bluuebunny/crossref_metadata_2025 huggingface dataset:
Interatrial shunt closure devices in patients with nickel allergy
Authors: Reddy Bhavananda T. , Patel Jeetendra B. , Powell Douglas L. , Michaels Andrew D.
Published: May 2009

We assessed outcomes in nickel allergic patients treated with percutaneous interatrial shunt device closure with the Helex device. Nickel toxicity has been well described in patients undergoing interatrial shunt closure with the Amplatzer device, which has a nitinol design. There have been no reports using Helex in nickel allergic patients. Ninety‐five consecutive patients underwent percutaneous interatrial shunt closure at a single US center by one operator. In those with possible nickel allergy, patch testing with the North American Contact Dermatitis Group standard series and a metal series was performed. The mean age was 48 ± 16 years (range 18‐81), 48% were male, 21 (22%) had atrial septal defect, and 74 (78%) had patent foramen ovale. Six patients had a positive skin test to nickel and underwent successful closure with Helex. Of the remaining 89 patients, 88 were closed with Amplatzer and one with Helex. All procedures were successful with no deaths, myocardial infarctions, strokes, or systemic emboli at six‐month followup. None of the Helex patients developed an allergic reaction, significant chest pain, or arrhythmia. Of those without pre‐procedural known nickel allergy, 12% had palpitations, 5% had atrial fibrillation, and 13% had chest pain. When compared with a published report that 89% of nickel‐allergic patients developing an allergic reaction to the Amplatzer or Premere device, Helex appeared far safer in nickel allergic patients (P < 0.001). In patients with nickel allergy, percutaneous interatrial shunt device closure with Helex device is safe, and is not associated with allergy to nickel. © 2009 Wiley‐Liss, Inc.
The risk of cardiac complications following noncardiac surgery in patients with drug eluting stents implanted at least six months before surgery
Authors: Assali Abid , Vaknin‐Assa Hana , Lev Eli , Bental Tamir , Ben‐Dor Itsik , Teplitsky Igal , Brosh David , Fuchs Shmuel , Eidelman Leonid , Battler Alexander , Kornowski Ran
Published: May 2009

Aims: Given the anecdotal reports and case series suggesting that drug‐eluting coronary stents [DES] may be still vulnerable to coronary thrombosis after six months, we sought to assess this risk in patients undergoing non‐cardiac surgery six months after stenting. Methods and Results: Linking the Rabin Medical Centre interventional cardiology database with its non‐cardiac surgical database, we identified 78 patients who underwent DES placement and subsequently [after six months] had noncardiac surgery [15‐vascular, 37‐ abdominal and genitourinary and 26‐others, excluding ophthalmic surgery]. Outcome measures included 30‐day rate of postoperative myocardial infarction (MI), DES‐related thrombosis, and cardiac mortality. Major adverse cardiac events [death and non‐fatal MI] occurred in 6 (7.7%) patients including 2 cardiac deaths (2.6%), 4 (5.1%) non‐fatal myocardial infarctions (MIs). Two patients (2.6%) sustained stent thrombosis [one patient had ‘definite’ and one ‘probable’ stent thrombosis]. All MIs [including stent thrombosis] occurred in the vascular and abdominal surgery group. Two of the MIs events occurred while the patients were on dual antiplatelet agents. In conclusions: Perioperative cardiac events during non cardiac surgery after six months of DES deployment still occur. These cardiac complications [not entirely prevented by continued dual antiplatelet agents] remain a matter of diagnostic and therapeutic challenge and concern. © 2009 Wiley‐Liss, Inc.
Contralateral transradial approach for carotid artery stenting: A feasibility study
Authors: Patel Tejas , Shah Sanjay , Ranjan Alok , Malhotra Hemant , Pancholy Samir , Coppola John
Published: May 2009

Background: Carotid artery stenting (CAS) has become an accepted modality of treatment for revascularization of the internal carotid artery (ICA). CAS from femoral approach has got wide acceptance, however, it can be problematic due to access site complication as well as technical difficulties related to peripheral vascular disease and/or anatomical variations of the aortic arch. Small feasibility studies of CAS through ipsilateral transradial approach have been described in the literature. The purpose of the present study is to evaluate the feasibility of contralateral transradial approach as an alternative approach for CAS. Methods: Twenty patients (mean age: 65 ± 5, 17 male) underwent CAS using contralateral transradial approach. All had a CA stenosis greater than 80%. The target common carotid artery (CCA) was initially cannulated via the contralateral radial artery using a 5F Simmons 1 diagnostic catheter or a 5F TIG diagnostic catheter, which was then advanced to the external CA (ECA) over an exchange length of 0.032″ Terumo Glidewire or a 0.025″ Glidewire. Once the catheter was parked in the optimal position in ECA, the wire was removed and was replaced by 0.035″ Amplatz Super stiff Guide wire. Following that, the Simmons 1 or the TIG catheter was removed and 6F Pinnacle Sheath was exchanged and positioned in the distal CCA. CAS was performed using standard techniques with weight‐based heparin for anticoagulation. Results: CAS was successful in 16/20 (80%) patients, including 12/12 (100%) right CA, 4/8 (50%) left CA. Mean interventional time was 40 ± 5 min. The sheath was removed immediately after the procedure. There were no radial access site complications. One patient sustained a transient ischemic attack and recovered completely with complete resolution of symptoms within 1 hr. Median Hospital stay was 3 ± 0.5 days. Angulation of left CCA with the aortic arch was the technical cause of failure in the four unsuccessful cases. Conclusion: CAS using the contralateral transradial approach appears to be safe and technically feasible. The technique may be particularly useful in patients with right ICA lesions because of the favorable right CCA angle with the aortic arch. © 2009 Wiley‐Liss, Inc.
The impact of micro troponin leak on long‐term outcomes following elective percutaneous coronary intervention
Authors: Milani Richard V. , Fitzgerald Robert , Milani Jenna N. , Lavie Carl J.
Published: May 2009

