bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological instability of a non-equilibrium ice–colloid interface
Authors: Peppin S. S. L. , Majumdar A. , Wettlaufer J. S.
Published: October 2009

We assess the morphological stability of a non-equilibrium ice–colloidal suspension interface, and apply the theory to bentonite clay. An experimentally convenient scaling is employed that takes advantage of the vanishing segregation coefficient at low freezing velocities, and when anisotropic kinetic effects are included, the interface is shown to be unstable to travelling waves. The potential for travelling-wave modes reveals a possible mechanism for the polygonal and spiral ice lenses observed in frozen clays. A weakly nonlinear analysis yields a long-wave evolution equation for the interface shape containing a new parameter related to the highly nonlinear liquidus curve in colloidal systems. We discuss the implications of these results for the frost susceptibility of soils and the fabrication of microtailored porous materials.
The application of enzyme reaction, nonlinear diffusion models to the malting process
Authors: Fowkes Neville , O’Brien Ricky
Published: October 2009

We extend the classic Michaelis–Menten kinetics model of the enzyme-mediated conversion of substrate to product to situations in which the enzymes need to diffuse through the underlying structure to reach unconverted substrate and in which the diffusivity is greatly increased by the conversion. The work was prompted by the study of the germination and modification of barley grain that occurs during malting, but is broadly applicable. A nonlinear diffusion, enzyme reaction model of the modification process is proposed and some accurate approximate analytic solutions are derived. We find that a sharp modification front is set up between the modified and the unmodified regions of the barley grain. This front propagates with an almost constant speed through the medium and our findings are consistent with the available experimental observations.
Rapid inexpensive genome-wide association using pooled whole blood
Authors: Craig Jamie E. , Hewitt Alex W. , McMellon Amy E. , Henders Anjali K. , Ma Lingjun , Wallace Leanne , Sharma Shiwani , Burdon Kathryn P. , Visscher Peter M. , Montgomery Grant W. , MacGregor Stuart
Published: October 2009

Genome-wide association studies (GWAS) have now successfully identified important genetic variants associated with many human traits and diseases. The high cost of genotyping arrays in large data sets remains the major barrier to wider utilization of GWAS. We have developed a novel method in which whole blood from cases and controls, respectively, is pooled prior to DNA extraction for genotyping. We demonstrate proof of principle by clearly identifying the associated variants for eye color, age-related macular degeneration, and pseudoexfoliation syndrome in cohorts not previously studied. Blood pooling has the potential to reduce GWAS cost by several orders of magnitude and dramatically shorten gene discovery time. This method has profound implications for translation of modern genetic approaches to a multitude of diseases and traits yet to be analyzed by GWAS, and will enable developing nations to participate in GWAS.
The Association of the Arabidopsis Actin-Related Protein2/3 Complex with Cell Membranes Is Linked to Its Assembly Status But Not Its Activation
Authors: Kotchoni Simeon O. , Zakharova Taya , Mallery Eileen L. , Le Jie , El-Assal Salah El-Din , Szymanski Daniel B.
Published: October 2009

In growing plant cells, the combined activities of the cytoskeleton, endomembrane, and cell wall biosynthetic systems organize the cytoplasm and define the architecture and growth properties of the cell. These biosynthetic machineries efficiently synthesize, deliver, and recycle the raw materials that support cell expansion. The precise roles of the actin cytoskeleton in these processes are unclear. Certainly, bundles of actin filaments position organelles and are a substrate for long-distance intracellular transport, but the functional linkages between dynamic actin filament arrays and the cell growth machinery are poorly understood. The Arabidopsis (Arabidopsis thaliana) “distorted group” mutants have defined protein complexes that appear to generate and convert small GTPase signals into an Actin-Related Protein2/3 (ARP2/3)-dependent actin filament nucleation response. However, direct biochemical knowledge about Arabidopsis ARP2/3 and its cellular distribution is lacking. In this paper, we provide biochemical evidence for a plant ARP2/3. The plant complex utilizes a conserved assembly mechanism. ARPC4 is the most critical core subunit that controls the assembly and steady-state levels of the complex. ARP2/3 in other systems is believed to be mostly a soluble complex that is locally recruited and activated. Unexpectedly, we find that Arabidopsis ARP2/3 interacts strongly with cell membranes. Membrane binding is linked to complex assembly status and not to the extent to which it is activated. Mutant analyses implicate ARP2 as an important subunit for membrane association.
Multiple Biochemical and Morphological Factors Underlie the Production of Methylketones in Tomato Trichomes
Authors: Ben-Israel Imri , Yu Geng , Austin Michael B. , Bhuiyan Nazmul , Auldridge Michele , Nguyen Thuong , Schauvinhold Ines , Noel Joseph P. , Pichersky Eran , Fridman Eyal
Published: October 2009

Genetic analysis of interspecific populations derived from crosses between the wild tomato species Solanum habrochaites f. sp. glabratum, which synthesizes and accumulates insecticidal methylketones (MK), mostly 2-undecanone and 2-tridecanone, in glandular trichomes, and cultivated tomato (Solanum lycopersicum), which does not, demonstrated that several genetic loci contribute to MK metabolism in the wild species. A strong correlation was found between the shape of the glandular trichomes and their MK content, and significant associations were seen between allelic states of three genes and the amount of MK produced by the plant. Two genes belong to the fatty acid biosynthetic pathway, and the third is the previously identified Methylketone Synthase1 (MKS1) that mediates conversion to MK of β-ketoacyl intermediates. Comparative transcriptome analysis of the glandular trichomes of F2 progeny grouped into low- and high-MK-containing plants identified several additional genes whose transcripts were either more or less abundant in the high-MK bulk. In particular, a wild species-specific transcript for a gene that we named MKS2, encoding a protein with some similarity to a well-characterized bacterial thioesterase, was approximately 300-fold more highly expressed in F2 plants with high MK content than in those with low MK content. Genetic analysis in the segregating population showed that MKS2's significant contribution to MK accumulation is mediated by an epistatic relationship with MKS1. Furthermore, heterologous expression of MKS2 in Escherichia coli resulted in the production of methylketones in this host.
Aspherical electron scattering factors and their parameterizations for elements from H to Xe
Authors: Zheng Jin-Cheng , Wu Lijun , Zhu Yimei
Published: October 2009

