bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pooled analysis of percutaneous mitral valvuloplasty in Egypt
Authors: Sherif Mohammad A. , Khashaba Ahmed A. , Gomaa Yaser , Khaled Saeed , Refaie Osama , Ramzy Ali 
Published: November 2008

AbstractBackground:Till now, no pooled analysis summarizing the Egyptian experience in percutaneous mitral valvuloplasty (PMV) exists.Objectives and Methods:To pool the data of PMV procedures and perform a new analysis regarding the immediate outcome and follow‐up results as well as to compare the results of different techniques.Results:Patients (2,256) with mitral stenosis of rheumatic origin were included, 292 males and 1,964 females. Double balloon (DB) was used in 1,148 patients (51%), Inoue balloon (IB) in 914 patients (40.5%), metallic commissurotome (MC) in 142 patients (6%), Multi‐Track in 33 patients (1.5%), and single balloon in 19 patients (1%). The mitral valve area (MVA) increased from 0.94 ± 0.18 cm2 to 1.92 ± 0.36 cm2; mean pressure gradient dropped from 15.94 ± 5.46 mmHg to 5.85 ± 2.6 mmHg. The most common complication was the occurrence of a new mitral regurgitation (MR) and/or increase in its grade (36%). Inadequate dilatation occurred in 192 patients (8.5%). Follow‐up data (for 5.7 ± 5.9 months) showed that the immediate results of PMV on MVA persisted through the follow‐up period (1.78 ± 0.35 cm2). Multi‐Track system resulted in the largest increase in MVA and also resulted in the largest immediate increase in the grade of MR.Conclusions:This study confirms the success of PMV and its results during follow‐up. The Multi‐Track system, and the DB resulted in the largest MVA, the IB and the single balloon resulted in the least increase in MR. The most common complication of PMV is the increase in the degree of MR. © 2009 Wiley‐Liss, Inc.
Light‐Driven Rotary Molecular Motors on Gold Nanoparticles
Authors: Pollard Michael M. , ter Wiel Matthijs K. J. , van Delden Richard A. , Vicario Javier , Koumura Nagatoshi , van den Brom Coenraad R. , Meetsma Auke , Feringa Ben L. 
Published: November 2008

AbstractWe report the synthesis of unidirectional light‐driven rotary molecular motors based on chiral overcrowded alkenes and their immobilisation on the surface of gold nanoparticles through two anchors. Using a combination of 1H and 13C NMR, UV/Vis and CD spectroscopy, we show that these motors preserve their photochemical and thermal behaviour after they have been attached to gold nanoparticles. Furthermore, we describe the synthesis of 2H‐ and 13C‐labelled derivatives that were used to verify the unidirectionality of the rotary cycle of these motors both in solution and while grafted to gold nanoparticles. Taken together, these data support the conclusion that these motors maintain their unidirectional rotary cycle when grafted to the surface of small (ca. 2 nm) gold nanoparticles. Thus, continuous irradiation of the system under appropriate conditions leads to unidirectional rotation of the upper half of the molecules relative to the entire nanoparticle.
Enantiomer self‐disproportionation of chiral compounds on achiral ordered mesoporous silica M41S and regular silica gel as a stationary phase
Authors: Mayani V. J. , Abdi S. H. R. , Kureshy R. I. , Khan N. H. , Agrawal S. , Jasra R. V. 
Published: November 2008

AbstractChromatographic behavior of nonracemic mixtures, viz., mandelic acid and stilbene oxide as analytes has been studied in detailed by enantiomer self‐disproportionation on achiral ordered mesoporous material M41S and regular silica gel as stationary phases. Enantiomer self‐disproportionation gave enhanced separation of analytes. The extent and magnitude of enantiomer self‐disproportionation is dependent on the optical purity of the starting non‐racemic molecules, presence of intermolecular hydrogen bonding/π–π interactions and the nature of eluents used. The present study and previous literature data suggest that percentage ee of a nonracemic mixture needs to be determined before any chromatographic purification is taken up as enantiomer self‐disproportionation phenomenon could occur during purification. The data show that enantiomer self‐disproportionation of nonracemic mixtures can be harnessed for its enantioenrichment on inexpensive achiral stationary phases. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Circular dichroism of tocopherols versus tocotrienols
Authors: Mazzini Francesco , Pescitelli Gennaro , Di Bari Lorenzo , Netscher Thomas , Salvadori Piero 
Published: November 2008