Objective: To evaluate the clinical impact of microleaks of troponin, which are below the reference standard defining troponin elevation, on cardiovascular outcomes in stable coronary patients undergoing elective percutaneous coronary intervention (PCI). Background: Troponin elevation, either pre‐ or post‐PCI, has been shown to predict poor cardiovascular outcomes. However, troponin measurements that are above the limit of detection but below the 99th percentile limit defining elevation (“microleak”) have uncertain clinical significance. Methods: We assessed subsequent myocardial infarction (MI) and death over a mean follow‐up of 4.2 years in 2,272 patients undergoing elective PCI, where baseline troponins were normal and follow‐up troponins were obtained 12–24 hr post‐PCI. Patients were divided into three groups based on post‐PCI troponin levels: Group 1 (n = 1,313) nondetectable; group 2 (n = 587) microleak, and group 3 (n = 372) elevated suggesting myocardial necrosis. Results: The combined endpoint of MI and death was similar in groups 2 and 3 (50.3 vs. 51.9%, respectively, P = NS), which was significantly more than group 1 patients (35.6%, P < 0.01) over the follow‐up period. Multivariate analysis of patients in groups 1 and 2 demonstrated that troponin microleak was an independent predictor of MI and death (P = 0.01). Conclusions: Microleak of troponin following elective PCI suggests myocardial injury and predicts an increased risk of subsequent MI and death. Troponins should be routinely assessed following PCI, and preventive therapies are needed to reduce micro and macro troponin elevation in the PCI setting. © 2009 Wiley‐Liss, Inc.
Cover Picture: Polymerase‐Catalysed Incorporation of Glucose Nucleotides into a DNA Duplex (Chem. Eur. J. 22/2009)
Authors: Renders Marleen , Abramov Mikhail , Froeyen Matheus , Herdewijn Piet
Published: May 2009

Surprise, surprise DNA polymerases may accept glucose nucleotides as substrates. This unexpected broad substrate specificity of polymerases points to its role in the catalytic process of phosphodiester formation, rather than being involved in base pair recognition. In their Full Paper on page 5463 ff., P. Herdewijn et al. describe their findings in detail.

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Organic carbonates as alternative solvents for asymmetric hydrogenation
Authors: Schäffner Benjamin , Andrushko Vasyl , Bayardon Jerome , Holz Jens , Börner Armin
Published: May 2009

Organic carbonates like propylene carbonate (PC) or butylene carbonate (BC) belong to the class of aprotic, highly dipolar solvents (AHD). Interestingly, their potential as solvents for asymmetric catalysis has been overlooked for a long time. The aim of this work is to evaluate organic carbonates and other organic solvents like THF, CH2Cl2, and acetonitrile as well as members of the AHD‐family (DMF, DMSO, etc.) as media for homogeneous asymmetric hydrogenation. For this reason cationic Rh‐complexes based on chiral phosphine ligands were tested in the hydrogenation of typical benchmark substrates. In several trials, significant advantages of organic carbonates were found. In contrast to DMSO, DMF and acetonitrile, in PC and BC high conversion rates and excellent enantioselectivities were usually observed. Chirality 2009. © 2009 Wiley‐Liss, Inc.
Three enigmatic examples and inference from likelihood
Authors: Fraser D. A. S. , Wong A. , Sun Y.
Published: May 2009

Statistics has many inference procedures for examining a model with data to obtain information concerning the value of a parameter of interest. If these give different results for the same model and data, one can reasonably want a satisfactory explanation. Over the last eighty years, three very simple examples have appeared intermittently in the literature, often with contradictory or misleading results; these enigmatic examples come from Cox, Behrens, and Box & Cox. The procedures in some generality begin with an observed likelihood function, which is known to provide just first order accuracy unless there is additional information that calibrates the parameter. In particular, default Bayes analysis seeks such calibration in the form of a model‐based prior; such a prior with second order accuracy is examined for the Behrens problem, but none seems available for the Box and Cox problem. Alternatively, higher‐order likelihood theory obtains such information by examining likelihood at and near the data and achieves third order accuracy. We examine both Bayesian and frequentist procedures in the context of the three enigmatic examples; simulations support the indicated accuracies. The Canadian Journal of Statistics © 2009 Statistical Society of Canada
Bootstrap tests for variance components in generalized linear mixed models
Authors: Sinha Sanjoy K.
Published: May 2009

In many applications of generalized linear mixed models to clustered correlated or longitudinal data, often we are interested in testing whether a random effects variance component is zero. The usual asymptotic mixture of chi‐square distributions of the score statistic for testing constrained variance components does not necessarily hold. In this article, the author proposes and explores a parametric bootstrap test that appears to be valid based on its estimated level of significance under the null hypothesis. Results from a simulation study indicate that the bootstrap test has a level much closer to the nominal one while the asymptotic test is conservative, and is more powerful than the usual asymptotic score test based on a mixture of chi‐squares. The proposed bootstrap test is illustrated using two sets of real‐life data obtained from clinical trials. The Canadian Journal of Statistics © 2009 Statistical Society of Canada
Likelihood analysis of joint marginal and conditional models for longitudinal categorical data
Authors: Chen Baojiang , Yi Grace Y. , Cook Richard J.
Published: May 2009

