earthquakes or part of a centuries-long interseismic period between much larger (moment magnitude,
M
w
, 7.2 to 7.6) events. Geologic slip rates and relations between moment magnitude, average coseismic slip, and rupture area show that either of these hypotheses is possible, but that the latter is the more plausible of the two. The average time between
M
w
7.2 to 7.6 earthquakes from a combination of six fault systems within the metropolitan area was estimated to be about 140 years.
Metastable Phases in Polar Stratospheric Aerosols
Authors: Fox Lewis E. , Wofsy Steven C. , Worsnop Douglas R. , Zahniser Mark S.
Published: October 2006

Phase changes in stratospheric aerosols were studied by cooling a droplet of sulfuric acid (H
2
SO
4
) in the presence of nitric acid (HNO
3
) and water vapor. A sequence of solid phases was observed to form that followed Ostwald's rule for phase nucleation. For stratospheric partial pressures at temperatures between 193 and 195 kelvin, a metastable ternary H
2
SO
4
-HNO
3
hydrate, H
2
SO
4
⋅ HNO
3
⋅ 5H
2
O, formed in coexistence with binary H
2
SO
4
⋅
k
H
2
O hydrates (
k
= 2, 3, and 4) and then transformed to nitric acid dihydrate, HNO
3
⋅ 2H
2
O, within a few hours. Metastable HNO
3
⋅ 2H
2
O always formed before stable nitric acid trihydrate, HNO
3
⋅ 3H
2
O, under stratospheric conditions and persisted for long periods. The formation of metastable phases provides a mechanism for differential particle growth and sedimentation of HNO
3
from the polar winter stratosphere.
Domain Shapes and Patterns: The Phenomenology of Modulated Phases
Authors: Seul Michael , Andelman David
Published: October 2006

A wide variety of two- and three-dimensional physical-chemical systems display domain patterns in equilibrium. The phenomenology of these patterns, and of the shapes of their constituent domains, is reviewed here from a point of view that interprets these patterns as a manifestation of modulated phases. These phases are stabilized by competing interactions and are characterized by periodic spatial variations of the pertinent order parameter, the corresponding modulation period generally displaying a dependence on temperature and other external fields. This simple picture provides a unifying framework to account for striking and substantial similarities revealed in the prevalent "stripe" and "bubble" morphologies as well as in commonly observed, characteristic domain-shape instabilities. Several areas of particular current interest are discussed.
Energy Dependence of Abstractive Versus Dissociative Chemisorption of Fluorine Molecules on the Silicon (111)-(7×7) Surface
Authors: Jensen John A. , Yan Chun , Kummel Andrew C.
Published: October 2006

Scanning tunneling microscopy and monoenergetic molecular beams have been used to obtain real-space atomic images of the competition between abstractive and dissociative chemisorption. The size distribution of Si-F adsorbates on the Si(111)-(7×7) surface was examined as a function of the incident translational energy of the F
2
molecules. For F
2
molecules with 0.03 electron volt of incident energy, the dominant adsorbate sites were isolated Si-F species. As an F
2
molecule with low translational energy collides with the surface, abstraction occurs and only one of the F atoms chemisorbs; the other is ejected into the gas phase. For F
2
molecules with 0.27 electron volt of incident energy, many adjacent Si-F adsorbates (dimer sites) were observed because F
2
molecules with high translational energy collide with the surface and chemisorb dissociatively so that both F atoms react to form adjacent Si-F adsorbates. For halogens with very high incident energy (0.5-electron volt Br
2
), dissociative chemisorption is the dominant adsorption mechanism and dimer sites account for nearly all adsorbates.