AbstractVitamin E is an essential nutrient of still increasing economic importance. Vitamin E derivatives include many nonracemic chiral compounds whose chirooptical characterization is scarcely described in the literature. We report the CD spectra of δ‐tocopherol and its unsaturated analog δ‐tocotrienol. TDDFT calculations demonstrate that the weak CD of δ‐tocopherol is determined by the helicity of dihydropyrane ring. In addition, the moderate CD of δ‐tocotrienol is due to the exciton interaction between the aromatic ring and the closest alkene group. Direct exciton‐coupled CD calculations on structures generated by two different conformational sampling approaches reveal that, although such exciton coupling is expected to be weak, it is sufficient to explain the spectral differences between tocopherol and tocotrienol. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Impact of Anemia on Physical Function and Survival Among Patients with Coronary Artery Disease
Authors: Patel Uptal D. , Grab Joshua , Kosiborod Mikhail , Lytle MS Barbara , Peterson Eric D. , Alexander Karen P. 
Published: November 2008

AbstractBackgroundAnemia is a purported risk factor for adverse outcomes, particularly among patients with cardiac disease. Although anemia at the time of discharge has been associated with poor functional status and survival, its impact over time is not clear.HypothesisAmong patients with significant coronary artery disease (CAD), anemia (hemoglobin < 11 g/dL) is prevalent, and is associated with poor physical function (PF) and survival over time.MethodsPatients with significant CAD at the time of cardiac catheterization (n = 1, 821) were enrolled into a single‐center, observational, and prospective study. All patients were followed for up to 1 y for clinical events and self‐reported PF. Prevalence of anemia at discharge and its' associations with outcomes over time were examined.ResultsAnemia at the time of discharge was very common (40.4%), and was associated with increased odds of death at 12 mo (odds ratio [OR] 1.55, 95% confidence interval [CI] 1.12–2.15), yet other clinical factors accompanying anemia accounted for this association (adjusted OR 1.13, 95% CI 0.79–1.62). Discharge anemia was also associated with significantly lower self‐reported PF at 6 and 12 mo (p < 0.05 for both); however, other clinical factors accompanying anemia also accounted for these associations.ConclusionsAlthough discharge anemia is highly prevalent, its association with adverse outcomes is largely explained by baseline patient characteristics. Further research is needed to clarify the relationship between anemia and outcomes in this population and to identify subpopulations that do not recover independently and for whom available therapies may be beneficial. Copyright © 2008 Wiley Periodicals, Inc.
Functional studies of an evolutionarily conserved, cytochrome b5 domain protein reveal a specific role in axonemal organisation and the general phenomenon of post‐division axonemal growth in trypanosomes
Authors: Farr Helen , Gull Keith 
Published: November 2008

AbstractEukaryotic cilia and flagella are highly conserved structures composed of a canonical 9+2 microtubule axoneme. Several recent proteomic studies of cilia and flagella have been published, including a proteome of the flagellum of the protozoan parasite Trypanosoma brucei. Comparing proteomes reveals many novel proteins that appear to be widely conserved in evolution. Amongst these, we found a previously uncharacterised protein which localised to the axoneme in T. brucei, and therefore named it Trypanosome Axonemal protein (TAX)‐2. Ablation of the protein using RNA interference in the procyclic form of the parasite has no effect on growth but causes a reduction in motility. Using transmission electron microscopy, various structural defects were seen in some axonemes, most frequently with microtubule doublets missing from the 9+2 arrangement. RNAi knockdown of TAX‐2 expression in the bloodstream form of the parasite caused defects in growth and cytokinesis, a further example of the effects caused by loss of flagellar function in bloodstream form T. brucei. In procyclic cells we used a new set of vectors to ablate protein expression in cells expressing a GFP:TAX‐2 fusion protein, which enabled us to easily quantify protein reduction and visualise axonemes made before and after RNAi induction. This establishes a useful generic technique but also revealed a specific observation that the new flagellum on the daughter trypanosome continues growth after cytokinesis. Our results provide evidence for TAX‐2 function within the axoneme, where we suggest that it is involved in processes linking the outer doublet microtubules and the central pair. Cell Motil. Cytoskeleton 2008. © 2008 Wiley‐Liss, Inc.
Mixed‐Model QSAR at the Glucocorticoid Receptor: Predicting the Binding Mode and Affinity of Psychotropic Drugs
Authors: Spreafico Morena , Ernst Beat , Lill Markus A. , Smiesko Martin , Vedani Angelo 
Published: November 2008