The formalism for, and the values of, aspherical electron scattering factors using relativistic wavefunctions are presented. The parameterizations of electron form factors valid for a full range of scattering vectors from 0.0 to 6.0 Å−1were obtained for atoms with atomic number 1 (H) to 54 (Xe) by fitting a linear combination of Gaussian functions. Eight Gaussians were needed to achieve high-quality fittings. The tabulated aspherical p- and d-orbital parameters are invaluable for probing orbital electrons and calculating high-resolution electron microscopy images and diffractions, especially those involving interfaces and defects.
PeckCryst: a program for structure determination from powder diffraction data using a particle swarm optimization algorithm
Authors: Feng Zhen Jie , Dong Cheng , Jia Rong Rong , Deng Xiao Di , Cao Shi Xun , Zhang Jin Cang
Published: October 2009

PeckCrysthas been developed for the solution of molecular crystal structures from powder diffraction data using a particle swarm optimization (PSO) algorithm. In order to speed up the calculation process, a modified BraggRfactor is used as the evaluation function for the PSO algorithm. The effectiveness of the program has been tested by solving four known structures from powder diffraction data. A Python script is also provided for convenient repetitive running ofPeckCryst. The distributedPeckCrystprogram is freely available from the authors upon request, and runs on Linux and Windows (32- and 64-bit) platforms.
Towards extracting the charge density from normal-resolution data
Authors: Dittrich B. , Hübschle C. B. , Holstein J. J. , Fabbiani F. P. A.
Published: October 2009

The limiting factor for charge-density studies is crystal quality. Although area detection and low temperatures enable redundant data collection, only compounds that form well diffracting single crystals without disorder are amenable to these studies. If thermal motion and electron density ρ(r) were de-convoluted, multipole parameters could also be refined with lower-resolution data, such as those commonly collected for macromolecules. Using the invariom database for first refining conventional parameters (x,y,zand atomic displacement parameters), de-convolution can be achieved. In a subsequent least-squares refinement of multipole parameters only, information on the charge density becomes accessible also for data not fulfilling charge-density requirements. A critical aspect of this procedure is the missing information on the correlation between refined and non-refined parameters. This correlation is investigated in detail by comparing a full multipole refinement on high-resolution and a blocked refinement on `normal-resolution' data sets of ciprofloxacin hexahydrate. Topological properties and dipole moments are shown to be in excellent agreement for the two refinements. A `normal-resolution' data set of ciprofloxacin hydrochloride 1.4-hydrate is also evaluated in this manner.
Structural characterization of manganese-substituted nanocrystalline zinc oxide using small-angle neutron scattering and high-resolution transmission electron microscopy
Authors: Roy B. , Karmakar B. , Bahadur J. , Mazumder S. , Sen D. , Pal M.
Published: October 2009

A series of zinc oxide (ZnO) nanoparticles, substituted with manganese di-oxide, have been synthesized through a modified ceramic route using urea as a fuel. X-ray diffraction and high-resolution transmission electron microscopy studies indicate that the sizes of the ZnO particles are of nanometer dimension. Particles remain as single phase when the doping concentration is below 15 mol%. Small-angle neutron scattering indicates fractal-like agglomerates of these nanoparticles in powder form. The size distributions of the particles have been estimated from scattering experiments as well as microscopy studies. The average particle size estimated from small-angle scattering experiments was found to be somewhat more than that obtained from X-ray diffraction or electron microscopy measurement.
The crystal structure of perdeuterated methanol monoammoniate (CD3OD·ND3) determined from neutron powder diffraction data at 4.2 and 180 K
Authors: Fortes A. D. , Wood I. G. , Knight K. S.
Published: October 2009

The crystal structure of perdeuterated methanol monoammoniate, CD3OD·ND3, has been solved from neutron powder diffraction data collected at 4.2 and 180 K. The crystal structure is orthorhombic, space groupPbca(Z= 8), with unit-cell dimensionsa= 11.02320 (7),b= 7.66074 (6),c= 7.59129 (6) Å,V= 641.053 (5) Å3[ρcalc= 1162.782 (9) kg m−3] at 4.2 K, anda= 11.21169 (5),b= 7.74663 (4),c= 7.68077 (5) Å,V= 667.097 (4) Å3[ρcalc= 1117.386 (7) kg m−3] at 180 K. The crystal structure was determined byab initiomethods from the powder data; atomic coordinates and anisotropic displacement parameters were subsequently refined by the Rietveld method toRp< 3% at both temperatures. The crystal comprises a sheet-like structure in thebccrystallographic plane, consisting of strongly hydrogen bonded elements; these sheets are stacked along theaaxis, and adjacent sheets are linked by what may be comparatively weak C—D...O hydrogen bonds. Within the strongly bonded sheet structure, ND3molecules are tetrahedrally coordinated by the hydroxy moieties of the methanol molecule, accepting one hydrogen bond (O—D...N) of length ∼1.75 Å, and donating three hydrogen bonds (N—D...O) of length 2.15–2.25 Å. Two of the methyl deuterons appear to participate in weak interlayer hydrogen bonds (C—D...O) of length 2.7–2.8 Å. The hydrogen bonds are ordered at both 4.2 and 180 K. The relative volume change on warming from 4.2 to 180 K, ΔV/V, is +4.06%, which is comparable to, but more nearly isotropic (as determined from the relative change in axial lengths,e.g.Δa/a) than, that observed in deuterated methanol monohydrate.
The expression of dipeptidyl peptidase IV (DPPIV/CD26) is associated with enhanced chemosensitivity to paclitaxel in epithelial ovarian carcinoma cells
Authors: Kajiyama Hiroaki , Shibata Kiyosumi , Ino Kazuhiko , Mizutani Shigehiko , Nawa Akihiro , Kikkawa Fumitaka
Published: October 2009