The authors develop a Markov model for the analysis of longitudinal categorical data which facilitates modelling both marginal and conditional structures. A likelihood formulation is employed for inference, so the resulting estimators enjoy the optimal properties such as efficiency and consistency, and remain consistent when data are missing at random. Simulation studies demonstrate that the proposed method performs well under a variety of situations. Application to data from a smoking prevention study illustrates the utility of the model and interpretation of covariate effects. The Canadian Journal of Statistics © 2009 Statistical Society of Canada
Robust transformation mixed‐effects models for longitudinal continuous proportional data
Authors: Zhang Peng , Qiu Zhenguo , Fu Yuejiao , Song Peter X.‐K.
Published: May 2009

The authors propose a robust transformation linear mixed‐effects model for longitudinal continuous proportional data when some of the subjects exhibit outlying trajectories over time. It becomes troublesome when including or excluding such subjects in the data analysis results in different statistical conclusions. To robustify the longitudinal analysis using the mixed‐effects model, they utilize the multivariate t distribution for random effects or/and error terms. Estimation and inference in the proposed model are established and illustrated by a real data example from an ophthalmology study. Simulation studies show a substantial robustness gain by the proposed model in comparison to the mixed‐effects model based on Aitchison's logit‐normal approach. As a result, the data analysis benefits from the robustness of making consistent conclusions in the presence of influential outliers. The Canadian Journal of Statistics © 2009 Statistical Society of Canada
Data‐driven choice of the smoothing parametrization for kernel density estimators
Authors: Chacón José E.
Published: May 2009

There are several levels of sophistication when specifying the bandwidth matrix H to be used in a multivariate kernel density estimator, including H to be a positive multiple of the identity matrix, a diagonal matrix with positive elements or, in its most general form, a symmetric positive‐definite matrix. In this paper, the author proposes a data‐based method for choosing the smoothing parametrization to be used in the kernel density estimator. The procedure is fully illustrated by a simulation study and some real data examples. The Canadian Journal of Statistics © 2009 Statistical Society of Canada
Longitudinal Changes in the B‐Type Natriuretic Peptide Levels in Normal Pregnancy and Postpartum
Authors: Hameed Afshan Batool , Chan Kenneth , Ghamsary Mark , Elkayam Uri
Published: May 2009

Normal levels of B‐type natriuretic peptide (BNP) are not well established in pregnancy. We obtained longitudinal BNP levels in 29 healthy pregnant women in each trimester and postpartum period, and compared these levels to the 25 nonpregnant controls. There were no significant differences among the cases and controls with respect to weight, diastolic blood pressure, and ethnicity. A total of 116 BNP values were obtained during pregnancy. The median (and range) BNP level during pregnancy was 19 (10–143) pg/ml versus 10 (10–37) pg/ml in the nonpregnant controls (p = 0.003). However, there were no statistically significant differences in the median BNP levels at various stages of pregnancy: first trimester 20 (10–115) pg/ml versus the second trimester 18 (10–112) pg/ml (p = 0.8), second trimester 18 pg/ml versus third trimester 26 (10–143) pg/ml (p = 0.06), and third trimester 26 pg/ml versus postpartum18 (10–62) pg/ml (p = 0.08). There were no significant differences between the BNP levels throughout the trimesters and postpartum period. Pregnant BNP levels were approximately twice as high as the nonpregnant BNP levels. Our study is unique in evaluating longitudinal changes in BNP levels in normal pregnancies and the postpartum period in comparison with healthy, nonpregnant controls. It demonstrates that pregnant BNP levels are approximately 2‐fold higher than their nonpregnant counterparts, and do not significantly fluctuate during pregnancy. In conclusion, pregnancy is associated with a significant, but small increase in the BNP levels compared with nonpregnant women. Copyright © 2009 Wiley Periodicals, Inc.
Electrocardiographic Abnormalities in Young Athletes with Mitral Valve Prolapse
Authors: Markiewicz‐Łoskot Grażyna , Łoskot Maria , Moric‐Janiszewska Ewa , Dukalska Maria , Mazurek BogusŁaw , Kohut Joanna , SzydŁowski LesŁaw
Published: May 2009

Background

Mitral valve prolapse (MVP) is the most common primary valvular abnormality in a young population. In some individuals, MVP is silent or associated with palpitations, dizziness, chest pain, and abnormal electrocardiogram (ECG) repolarization with or without ventricular arrhythmias.

Hypothesis

The aim of the present study was to assess the occurrence of the clinical and electrocardiographic abnormalities in young athletes with silent MVP.

Methods

A group of 10 children, who have been sport training intensively, with preparticipation silent MVP were examined for symptoms and/or ECG abnormalities. The diagnosis of MVP was made by echocardiography.

Results

Three athletes were asymptomatic at initial presentation. The other 7 athletes presented with symptoms. The QTc intervals > 440 msec were recorded in 2 athletes (1 with syncope). Abnormal ECG repolarization was found in 7 athletes (4 athletes were symptomatic and 3 were asymptomatic). A large variety of T‐waves was registered in athletes who presented with symptoms. In asymptomatic athletes, the tall and flat T‐waves were recorded.

