bluuebunny/crossref_metadata_2025 huggingface dataset:
Endomorphin 1‐ and Endomorphin 2‐Containing Neurons in Nucleus Tractus Solitarii Send Axons to the Parabrachial Nuclei in the Rat
Authors: Lü Bo‐Chang , Li Hui , Chen Tao , Huo Fu‐Quan , Zhang Ting , Li Yun‐Qing
Published: March 2009

Endomorphin‐1 (EM1) and endomorphin‐2 (EM2) are the selective endogenous ligands for the μ‐opioid receptor (MOR). Since EMs‐expressing neuronal cell bodies or axonal components have been observed, respectively, in the nucleus tractus solitarii or the parabrachial nuclei, we examined if EMs‐expressing neurons in the NTS of the rat might send their axons to the PBN. Immunofluorescent stainings for EM1 or EM2 were combined with retrograde or anterograde tract‐tracing method. After injecting tetramethyl rhodamine dextran‐amine (TMR) into the parabrachial nuclei of rats, some EM1‐ or EM2‐immunoreactive neurons in the nucleus tractus solitarii were labeled retrogradely with TMR. The majority of the EM1/TMR and EM2/TMR double‐labeled neurons were observed in the medial, commissural, and dorsolateral subnuclei of the nucleus tractus solitarii. Following injection of biotinylated dextran amine (BDA) into the medial, commissural, or dorsolateral subnuclei of the nucleus tractus solitarii, EM1‐ or EM2‐immunopositive axons and axon terminals were anterogradely labeled with BDA mainly in the lateral parabrachial nucleus. The present results have indicated that endomorphinergic neurons in the nucleus tractus solitarii project to the parabrachial nuclei. This suggests that EMs released from NTS‐PBN projection fibers may bind to MOR on the PBN neurons to be implicated in processing of visceral information within the parabrachial nuclei. Anat Rec, 292:488–497, 2009. © 2009 Wiley‐Liss, Inc.
Rotation of Organizer Tissue Contributes to Left–Right Asymmetry
Authors: Cui Cheng , Little Charles D. , Rongish Brenda J.
Published: March 2009

Current hypotheses regarding vertebrate left‐right asymmetry patterns are based on the presumption that genetic regulatory networks specify sidedness via extracellular morphogens and/or ciliary activity. We show empirical time‐lapse evidence for an asymmetric rotation of epiblastic nodal tissue in avian embryos. This rotation spans the interval when initial symmetric expression of Shh and Fgf8 becomes asymmetrical with respect to the midline. Anat Rec, 292:557–561, 2009. © 2009 Wiley‐Liss, Inc.
Age Classes and Sex Differences in the Skull of the Mediterranean Monk Seal, Monachus monachus (Hermann, 1779). A study Based on Bone Shape and Density
Authors: Mo Giulia , Zotti Alessandro , Agnesi Sabrina , Finoia Maria Grazia , Bernardini Daniele , Cozzi Bruno
Published: March 2009

This study analyzes morphometrically 17 skulls of the Mediterranean monk seal Monachus monachus housed in different Italian Museums and collections. We considered several morphometric variables (31 linear, 1 volumetric and 1 surface area measurements). In addition, we identified, measured and compared two nonmorphometric variables, namely, the bone densities of selected areas obtained using a dual‐energy X‐ray absorptiometry (DXA) device. The high correlation coefficient of all variables indicated continuous growth with the onset of age. The ranking of the hierarchical cluster analysis identified the presence of three main groups containing individuals of similar sizes: lactating pups and yearlings; subadult individuals and adult females; and adult males. Smaller groups were identified within these clusters, and their respective allocations into two subgroups were argued on the basis of skull development and other factors. The discriminant analysis of the three main groups indicated a discriminant diagnostic key, based on condilobasilar length (CBlr‐L); maximum mandibular branch height (MB‐H); and surface area of the bulla tympanica. The proposed diagnostic key is useful to classify monk seal skulls of unidentified age and sex. The data reported here suggest that in this species certain adult skull growth features (enhanced tympanic bullae surface area extension, occipital bone density) are sexually dimorphic and possibly related to specific anatomical functions. These functions may include an enhanced auditory capacity; an increased development of the cranial musculature capable of supporting a large skull and guaranteeing the mandibular strength necessary for mastication; and male to male social interactions. Anat Rec, 292:544–556, 2009. © 2009 Wiley‐Liss, Inc.
Three‐Dimensional Reconstruction of Efferent Ducts in Wild‐Type and Lgr4 Knock‐Out Mice
Authors: Lambot Marie‐Alexandra H. , Mendive Fernando , Laurent Patrick , Van Schoore Gregory , Noël Jean‐Christophe , Vanderhaeghen Pierre , Vassart Gilbert
Published: March 2009

We have recently shown that Lgr4 knock‐out (LGR4KO) male mice are infertile due to a developmental defect of the reproductive tract. Spermatozoa do not reach the epididymis and accumulate at the rete testis and efferent ducts (ED). We have proposed that in LGR4KO, ED might fail to connect resulting in blind‐ended tubes that preclude the normal transit of sperm cells. To explore this possibility, we reconstructed the three‐dimensional (3D) structure of the organ from serial microphotographs. The resulting model allowed to individualize and follow each ED from the testis up to the epididymis, and to display the spatial distribution of their content. The transit of spermatozoa is indeed blocked in LGR4KO mice but, contrary to the expectation, the ducts connect normally to each other, forming a single tube that flows into the epididymis, as in the wild‐type animals. In the KO however, transit of the sperm is abruptly blocked at the same level syncytial‐like aggregates appear in the luminal space. The model also allowed calculating, for the first time, morphometric parameters of the mouse ED, such as total volume, surface, radius, and length. These data unambiguously showed that ED in the mutant mouse are dramatically shortened and less convoluted than in the wild‐type animal, providing an explanation to the phenotype observed in LGR4KO. Combined with in situ immunodetection or RNA in situ hybridization, 3D reconstruction of serial histological sections will provide an efficient mean to study expression profiles in organs which do not lend themselves to whole‐mount studies. Anat Rec, 292:595–603, 2009. © 2009 Wiley‐Liss, Inc.
Folic acid, methylation and neural tube closure in humans
Authors: Blom Henk J.
Published: March 2009