AbstractThe glucocorticoid receptor (GR) is a member of the nuclear receptor superfamily that affects immune response, development, and metabolism in target tissues. Glucocorticoids are widely used to treat diverse pathophysiological conditions, but their clinical applicability is limited by side effects. A prediction of the binding affinity toward the GR would be beneficial for identifying glucocorticoid‐mediated adverse effects triggered by drugs or chemicals. By identifying the binding mode to the GR using flexible docking (software Yeti) and quantifying the binding affinity through multidimensional QSAR (software Quasar), we validated a model family based on 110 compounds, representing four different chemical classes. The correlation with the experimental data (cross‐validated r2=0.702; predictive r2=0.719) suggests that our approach is suited for predicting the binding affinity of related compounds toward the GR. After challenging the model by a series of scramble tests, a consensus approach (software Raptor), and a prediction set, it was incorporated into our VirtualToxLab and used to simulate and quantify the interaction of 24 psychotropic drugs with the GR.
Universality in the two‐matrix model: a Riemann‐Hilbert steepest‐descent analysis
Authors: Duits Maurice , Kuijlaars Arno B. J. 
Published: November 2008

AbstractThe eigenvalue statistics of a pair (M1, M2) of n × n Hermitian matrices taken randomly with respect to the measure

can be described in terms of two families of biorthogonal polynomials. In this paper we give a steepest‐descent analysis of a 4 × 4 matrix‐valued Riemann‐Hilbert problem characterizing one of the families of biorthogonal polynomials in the special case W(y) = y4/4 and V an even polynomial. As a result, we obtain the limiting behavior of the correlation kernel associated to the eigenvalues of M1 (when averaged over M2) in the global and local regime as n → ∞ in the one‐cut regular case. A special feature in the analysis is the introduction of a vector equilibrium problem involving both an external field and an upper constraint. © 2008 Wiley Periodicals, Inc.
A detailed analysis of 3D subcellular signal localization
Authors: Pinidiyaarachchi Amalka , Zieba Agata , Allalou Amin , Pardali Katerina , Wählby Carolina 
Published: November 2008

AbstractDetection and localization of fluorescent signals in relation to other subcellular structures is an important task in various biological studies. Many methods for analysis of fluorescence microscopy image data are limited to 2D. As cells are in fact 3D structures, there is a growing need for robust methods for analysis of 3D data. This article presents an approach for detecting point‐like fluorescent signals and analyzing their subnuclear position. Cell nuclei are delineated using marker‐controlled (seeded) 3D watershed segmentation. User‐defined object and background seeds are given as input, and gradient information defines merging and splitting criteria. Point‐like signals are detected using a modified stable wave detector and localized in relation to the nuclear membrane using distance shells. The method was applied to a set of biological data studying the localization of Smad2‐Smad4 protein complexes in relation to the nuclear membrane. Smad complexes appear as early as 1 min after stimulation while the highest signal concentration is observed 45 min after stimulation, followed by a concentration decrease. The robust 3D signal detection and concentration measures obtained using the proposed method agree with previous observations while also revealing new information regarding the complex formation. © 2008 International Society for Advancement of Cytometry
A novel fluorescent cross‐reactive formylpeptide receptor/formylpeptide receptor‐like 1 hexapeptide ligand
Authors: Strouse J. Jacob , Young Susan M. , Mitchell Hugh D. , Ye Richard D. , Prossnitz Eric R. , Sklar Larry A. , Edwards Bruce S. 
Published: November 2008