Conclusions

Young athletes with MVP are often predisposed to electrocardiographic abnormalities of ventricular repolarization, which requires annual cardiologic evaluation. Copyright © 2009 Wiley Periodicals, Inc.
Twelve Months Clinical Outcome of Drug‐Eluting Stents Implantation or Coronary Artery Bypass Surgery for the Treatment of Diabetic Patients with Multivessel Disease
Authors: Qiao Yan , Ma Changsheng , Nie Shaoping , Liu Xiaohui , Kang Junping , Lv Qiang , Du Xin , Hu Rong , Zhang Yin , Jia Changqi , Liu Xinmin , Dong Jianzeng , Chen Fang , Zhou Yujie , Lv Shuzheng , Huang Fangjiong , Gu Chengxiong , Wu Xuesi
Published: May 2009

Background

Studies comparing coronary artery bypass grafting (CABG) with drug‐eluting stent (DES) for the treatment of diabetic patients with multivessel disease are relatively scarce although controversies exist concerning the relative efficacy of CABG versus DES.

Hypothesis

The aim of this study was to evaluate the effect of drug‐eluting stent (DES) implantation in diabetic patients with multivessel disease compared with CABG.

Methods

We included 645 consecutive diabetic patients who underwent either CABG (n = 282) or DES implantation (n = 363) in our institution from July 2003 to December 2005.

Results

At 12 mo after index revascularization procedure, the total mortality rate was similar in the CABG and DES group (3.2% versus 3.0%, hazard ratio [HR] of CABG versus percutaneous coronary intervention [PCI] 0.58, 95% confidence interval [CI]: 0.14 to 2.45, p = 0.460), but the rate of major adverse cardiac cerebrovascular events was lower in the CABG group (7.8% versus 17.9%, HR: 0.15, 95% CI: 0.06 to 0.37, p < 0.001) mainly due to less repeat revascularization with CABG (1.4% versus 11.6%, HR: 0.02, 95% CI: 0.01 to 0.13, p < 0.001). Age, 3‐vessel disease, and serum creatinine ≥1.5 mg/dl were positive independent predictors of 12 mo death.

Conclusions

At 12 mo, CABG was associated with less adverse events primarily due to less repeat revascularization compared with DES although there was no significant difference in mortality and myocardial infarction (MI) rates between the 2 groups; high repeat revascularization rate related to DES resulted from high restenosis rate in diabetic patients and lower rate of complete revascularization offered by PCI. Copyright © 2009 Wiley Periodicals, Inc.
Unusual Presentation of Nickel Allergy Requiring Explantation of an Amplatzer Atrial Septal Occluder Device
Authors: Rabkin David G. , Whitehead Kevin J. , Michaels Andrew D. , Powell Douglas L. , Karwande S.V.
Published: May 2009

Systemic allergic reaction to a percutaneous patent foramen ovale (PFO) occlusion device is a rare event with only scattered reports in the literature. Serious allergic reactions to these devices have a poorly defined incidence, presentation, and natural history. We present a woman with a previously unknown nickel allergy who developed severe chest pain beginning the morning after percutaneous device closure of the PFO. Despite multiple visits to her cardiologists and primary care physicians, the cause of her chest pain remained unclear. After seeking a second opinion at our medical center, skin testing showed a severe reaction to nickel. These symptoms were refractory to treatment until device explantation 18 mo later. This case highlights the importance of recognizing nickel allergy as a cause of chest pain following implantation of certain types of devices used for closure of PFOs and other heart defects. Copyright © 2009 Wiley Periodicals, Inc.
Diastolic Function Predicts Outcome After Aortic Valve Replacement in Patients with Chronic Severe Aortic Regurgitation
Authors: Çaylı Murat , Kanadaşı Mehmet , Akpınar Onur , Usal Ayhan , Poyrazoglu Hakan
Published: May 2009

Background

Due to eccentric hypertrophy and fibrosis, patients with severe aortic regurgitation (AR) have diastolic dysfunction. Increased fibrosis correlates with increased myocardial stiffness and worsening of diastolic function. Patients with irreversible left ventricular (LV) dysfunction have severe myocardial fibrosis and myocyte apoptosis and do not benefit from aortic valve replacement (AVR).

Hypothesis

To investigate whether diastolic properties of LV predicts outcome after AVR in patients with chronic severe AR and LV systolic dysfunction.

Methods

The study population consisted of 41 patients with chronic severe AR and LV systolic dysfunction. Preoperative echocardiographic examinations were repeated at the postoperative 6th month. Left ventricular ejection fraction (LVEF) was calculated. Diastolic function was evaluated with Doppler echocardiography. Patients were classified as Group 1 (impaired relaxation), Group 2 (pseudonormalization), and Group 3 (restrictive pattern).

Results

Postoperative LVEF was significantly increased in Group 1, whereas it tended to decrease in Group 3. Left ventricular size was significantly decreased in Group 1 and 2 during the postoperative period. Multivariate linear regression analysis showed that deceleration time and early/late ratio were independent predictors of postoperative changes in LVEF.

Conclusions

Assessment of diastolic function is a reliable parameter in predicting outcome of AVR in patients with chronic AR and systolic dysfunction. Copyright © 2009 Wiley Periodicals, Inc.
Long‐Term Survival and Outcomes After Hospitalization for Acute Myocardial Infarction Complicated by Cardiogenic Shock
Authors: Drakos Stavros G. , Bonios Michael J. , Anastasiou‐Nana Maria I. , Tsagalou Eleftheria P. , Terrovitis John V. , Kaldara Elisabet , Maroulidis George , Nanas Serafim N. , Kanakakis John , Nanas John N.
Published: May 2009

Background

Cardiogenic shock is the leading cause of death during hospitalization for acute myocardial infarction (MI). However, little data exist regarding the long‐term outcomes of patients who survived the acute phase of MI and were discharged from the hospital.