This review provides a brief description of folate use and folic acid metabolism in relation to neural tube defect (NTD) risk. First, a meta‐analysis of reduction in NTD recurrence and occurrence risk with periconceptional folic acid supplementation is presented. Second, an overview of the complex folate metabolism is given. Third, SNPs for genes involved in folate and homocysteine metabolism that have been studied in relation to NTD riskare discussed. Fourth, the questions whether folate receptor autoantibodies or hampered methylation are mechanisms underlying NTDs are briefly discussed. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.
Preparation and properties of starch acetate fibers for potential tissue engineering applications
Authors: Reddy Narendra , Yang Yiqi
Published: March 2009

This article reports the development of fibers from starch acetates that have mechanical properties and water stability better than most polysaccharide‐based biomaterials and protein fibers used in tissue engineering. In this research, starch acetates with three different degrees of substitution (DS) have been used to develop fibers for potential use as tissue engineering scaffolds. Varying the DS of starch acetate will provide fibers with different mechanical properties, hydrophilicity, and degradation behavior. Fibers made from DS 2.3 and 2.8 starch acetates have mechanical properties and water stability required for tissue engineering applications. The starch acetate fibers support the adhesion of fibroblasts demonstrating that the fibers would be suitable for tissue engineering and other medical applications. Biotechnol. Bioeng. 2009;103: 1016–1022. © 2009 Wiley Periodicals, Inc.
Modeling nutrient consumptions in large flow‐through bioreactors for tissue engineering
Authors: Devarapalli Mamatha , Lawrence Benjamin J. , Madihally Sundararajan V.
Published: March 2009

Flow‐through bioreactors are utilized in tissue regeneration to ensure complete nutrient distribution and apply defined hydrodynamic stresses. The fundamental concepts in designing these bioreactors for regenerating large high aspect ratio tissues (large surface area relative to the thickness of the matrix such as skin, bladder, and cartilage) are not well defined. Further, tissue regeneration is a dynamic process where the porous characteristics change due to proliferation of cells, de novo deposition of matrix components, and degradation of the porous architecture. These changes affect the transport characteristics and there is an imminent need to understand the influence of these factors. Using computational fluid dynamic tools, changes in the pressure drop, shear stress distribution and nutrient consumption patterns during tissue regeneration were assessed in rectangular and circular reactors described by Lawrence et al. [Biotechnol Bioeng 2009;102(3):935–947]. Further, six new designs with different inlet and outlet shapes were analyzed. The fluid flow was defined by the Brinkman equation on the porous regions using the pore characteristics of 85 µm and 120 pores/mm2. The minimum flow requirements to satisfy nutrient (oxygen and glucose) requirements for three different cell types (SMCs, chondrocytes, and hepatocytes) was evaluated using convective diffusion equation. For consumption reaction, the Michaelis–Menten rate law was used, with constants (km and vm values) extracted from literature. Simulations were performed by varying the flow rate as well as the cell number. One of the circular reactors with semicircular inlet and outlet shape decreased (i) non‐uniformity in hydrodynamic stress within the porous structure and (ii) non‐uniform nutrient distribution. All cell types showed increased consumption of oxygen than glucose. Hepatocytes needed a very high flow rate relative to other cell types. Increase in cell number suggested a need for increasing the flow in circular reactors. Biotechnol. Bioeng. 2009;103: 1003–1015. © 2009 Wiley Periodicals, Inc.
Liquid chromatography–tandem mass spectrometry method of loxoprofen in human plasma
Authors: Lee Hye Won , Ji Hye Young , Sohn Dong Hwan , Kim Se‐Mi , Lee Yong Bok , Lee Hye Suk
Published: March 2009

A rapid, sensitive and selective liquid chromatography–electrospray ionization mass spectrometric method for the determination of loxoprofen in human plasma was developed. Loxoprofen and ketoprofen (internal standard) were extracted from 20 µL of human plasma sample using ethyl acetate at acidic pH and analyzed on an Atlantis dC18 column with the mobile phase of methanol:water (75:25, v/v). The analytes were quantified in the selected reaction monitoring mode. The standard curve was linear over the concentration range of 0.1–20 µg/mL with a lower limit of quantification of 0.1 µg/mL. The coefficient of variation and relative error for intra‐ and inter‐assay at four quality control levels were 2.8–5.2 and 4.8–7.0%, respectively. The recoveries of loxoprofen and ketoprofen were 69.7 and 67.6%, respectively. The matrix effects for loxoprofen and ketoprofen were practically absent. This method was successfully applied to the pharmacokinetic study of loxoprofen in humans. Copyright © 2009 John Wiley & Sons, Ltd.
Prediction of drug bioavailability in humans using immobilized artificial membrane phosphatidylcholine column chromatography andin vitrohepatic metabolic clearance
Authors: Shin Beom Soo , Yoon Chi Ho , Balthasar Joseph P. , Choi Bu Young , Hong Seok Hyun , Kim Hyoung Jun , Lee Jong Bong , Hwang Sang Wook , Yoo Sun Dong
Published: March 2009