AbstractFormylpeptide receptors (FPRs) are implicated in a variety of immunological and inflammatory response cascades. Further understanding of FPR‐family ligand interactions could play an integral role in biological and therapeutic discovery. Fluorescent reporter ligands for the family are desirable experimental tools for increased understanding of ligand/receptor interactions. The ligand binding affinity and fluorescent reporting activity of the peptide WK(FL)YMVm was explored though use of the high throughput HyperCyt® flow cytometric platform. Relative binding affinities of several known FPR and FPRL1 peptide ligands were compared in a duplex assay format. The fluorescent W‐peptide ligand, WK(FL)YMVm, proved to be a high‐affinity, cross‐reactive reporter ligand for the FPR/FPRL1 duplex assay. Ligand specificity was demonstrated for each receptor, with known, selective peptide ligands. The binding site specificity of the reporter ligand was further verified by a fluorescent confocal microscopy internalization experiment. The fluorescent peptide ligand WK(FL)YMVm binds with high affinity to both FPR and FPRL1. The differential affinities of known peptide ligands were observed with the use of this fluorescent probe in high throughput screening flow cytometry. © 2008 International Society for Advancement of Cytometry
CD25+ T cells induce Helicobacter pylori‐specific CD25− T‐cell anergy but are not required to maintain persistent hyporesponsiveness
Authors: Stuller Kathleen A. , Ding Hua , Redline Raymond W. , Czinn Steven J. , Blanchard Thomas G. 
Published: November 2008

AbstractThe gastric pathogen Helicobacter pylori infects over half the world's population. The lifelong infection induces gastric inflammation but the host fails to generate protective immunity. To study the lack of protective H. pylori immunity, CD4+CD25+ Treg cells were investigated for their ability to down‐regulate H. pylori‐specific CD4+CD25− cells in a murine model. CD25− lymphocytes from infected mice were hyporesponsive to antigenic stimulation in vitro even in the absence of CD25+ Treg cells unless treated with high‐dose IL‐2. Transfer of CD45RBhi naïve CD25− cells from infected mice into rag1−/− mice challenged with H. pylori resulted in severe gastritis and reduced bacterial loads, whereas transfer of CD45RBlo memory CD25− cells from H. pylori‐infected mice resulted in only mild gastritis and persistent infection. CD25− cells stimulated in the absence of CD25+ cells in rag1−/− mice promoted bacterial clearance, but lost this ability when subsequently transferred to WT mice harboring CD25+ cells. These results demonstrate that CD25+ cells induce anergy in CD25− cells in response to H. pylori infection but are not required to maintain hyporesponsiveness. In addition, CD25+ cells are able to suppress previously activated CD25− cells when responding to H. pylori challenge in vivo.
Copy number gain at 8q12.1‐q22.1 is associated with a malignant tumor phenotype in salivary gland myoepitheliomas
Authors: Vékony Hedy , Röser Kerstin , Löning Thomas , Ylstra Bauke , Meijer Gerrit A. , van Wieringen Wessel N. , van de Wiel Mark A. , Carvalho Beatriz , Kok Klaas , René Leemans C. , van der Waal Isaäc , Bloemena Elisabeth 
Published: November 2008

AbstractSalivary gland myoepithelial tumors are relatively uncommon tumors with an unpredictable clinical course. More knowledge about their genetic profiles is necessary to identify novel predictors of disease. In this study, we subjected 27 primary tumors (15 myoepitheliomas and 12 myoepithelial carcinomas) to genome‐wide microarray‐based comparative genomic hybridization (array CGH). We set out to delineate known chromosomal aberrations in more detail and to unravel chromosomal differences between benign myoepitheliomas and myoepithelial carcinomas. Patterns of DNA copy number aberrations were analyzed by unsupervised hierarchical cluster analysis. Both benign and malignant tumors revealed a limited amount of chromosomal alterations (median of 5 and 7.5, respectively). In both tumor groups, high frequency gains (≥20%) were found mainly at loci of growth factors and growth factor receptors (e.g., PDGF, FGF(R)s, and EGFR). In myoepitheliomas, high frequency losses (≥20%) were detected at regions of proto‐cadherins. Cluster analysis of the array CGH data identified three clusters. Differential copy numbers on chromosome arm 8q and chromosome 17 set the clusters apart. Cluster 1 contained a mixture of the two phenotypes (n = 10), cluster 2 included mostly benign tumors (n = 10), and cluster 3 only contained carcinomas (n = 7). Supervised analysis between malignant and benign tumors revealed a 36 Mbp‐region at 8q being more frequently gained in malignant tumors (P = 0.007, FDR = 0.05). This is the first study investigating genomic differences between benign and malignant myoepithelial tumors of the salivary glands at a genomic level. Both unsupervised and supervised analysis of the genomic profiles revealed chromosome arm 8q to be involved in the malignant phenotype of salivary gland myoepitheliomas. © 2008 Wiley‐Liss, Inc.
Liver X receptor mediates hepatitis B virus X protein–induced lipogenesis in hepatitis B virus–associated hepatocellular carcinoma #
Authors: Na Tae-Young , Shin Young Kee , Roh Kyung Jin , Kang Shin-Ae , Hong Il , Oh Sae Jin , Seong Je Kyung , Park Cheol Keun , Choi Yoon La , Lee Mi-Ock 
Published: November 2008