Dipeptidyl peptidase IV (DPPIV/CD26) is a multifunctional cell surface aminopeptidase that is widely expressed in different cell types. Recent studies have suggested that DPPIV plays an important role in tumor progression in several human malignancies. In the current study, we investigated the role of DPPIV in paclitaxel resistance in epithelial ovarian carcinoma (EOC) cells. We first examined the correlation between expression levels of DPPIV and sensitivity to paclitaxel in various EOC cell lines. Subsequently, to clarify the cellular functions of DPPIV, we investigated the role of this molecule in the sensitivity of EOC to paclitaxel in vitro and in vivo using stably DPPIV‐transfected EOC cells. We identified a positive correlation between DPPIV expression and paclitaxel sensitivity in various EOC cell lines. In addition, we observed a significant increase in the paclitaxel sensitivity of DPPIV‐overexpressing EOC cells. Furthermore, no apparent alteration in paclitaxel sensitivity was noted by the addition of a specific inhibitor of DPPIV activity in DPPIV‐transfected or natively DPPIV‐overexpressing EOC cells. In a subcutaneous murine model treated with paclitaxel, on Day 39, the tumor size of the DPPIV‐transfected cell‐inoculated group was as large as that of the vector‐transfected cell‐inoculated group. In contrast, on Day 61, the former was smaller than the latter. The present findings show that DPPIV may be involved in the increased sensitivity to paclitaxel of EOC cells regardless of the involvement of DPPIV activity. (Cancer Sci 2009)
Steroid and xenobiotic receptor in human esophageal squamous cell carcinoma: A potent prognostic factor
Authors: Takeyama Daisuke , Miki Yasuhiro , Fujishima Fumiyoshi , Suzuki Takashi , Akahira Jun‐ichi , Hata Shuko , Miyata Go , Satomi Susumu , Sasano Hironobu
Published: October 2009

Steroid and xenobiotic receptor (SXR) is a nuclear receptor activated by diverse exogenous and endogenous compounds and has been demonstrated to play a pivotal role in detoxification through its regulation of various metabolizing enzymes and transporters. Recent studies also demonstrated the potential roles of SXR in the regulation of apoptosis and inflammation in various carcinoma cells, but the status of SXR in human esophageal squamous cell carcinoma (ESCC) has not been examined. Therefore, in this study, we performed immunohistochemical and quantitative RT‐PCR evaluations in human ESCC in order to clarify its biological and clinical significance. We first immunolocalized SXR in 73 human ESCC cases. SXR immunoreactivity was detected in the nuclei, or in both nuclei and cytoplasm of carcinoma cells (98%, 20% of cases, respectively). The status of nuclear SXR immunoreactivity was inversely correlated with histological grade, lymph node status, ki67/MIB1 labeling index, and positively correlated with retinoid X receptor α status. In addition, high nuclear SXR expression was significantly correlated with favorable clinical outcome of the patients. Multivariate analysis further demonstrated SXR status in carcinoma cells as an independent favorable prognostic factor of the patients. Results of quantitative RT‐PCR study demonstrated that SXR mRNA expression was detected in three of five cases, and was marked higher in the cancerous tissue than non‐neoplastic tissue of these patients. This is the first study to demonstrate the status of SXR in human ESCC and the results suggest that SXR is a potent favorable prognostic factor of human ESCC. (Cancer Sci 2009)
Correlation of vertical electrical sounding and electrical borehole log data for groundwater exploration
Authors: Hodlur G.K. , Dhakate Ratnakar
Published: October 2009

We have correlated the longitudinal unit conductance CL obtained from interpreted vertical electrical sounding data with the formation resistivity Rt and the formation resistivity factor F, obtained by carrying out electrical borehole logging. Interpreted geophysical data of eleven soundings and two electrical borehole log records are used for the analysis. The geophysical data used were acquired in a sedimentary basin. The study area is called Lower Maner Basin located in the province of Andhra Pradesh, India. Vertical electrical soundings were carried out using a Schlumberger configuration with half current electrode separation varying from 600–1000 m. For logging the two boreholes, a Widco logger‐model 3200 PLS was used. True formation resistivity Rt was calculated from a resistivity log. Formation resistivity factor F was also calculated at various depths using Rt values. An appreciable inverse relation exists between the correlated parameters. The borehole resistivity Rt and the formation resistivity factor F decrease with the increase in the longitudinal unit conductance CL. We have shown the use of such a relation in computing borehole resistivity Rt and formation resistivity factor F at sites that posses only vertical electrical sounding data, with a fair degree of accuracy. Validation of the correlation is satisfactory. Scope for updating the correlation is discussed. Significance and applications of the relation for exploration of groundwater, namely to update the vertical electrical sounding data interpretation by translating the vertical electrical sounding data into electrical borehole log parameters, to facilitate correlations studies and to estimate the porosity (φ), permeability (K) and water saturation Sw of water bearing zones are discussed.
Preoperative stoma siting and education by stomatherapists of colorectal cancer patients: a descriptive study in twelve Spanish colorectal surgical units
Authors: Millan Monica , Tegido Montse , Biondo Sebastiano , García‐Granero Eduardo
Published: October 2009

Objective  Patients with colorectal cancer who need a stoma should undergo preoperative marking of the stoma site and education by a trained stomatherapist. This study examined the care received by ostomy patients with colorectal cancer in Spanish colorectal surgery units, to assess its quality and to detect areas for improvement.