This study reports a rapid screening method for the prediction of oral drug bioavailability in humans based on combined immobilized artificial membrane (IAM) chromatographic capacity factor (kIAM) andin vitrostability in hepatic microsomes. The fraction of drug absorbed (Fa) in humans was predicted for a set of 15 structurally diverse commercial drugs based onkIAMvalues using a mobile phase consisting of acetonitrile: Dulbecco's phosphate‐buffered saline. The hepatic intrinsic clearance (CL) was calculated fromin vitrodisappearance half‐life, and the oral bioavailability was predicted usingin vitrohepatic clearance (CLh) andFa. Significant correlations were observed for the relationships between predicted hepatic extraction ratios (ERh) and actual presystemic metabolism (r= 0.854) and between predicted and observed oral bioavailabilities (r= 0.805;p< 0.01). The IAM capacity factor together with the hepatic microsomal disappearance half‐life may be useful in identifying compounds with high oral absorption potential in early drug discovery processes. Copyright © 2009 John Wiley & Sons, Ltd.
Wavelet based signal analysis in three phase circuits using neural network
Authors: Suja S. , Jerome Jovitha
Published: March 2009

This article proposes the use of wavelet based neural network in recognizing the harmonics. The discrete wavelet transforms is used in calculating the effective values of three phase active and reactive power. The discrete wavelet transforms with probabilistic neural network (PNN) model is used in constructing the classifier of harmonics. There are four stages in identification of harmonics. First stage is simulation of a three phase inverter circuit. The second stage is the conversion of the three phase current and voltage by PQ theory into alpha–beta reference frame. The third stage is that these alpha–beta vectors are subjected to multi resolution analysis. The signals are then decomposed by discrete wavelet transform (DWT) at six levels. The final stage is that the coefficients generated are used in the calculation of active, reactive power and energy. The DWT coefficients are used in identifying the harmonics using PNN. The main advantage in this analysis is that the active and reactive power calculated is done at various frequency bands. This covers the harmonic power at various frequencies. Wavelet is used in this article since they can detect and locate the disturbance accurately. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 537–546, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20223
Web‐based application for descriptive geometry learning
Authors: Rubio L. , Muñoz‐Abella B. , Castejón C. , Muñoz‐Sánchez A.
Published: March 2009

In the education of basic matters of technical studies, as representation systems, it is necessary to introduce new technologies that allow individual learning to students. Learning can be traditional face to face or remotely by means of e‐learning. In this work, a web‐based computer specific application to study the Monge Projection is presented. The web site is design to have two different parts: the theoretical tutorials to remind the most important concepts of the subject, and some step by step solved exercises with indications, in order to fix the main ideas of the subject in the students mind. Likewise, and for a better comprehension, the students have the possibility, once finished the exercise, to visualize the three‐dimensional solution of the two‐dimensional problem. This application is initially thought to support the master classes, but it is also valid for distance learning, where students face alone the learning. This type of applications allows bringing basic matters closer to the students by the use of new technologies. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 574–581, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20244
Membrane‐Aerated Biofilm Reactor Behaviors for the Treatment of High‐Strength Ammonium Industrial Wastewater
Authors: Cao C. , Zhao L. , Xu D. , Geng Q.
Published: March 2009

A single‐tube membrane‐aerated biofilm reactor (MABR) was used to investigate the effect of the reaction time, reaction temperature, pH value, C/N ratio, and sludge concentration on the removal rates of the NOx–‐N and COD in high‐strength ammonium industrial water by supplying oxygen during the batch experiment. The homogeneous mathematical model is developed to predict their transient responses using Monod kinetics with dual substrate limitation. The model incorporates mass transport by convection and diffusion in the surrounding liquid contained inside the interconnected pores and channels within the biofilm. Transport and kinetic parameters are estimated from experiments and the model successfully predicts concentration measurements in some of the sets of experiments.
Sensing Abilities of Crown Ether Functionalized Polythiophenes
Authors: Casanovas Jordi , Preat Julien , Zanuy David , Alemán Carlos
Published: March 2009

Tuning sensing abilities! The affinity of three different [15]crown‐5 ether functionalized polythiophenes for alkali ions has been explored (see figure). Ab initio and DFT quantum mechanical calculations show that the binding energy between neutral conducting polymers and metallic ions, which interact attractively, decreases as the size of the ion increases. Oxidation of these polythiophene derivatives significantly reduces their affinity towards alkali ions, becoming low or even nonexistent.

magnified image

This work reports a theoretical study of the affinity of three different [15]crown‐5 ether functionalized polythiophenes for alkali ions. Ab initio and DFT quantum mechanical calculations have evidenced that the binding energy between neutral conducting polymers and metallic ions, which interact attractively, decreases as the size of the ion increases. However, the preferences of these polythiophene derivatives have been found to be influenced by the entropic contribution, which favors binding with Na+ in preference to Li+. Molecular dynamics simulations have shown that this behavior can be accounted for on the basis of the large fluctuations that Li+ undergoes when it is contained in the cavity of the [15]crown‐5 ether macrocycle. In contrast, the fluctuations detected for complexes with Na+ and K+ were particularly low, even though only the former ion fits into the center of the macrocyclic cavity. Oxidation of these polythiophene derivatives produces a drastic change in their sensing abilities, their affinities towards alkali ions becoming low or even nonexistent. Moreover, calculations indicate that the presence of unsubstituted thiophene rings directly attached to a functionalized thiophene modulates the strength of the binding in the oxidized state by reducing the repulsive interaction between the metallic cation and the π‐conjugated system. On the other hand, the influence of alkali ions on the electronic properties, in particular, on the ionization potentials and the lowest π–π* transitions, of both the neutral and oxidized polythiophenes is discussed.
A First Total Synthesis of Ganglioside HLG‐2
Authors: Iwayama Yuki , Ando Hiromune , Ishida Hideharu , Kiso Makoto
Published: March 2009