Methods

We retrospectively reviewed the records of 81 consecutive patients referred for management of acute MI and cardiogenic shock to analyze their in‐hospital and long‐term outcomes.

Results

Mean systemic systolic and central venous pressures at presentation were 74 ± 15 and 17 ± 7 mm Hg, respectively. Intra‐aortic balloon counterpulsation (IABC) was implemented in all patients for a mean of 88 ± 83 hours. Thrombolytics were administered in 49% and mechanical ventilation applied in 46% of patients. Primary angioplasty could not be performed in any patient, while 17 patients later underwent myocardial revascularization during hospitalization. There were 37 in‐hospital survivors (45.7%). The 1‐year survival after discharge from the hospital was 87.6% in the overall population, versus 100% among patients who underwent in‐hospital myocardial revascularization, versus 78.9% among nonrevascularized patients (p = 0.079). Over a mean follow‐up of 85 ± 47 mo, survival after discharge from the index hospitalization was 44.9% in the overall population, versus 56.2% among revascularized patients, versus 36.4% among nonrevascularized patients (p = 0.277). Heart failure developed in 51.6% of patients who were discharged from the hospital.

Conclusions

In this single center analysis, the long‐term survival after acute MI complicated by cardiogenic shock was high with nearly 50% of patients surviving free from heart failure. Copyright © 2009 Wiley Periodicals, Inc.
Propionibacterium acnes Endocarditis of a Prosthetic Aortic Valve
Authors: List Richard J. , Sheikh Nabeel , Theologou Thomas , Mitchell Ian M. , Mathew Thomas
Published: May 2009

In the few reported cases of Propionibacterium infective endocarditis involving prosthetic aortic valves, abscess is common and frequently requires surgery. We report a case of P. acnes infective endocarditis idtified on prolonged blood cultures with aortic root abscess involving a Starr‐Edwards valve. Intravenous antibiotics and valve replacement led to recovery. Copyright © 2009 Wiley Periodicals, Inc.
Prologue
Authors: Cardillo Mark J.
Published: May 2009

The Camille & Henry Dreyfus Foundation, chartered in 1946 by Camille Dreyfus as a tribute to his brother and partner in science, Henry, hosted Climate, Energy, and the Changing Environment: A Dreyfus Foundation Symposium on Environmental Chemistry Research, at the New York Academy of Sciences in October 2008. After having awarded ca. 100 fellowships, it seemed an appropriate time to assess the status of this rapidly growing field.

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Cover Picture: Towards the Efficient, Total Glycan Utilization of Biomass (ChemSusChem 5/2009)
Authors: Mascal Mark , Nikitin Edward B.
Published: May 2009

The cover picture shows common sources of waste biomass (agricultural, municipal, forestry) being processed into a mixture of substituted furans in the biomass digester described by M. Mascal and E. B. Nikitin in their Communication on page 423. The method is remarkably simple and is based on a biphasic reactor incorporating a solvent extraction loop. Isolated product yields from raw biomass approach 90 % of the theoretical, from which can be derived new generation “furanoline” biofuels such as 5‐ethoxymethylfurfural and 5‐methylfurfural, as well as the value‐added products furfural and levulinic acid (picture courtesy of Gorkem Gunbas, Department of Chemistry, UC Davis).

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Dynamics of Patterns in Nonlinear Equivariant PDEs
Authors: Beyn Wolf‐Jürgen , Thümmler Vera
Published: May 2009

Many solutions of nonlinear time dependent partial differential equations show particular spatio‐temporal patterns, such as traveling waves in one space dimension or spiral and scroll waves in higher space dimensions. The purpose of this paper is to review some recent progress on the analytical and the numerical treatment of such patterns. Particular emphasis is put on symmetries and on the dynamical systems viewpoint that goes beyond existence, uniqueness and numerical simulation of solutions for single initial value problems. The nonlinear asymptotic stability of dynamic patterns is discussed and a numerical approach (the freezing method) is presented that allows to compute co‐moving frames in which solutions converging to the patterns become stationary. The results are related to the theory of relative equilibria for equivariant evolution equations. We discuss several applications to parabolic systems with nonlinearities of FitzHugh‐Nagumo and Ginzburg‐Landau type (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectral Theory for Perturbed Systems
Authors: Colonius Fritz , Kliemann Wolfgang
Published: May 2009

This paper presents an overview of topological, smooth, and control techniques for dynamical systems and their interrelations for the study of perturbed systems. We concentrate on spectral analysis via linearization of systems. Emphasis is placed on parameter dependent perturbed systems and on a comparison of the Markovian and the dynamical structure of systems with Markov diffusion perturbation process. A number of applications is provided (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tethered satellite systems: A challenge for mechanics and applied mathematics
Authors: Schwarzbart Michael , Steindl Alois , Steiner Wolfgang , Troger Hans , Wiedermann Georg
Published: May 2009

Tethered satellite systems that is two or more satellites in orbit connected by thin long cables, pose a number of challenging problems in mechanics concerning modeling and derivation of the equations of motion and in applied mathematics, concerning the numerical simulation of their dynamics, deciding on stability of relative equilibria and the proof of chaotic dynamics. We also compare for the practically important process of deployment of one satellite from another satellite uncontrolled deployment with steered deployment, according to Pontrijagin's Maximum Principle. Related to the stability of relative equilibria, as example the Space elevator, which is a tethered system extending from the surface of the Earth beyond geostationary height, is considered (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
V(D)J targeting mistakes occur at low frequency in acute lymphoblastic leukemia
Authors: Vanura Katrina , Vrsalovic Maruska Marusic , Le Trang , Marculescu Rodrig , Kusec Rajko , Jäger Ulrich , Nadel Bertrand
Published: May 2009