Method  A prospective study was conducted in twelve Spanish colorectal surgery units in Spain including patients visited by the stomatherapist after surgery for colorectal cancer. Each patient answered a questionnaire about their stoma care.

Results  Between September 2007 and May 2008, 270 patients were included, (63% colostomies, 37% ileostomies). Of whom; 75% had elective and 25% emergency surgery. Stomatherapist marked the stoma site in 45,6% of patients (0% emergency created stomas and 58,8% elective). However, patients who saw a stoma therapist preoperatively presented significantly lower rates of stoma complications (p < 0.001) and anxiety (p < 0.001) compared to those who did not postoperatively.

Conclusions  The study has demonstrated the importance of preoperative stomatherapy assessment.
Irradiation to the immature brain attenuates neurogenesis and exacerbates subsequent hypoxic‐ischemic brain injury in the adult
Authors: Zhu Changlian , Huang Zhiheng , Gao Jianfeng , Zhang Yu , Wang Xiaoyang , Karlsson Niklas , Li Qian , Lannering Birgitta , Björk‐Eriksson Thomas , Georg Kuhn H. , Blomgren Klas
Published: October 2009

Cranial radiotherapy is common in pediatric oncology. Our purpose was to investigate if irradiation (IR) to the immature brain would increase the susceptibility to hypoxic‐ischemic injury in adulthood. The left hemisphere of postnatal day 10 (P10) mice was irradiated with 8 Gy and subjected to hypoxia‐ischemia (HI) on P60. Brain injury, neurogenesis and inflammation were evaluated 30 days after HI. IR alone caused significant hemispheric tissue loss, or lack of growth (2.8 ± 0.42 mm3, p < 0.001). Tissue loss after HI (18.2 ± 5.8 mm3, p < 0.05) was synergistically increased if preceded by IR (32.0 ± 3.5 mm3, p < 0.05). Infarct volume (5.1 ± 1.6 mm3) nearly doubled if HI was preceded by IR (9.8 ± 1.2 mm3, p < 0.05). Pathological scoring revealed that IR aggravated hippocampal, cortical and striatal, but not thalamic, injury. Hippocampal neurogenesis decreased > 50% after IR but was unchanged by HI alone. The number of newly formed microglia was three times higher after IR + HI than after HI alone. In summary, IR to the immature brain produced long‐lasting changes, including decreased hippocampal neurogenesis, subsequently rendering the adult brain more susceptible to HI, resulting in larger infarcts, increased hemispheric tissue loss and more inflammation than in non‐irradiated brains.
Glycogen synthase kinase 3β in the nucleus accumbens core mediates cocaine‐induced behavioral sensitization
Authors: Xu Chun‐mei , Wang Jun , Wu Ping , Zhu Wei‐li , Li Qian‐qian , Xue Yan‐xue , Zhai Hai‐fen , Shi Jie , Lu Lin
Published: October 2009

Glycogen synthase kinase 3β (GSK‐3β) is a ubiquitous serine/threonine protein kinase involved in a number of signaling pathways. Previous studies have demonstrated a role for GSK‐3β in the synaptic plasticity underlying dopamine‐associated behaviors and diseases. Drug sensitization is produced by repeated exposure to the drug and is thought to reflect neuroadaptations that contribute to addiction. However, the role of GSK‐3β in cocaine‐induced behavior sensitization has not been examined. The present study investigated the effects of chronic cocaine exposure on GSK‐3β activity in the nucleus accumbens (NAc) and determined whether changes in GSK‐3β activity in the NAc are associated with cocaine‐induced locomotor sensitization. We also explored whether blockade of GSK‐3β activity in the NAc inhibits the initiation and expression of cocaine‐induced locomotor sensitization in rats using systemic or brain region‐specific administration of the GSK‐3β inhibitors lithium chloride (LiCl) and SB216763. GSK‐3β activity in the NAc core, but not NAc shell, increased after chronic cocaine (10 mg/kg, i.p.) administration. The initiation and expression of cocaine‐induced locomotor sensitization was attenuated by systemic administration of LiCl (100 mg/kg, i.p.) or direct infusion of SB216763 (1 ng/side) into the NAc core, but not NAc shell. Collectively, these results indicate that GSK‐3β activity in the NAc core, but not NAc shell, mediates the initiation and expression of cocaine‐induced locomotor sensitization, suggesting that GSK‐3β may be a potential target for the treatment of cocaine addiction.
The microtubule interacting drug candidate NAP protects against kainic acid toxicity in a rat model of epilepsy
Authors: Zemlyak Ilona , Manley Nathan , Vulih‐Shultzman Inna , Cutler Andrew B. , Graber Kevin , Sapolsky Robert M. , Gozes Illana
Published: October 2009