A neuritegenic ganglioside from sea cucumber, HLG‐2 (see figure), has been synthesized for the first time. The unique tandem of sialic acids, Neu5Gc‐α(2,4)‐NeuAc, was established by the combination of a reactive N‐Troc sialyl donor and a 1,5‐lactamized sialyl acceptor. The ceramide counterpart was assembled in a stereoselective manner. Direct connection of the trisaccharide and the ceramide successfully afforded a precursor of HLG‐2, which was converted to ganglioside HLG‐2 in pure form.

magnified image

A first synthesis of the neuritegenic ganglioside HLG‐2, which was identified in extracts of the sea cucumber Holothuria leucospilota, is described. The characteristic sequence of the trisaccharide part, α‐N‐glycolylsialyl‐(2,4)‐α‐N‐acetylsialyl‐(2,6)‐glucoside, was efficiently assembled by coupling of a highly active N‐2,2,2‐trichloroethoxycarbonyl (Troc)‐protected sialyl donor and a 1,5‐lactamized sialyl acceptor with high stereoselectivity. The corresponding trisaccharyl imidate donor was directly glycosidated with the primary hydroxyl group of the ceramide part, producing protected HLG‐2 in relatively high yield, global deprotection of which furnished ganglioside HLG‐2 in highly pure form.
The Search for the Mechanism of the Reaction Catalyzed by Farnesyltransferase
Authors: Sousa Sérgio Filipe , Fernandes Pedro Alexandrino , Ramos Maria João
Published: March 2009

Atomic‐level portrait: The mechanism of the reaction catalyzed by the puzzling enzyme farnesyltransferase is elucidated by using computational methods, allowing the obtainment of the first real detailed atomistic quantum‐chemical transition‐state structure (see figure) for the reaction catalyzed by this enzyme. The results obtained provide an atomic‐level framework for the design of more potent and specific inhibitors for this important enzyme.

magnified image
Structural replacement or structural inducement: government ties of Chinese business executives
Authors: Yao Xiaotao , Li Stan Xiao , Sue‐Chan Christina , Xi Youmin
Published: March 2009

We suggest that the structural replacement thesis, which proposes that managers in Chinese nonstate‐owned enterprises (NSOEs) possess more government ties than managers in Chinese state‐owned enterprises (SOEs), is theoretically incomplete because it considers only the motivation of managers of NSOEs. The extensiveness of social ties is influenced also by the capability and opportunity for social actors to cultivate these social ties. We introduce the structural inducement thesis, which holds that SOE managers have more government ties than do NSOE managers, as an alternative to the structural replacement thesis. Our analysis of 250 Chinese managers' ties supports this structural inducement thesis. The theoretical and applied implications of these findings are discussed. Copyright © 2009 ASAC. Published by John Wiley & Sons, Ltd.
Exploring a non‐dimensional varying exponent equation relating minimum spouting velocity to maximum spoutable bed depth
Authors: Du Wei , Bi Xiaotao , Epstein Norman
Published: March 2009

The equation $U_{{\rm ms}} /U_{{\rm mf}} = (H/H_{\rm m} )^{1 - (0.5\,H/H_{\rm m} )}$ was critically examined for spouting both in small conical‐cylindrical columns (Dc < 0.5 m) and large cone‐base or flat‐bottom cylindrical columns (Dc ≥ 0.5 m). For small columns, a data base of 36 points with experimental measurements of both Hm and Um(=Ums at H = Hm) afforded some insights into the components of this equation and to the merits of the equation itself. For large columns, in the absence of verifiable methods of predicting Hm, correlation of Ums/Umf as a function of H/Hm, using the available experimental data on Ums, has not been achieved.
CFD modelling of a semi‐cylindrical spouted bed: Numerical simulation and experimental verification
Authors: Béttega Rodrigo , de Almeida André Ricardo Felkl , Corrêa Ronaldo Guimarães , Freire José Teixeira
Published: March 2009

It is well known that a special attention is necessary to infer process information of a spouted bed at full‐column using data from semi‐cylindrical vessels. In this work experimental data are obtained from a semi‐cylindrical spouted bed for comparison with CFD simulations performed using a 3D simulation scheme. The purpose of this paper is to contribute on the discussing about the influence of the flat wall in the solid behaviour inside the semi‐cylindrical vessel by comparing numerical results with experimental data. Simulated results of fountain height, spout diameter and particle velocities inside the bed are compared with image data obtained from a semi‐cylindrical column. The simulations were accomplished using the commercial package FLUENT 6.3.26.
Drying of herbal extract in a draft‐tube spouted bed
Authors: Souza C.R.F. , Oliveira W.P.
Published: March 2009