Translocations of proto‐oncogenes to the B‐cell or T‐cell antigen receptor loci in acute T‐ or B‐cell leukemia and lymphoma have been, in most cases, accredited to V(D)J or switch recombination depending on the location of the breakpoint at the receptor locus. Only in rare instances, the reports take into account mechanistic characteristics of the translocation mechanism. To assess the functional ability of several sites implicated in supposedly V(D)J‐mediated translocations, we tested five sites at four proto‐oncogene loci in an ex vivo recombination substrate assay for their potential to act as direct target for V(D)J recombination. Our results show that the LMO2/RBTN2/TTG2 site and one LCK/P56 site readily engage in recombination with a genuine TCR element with the majority of breakpoint junctions showing the characteristics of V(D)J recombination, which strongly supports the involvement of this mechanism in the pathogenesis of the corresponding translocations in vivo. The site at the TLX1/HOX11 locus yielded 0.8% V(D)J‐specific junctions. Sites at the LCK/P56 and TCF3/E2A proto‐oncogenes resulted in exclusively unspecific breakpoints scattered over part of or the entire proto‐oncogene region tested, marking them as unlikely V(D)J recombination targets. Our data suggest that, while being a potentially dangerous mechanism due to the introduction of DNA breaks, V(D)J recombination is a tightly controlled mechanism allowing for only few direct mistakes. © 2009 Wiley‐Liss, Inc.
Arachidonic acid: A key molecule for astrocyte survival to peroxynitrite
Authors: Palomba Letizia , Cerioni Liana , Cantoni Orazio
Published: May 2009

Nontoxic concentrations of peroxynitrite (ONOO−) nevertheless commit rat astrocytes to mitochondrial permeability transition‐dependent toxicity, however prevented by a signaling response driven by arachidonic acid (ARA). The lipid messenger was released upon ONOO−‐dependent activation of cytosolic phospholipase A2 and its pharmacological inhibition, or knock‐down, was invariably associated with a prompt apoptotic response sensitive to exogenous ARA, but insensitive to other polyunsaturated fatty acids, as eicosapentaenoic or linoleic acid. Interestingly, while microglia also used ARA to cope with ONOO−, cerebellar granule cells were killed by the same concentrations of ONOO− employed in astrocyte/microglia experiments via a mechanism sensitive to inhibition of ARA release. These results collectively support the notion that resistance of glial cells to ONOO−, a species extensively produced under neuroinflammatory conditions, is largely based on a critical survival signaling triggered by the inflammatory product ARA. In remarkable contrast with these results, the lipid messenger appears to mediate toxicity in neuronal cells. © 2009 Wiley‐Liss, Inc.
Jagged1 regulates the activation of astrocytes via modulation of NFκB and JAK/STAT/SOCS pathways
Authors: Morga Eleonora , Mouad‐Amazzal Laila , Felten Paul , Heurtaux Tony , Moro Mike , Michelucci Alessandro , Gabel Sebastien , Grandbarbe Luc , Heuschling Paul
Published: May 2009

The Notch pathway is implicated in many aspects of the central nervous system (CNS) development and functions. Recently, we and others identified the Notch pathway to be involved in inflammatory events of the CNS. To understand the implication of this pathway on astrocytes, we have studied the Jagged‐Notch‐Hes pathway under inflammatory conditions. LPS exposure induced an upregulation of Jagged1 expression on cultured astrocytes. To address the role of Jagged1 in the modulation of inflammation, we used a siRNA mediated silencing of Jagged1 (siRNA J1). Jagged1 inhibition induced important variations on the Notch pathway components like Hes1, Hes5, Notch3, and RBP‐Jκ. siRNA J1 repressed the mRNA expression of genes known as hallmarks of the gliosis like GFAP and endothelin(B) receptor. On activated astrocytes, the inhibition of Jagged1 had antiinflammatory effects and resulted in a decrease of LPS‐induced proinflammatory cytokines (IL1β, IL1α, and TNFα) as well as the iNOS expression. The inhibition of Jagged1 induced a modulation of the JAK/STAT/SOCS signaling pathway. Most interestingly, the siRNA J1 decreased the LPS‐induced translocation of NFκB p65 and this could be correlated to the phosphorylation of IκBα. These results suggest that during inflammatory and gliotic events of the CNS, Jagged1/Notch signaling sustains the inflammation mainly through NFκB and in part through JAK/STAT/SOCS signaling pathways. © 2009 Wiley‐Liss, Inc.
Involvement of ADAM10 in axonal outgrowth and myelination of the peripheral nerve
Authors: Jangouk Parastoo , Dehmel Thomas , Meyer Zu Hörste Gerd , Ludwig Andreas , Lehmann Helmar C. , Kieseier Bernd C.
Published: May 2009

