bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Chromatographic 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

Vitamin 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

Background

Anemia 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.

Hypothesis

Among 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.

Methods

Patients 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.

Results

Anemia 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.

Conclusions

Although 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

Eukaryotic 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

The 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

The 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

Detection 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

Formylpeptide 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

The 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

Salivary 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

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

Dendritic 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.
Flavonoid intake and ovarian cancer risk in a population‐based case‐control study
Authors: Gates Margaret A. , Vitonis Allison F. , Tworoger Shelley S. , Rosner Bernard , Titus‐Ernstoff Linda , Hankinson Susan E. , Cramer Daniel W.
Published: November 2008

Several recent studies have evaluated the association between dietary flavonoid intake and ovarian cancer risk, and all reported significant or suggestive inverse associations with certain flavonoids or flavonoid subclasses; however, most of these studies were small to moderate in size. We, therefore, examined this association in a large, population‐based case‐control study. We calculated intake of 5 common dietary flavonoids (myricetin, kaempferol, quercetin, luteolin, and apigenin), as well as total intake of these flavonoids, for 1,141 cases and 1,183 frequency‐matched controls. We used unconditional logistic regression to estimate the relative risk (RR) of ovarian cancer for each quintile of flavonoid intake when compared with the lowest quintile. We did not observe an association between total flavonoid intake and ovarian cancer risk. The multivariable‐adjusted RR for the highest versus lowest quintile of total flavonoid intake was 1.06 (95% confidence interval [CI] = 0.78–1.45). In analyses of each individual flavonoid, only intake of apigenin was associated with a borderline significant decrease in risk (RR, highest vs. lowest quintile = 0.79, 95% CI = 0.59–1.06; p‐trend = 0.26), and this association was significant after adjustment for intake of the other 4 individual flavonoids (comparable RR = 0.72, 95% CI = 0.53–0.98; p‐trend = 0.09). These results provide limited support for an association between flavonoid intake and ovarian cancer risk. However, given the findings of previous studies and the biologic plausibility of this association, additional studies are warranted. © 2008 Wiley‐Liss, Inc.
Investigating the role of Aurora kinases in RAS signaling
Authors: Kosik Audrey , Bekier Michael E. , Katusin Jamie D. , Kaur Harpreet , Zhou Xiaofeng , Diakonova Maria , Chadee Deborah N. , Taylor William R.
Published: November 2008

Activating ras mutations are frequently found in malignant tumors of the pancreas, colon, lung and other tissues. RAS activates a number of downstream pathways that ultimately cause cellular transformation. Several recent studies suggested that one of those pathways involves Aurora kinases. Overexpression of Aurora‐B kinase can augment transformation by oncogenic RAS, however the mechanism was not determined. The cooperative effect of high levels of Aurora kinase is important since this kinase is frequently overexpressed in human tumors. We have used two Aurora kinase inhibitors to test their effect on RAS signaling. We find that these inhibitors have no effect on the phosphorylation of MEK1/2 or MAPK in response to RAS. Furthermore, inhibiting Aurora kinases in human cancer cells with or without activated RAS did not change the length of the cell cycle nor induce apoptosis suggesting that these kinases do not play a direct role in these key cellular responses to activated RAS. Overexpression of Aurora B can cause cells to become polyploid. Also, inducing polyploidy with cytochalasin D was reported to induce neoplastic transformation, suggesting that Aurora overexpression may cooperate with RAS indirectly by inducing polyploidy. We find that inducing polyploidy with cytochalasin D or blebbistatin does not enhance transformation by oncogenic RAS. Our observations argue against a direct role for Aurora kinases in the RAS‐MAPK pathway, and suggest that the polyploid state does not enhance transformation by RAS. J. Cell. Biochem. 106: 33–41, 2009. © 2008 Wiley‐Liss, Inc.
In embryonic chicken erythrocytes actively transcribed alpha globin genes are not associated with the nuclear matrix
Authors: Iarovaia O.V. , Borounova V.V. , Philonenko E.S. , Kantidze O.L. , Vassetzky Y.S. , Razin S.V.
Published: November 2008