This work evaluates the feasibility of the draft‐tube spouted bed for drying of herbal extract. Drying runs were carried out according to a central composite design in a conical–cylindrical draft‐tube spouted bed. The variables studied were the percentage of the drying aid (ADJ), the drying gas flow rate relative to gas flow at minimum spouting (Q/Qms), and the flow rate of extract fed to the system relative to the spouting gas flow rate (Ws/Wg). Colloidal silicon dioxide was the drying aid used in order to improve drying performance. Statistical analysis of the effects of processing parameters on product recovery, product accumulation in the bed, and product properties permitted the identification of parameters presenting significant effects on drying. Optimized drying conditions were related to experimental parameters as follow: high levels of the percentage of drying adjuvant (ADJ), high airflow rate relative to minimum spouting (Q/Qms), and low values of the feed flow rate of the extract relative to the gas flow rate (Ws/Wg).
The Impact of Aspirin Resistance on the Long‐term Cardiovascular Mortality in Patients with Non‐ST Segment Elevation Acute Coronary Syndromes
Authors: Foussas Stefanos G. , Zairis Michael N. , Tsirimpis Vasilios G. , Makrygiannis Stamatis S. , Patsourakos Nikolaos G. , Adamopoulou Evdokia N. , Mytas Demetrios Z. , Prekates Athanasios A. , Perdiou Anna J. , Tsoukanas Vasilios K. , Argyrakis Spyros K.
Published: March 2009

Background

Aspirin resistance has been associated with an adverse long‐term outcome in patients with atherosclerotic coronary artery disease, but more studies are needed.

Hypothesis

The aim of this study was to investigate the impact of aspirin resistance, assessed by the Platelet Function Analyzer‐100 (PFA‐100) (Dade Behring Inc., Deerfield, Ill., USA) on the long‐term prognosis in patients with non‐ST segment elevation acute coronary syndromes (NSTE‐ACS).

Methods

A total of 496 consecutive patients were studied. The 1‐y incidence of cardiovascular death was the prespecified study endpoint. The patients were divided, according to the values of PFA‐100 collagen epinephrine closure time (CEPI‐CT) upon presentation, into aspirin sensitives (those with a PFA‐100 CEPI‐CT > 193 sec) and aspirin resistants (those with a PFA‐100 CEPI‐CT ≤ 193 sec).

Results

Aspirin resistants were younger (p‐value = 0.04), and less frequently hypertensives (p‐value = 0.05) or diabetics (p‐value = 0.04) than aspirin sensitives. By 1 y, the incidence of cardiovascular deaths in the entire cohort was 12.9% (64/496), and aspirin resistants were at significantly higher risk of cardiovascular death (23.1% versus 9.6%; hazard ratio [HR] = 2.6; 95% confidence interval [CI] = 1.6–4.3; p‐value < 0.001), than aspirin sensitives. By multivariate Cox regression analysis, aspirin resistance (a PFA‐100 CEPI‐CT ≤ 193 sec) was among the most potent predictors of the 1‐y incidence of cardiovascular death (HR = 2.8; 95% CI = 1.7–4.6; p‐value < 0.001).

Conclusion

According to the present data, aspirin resistance, assessed by the PFA‐100, is an independent predictor of long‐term cardiovascular mortality in patients with NSTE‐ACS. Copyright © 2009 Wiley Periodicals, Inc.
QPV Interval as a Measure of Arterial Stiffness in Women with Systemic Lupus Erythematosus
Authors: Qureshi Ghazanfar , Salciccioli Louis , Lee Susan , Qureshi Mohammad , Kapoor Amit , Ginzler Ellen , Lazar Jason M.
Published: March 2009

Background

Systemic lupus erythematosus (SLE) is associated with premature atherosclerosis and increased arterial stiffness. The QPV interval has been proposed as a measure of arterial stiffness. The QPV interval is based on the premise that transit time from cardiac ejection to brachial artery flow is shortened in patients with increased arterial stiffness.

Hypothesis

The objective of this study was to determine the significance of the QPV interval as a measure of arterial stiffness in patients with SLE.

Methods

We prospectively studied 46 female SLE patients. The QPV interval was calculated as the time from onset of the QRS complex to peak flow velocity of the brachial artery during ultrasound examination. Measurements of arterial stiffness: augmentation index (AI) and pulse wave velocity (PWV) were obtained by applanation tonometry while patients were on a stable medical regimen.

Results

Mean age was 44 ± 14 y and mean QPV interval was 198 ± 18 msec QPV interval correlated inversely with age (r = − 0.39, p = 0.008), AI (r = − 0.41, p = 0.004), PWV (r = − 0.39, p = 0.007), and aortic pulse pressure (PP) (r = − 0.45, p = 0.002). On multivariate regression analysis, QPV interval was found to be an independent predictor of PWV after adjusting for age (R2 = 0.26, p < 0.001).

Conclusion

In women with SLE, QPV decreases with age and is inversely related with measures of arterial stiffness. QPV may be useful in identifying SLE patients with higher arterial stiffness in the clinical or research setting. Further larger studies are needed to confirm these preliminary results. Copyright © 2009 Wiley Periodicals, Inc.
Clinical Diagnosis of Posttraumatic Stress Disorder After Myocardial Infarction
Authors: Guler Erika , Schmid Jean‐Paul , Wiedemar Lina , Saner Hugo , Schnyder Ulrich , Känel Roland von
Published: March 2009

Background

Clinician‐rated large‐scale studies estimating the prevalence of posttraumatic stress disorder (PTSD) related to myocardial infarction (MI) and identifying predictors of clinical PTSD are currently lacking.

Hypotheses

We hypothesized that PTSD is prevalent in post‐MI patients and that the subjective experience of the MI determines PTSD status.

Methods

We approached 951 post‐MI patients with a questionnaire screening for PTSD symptoms related to their MI. Those responding and meeting a cutoff of PTSD symptom levels were invited to participate in a structured clinical interview to diagnose PTSD following Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV) criteria. Fear of dying, feelings of helplessness, and severity of pain perceived during the MI were also assessed by visual analog scales.