NAP (NAPVSIPQ, generic name, davunetide), a neuroprotective peptide in clinical development for neuroprotection against Alzheimer’s disease and other neurodegenerative indications, has been recently shown to provide protection against kainic acid excitotoxicity in hippocampal neuronal cultures.In vivo, kainic acid toxicity models status epilepticus that is associated with hippocampal cell death. Kainic acid toxicity has been previously suggested to involve the microtubule cytoskeleton and NAP is a microtubule‐interacting drug candidate. In the current study, kainic acid‐treated rats showed epileptic seizures and neuronal death. Injection of NAP into the dentate gyrus partially protected against kainic acid‐induced CA3 neuron death. Microarray analysis (composed of > 31 000 probe sets, analyzing over 30 000 transcripts and variants from over 25 000 well‐substantiated rat genes) in the kainic acid‐injured rat brain revealed multiple changes in gene expression, which were prevented, in part, by NAP treatment. Selected transcripts were further verified by reverse transcription coupled with quantitative real‐time polymerase chain reaction. Importantly, among the transcripts regulated by NAP were key genes associated with proconvulsant properties and with long‐lasting changes that underlie the epileptic state, including activin A receptor (associated with apoptosis), neurotensin (associated with proper neurotransmission) and the Wolfram syndrome 1 homolog (human, associated with neurodegeneration). These data suggest that NAP may provide neuroprotection in one of the most serious neurological conditions, epilepsy.
Regulation of striatal nitric oxide synthesis by local dopamine and glutamate interactions
Authors: Park Diana J. , West Anthony R.
Published: October 2009

Nitric oxide (NO) is a key neuromodulator of corticostriatal synaptic transmission. We have shown previously that dopamine (DA) D1/5 receptor stimulation facilitates neuronal NO synthase (nNOS) activity in the intact striatum. To study the impact of local manipulations of D1/5 and glutamatergic NMDA receptors on striatal nNOS activity, we combined the techniques ofin vivoamperometry and reverse microdialysis. Striatal NO efflux was monitored proximal to the microdialysis probe in urethane‐anesthetized rats during local infusion of vehicle or drug. NO efflux elicited by systemic administration of SKF‐81297 was blocked following intrastriatal infusion of: (i) the D1/5 receptor antagonist SCH‐23390, (ii) the nNOS inhibitor 7‐nitroindazole, (iii) the non‐specific ionotropic glutamate receptor antagonist kynurenic acid, and (iv) the selective NMDA receptor antagonist 3‐phosphonopropyl‐piperazine‐2‐carboxylic acid. Glycine co‐perfusion did not affect SKF‐81297‐induced NO efflux. Furthermore, intrastriatal infusion of SKF‐81297 potentiated NO efflux evoked during electrical stimulation of the motor cortex. The facilitatory effects of cortical stimulation and SKF‐81297 were both blocked by intrastriatal infusion of SCH‐23390, indicating that striatal D1/5 receptor activation is necessary for the activation of nNOS by corticostriatal afferents. These studies demonstrate for the first time that reciprocal DA‐glutamate interactions play a critical role in stimulating striatal nNOS activity.
Vitamin‐regulated cytokines and growth factors in the CNS and elsewhere
Authors: Scalabrino Giuseppe
Published: October 2009

There is a growing awareness that natural vitamins (with the only exception of pantothenic acid) positively or negatively modulate the synthesis of some cytokines and growth factors in the CNS, and various mammalian cells and organs. As natural vitamins are micronutrients in the human diet, studying their effects can be considered a part of nutritional genomics or nutrigenomics. A given vitamin selectively modifies the synthesis of only a few cytokines and/or growth factors, although the same cytokine and/or growth factor may be regulated by more than one vitamin. These effects seem to be independent of the effects of vitamins as coenzymes and/or reducing agents, and seem to occur mainly at genomic and/or epigenetic level, and/or by modulating NF‐κB activity. Although most of the studies reviewed here have been based on cultured cell lines, but their findings have been confirmed by some keyin vivostudies. The CNS seems to be particularly involved and is severely affected by most avitaminoses, especially in the case of vitamin B12. However, the vitamin‐induced changes in cytokine and growth factor synthesis may initiate a cascade of events that can affect the function, differentiation, and morphology of the cells and/or structures not only in the CNS, but also elsewhere because most natural vitamins, cytokines, and growth factors cross the blood–brain barrier. As cytokines are essential to CNS‐immune and CNS‐hormone system communications, natural vitamins also interact with these circuits. Further studies of such vitamin‐mediated effects could lead to vitamins being used for the treatment of diseases which, although not true avitaminoses, involve an imbalance in cytokine and/or growth factor synthesis.
Thrombin potentiatesd‐aspartate efflux from cultured astrocytes under conditions of K+homeostasis disruption
Authors: Vázquez‐Juárez Erika , Hernández‐Benítez Reyna , López‐Domínguez Alejandra , Pasantes‐Morales Herminia
Published: October 2009

Thrombin levels increase in brain during ischemia and hemorrhagic episodes, and may contribute to excitotoxic neural damage. This study examined the effect of thrombin on glutamate efflux from rat cortical cultured astrocytes using3H‐d‐aspartate as radiotracer. The glutamate efflux was initiated by addition of 100 mM K+plus 1 mM ouabain (K/O) to replicate extracellular and intracellular ionic changes that occur during cerebral ischemia. Upon exposure to K/O, astrocytes swelled slowly and progressively with no evidence of volume regulation. The K/O‐induced swelling was inhibited by 65% with bumetanide and 25% with BaCl2, suggesting contribution of Na+/K+/Cl−co‐transporter and Kir channels. K/O‐elicited3H‐d‐aspartate that consisted of two phases. The first transient component of the release corresponded to 13.5% of total3H‐d‐aspartate loaded. It was markedly reduced (61%) by the glutamate transporter blocker DL‐threo‐b‐Benzyloxyaspartic acid and weakly inhibited (21%) by the volume‐sensitive anion channel blocker 4‐[(2‐Butyl‐6,7dichloro‐2‐cyclopentyl‐2,3‐dihidro‐1oxo‐1H‐inden‐5‐yl)oxy] butanoic acid (DCPIB). During the second sustained phase of release, cells lost 45% of loaded of3H‐d‐aspartate via a mechanism that was insensitive to DL‐threo‐b‐Benzyloxyaspartic acid but nearly completely suppressed by DCPIB. Thrombin (5 U/mL) had only marginal effects on the first phase but strongly potentiated (more than two‐fold)3H‐d‐aspartate efflux in the second phase. The effect of thrombin effect was proportional to cell swelling and completely suppressed by DCPIB. Overall our data showed that under K/O swelling conditions, thrombin potently enhance glutamate release via volume‐sensitive anion channel. Similar mechanisms may contribute to brain damage in neural pathologies which are associated with cell swelling, glutamate efflux and increased thrombin levels.
PRIMARY CARBON AND NITROGEN METABOLIC GENE EXPRESSION IN THE DIATOMTHALASSIOSIRA PSEUDONANA(BACILLARIOPHYCEAE): DIEL PERIODICITY AND EFFECTS OF INORGANIC CARBON AND NITROGEN1
Authors: Granum Espen , Roberts Karen , Raven John A. , Leegood Richard C.
Published: October 2009

