bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualizing lignin coalescence and migration through maize cell walls following thermochemical pretreatment
Authors: Donohoe Bryon S. , Decker Stephen R. , Tucker Melvin P. , Himmel Michael E. , Vinzant Todd B. 
Published: May 2008

AbstractPlant cell walls are composed primarily of cellulose, hemicelluloses, lignins, and pectins. Of these components, lignins exhibit unique chemistry and physiological functions. Although lignins can be used as a product feedstock or as a fuel, lignins are also generally seen as a barrier to efficient enzymatic breakdown of biomass to sugars. Indeed, many pretreatment strategies focus on removing a significant fraction of lignin from biomass to better enable saccharification. In order to better understand the fate of biomass lignins that remain with the solids following dilute acid pretreatment, we undertook a structural investigation to track lignins on and in biomass cell walls. SEM and TEM imaging revealed a range of droplet morphologies that appear on and within cell walls of pretreated biomass; as well as the specific ultrastructural regions that accumulate the droplets. These droplets were shown to contain lignin by FTIR, NMR, antibody labeling, and cytochemical staining. We provide evidence supporting the idea that thermochemical pretreatments reaching temperatures above the range for lignin phase transition cause lignins to coalesce into larger molten bodies that migrate within and out of the cell wall, and can redeposit on the surface of plant cell walls. This decompartmentalization and relocalization of lignins is likely to be at least as important as lignin removal in the quest to improve the digestibility of biomass for sugars and fuels production. © 2008 Wiley Periodicals, Inc.
Studies on the Electrochemical Property of Dinuclear Copper(II) Complex Containing Dimethylglyoxime and Its Interaction with DNA
Authors: Xu Guiyun , Fan Jinshi , Jiao Kui 
Published: May 2008

AbstractThe electrochemical property of dinuclear copper(II) complex containing dimethylglyoxime [Cu2(Hdmg)4] was studied with cyclic voltammetry. Cu2(Hdmg)4 had an irreversible oxidation peak in pH 5.0 B–R buffer solution at the stearic acid‐modified carbon paste electrode. Cyclic voltammetry, UV‐vis absorption spectra and viscosity measurements were used to study the interaction of Cu2(Hdmg)4 with herring fish sperm DNA. Cu2(Hdmg)4 interacts with the bases of DNA to form nonelectroactive adducts. The interaction of Cu2(Hdmg)4 with ssDNA was stronger than that of Cu2(Hdmg)4 with dsDNA because of the exposed bases of ssDNA. The gene sequence related to the BAR transgene in the transgenic corn was detected using Cu2(Hdmg)4 as electroactive indicator.
Selective Determination of Dopamine in the Presence of Ascorbic Acid at Porous‐Carbon‐Modified Glassy Carbon Electrodes
Authors: Song Shuqing , Gao Qiuming , Xia Kaisheng , Gao Lu 
Published: May 2008

AbstractSelective dopamine (DA) determinations using porous‐carbon‐modified glassy carbon electrodes (GCE) in the presence of ascorbic acid (AA) were studied. The effects of structure textures and surface functional groups of the porous carbons on the electrochemical behavior of DA was analyzed based on both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements. The differential pulse voltammetry of DA on the modified GCE was determined in the presence of 400‐fold excess of AA, and the linear determination ranges of 0.05–0.99, 0.20–1.96, and 0.6–12.60 μM with the lowest detected concentrations of 4.5×10−3, 4.4×10−2, and 0.33 μM were obtained on the mesoporous carbon, mesoporous carbon with carboxylic and amino groups modified electrodes, respectively.
Characterization of acid‐sensing ion channel expression in oligodendrocyte‐lineage cells
Authors: Feldman Daniel H. , Horiuchi Makoto , Keachie Krista , Mccauley Erica , Bannerman Peter , Itoh Aki , Itoh Takayuki , Pleasure David 
Published: May 2008