The spatial organization of a 250 Kb region of chicken chromosome 14, which includes the alpha globin gene cluster, was studied using in situ hybridization of a corresponding BAC probe with nuclear halos. It was found that in non‐erythroid cells (DT40) and cultured erythroid cells of definite lineage (HD3) the genomic region under study was partially (DT40 cells) or fully (HD3 cells) associated with the nuclear matrix. In contrast, in embryonic red blood cells (10‐day RBC) the same area was located in the crown of DNA loops surrounding the nuclear matrix, although both globin genes and surrounding house‐keeping genes were actively transcribed in these cells. This spatial organization was associated with the virtual absence of RNA polymerase II in nuclear matrices prepared from 10‐day RBC. In contrast, in HD3 cells a significant portion of RNA polymerase II was present in nuclear matrices. Taken together, these observations suggest that in embryonic erythroid cells transcription does not occur in association with the nuclear matrix. J. Cell. Biochem. 106: 170–178, 2009. © 2008 Wiley‐Liss, Inc.
Using support vector machines for prediction of protein structural classes based on discrete wavelet transform
Authors: Qiu Jian‐Ding , Luo San‐Hua , Huang Jian‐Hua , Liang Ru‐Ping
Published: November 2008

The prediction of secondary structure is a fundamental and important component in the analytical study of protein structure and functions. How to improve the predictive accuracy of protein structural classification by effectively incorporating the sequence‐order effects is an important and challenging problem. In this study, a new method, in which the support vector machine combines with discrete wavelet transform, is developed to predict the protein structural classes. Its performance is assessed by cross‐validation tests. The predicted results show that the proposed approach can remarkably improve the success rates, and might become a useful tool for predicting the other attributes of proteins as well. © 2008 Wiley Periodicals, Inc. J Comput Chem 2009
Galanin inhibition of voltage‐dependent Ca2+influx in rat cultured myenteric neurons is mediated by galanin receptor 1
Authors: Anselmi Laura , Stella Salvatore L. , Brecha Nicholas C. , Sternini Catia
Published: November 2008

Galanin activates three receptors, the galanin receptor 1 (GalR1), GalR2, and GalR3. In the gastrointestinal tract, GalR1 mediates the galanin inhibition of cholinergic transmission to the longitudinal muscle and reduction of peristalsis efficiency in the small intestine. Galanin has also been shown to inhibit depolarization‐evoked Ca2+increases in cultured myenteric neurons. Because GalR1 immunoreactivity is localized to cholinergic myenteric neurons, we hypothesized that this inhibitory action of galanin on myenteric neurons is mediated by GalR1. We investigated the effect of galanin 1‐16, which has high affinity for GalR1 and GalR2, in the presence or absence of the selective GalR1 antagonist, RWJ‐57408, and of galanin 2‐11, which has high affinity for GalR2 and GalR3, on Ca2+influx through voltage‐dependent Ca2+channels in cultured myenteric neurons. Myenteric neurons were loaded with fluo‐4 and depolarized by high K+concentration to activate voltage‐dependent Ca2+channels. Intracellular Ca2+levels were quantified with confocal microscopy. Galanin 1‐16 (0.01–1 μM) inhibited the depolarization‐evoked Ca2+increase in a dose‐dependent manner with an EC50of 0.172 μM. The selective GalR1 antagonist, RWJ‐57408 (10 μM), blocked the galanin 1‐16 (1 μM)‐mediated inhibition of voltage‐dependent Ca2+channel. By contrast, the GalR2/GalR3 agonist, galanin 2‐11 did not affect the K+‐evoked Ca2+influx in myenteric neurons. GalR1 immunoreactivity was localized solely to myenteric neurons in culture, as previously observed in intact tissue. These findings indicate that the inhibition of depolarization‐evoked Ca2+influx in myenteric neurons in culture is mediated by GalR1 and confirm the presence of functional GalR1 in the myenteric plexus. This is consonant with the hypothesis that GalR1 mediates galanin inhibition of transmitter release from myenteric neurons. © 2008 Wiley‐Liss, Inc.
Nimodipine inhibits TMB‐8 potentiation of AMPA‐induced hippocampal neurodegeneration
Authors: Bernal Fabián , Petegnief Valerie , Rodríguez Manuel José , Ursu Gloria , Pugliese Marco , Mahy Nicole
Published: November 2008