Results

The screening questionnaire was completed by 394 patients, whereby 77 met the cutoff for the interview (8 patients declined the interview). Forty of 394 patients (10.2%) had clinical PTSD (subsyndromal and syndromal forms combined). Younger age (OR 0.95, 95% CI 0.91–0.99), greater fear of dying (OR 2.77, 95% CI 1.28–5.97), and more intense feelings of helplessness (OR 2.97, 95% CI 1.42–6.21) were independent predictors of PTSD status. Perceived pain intensity during MI, sex, type of index MI, left ventricular ejection fraction, number of coronary occlusions, and highest level of total creatinine kinase were not significant predictors.

Conclusions

Clinical PTSD is prevalent in post‐MI patients. Demographic and particularly psychological variables related to the subjective experience of the event were stronger predictors of PTSD status than were objective measures of MI severity. Copyright © 2009 Wiley Periodicals, Inc.
Actin isoform expression patterns during mammalian development and in pathology: Insights from mouse models
Authors: Tondeleir Davina , Vandamme Drieke , Vandekerckhove Joël , Ampe Christophe , Lambrechts Anja
Published: March 2009

The dynamic actin cytoskeleton, consisting of six actin isoforms in mammals and a variety of actin binding proteins is essential for all developmental processes and for the viability of the adult organism. Actin isoform specific functions have been proposed for muscle contraction, cell migration, endo‐ and exocytosis and maintaining cell shape. However, these specific functions for each of the actin isoforms during development are not well understood. Based on transgenic mouse models, we will discuss the expression patterns of the six conventional actin isoforms in mammals during development and adult life. Ablation of actin genes usually leads to lethality and affects expression of other actin isoforms at the cell or tissue level. A good knowledge of their expression and functions will contribute to fully understand severe phenotypes or diseases caused by mutations in actin isoforms. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Mechanistic Insights into Cyclooxygenase Irreversible Inactivation by Aspirin
Authors: Tosco Paolo , Lazzarato Loretta
Published: March 2009

A mechanistic hypothesis for the acetylation of cyclooxygenase (COX) by aspirin is proposed on the basis of a QM/MM study. This mechanism is consistent with previous experimental findings by other investigators. Ser 530 appears to be acetylated under intramolecular general base catalysis provided by the carboxylate moiety of aspirin, while Tyr 385 plays a crucial role in orienting and polarizing the acetyl group.

magnified image
Practical aspects of 15N CPMG transverse relaxation experiments for proteins in solution
Authors: Myint Wazo , Gong Qingguo , Ishima Rieko
Published: March 2009

The 15N transverse relaxation as measured by the Carr‐Purcell‐Meiboom‐Gill (CPMG) sequence is often used to characterize protein backbone dynamics in solution. In the 15N CPMG experiment, the delay between 15N CPMG pulses typically is set sufficiently short to minimize the effects of relaxation by the 15N‐1H antiphase component. This limits the total relaxation duration of the CPMG experiment because frequent application of the high B1 field to the heteronucleus may cause probe damage. The resulting antiphase component can be minimized by using 1H composite decoupling or by applying 1H 180° pulses more frequently than the 15N CPMG pulses. In this study, we simulated 15N CPMG relaxation in the presence of either 1H composite decoupling or 1H 180° pulses and compared the results with the experimental transverse relaxation data acquired with [u‐15N]‐ or [u‐15N, u‐2H]‐ubiquitin samples. We explain systematic errors resulting from these CPMG experiments and describe a method for recording 15N transverse relaxation in a manner that minimizes probe problems. © 2009 Wiley Periodicals, Inc. Concepts Magn Reson Part A 34A: 63–75, 2009.
Roles of magnetic gradient field and transverse relaxation in distant dipolar field signal
Authors: Ki Wong Chung , Zhong Jianhui
Published: March 2009

Distant dipolar field (DDF) effect as an alternative signal formation mechanism has attracted a lot of attention in the magnetic resonance community in the past two decades. The signal formed under the influence of DDF is usually much smaller than the signal acquired with the conventional method, and is observable only when magnetic field gradients are utilized to modulate the magnetization distribution spatially. This article reviews the formation of the DDF signals and explains in detail the roles of the gradient fields in observing the DDF effect by examining the evolution of magnetization according to the classical Bloch equation. The magnetization evolution is calculated analytically in two common pulse sequences: i) the COrrelation SpectroscopY (COSY) sequence and ii) the COSY Revamped by Asymmetric Z‐gradient Echo Detection (CRAZED) sequence. The detailed comparison of the two sequences elucidates how the implementation of the gradient fields introduces extra dephasing to the signal and why gradient fields are indispensable in observing the DDF effect in biological samples. In addition, the DDF signal is analytically shown to have an intrinsically higher sensitivity to the change of transverse relaxation (T2) than the signal acquired with the conventional method for biological tissues. This manifests that the DDF signal has a higher T2 contrast than the conventional signal under the same signal‐to‐noise ratio and provides a potential new contrast mechanism in magnetic resonance imaging. © 2009 Wiley Periodicals, Inc. Concepts Magn Reson Part A 34A: 76–90, 2009.
Are Mixed Explicit/Implicit Solvation Models Reliable for Studying Phosphate Hydrolysis? A Comparative Study of Continuum, Explicit and Mixed Solvation Models
Authors: Kamerlin Shina C. L. , Haranczyk Maciej , Warshel Arieh
Published: March 2009

Are all solvation models equal? An in‐depth comparison of mixed implicit/explicit solvation models shows that while both the implicit and explicit (QM/MM–FEP) solvation models can reproduce activation free energies for phosphate diester hydrolysis in solution with high accuracy, the use of a mixed solvation model tends to be unreliable for modelling phosphate hydrolysis in solution.