Diel periodicity and effects of inorganic carbon (Ci) and NO3−on the expression of 11 key genes for primary carbon and nitrogen metabolism, including potential C4photosynthesis, in the marine diatomThalassiosira pseudonanaHasle et Heimdal were investigated. Target gene transcripts were measured by quantitative reverse transcriptase–PCR, and some of the gene‐encoded proteins were analyzed by Western blotting. The diatom was grown with a 12 h photoperiod at two different Ciconcentrations maintained by air‐equilibration with either 380 μL · L−1(near‐ambient) or 100 μL · L−1(low) CO2. Transcripts of the principal Ciand NO3−assimilatory genes RUBISCO LSU (rbcL) and nitrate reductase displayed very strong diel oscillations with peaks at the end of the scotophase. Considerable diel periodicities were also exhibited by the β‐carboxylase genes phosphoenolpyruvate carboxylase (PEPC1andPEPC2) and phosphoenolpyruvate carboxykinase (PEPCK), and the Benson–Calvin cycle gene sedoheptulose–bisphosphatase (SBPase), with peaks during mid‐ to late scotophase. In accordance with the transcripts, there were substantial diel periodicities in PEPC1, PEPC2, PEPCK, and especially rbcL proteins, although they peaked during early to mid‐photophase. Inorganic carbon had some transient effects on the β‐carboxylase transcripts, and glycine decarboxylase P subunit was highly up‐regulated by low Ciconcentration, indicating increased capacity for photorespiration. Nitrogen‐starved cells had reduced amounts of carbon metabolic gene transcripts, but thePEPC1,PEPC2,PEPCK, andrbcL transcripts increased rapidly when NO3−was replenished. The results suggest that the β‐carboxylases inT. pseudonanaplay key anaplerotic roles but show no clear support for C4photosynthesis.
Constrained Sintering of a Glass Ceramic Composite: I. Asymmetric Laminate
Authors: Ollagnier Jean‐Baptiste , Guillon Olivier , Rödel Jürgen
Published: October 2009

The camber of asymmetric laminates has been experimentally measured and predicted. Two cases are distinguished: (i) sintering of a viscous layer on a viscous substrate and (ii) sintering of a viscous layer on an elastic substrate. In the first case, particular attention is paid to the microstructure of the shrinking layer: a gradient in porosity as well as in pore size has been found along the thickness. Microstructural observations have been rationalized through an asymmetric stress state in the shrinking layer. In the second case, substrate cracking is predicted as function of Young's modulus and thickness ratio of the elastic substrate.
Neurotrophic factors promote cholinergic differentiation in human embryonic stem cell‐derived neurons
Authors: Nilbratt Mats , Porras Omar , Marutle Amelia , Hovatta Outi , Nordberg Agneta
Published: October 2009

Cholinergic neurotransmission is essential for many important functions in the brain, including cognitive mechanisms. Here we demonstrate that human embryonic stem (hES) cells differentiate into a population of neuronal cells that express the cholinergic enzyme choline acetyltransferase and homeobox proteins specifying neuronal progenitors of ventral telencephalic lineage. These differentiated cells express transcripts for cholinergic α3, α4 and α7 nicotinic acetylcholine (ACh) receptor subunits and for M1, M2 and M3 muscarinic acetylcholine receptor (mAChR) subtypes. Stimulation with brain‐derived neurotrophic factor, neurotrophin‐3, ciliary neurotrophic factor and nerve growth factor increases the proportion of cholinergic neurons. These cholinergic receptors also mediate ACh‐evoked increase in cytosolic calcium levels, and this response was unaffected by extracellular calcium removal and was abolished by the mAChR antagonist scopolamine. Our findings demonstrate expression of functional cholinergic receptors on hES cell‐derived neurons, which may provide a source of expandable cells to facilitate screening of novel cholinergic drugs and useful for evaluating cell transplantation in animal models of cholinergic dysfunction.
The actin filament cross‐linker L‐plastin confers resistance to TNF‐α in MCF‐7 breast cancer cells in a phosphorylation‐dependent manner
Authors: Janji Bassam , Vallar Laurent , Tanoury Ziad Al , Bernardin François , Vetter Guillaume , Schaffner‐Reckinger Elisabeth , Berchem Guy , Friederich Evelyne , Chouaib Salem
Published: October 2009