Human cerebral calcification has been related to deregulation of intracellular calcium homeostasis. In rat basal ganglia, nimodipine and TMB‐8, two commonly used calcium antagonists, worsen the chronic AMPA‐induced lesion, whereas only nimodipine potentiates calcification. To investigate whether similar effects are present in the hippocampus, AMPA dose–response and calcium movement blockade were performed. A dose‐related increase of both hippocampal lesion and calcification was evident in a saturable mode, mostly different from the continuous globus pallidus response previously observed. The value of 2.7 nmol AMPA, selected as yielding 60% of maximum calcification, was coinjected with nimodipine or/and TMB‐8 to determine their influence on tissue damage. TMB‐8 increased the AMPA lesion in terms of calcified area, and nimodipine reversed this increase, with no effect alone. These results, divergent from those for the globus pallidus, reveal differences in extra‐ and intracellular calcium movement between the two neurodegenerative processes. Future work focused on other brain areas is required to understand how control of calcium stores may influence neurodegenerative disease evolution. © 2008 Wiley‐Liss, Inc.
Multiclass discrimination of cervical precancers using Raman spectroscopy
Authors: Kanter Elizabeth M. , Majumder Shovan , Vargis Elizabeth , Robichaux‐Viehoever Amy , Kanter Gary J. , Shappell Heidi , Jones III Howard W. , Mahadevan‐Jansen Anita
Published: November 2008

Raman spectroscopy has the potential to differentiate among the various stages leading to high‐grade cervical cancer such as normal, squamous metaplasia, and low‐grade cancer. For Raman spectroscopy to successfully differentiate among the stages, an applicable statistical method must be developed. Algorithms like linear discriminant analysis (LDA) are incapable of differentiating among three or more types of tissues. We developed a novel statistical method combining the method of maximum representation and discrimination feature (MRDF) to extract diagnostic information with sparse multinomial logistic regression (SMLR) to classify spectra based on nonlinear features for multiclass analysis of Raman spectra. We found that high‐grade spectra classified correctly 95% of the time; low‐grade data classified correctly 74% of the time, improving sensitivity from 92 to 98% and specificity from 81 to 96% suggesting that MRDF with SMLR is a more appropriate technique for categorizing Raman spectra. SMLR also outputs a posterior probability to evaluate the algorithm's accuracy. This combined method holds promise to diagnose subtle changes leading to cervical cancer. Copyright © 2008 John Wiley & Sons, Ltd.
Multiphysics Modeling of Electrochemomechanically Smart Microgels Responsive to Coupled pH/Electric Stimuli
Authors: Li Hua , Luo Rongmo , Lam Khin Yong
Published: November 2008

A multiphysics model is developed to simulate the responsive behavior of smart pH‐/electric‐sensitive hydrogels when immersed into pH buffer solution and subjected to an externally applied electric field, which is termed the MECpHe model. Comparison with experimental data shows the MECpHe model to be accurate and stable. The influence of the externally applied electric voltage is discussed with respect to the distribution of diffusive ionic species and the displacement of the hydrogel strip. The influences of initial charge density and ionic strength on the swelling ratio and the bending deformation of the microgel strip are studied.

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Successive Chain‐Growth Condensation Polymerization for the Synthesis of Well‐Defined Diblock Copolymers of Aromatic Polyamide and Aromatic Polyether
Authors: Yokoyama Akihiro , Masukawa Tomohiro , Yamazaki Yuka , Yokozawa Tsutomu
Published: November 2008

Well‐defined diblock condensation copolymers composed of an aromatic polyamide and an aromatic polyether have been synthesized by means of successive chain‐growth condensation polymerizations. Polymerization of a polyamide monomer with an orthogonally difunctional initiator is accompanied with side reactions. On the other hand, polymerization with a monofunctional initiator afforded well‐defined polyamide, which has been converted into a macroinitiator by introduction of a terminal 4‐fluorobenzophenone unit. Well‐defined diblock copolymers are obtained by polymerization of a polyether monomer in the presence of this macroinitiator.

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Bowel movement frequency in late‐life and substantia nigra neuron density at death
Authors: Petrovitch Helen , Abbott Robert D. , Ross G. Webster , Nelson James , Masaki Kamal H. , Tanner Caroline M. , Launer Lenore J. , White Lon R.
Published: November 2008