The disintegrin and metalloproteinase 10 (ADAM10) is a membrane‐anchored metalloproteinase with both proteolytic and disintegrin characteristics. Here, we investigate the expression, regulation, and functional role of ADAM10 in axonal outgrowth and myelination of the peripheral nerve. Expression pattern analysis of 11 ADAM family members in co‐cultures of rat dorsal root ganglia (DRG) neurons and Schwann cells (SCs) demonstrated the most pronounced mRNA expression for ADAM10. In further studies, ADAM10 was found to be consistently upregulated in DRG‐SC co‐cultures before the induction of myelination. Neurons as well as SCs widely expressed ADAM10 at the protein level. In neurons, the expression of ADAM10 was exclusively limited to the axons before the induction of myelination. Inhibition of ADAM10 activity by the hydroxamate‐based inhibitors GI254023X and GW280264X resulted in a significant decrease in the mean axonal length. These data suggest that ADAM10 represents a prerequisite for myelination, although its activity is not required during the process of myelination itself as demonstrated by expression analysis of myelin protein zero (P0) and Sudan black staining. Hence, during the process of myelin formation, ADAM10 is highly upregulated and appears to be critically involved in axonal outgrowth that is a requirement for myelination in the peripheral nerve. © 2009 Wiley‐Liss, Inc.
Proteasome inhibition suppresses Schwann cell dedifferentiation in vitro and in vivo
Authors: Lee Hyun Kyoung , Shin Yoon Kyung , Jung Junyang , Seo Su‐Yeong , Baek Sun‐Yong , Park Hwan Tae
Published: May 2009

The ubiquitin‐proteasome system (UPS), lysosomes, and autophagy are essential protein degradation systems for the regulation of a variety of cellular physiological events including the cellular response to injury. It has recently been reported that the UPS and autophagy mediate the axonal degeneration caused by traumatic insults and the retrieval of nerve growth factors. In the peripheral nerves, axonal degeneration after injury is accompanied by myelin degradation, which is tightly related to the reactive changes of Schwann cells called dedifferentiation. In this study, we examined the role of the UPS, lysosomal proteases, and autophagy in the early phase of Wallerian degeneration of injured peripheral nerves. We found that nerve injury induced an increase in the ubiquitin conjugation and lysosomal‐associated membrane protein‐1 expression within 1 day without any biochemical evidence for autophagy activation. Using an ex vivo explant culture of the sciatic nerve, we observed that inhibiting proteasomes or lysosomal serine proteases prevented myelin degradation, whereas this was not observed when inhibiting autophagy. Interestingly, proteasome inhibition, but not leupeptin, prevented Schwann cells from inducing dedifferentiation markers such as p75 nerve growth factor receptor and glial fibrillary acidic protein in vitro and in vivo. In addition, proteasome inhibitors induced cell cycle arrest and cellular process formation in cultured Schwann cells. Taken together, these findings indicate that the UPS plays a role in the phenotype changes of Schwann cells in response to nerve injury. © 2009 Wiley‐Liss, Inc.
Olfactory ensheathing cells: Nitric oxide production and innate immunity
Authors: Harris Julie A. , West Adrian K. , Chuah Meng Inn
Published: May 2009

Olfactory nerves extend from the nasal cavity to the central nervous system and provide therefore, a direct route for pathogenic infection of the brain. Since actual infection by this route remains relatively uncommon, powerful endogenous mechanisms for preventing microbial infection must exist, but these remain poorly understood. Our previous studies unexpectedly revealed that the unique glial cells that ensheath olfactory nerves, olfactory ensheathing cells (OECs), expressed components of the innate immune response. In this study, we show that OECs are able to detect and respond to bacterial challenge via the synthesis of nitric oxide. In vitro studies revealed that inducible nitric oxide synthase (iNOS) mRNA and protein were present in Escherichia coli‐ and Staphylococcus aureus‐incubated OECs, but were barely detectable in untreated OECs. Neuronal NOS and endothelial NOS were not expressed by OECs pre‐ and post‐bacterial incubation. Nuclear translocation of nuclear factor kappa B (NFκB), detectable in the majority of OECs 1 h following bacterial incubation, preceded iNOS induction which resulted in the production of nitric oxide. NG‐methyl‐L‐arginine significantly attenuated nitric oxide (P < 0.001) and nitrite production (P < 0.001) by OECs. In rat olfactory mucosa which was compromised by irrigation with 0.17M zinc sulfate or 0.7% Triton X‐100 to facilitate bacterial infiltration, OECs contributed to a robust synthesis of iNOS. These data strongly support the hypothesis that OECs are an essential component of the innate immune response against bacterial invasion of the central nervous system via olfactory nerves. © 2009 Wiley‐Liss, Inc.
Treatment and follow‐up of oral dysplasia — A systematic review and meta‐analysis
Authors: Mehanna Hisham M. , Rattay Tim , Smith Joel , McConkey Christopher C.
Published: May 2009

Background.

The aim of this study was to inform an evidence‐based management policy for oral dysplastic lesions.

Methods.

Systematic review was performed with meta‐analysis. Studies reporting follow‐up of patients with histologically confirmed oral dysplasia were included. Outcome measures included malignant transformation rate (MTR) and time to malignant transformation (TMT). Subgroup analysis was performed by histologic grade, clinical risk factors, and treatment modality. Heterogeneity was assessed.

Results.

Fourteen nonrandomized studies, reporting on 992 patients, were included. There was considerable heterogeneity between studies: mean overall MTR = 12.1% (confidence interval: 8.1%, 17.9%) and mean TMT = 4.3 years. Histologic grade significantly affected mean MTR (p < .008). Lesions that were not excised demonstrated considerably higher MTR than those that were excised (p = .003).

Conclusions.

Oral dysplasia showed a significant rate of transformation to cancer, which was related to grade and was decreased significantly but not eliminated by excision. This suggested the need for excision and continued surveillance. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
Laryngeal reconstruction following CO2 laser surgery for glottic cancer
Authors: Cavanagh Jonathan P. , Hart Robert D. , Brown Tim , Trites Jonathan R. B. , Brake Maria , Taylor S. Mark
Published: May 2009

CO2 laser has become a common surgical technique in the management of glottic cancer. The patients treated with this modality may benefit from additional phonosurgical techniques used to improve postoperative vocal outcome.