We used a tumour necrosis factor (TNF)‐α resistant breast adenocarcinoma MCF‐7 cell line to investigate the involvement of the actin cytoskeleton in the mechanism of cell resistance to this cytokine. We found that TNF resistance correlates with the loss of cell epithelial properties and the gain of a mesenchymal phenotype, reminiscent of an epithelial‐to‐mesenchymal transition (EMT). Morphological changes were associated with a profound reorganization of the actin cytoskeleton and with a change in the repertoire of expressed actin cytoskeleton genes and EMT markers, as revealed by DNA microarray‐based expression profiling. L‐plastin, an F‐actin cross‐linking and stabilizing protein, was identified as one of the most significantly up‐regulated genes in TNF‐resistant cells. Knockdown of L‐plastin in these cells revealed its crucial role in conferring TNF resistance. Importantly, overexpression of wild‐type L‐plastin in TNF‐sensitive MCF‐7 cells was sufficient to protect them against TNF‐mediated cell death. Furthermore, we found that this effect is dependent on serine‐5 phosphorylation of L‐plastin and that non‐conventional protein kinase C isoforms and the ceramide pathway may regulate its phosphorylation state. The protective role of L‐plastin was not restricted to TNF‐α resistant MCF‐7 cells because a correlation between the expression of L‐plastin and the resistance to TNF‐α was observed in other breast cancer cell lines. Together, our study discloses a novel unexpected role of the actin bundling protein L‐plastin as a cell protective protein against TNF‐cytotoxicity.
Translational up‐regulation of Aurora‐A in EGFR‐overexpressed cancer
Authors: Lai Chien‐Hsien , Tseng Joseph T. , Lee Yi‐Chao , Chen Ying‐Ju , Lee Jeng‐Chang , Lin Bo‐Wen , Huang Tai‐Chien , Liu Yao‐Wen , Leu Tzeng‐Horng , Liu Yi‐Wen , Chen Ya‐Ping , Chang Wen‐Chang , Hung Liang‐Yi
Published: October 2009

Abnormal expression of Aurora‐A and epidermal growth factor receptor (EGFR) is observed in different kinds of cancer and associated with poor prognosis in cancer patients. However, the relationship between Aurora‐A and EGFR in tumour development was not clear. In previous reports, we found that EGFR translocates to nucleus to activate Aurora‐A expression after EGF treatment in EGFR‐overexpressed cells. However, we also observed that not all the EGFR‐overexpressed cells have the nuclear EGFR pathway to mediate the Aurora‐A expression. In this study, we demonstrated that EGF signalling increased the Aurora‐A protein expression in EGFR‐overexpressed colorectal cancer cell lines via increasing the translational efficiency. In addition, the overexpression of EGFR was also associated with higher expression of Aurora‐A in clinical colorectal samples. Activation of the PI3K/Akt/mTOR and MEK/ERK pathways mediated the effect of EGF‐induced translational up‐regulation. Besides, only the splicing variants containing exon 2 of Aurora‐A mRNA showed increased interaction with the translational complex to synthesize Aurora‐A protein under EGF stimulus. Besides, the exon 2 containing splicing variants were the major Aurora‐A splicing forms expressed in human colorectal cancers. Taken together, our results propose a novel regulatory mechanism for the abnormal expression of Aurora‐A in EGFR‐overexpressed cancers, and highlight the importance of alternative 5′‐UTR splicing variants in regulating Aurora‐A expression. Furthermore, the specific expression of exon 2 containing splicing variants in cancer tissues may serve as a potential target for cancer therapy in the future.
Functional characterization of the progestagen‐associated endometrial protein gene in human melanoma
Authors: Ren Suping , Liu Suhu , Howell Jr Paul M. , Zhang Guangyu , Pannell Lewis , Samant Rajeev , Shevde‐Samant Lalita , Tucker J. Allan , Fodstad Oystein , Riker Adam I.
Published: October 2009

Utilizing gene microarray profiling of melanoma samples, we have recently identified a novel gene overexpressed in both thick primary and metastatic melanomas. This gene, progestagen‐associated endometrial protein (PAEP), has never before been implicated in the oncogenic processes of melanoma, with its true function in oncogenesis and tumour progression relatively unknown. Overexpression of the PAEP gene in freshly procured thick primary and metastatic melanoma samples (58%) and daughter cell lines (77%) is confirmed by quantitative RT‐PCR, immunohistochemistry, Western blotting and mass spectrometric analysis. We suggest that PAEP gene overexpression is involved with melanoma tumour progression as well as an aggressive phenotype. Transfection of melanoma cells with PAEP small interfering RNA (siRNA) reveals a significant decrease in soft agar colony formation and a marked inhibition of both cell migration and cell invasion. Furthermore, we establish stable melanoma transfectants via PAEP lentiviral small hairpin RNA (shRNA), examine their growth characteristics in a murine xenograft model and reveal that tumour growth is significantly inhibited in two separate melanoma cell lines. Our data strongly implicate the PAEP gene as a tumour growth promoter with oncogenic properties and a potential therapeutic target for patients with advanced melanoma.
Haematopoietic stem cells in spleen have distinct differentiative potential for antigen presenting cells
Authors: Tan Jonathan K.H. , O’Neill Helen C.
Published: October 2009

Dendritic cells (DC) are known to develop from macrophage dendritic progenitors (MDP) in bone marrow (BM), which give rise to conventional (c)DC and monocytes, both dominant antigen presenting cell (APC) subsets in spleen. This laboratory has however defined a distinct dendritic‐like cell subset in spleen (L‐DC), which can also be derived in long‐term cultures of spleen. In line with the restricted in vitro development of only L‐DC in these stromal cultures, we questioned whether self‐renewing HSC or progenitors exist in spleen with restricted differentiative capacity for only L‐DC. Neonatal spleen and BM were compared for their ability to reconstitute mice and to give rise to L‐DC, as well as other splenic APC. Neonatal spleen cells were transplanted into allotype‐distinct lethally irradiated hosts along with host‐type competitor BM cells, and assayed over 8 to 51 weeks for haematopoietic reconstitution of L‐DC and cDC subsets, along with other lymphoid and myeloid cells. In this study, neonatal spleen showed multilineage haematopoietic reconstitution in mouse chimeras, rather than specific or restricted ability to differentiate into L‐DC. However, the representation of individual APC subsets was found to be unequal in chimeras partially reconstituted with donor cells, such that more donor‐derived progeny were seen for L‐DC than for myeloid and cDC subsets. The ability of HSC in spleen to develop into L‐DC was indicated by a strong bias in the subset size of these cells over other splenic APC subsets. This type of evidence supports a model whereby spleen represents an important site for haematopoiesis of this distinct DC subset. The conditions under which haematopoiesis of L‐DC occurs in spleen, or the progenitors involved, will require further investigation.
Familial and racial determinants of tumour suppressor genes promoter hypermethylation in breast tissues from healthy women
Authors: Dumitrescu R.G. , Marian C. , Krishnan S.S. , Spear S.L. , Kallakury B.V.S. , Perry D. J. , Convit J. R. , Seillier‐Moiseiwitsch F. , Yang Y. , Freudenheim J.L. , Shields P.G.
Published: October 2009