Constipation is associated with future risk of Parkinson's disease (PD) and with incidental Lewy bodies (LB) in the locus ceruleus or substantia nigra (SN). Our purpose is to examine the independent association between bowel movement frequency in late‐life and postmortem SN neuron density. Bowel movement frequency was assessed in the Honolulu‐Asia Aging Study from 1991 to 1993 in 414 men aged 71 to 93 years with later postmortem evaluations. Brains were examined for LB in the SN and locus ceruleus and neurons were counted in four quadrants from a transverse section of SN. In nonsmokers, neuron densities (counts/mm2) for men with >1, 1, and <1 bowel movement daily were 18.5, 18.8, 10.1 (P < 0.001) for dorsomedial; 15.3, 16.4, 10.2 (P < 0.03) for ventromedial; and 18.6, 18.3, 10.9 (P = 0.011) for ventrolateral quadrants. Relationships were not significant in the dorsolateral quadrant or in any quadrant among smokers. After adjustment for age, time to death, coffee drinking, tricep skinfold thickness, excessive daytime sleepiness, cognitive function, PD, and incidental LB, density ratios in nonsmokers with 1 or more bowel movement(s) daily were significantly higher compared to those with <1 daily. Constipation is associated with low SN neuron density independent of the presence of LB. © 2008 Movement Disorder Society
A CPW‐fed two‐arm spiral slot antenna
Authors: Wang Chien‐Jen , Wu Jin‐Wei
Published: November 2008

A wideband coplanar waveguide (CPW)‐fed two‐arm spiral slot antenna without a balun circuit is presented in this article. Phase progressions at arm ports are realized through the coplanar waveguide excitations. A detailed characterization of all antenna components and parameters is provided along with guidelines and recommendations for broad bandwidth and small reflection. Variations of the impedance matching due to the turn numbers, the ground width separated between two neighboring turns and the slot width are tested and studied. The measured impedance bandwidth of a S11 ≤ 10 dB ranges from 1.63 to 8 GHz and covers most of the commercial wireless communication systems, such as DCS, PCS, IMT‐2000, WLAN, Bluetooth, and HIPERLAN. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 222–225, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23947
Electromagnetic scattering from inhomogeneous impedance periodic rough surfaces by transform technique
Authors: Serkan Tezel Necmi
Published: November 2008

In this study, electromagnetic scattering from inhomogeneous impedance periodic surfaces have been solved by means of transformation of problem into equivalent problem, that is, scattering from plane represented by transformed boundary condition. Transformed boundary condition is determined by functions of the shape and impedance of the surface. Then, transformed equivalent problem is solved by means of series expansion method using Floquet modes. This transformation makes the problem simple formulation and computational effectively without involving calculation of slowly converging periodic Green's function. Results and computational times obtained by transform method and those obtained by Method of Moment (MoM) technique are compared. Good agreements are observed in results. It is also observed that transform method needs much less computational time than MoM method.© 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 116–119, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23954
Self‐heterodyne diode mixer with GCPW using thin film process at 60 GHz
Authors: Choi Seung‐Woon , Kim Yong‐Hoon
Published: November 2008

A self‐heterodyne diode mixer is proposed using thin film process based on alumina substrate at 60 GHz in conjunction with grounded coplanar waveguide transition. To down‐convert both very low RF and LO signals received simultaneously from transmitter for self‐heterodyne communication scheme, the proposed mixer adapted with the knee voltage bias condition of 0.65 [V] improves its mixing efficiency significantly. The designed SHM shows the conversion loss of −15.13 dB at RF and LO frequencies of 60.565 and 59.01 GHz, respectively, with both input powers of −15 dBm and it also can defines IMD free input dynamic range as −30 dBm. The measured return losses satisfies with more than 20 dB and 9 dB for RF/LO input and IF output port, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 13–15, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23959
Numerical investigation on the performance of a septum polarizer by inserting additional stubs for its applications in the CP horn antennas
Authors: Chou Hsi‐Tseng , Lee Wen‐Wen
Published: November 2008

A septum polarizer influenced by inserting short stubs inside the waveguide is studied. Several configurations of stub insertion are investigated to exhibit their physical behaviors. Numerical results show that proper stub insertions may provide additional freedoms to optimally design the polarizer with a better return loss and a flexible phase tuning, which is particularly useful to compensate the deficiency of an imperfect horn antenna to radiate good circularly polarized fields. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 269–273, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23982
Experimental investigation into femtosecond fiber ring laser with passive mode locking
Authors: Xie Xiaoping , Zhang Jian‐Guo , Wen Yu , Zhao Wei
Published: November 2008