The aim of this article was to review those phonosurgical techniques described for glottic reconstruction after CO2 laser excision of glottic cancer. The indications for using each technique are discussed, with particular attention paid to functional outcomes following these reconstructive efforts. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
A Linking Test that investigates the feasibility of inverse modelling: application to a simple rainfall interception model for Mt Gambier, southeast South Australia
Authors: Pollacco J. A. P. , Angulo‐Jaramilo R.
Published: May 2009

Interception loss has an important influence on the water yield of forested areas. Nevertheless, in most studies stemflow is not measured, therefore the question of how to determine the feasibility of optimizing interception and stemflow parameters simultaneously by matching daily simulated throughfall to fortnightly measurements of cumulative throughfall is an important one. By applying a daily empirical interception model, a goodness fit of 2·2 mm/day is obtained between observed and simulated cumulative throughfall. However, by applying the simple but robust Linking Test, it was shown that the parameters are non‐unique and falsely linked, i.e. inter‐relationships between different vegetation parameter sets give similar throughfall but non‐unique net precipitation.

The Linking Test investigates the causes of obtaining falsely linked parameters and shows that objective equifinality is not the source of the problem. Objective equifinality occurs when an inappropriate objective function is used. The Linking Test also shows that falsely linked parameters are not caused by measuring throughfall on a non‐daily basis (termed frequency sampling equifinality). By expanding the interception model to the second degree, it was found that the non‐uniqueness is due to the inherent nature of interception and stemflow functions that behave similarly and therefore can easily compensate each other (termed similarity equifinality).

It is also shown that a simple daily empirical exponential interception model developed for conifers in the uplands of the United Kingdom is suitable to model interception in Pinus radiata plantations in the Mediterranean climate of southern Australia by using only daily gross precipitation data and two parameters. Copyright © 2009 John Wiley & Sons, Ltd.
Hydrogeochemical characteristics of surface water and groundwater in the karst basin, southwest China
Authors: Wu Pan , Tang Changyuan , Zhu Lijun , Liu Congqiang , Cha Xuefang , Tao Xiuzhen
Published: May 2009

Groundwater is a very significant water source used for irrigation and drinking purposes in the karst region, and therefore understanding the hydrogeochemistry of karst water is extremely important. Surface water and groundwater were collected, and major chemical compositions and environmental isotopes in the water were measured in order to reveal the geochemical processes affecting water quality in the Gaoping karst basin, southwest China. Dominated by Ca2+, Mg2+, HCO3− and SO42−, the groundwater is typically characterized by CaMgHCO3 type in a shallow aquifer, and CaMgSO4 type in a deeper aquifer. Dissolution of dolomite aquifer with gypsiferous rocks and dedolomitization in karst aquifers are important processes for chemical compositions of water in the study basin, and produce water with increased Mg2+, Ca2+ and SO42− concentrations, and also increased TDS in surface water and groundwater. Mg2+/Ca2+ molar ratios in groundwater decrease slightly due to dedolomitization, while the mixing of discharge of groundwater with high Mg2+/Ca2+ ratios may be responsible for Mg2+/Ca2+ ratios obviously increasing in surface water, and Mg2+/Ca2+ ratios in both surface water and groundwater finally tending to a constant. In combination with environmental isotopic analyses, the major mechanism responsible for the water chemistry and its geochemical evolution in the study basin can be revealed as being mainly from the water–rock interaction in karst aquifers, the agricultural irrigation and its infiltration, the mixing of surface water and groundwater and the water movement along faults and joints in the karst basin. Copyright © 2009 John Wiley & Sons, Ltd.
Long‐term change of seasonal snow cover and its effects on river runoff in the Tarim River basin, northwestern China
Authors: Xu Changchun , Chen Yaning , Hamid Yimit , Tashpolat Tiyip , Chen Yapeng , Ge Hongtao , Li Weihong
Published: May 2009

Spatio‐temporal variation of snow depth in the Tarim River basin has been studied by the empirical orthogonal function (EOF) based on the data collected by special sensor microwave/imager (SSM/I) and scanning multichannel microwave radiometer (SMMR) during the period from 1979 to 2005. The long‐term trend of snow depth and runoff was presented using the Mann‐Kendall non‐parametric test, and the effects of the variations of snow depth and climatic factors on runoff were analysed and discussed by means of the regression analysis. The results suggested that the snow depth variation on the entire basin was characterised by four patterns: all consistency, north–south contrast, north‐middle‐south contrast and complex. The first pattern accounting 39·13% of the total variance was dominant. The entire basin was mainly affected by one large‐scale weather system. However, the spatial and temporal differences also existed among the different regions in the basin. The significant snow depth changes occurred mainly in the Aksu River basin with the below‐normal snow depth anomalies in the 1980s and the above‐normal snow depth anomalies in the 1990s. The long‐term trend of snow depth was significant in the northwestern, western and southern parts of the basin, whereas the long‐term trend of runoff was significant in the northwestern and northeastern parts. The regression analysis revealed that the runoff of the rivers replenished by snow melt water and rainfall was related primarily to the summer precipitation, followed by the summer temperature or the maximum snow depth in the cold season. Our results suggest that snow is not the principal factor that contributes to the runoff increase in headstreams, although there was a slow increase in snow depth. It is the climatic factors that are responsible for the steady and continuous water increase in the headstreams. Copyright © 2009 John Wiley & Sons, Ltd.