Abstract
Although hepatitis B virus X protein (HBx) has been implicated in abnormal lipid metabolism in hepatitis B virus (HBV)–associated hepatic steatosis, its underlying molecular mechanism remains unclear. Liver X receptor (LXR) plays an important role in regulating the expression of genes involved in hepatic lipogenesis. Here we demonstrate that LXRα and LXRβ mediate HBV-associated hepatic steatosis. We have found that HBx induces the expression of LXR and its lipogenic target genes, such as sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), and peroxisome proliferator-activated receptor, and this is accompanied by the accumulation of lipid droplets. RNA interference with LXR expression decreases the amount of lipid droplets as well as the expression of the lipogenic genes, and this indicates that HBx-induced lipogenesis is LXR-dependent. LXRα and HBx colocalize in the nucleus and are physically associated. HBx induces the transactivation function of LXRα by recruiting CREB binding protein to the promoter of the target gene. Furthermore, we have observed that expression of LXR is increased in the livers of HBx-transgenic mice. Finally, there is a significant increase in the expression of LXRβ (P = 0.036), SREBP-1c (P = 0.008), FAS, and stearoyl–coenyzme A desaturase-1 (P = 0.001) in hepatocellular carcinoma (HCC) in comparison with adjacent nontumorous nodules in human HBV-associated HCC specimens. Conclusion: Our results suggest a novel association between HBx and LXR that may represent an important mechanism explaining HBx-induced hepatic lipogenesis during HBV-associated hepatic carcinogenesis. (Hepatology 2009.)
Neuronal hyperactivity sustains the basal dendrites of immature dentate granule cells: Time‐lapse confocal analysis using hippocampal slice cultures
Authors: Nakahara Soichiro , Tamura Makoto , Matsuki Norio , Koyama Ryuta 
Published: November 2008

AbstractDendritic morphogenesis is an essential process for the establishment of proper neural circuitry. In the epileptic hippocampus, mature dentate granule cells (GCs) possess basal dendrites (BDs), which is abnormal and is assumed to contribute to seizure progression. However, there is a lack of direct time‐lapse evidence showing that neuronal hyperactivity regulates the dendritic development of GCs. In the present study, we carried out time‐lapse confocal analysis of the dendritic morphogenesis of GCs in hippocampal slice cultures that were prepared from postnatal 6‐day‐old (P6) rats. By electroporating membrane‐targeted green fluorescent protein at 5 days in vitro (DIV), we found that most of the Prox1‐positive and calbindin‐negative immature GCs possessed several BDs and filopodia‐rich apical dendrites at 7 DIV. BDs were gradually eliminated from 7 to 9 DIV, and they completely vanished at 14 DIV in all the GCs examined. However, most BDs failed to retract from 7 to 9 DIV, when the GABAA receptor antagonist picrotoxin was chronically applied to induce epileptic conditions in the cultures. These effects were blocked by coapplying tetrodotoxin, a sodium channel blocker, thus convincing us that neuronal hyperactivity contributes to the maintenance of BDs. Further, in the picrotoxin‐treated cultures, most of the GCs persistently exhibited several BDs even after 14 DIV. In contrast, neither the progressive pruning of the filopodia nor the branch dynamics of the apical dendrites during the culture periods was affected by picrotoxin. These results, for the first time, provide us with direct evidence that neuronal hyperactivity contributes to the stability of pre‐existing BDs. © 2008 Wiley‐Liss, Inc.