A passively mode‐locked Er3+‐doped fiber ring laser is experimentally investigated, with the emphasis on its practical design by considering the effects of ring cavity length, pumping light power, and optical amplification on the femtosecond optical pulses obtained. It is shown that the designed fiber ring laser can operate at the center wavelength of 1550 nm to produce a train of periodic optical pulses with full width at half maximum (FWHM) of 270 fs, repetition frequency of 20 MHz, and average output optical power of 146 μW. The resulting femtosecond optical pulses are then amplified by using three kinds of Er3+‐doped optical fibers with different lengths and Er3+‐doped concentrations, respectively, while employing the same pumping laser. In the experiments, both the FWHM of amplified optical pulses and the amplifier gain are measured under different conditions. The optimization of optical pulse width is also carried out in terms of pumping light power. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 63–67, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23985
A high‐performance log‐periodic dipole‐antenna for radio frequency interference monitoring system at the Sardinia Radio Telescope
Authors: Bolli Pietro , Messina Filippo , Pisanu Tonino , Riminesi Cristiano
Published: November 2008

The Italian National Institute for Astrophysics (INAF) is currently involved in the construction of the Sardinia Radio Telescope (SRT). The radio observatory will be equipped with an accurate and sensitive Radio Frequency Interference (RFI) monitoring system, aimed to control if the radio bands allocated to the Radio Astronomy Service are actually free of interferences. This article describes a Log‐Periodic Dipole‐Antenna (LPDA) designed for such a system, operating with very high‐performance in L‐band and S‐band. The LPDA, consisting of 38‐elements, achieves a gain higher than 11 dBi with peaks up to 13 dBi and good impedance match in the whole band of interest: 1.2–2.5 GHz. The antenna was designed, manufactured, and finally tested in an anechoic chamber; the results for each step will be described in this article. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 132–136, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23997
A compact quasi‐elliptic bandpass filter using coupled dual quasi‐lumped LC resonators
Authors: Li Lin , Li Zheng‐Fan , Wei Qi‐fu
Published: November 2008

This letter proposes a compact microstrip bandpass filter using coupled dual quasi‐lumped LC resonators. With the proposed topology, two transmission zeros are generated at both low and high stopband near the passband to create quasi‐elliptic response. A filter sample is designed and fabricated to provide an experimental verification. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 158–160, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24009
Structure determination of salisomide and salisoflavan, two new secondary metabolites from Salsola imbricata, by 1D and 2D NMR spectroscopy
Authors: Saleem Muhammad , Akhter Naseem , Shaiq Ali Muhammad , Nazir Mamona , Riaz Naheed , Moazzam Muhammad , Arshad Muhammad , Jabbar Abdul
Published: November 2008

Chromatographic analysis of the alcoholic extract from Salsola imbricata yielded two new secondary metabolites, salisomide (1) and salisoflavan (2). Their structures were established with the help of spectroscopic techniques including COSY, HMQC and HMBC NMR experiments. Copyright © 2008 John Wiley & Sons, Ltd.
A uniform nodal strain tetrahedron with isochoric stabilization
Authors: Gee M. W. , Dohrmann C. R. , Key S. W. , Wall W. A.
Published: November 2008

A stabilized node‐based uniform strain tetrahedral element is presented and analyzed for finite deformation elasticity. The element is based on linear interpolation of a classical displacement‐based tetrahedral element formulation but applies nodal averaging of the deformation gradient to improve mechanical behavior, especially in the regime of near‐incompressibility where classical linear tetrahedral elements perform very poorly. This uniform strain approach adopted here exhibits spurious modes as has been previously reported in the literature. We present a new type of stabilization exploiting the circumstance that the instability in the formulation is related to the isochoric strain energy contribution only and we therefore present a stabilization based on an isochoric–volumetric splitting of the stress tensor. We demonstrate that by stabilizing the isochoric energy contributions only, reintroduction of volumetric locking through the stabilization can be avoided. The isochoric–volumetric splitting can be applied for all types of materials with only minor restrictions and leads to a formulation that demonstrates impressive performance in examples provided. Copyright © 2008 John Wiley & Sons, Ltd.
Inflammatory rather than infectious insults play a role in exocrine tissue damage in a mouse model for coxsackievirus B4‐induced pancreatitis
Authors: De Palma Armando M , Thibaut Hendrik J , Li Sandra , Van Aelst Ilse , Dillen Chris , Swinnen Melissa , Verbeken Erik , Neyts Johan , Opdenakker Ghislain
Published: November 2008