magnified image

Phosphate hydrolysis is ubiquitous in biology. However, despite intensive research on this class of reactions, the precise nature of the reaction mechanism remains controversial. Herein, we have examined the hydrolysis of three homologous phosphate diesters. The solvation free energy was simulated by means of either an implicit solvation model (COSMO), hybrid quantum mechanical/molecular mechanical free energy perturbation (QM/MM–FEP) or a mixed solvation model in which N water molecules were explicitly included in the ab initio description of the reacting system (where N=1–3), with the remainder of the solvent being implicitly modelled as a continuum. Here, both COSMO and QM/MM–FEP reproduce ΔGobs within an error of about 1 kcal mol−1. However, we demonstrate that in order to obtain any kind of reliable results from a mixed model, it is essential to carefully select the explicit water molecules from short QM/MM runs that act as a model for the true infinite system. Additionally, the mixed models tend to be increasingly unstable and miss larger entropic contributions as more explicit water molecules are placed into the system. Thus, our analysis indicates that this approach provides an unreliable way for modelling phosphate hydrolysis in solution.
Organic Solar Cells with Semitransparent Metal Back Contacts for Power Window Applications
Authors: Koeppe Robert , Hoeglinger Doris , Troshin Pavel A. , Lyubovskaya Rimma N. , Razumov Vladimir F. , Sariciftci Niyazi Serdar
Published: March 2009

A window to the world: Metal‐organic complexes such as zinc‐phthalocyanines and ‐naphthalocyanines show broad transmission windows in the visible spectral range and can be used together with fullerenes in semitransparent organic solar cells. By achieving a high transmission of visible light through silver electrodes, this property is exploited to construct organic solar cells that one can see through.

magnified image

To provide truly transparent solar cells for power window applications, both semiconductor and electrode materials have to have a very low absorption over as much of the visible spectrum as possible. We present some promising visible transparent semiconductor combinations, namely zinc‐phthalocyanine or zinc‐naphthalocyanine together with soluble fullerenes in conjunction with a method for obtaining highly transparent thin metal films by tuning the interference patterns in the multilayer organic solar cells structure. In an optimal combination, solar cells with an efficiency of about 0.5 % and a peak transparency of more than 60 % in the visible part of the spectrum were fabricated.
Vanadium Carbonyl Nitrosyl Compounds: The Carbonyl Nitrosyl Chemistry of an Oxophilic Early Transition Metal
Authors: Wang Hongyan , Xie Yaoming , King R. Bruce , Schaefer Henry F.
Published: March 2009

The vanadium carbonyl nitrosyl compounds V(NO)(CO)n (n = 5, 4, 3) and V2(NO)2(CO)n (n = 9, 8, 7) have been examined by density functional theory in order to assess the effect of the oxophilicity of vanadium on its metal carbonyl nitrosyl chemistry. The expected octahedral structure for the experimentally known, but surprisingly unstable, V(NO)(CO)5, is confirmed by DFT. The optimized structures of the unsaturated derivatives V(NO)(CO)4 and V(NO)(CO)3 can be derived from the octahedral V(NO)(CO)5 structure by loss of one or two carbonyl groups, respectively. This leads to anearly square‐planar predicted structure for V(NO)(CO)3. The lowest energy structures for the binuclear derivatives V2(NO)2(CO)n (n = 9, 8, 7) have exclusively two‐electron donor carbonyl groups and three‐electron donor linear nitrosyl groups with metal–metal distances corresponding to the formal bond orders required for the favored 18‐electron configurations. Bridging carbonyl groups appear to be preferred energetically over bridging nitrosyl groups in the V2(NO)2(CO)n structures in contrast to the similar carbonyl nitrosyl compounds of later transition metals. The saturated V2(NO)2(CO)9, with a relatively long V–V distance of 3.583 Å (B3LYP) or 3.205 Å (BP86), is thermodynamically unstable with respect to dissociation into V(NO)(CO)5 + V(NO)(CO)4.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Redox Chemistry of Tetrakis[5,6‐di(2‐pyridyl)‐2,3‐pyrazino]porphyrazinatocobalt(II): Isolation and Characterization of Solid Pure CoI, CoII, and CoIII Complexes
Authors: Viola Elisa , Donzello Maria Pia , Ciattini Samuele , Portalone Gustavo , Ercolani Claudio
Published: March 2009

Salt‐like hydrated complexes of formulae Na[Py8TPyzPzCo] and [Py8TPyzPzCo](SbCl6) containing CoI and CoIII, respectively, and the neutral CoII–bis(dimethyl sulfoxide) (DMSO) adduct [Py8TPyzPzCo(DMSO)2], bearing additional clathrated DMSO molecules, have been prepared and characterized {Py8TPyzPz = tetrakis[5,6‐di(2‐pyridyl)‐2,3‐pyrazino]porphyrazinato dianion}. The sodium CoI salt, the anion of which, [Py8TPyzPzCo]1–, had previously been identified by electrochemical solution studies, represents the first example of a CoI derivative of a tetrapyrrolic macrocyclic chromophore prepared as a solid pure material. Solutions of Na[Py8TPyzPzCo] in DMSO, under defined experimental conditions, allow the slow formation (months) of crystals of its corresponding CoII complex of formula [Py8TPyzPzCo(DMSO)2]·6 DMSO. The structure of the adduct, elucidated by single‐crystal X‐ray analysis, shows the central CoII ion surrounded by the four pyrrole N atoms of the porphyrazine macrocycle and two O atoms of the axially bonded DMSO molecules. Oxidation of the basic starting material [Py8TPyzPzCo] with phenoxathiin hexachloroantimonate (phenox‐SbCl6) led to the formation of the CoIII complex [Py8TPyzPzCo](SbCl6). Full characterization of the title CoI, CoII, and CoIII species has been accomplished by solution studies and from IR, UV/Vis, EPR and X‐ray crystallography data.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Stereoselective Functionalization of Dihydropyran‐3‐ols: Application to the Synthesis of Enantiopure Ethyl Deoxymonate B
Authors: Fernández de la Pradilla Roberto , Lwoff Nadia , Viso Alma
Published: March 2009