To determine the hypermethylation status of the promoter regions of tumour suppressor genes in breast tissues from healthy women and identify the determinants of these epigenetic changes. Questionnaires and breast tissues were collected from healthy women without a history of cancer and undergoing reduction mammoplasty (N= 141). Methylation for p16INK4, BRCA1, ERα and RAR‐β promoter regions from breast tissues were determined by methylation specific PCR. Associations were examined with chi‐square and Fisher’s exact test as well as logistic regression. All statistical tests were two‐sided. p16INK4, BRCA1, ERα and RAR‐β hypermethylation were identified in 31%, 17%, 9% and 0% of the women, respectively. Women with BRCA1 hypermethylation had an eight‐fold increase in the risk of ERα hypermethylation (P= 0.007). p16INK4 hypermethylation was present in 28% of African‐Americans, but 65% in European‐Americans (P= 0.02). There was an increased likelihood of p16INK4 or BRCA1 hypermethylation for women with family history of cancer (OR 2.3; 95%CI: 1.05–4.85 and OR 5.0; 95%CI: 1.55–15.81, respectively). ERα hypermethylation was associated with family history of breast cancer (OR 6.6; 95%CI: 1.58–27.71). After stratification by race, p16INK4 in European‐Americans and BRCA1 hypermethylation in African‐Americans were associated with family history of cancer (OR 3.8; 95%CI: 1.21–12.03 and OR 6.5; 95%CI: 1.33–31.32, respectively). Gene promoter hypermethylation was commonly found in healthy breast tissues from women without cancer, indicating that these events are frequent and early lesions. Race and family history of cancer increase the likelihood of these early events.
Effect of combination therapy of hydroxyurea with l‐carnitine and magnesium chloride on hematologic parameters and cardiac function of patients with β‐thalassemia intermedia
Authors: Karimi Mehran , Mohammadi Faranak , Behmanesh Farzane , Samani Soleiman M. , Borzouee Mohammad , Amoozgar Hamid , Haghpanah Sezaneh
Published: October 2009

Background:  l‐Carnitine and magnesium have antioxidant properties. They have the potential to stimulate production of fetal hemoglobin and stabilize the RBC membrane, respectively. Several studies have also shown the beneficial effects of hydroxyurea in thalassemic patients. We assessed the effect of combination therapy of hydroxyurea with l‐carnitine and magnesium chloride on hematologic parameters and cardiac function of patients with β‐thalassemia intermedia.

Methods:  One‐hundred‐and‐twenty patients with thalassemia intermedia (range, 4–35 yr; mean, 19 ± 6.4 yr) who had no need for blood transfusion or requirement for blood transfusion with an interval of >6 months were randomly selected. All patients had been on hydroxyurea for >6 months. They were randomly divided into four groups: group A (hydroxyurea alone); group B (hydroxyurea and l‐carnitine); group C (hydroxyurea and magnesium chloride); and group D (hydroxyurea, l‐carnitine and magnesium chloride).

Results:  In groups B, C, and D, mean Hb and hematocrit increased during 6‐month treatment (P < 0.001). Echocardiographic studies revealed a significant decrease in left ventricular end‐diastolic diameter in group B (P = 0.032), increase in pulmonary acceleration time in group C (P = 0.012), and increase in left ventricular ejection fraction in groups C and D (P < 0.000 and 0.006, respectively).

Conclusion:  Combination of hydroxyurea with l‐carnitine or magnesium could be more effective in improving hematologic parameters and cardiac status in patients with β‐thalassemia intermedia than hydroxyurea alone.
BCR‐ABL positive cells and chronic myeloid leukemia in immune suppressed organ transplant recipients
Authors: Le Coutre Philipp , Reinke Petra , Neuhaus Ruth , Trappe Ralf , Ringel Frauke , Lalancette Marc , Hemmati Philipp G. , Dörken Bernd , Daniel Peter T.
Published: October 2009

The constitutively activated tyrosine kinase activity of the p210bcr‐abl fusion protein, generated by a t(9;22)(q34;q11) chromosomal translocation, is pathogenetically associated with chronic myeloid leukemia (CML). However, mechanisms contributing to the expansion of a BCR‐ABL positive clone are largely obscure. In the presence of an impaired immune surveillance, cells carrying any of these alterations may become phenotypically relevant. Therefore, immunosuppressed solid organ recipients represent an optimal population to investigate the frequency of mRNA products of this translocation. Blood leukocytes were studied in 201 individuals (100 organ recipients and 101 control individuals) for the presence of BCR‐ABL transcripts by a nested‐reverse transcriptase‐polymerase chain reaction assay, routinely used in our institution. In 5/100 immunosuppressed patients, at least one out of two RT‐PCR products was bcr‐abl positive while all controls were negative. These findings were extended by four CML cases of organ transplant recipients (three renal and one liver transplants). Three of these cases developed CML in a total of 2088 transplantations in 9 yr, suggesting a higher incidence of CML in these patients.