Infection with coxsackievirus B4 (CVB4) may result in an acute severe necrotizing pancreatitis that mostly remains restricted to the acini of the exocrine parenchyma. The mechanisms responsible for this tissue damage, however, remain poorly understood. We here report that COAM, a polyanionic carboxylic acid, provides marked protection against CVB4‐induced pancreatitis in a mouse model. Despite the fact that COAM largely reduced disease severity, as detected by serum amylase and lipase levels as well as histologically, titres of replicating CVB4 in the pancreas were virtually unaffected. COAM treatment diminished the infection‐associated MMP‐9 levels and also resulted in a decreased influx of neutrophils into the infected pancreas. Moreover, we demonstrate that titres of replicating virus in the pancreas did not directly correlate with the severity of disease. In conclusion, our data suggest that immunopathological effects, rather than direct virus‐induced destruction, are responsible for the damage to acinar tissue in CVB4‐induced pancreatitis. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Bone marrow minimal disseminated disease (MDD) and minimal residual disease (MRD) in childhood T‐cell lymphoblastic lymphoma stage III, detected by flow cytometry (FC) and real‐time quantitative polymerase chain reaction (RQ‐PCR)
Authors: Stark Batia , Avigad Smadar , Luria Drorit , Manor Sigal , Reshef‐Ronen Tali , Avrahami Gali , Yaniv Isaac
Published: November 2008

Background

Despite overlapping features of T‐cell lymphoblastic lymphoma (T‐LLy) and T‐cell acute lymphoblastic leukemia (T‐ALL), which respond favorably to T‐ALL treatment, clinical and biological differences exist. We retrospectively assessed the prevalence of submicroscopic bone marrow (BM) minimal disseminated disease (MDD) at diagnosis and the early response to treatment (minimal residual disease—MRD) and their prognostic significance in 17 children with stage III T‐LLy treated according to Berlin‐Frankfurt‐Munster (BFM) non‐Hodgkin lymphoma protocols.

Procedure

Four‐color flow cytometry (FC) was used for lymphoma associated immunophenotype and real‐time quantitative polymerase chain reaction (RQ‐PCR) for T‐cell receptor (TCR β/δ/γ) gene rearrangements with at least 0.01% sensitivity.

Results

Two markers per patient were identified in all cases using FC and in 80% using RQ‐PCR. BM MDD at diagnosis of ≥0.01% was detected by FC and RQ‐PCR in 88% and 80% of patients, respectively, and by at least one of the methods in all patients. A significant correlation was achieved between the methods by Pearson correlation analysis (P = 0.004). MRD levels significantly decreased to very low levels on day 33 in 9 out of 10 patients studied. The only patient that remained positive relapsed.

Conclusions

MDD was prevalent in stage III T‐LLy, for which we could not prove a prognostic significance in the context of ALL‐like treatment. This study shows that both FC and RQ‐PCR methods are efficient for MDD and MRD analyses in T‐LLy. Pediatr Blood Cancer 2009;52:20–25. © 2008 Wiley‐Liss, Inc.
Gender affects survival for medulloblastoma only in older children and adults: A study from the surveillance epidemiology and end results registry
Authors: Curran Emily K. , Sainani Kristin L. , Le Gem M. , Propp Jennifer M. , Fisher Paul G.
Published: November 2008

Background

Males have a higher incidence of medulloblastoma (MB) than females, but the effect of gender on survival is unclear. Studies have yielded conflicting results, possibly due to small sample sizes or differences in how researchers defined MB. We aimed to determine the effect of gender on survival in MB using a large data set and strict criteria for defining MB.

Procedure

A sample of 1,226 subjects (763 males and 463 females) was identified from 1973 to 2002, using the Surveillance Epidemiology and End Results (SEER‐9) registry. MB was strictly defined to exclude non‐cerebellar embryonal tumors (primitive neuro‐ectodermal tumors). Because children <3 years of age are known to have worse survival, patients were stratified by age <3 years at diagnosis (95 males, 82 females) and >3 years (668 males, 381 females).

Results

Overall, there was no significant difference in survival between males and females (log rank P = 0.22). However, among subjects >3 years, females had significantly greater survival than males (log rank P = 0.02). In children <3 years, there was a non‐significant trend toward poorer survival in females (median survival: males 27 months, females 13 months; log rank P = 0.24). This interaction between age group and gender was statistically significant (P = 0.03).

Conclusion

Females with MB have a survival advantage only in subjects >3 years. In children <3 years, females may even have poorer outcome. The effect of gender on survival and incidence in MB warrants additional biologic investigation, and may differ in very young children with MB. Pediatr Blood Cancer 2009;52:60–64. © 2008 Wiley‐Liss, Inc.