The behavior of readily available enantiopure cis and trans 3,6‐disubstituted dihydropyran‐3‐ols and derivatives in epoxidation, osmium‐catalyzed dihydroxylations, SN2′, and Claisen‐related processes has been examined. The highly diastereoselective dihydroxylation of a suitably functionalized cis 3,6‐disubstituted dihydropyran‐3‐ol has been used in the synthesis of ethyl deoxymonate B from a 3‐sulfinyldihydropyran intermediate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Toll-like receptor 3 signaling attenuates liver regeneration #
Authors: Zorde-Khvalevsky Elina , Abramovitch Rinat , Barash Hila , Spivak-Pohis Irit , Rivkin Ludmila , Rachmilewitz Jacob , Galun Eithan , Giladi Hilla
Published: March 2009

The current model for liver regeneration suggests that cell damage triggers Toll-like receptor (TLR) signaling via MyD88, leading to the induction of nuclear factor κB (NF-κB) and secretion of inflammatory cytokines that in turn prime liver regeneration. TLR3 is unique among TLRs in that it signals through TRIF (TIR domain-containing adaptor-inducing interferon-β), not through MyD88, and may lead to activation of either the inflammatory or apoptotic pathway. The inflammatory pathway leads to NF-κB activation, whereas the apoptotic pathway, believed to be mediated by Rip3, leads to caspase-8 activation. In this study, we explored the role of TLR3 in liver regeneration by comparing the response to 70% partial hepatectomy of TLR3wt and TLR3−/− mice. We found that following partial hepatectomy, TLR3−/− mice demonstrated earlier hepatocyte proliferation. Furthermore, within the first hours, we observed a dramatic TLR3-dependent NF-κB activation and an increase in Rip3 levels in hepatocytes, accompanied by caspase-8 activation but without an apoptotic outcome. Conclusion: TLR3 plays an inhibitory role in the priming of liver regeneration, thus reinforcing the role of the innate immune system in balancing tissue regeneration. (Hepatology 2009.)
p21 is required for dextrose-mediated inhibition of mouse liver regeneration #
Authors: Weymann Alexander , Hartman Eric , Gazit Vered , Wang Connie , Glauber Martin , Turmelle Yumirle , Rudnick David A.
Published: March 2009

The inhibitory effect of dextrose supplementation on liver regeneration was first described more than 4 decades ago. Nevertheless, the molecular mechanisms responsible for this observation have not been elucidated. We investigated these mechanisms using the partial hepatectomy model in mice given standard or 10% dextrose (D10)-supplemented drinking water. The results showed that D10-treated mice exhibited significantly reduced hepatic regeneration compared with controls, as assessed by hepatocellular bromodeoxyuridine (BrdU) incorporation and mitotic frequency. D10 supplementation did not suppress activation of hepatocyte growth factor (HGF), induction of transforming growth factor alpha (TGF-α) expression, or tumor necrosis factor alpha–interleukin-6 cytokine signaling, p42/44 extracellular signal-regulated kinase (ERK) activation, immediate early gene expression, or expression of CCAAT/enhancer binding protein beta (C/EBPβ), but did augment expression of the mito-inhibitory factors C/EBPα, p21Waf1/Cip1, and p27Kip1. In addition, forkhead box M1 (FoxM1) expression, which is required for normal liver regeneration, was suppressed by D10 treatment. Finally, D10 did not suppress either FoxM1 expression or hepatocellular proliferation in p21 null mice subjected to partial hepatectomy, establishing the functional significance of these events in mediating the effects of D10 on liver regeneration.Conclusion:These data show that the inhibitory effect of dextrose supplementation on liver regeneration is associated with increased expression of C/EBPα, p21, and p27, and decreased expression of FoxM1, and that D10-mediated inhibition of liver regeneration is abrogated in p21-deficient animals. Our observations are consistent with a model in which hepatic sufficiency is defined by homeostasis between the energy-generating capacity of the liver and the energy demands of the body mass, with liver regeneration initiated when the functional liver mass is no longer sufficient to meet such demand. (Hepatology 2009.)
The intergenerational effects of trauma from terror: A real possibility
Authors: Kaitz Marsha , Levy Mindy , Ebstein Richard , Faraone Stephen V. , Mankuta David
Published: March 2009

The goals of this article are to discuss the potential risk of children whose parents were traumatized by terror, to present literature on parenting in the context of terror, and to consider factors that may mediate the transmission of trauma‐effects from parents to children. Mediators considered are parents' traumatic distress, disturbed parent–child interactions, trauma‐related disturbances in parents' thinking, and effects of stress on children's neural functioning. Also discussed are genetic and environmental factors that may moderate the transmission of intergenerational effects and promote children's risk and resilience. Points raised during the discussion are illustrated with segments from interviews of women who were pregnant or gave birth some time after direct exposure to a terror attack. The authors conclude that empirical studies are needed to learn more about the intergenerational transmission of trauma‐effects and processes that underlie it. The authors join others in the call to improve evaluation, treatment, and support of trauma victims and their children to stymie the transmission of problems from one generation to the next.