AbstractAcid‐sensing ion channels (ASICs) are widely expressed in neurons, where they serve in pain and mechanical sensation, and contribute to learning and memory. Six ASIC subunit proteins form homo‐ or heteromeric channel complexes with distinct physiological properties. Of such complexes, only monomeric ASIC1a channels are Ca2+ permeable. Prior pharmacologic and genetic studies have shown that ASIC1a channel inactivation markedly diminishes CNS susceptibility to ischemic damage. Here, we characterize ASIC expression in oligodendrocyte lineage cells (OLC) by molecular, electrophysiological, calcium imaging, and immunofluorescence techniques. ASIC1a, ASIC2a, and ASIC4 mRNAs were expressed in cultured rat OLC, with steady‐state levels of each of these mRNAs several‐fold higher in oligodendroglial progenitors than in mature oligodendroglia. ASIC transcripts were also detected in brain white matter, and ASIC1a protein expression was detected in white matter oligodendroglia. Inactivating, proton‐gated, amiloride‐sensitive OLC currents were detected by whole‐cell voltage clamp. These currents showed profound tachyphylaxis with slow recovery, and were predominantly blocked by psalmotoxin, indicating that homomeric ASIC1a comprised a large fraction of functional ASIC in the cultured OLC. ASIC activation substantially depolarized OLC plasma membrane in current clamp studies, and elicited transient elevations in intracellular Ca2+ in imaging studies. Thus, OLC ASIC1a channels provide a means by which an acid shift in CNS extracellular pH, by diminishing plasma membrane potential and increasing Ca2+ permeability, can activate OLC signaling pathways, and may contribute to OLC vulnerability to CNS ischemia. © 2008 Wiley‐Liss, Inc.
REG1A expression is a prognostic marker in colorectal cancer and associated with peritoneal carcinomatosis
Authors: Astrosini Christian , Roeefzaad Claudia , Dai Yi‐Yang , Dieckgraefe Brian K. , Jöns Thomas , Kemmner Wolfgang 
Published: May 2008

AbstractBy expression profiling of early staged colon carcinomas, we found regenerating islet‐derived 1 alpha (REG1A) to be upregulated in patients with an unfavorable clinical outcome. For validation, REG1A expression was quantified in another colorectal cancer (CRC) patient cohort by Taqman PCR. Aside from tumor and normal tissue from 63 nonpretreated CRC patients, 31 mucosa biopsies from healthy individuals as well as 22 adenomas were included in the investigation. REG1A was significantly upregulated in tumor specimens (p < 0.001) and adenoma (p < 0.01) as compared to normal colorectal tissue. REG1A expression in normal peritumoral tissue in turn proved to be significantly elevated compared to mucosa from healthy individuals (p < 0.01). Determination of REG1A expression might be useful for early tumor diagnosis with a sensitivity of 90.6%, and a specificity of 77.9%. REG1A expression was significantly increased in tumors with peritoneal carcinomatosis (p < 0.01). Moreover, REG1A turned out to be a significant predictor of disease‐free survival (p < 0.05). In conclusion, we present evidence that REG1A is a molecular marker of prognostic value and is associated with peritoneal carcinomatosis in CRC. REG1A turned out to be already significantly raised in peritumoral normal tissue compared to mucosa from healthy individuals, suggesting a molecular field effect of secreted REG1A. © 2008 Wiley‐Liss, Inc.
The HspA2 protein localizes in nucleoli and centrosomes of heat shocked cancer cells
Authors: Ścieglińska Dorota , Pigłowski Wojciech , Mazurek Agnieszka , Małusecka Ewa , Żebracka Jadwiga , Filipczak Piotr , Krawczyk Zdzisław 
Published: May 2008

AbstractThe human HSPA2 gene, which belongs to the HSP70 family of heat shock genes, is a counterpart of rodent testis‐specific HspA2 gene. Rodent genes are expressed mainly in pachytene spermatocytes, while transcripts of human HSPA2 gene have been detected in various normal somatic tissues, albeit translation of the messenger RNA into corresponding protein has not been yet unambiguously demonstrated, except for several cancer cell lines. The aim of our work, a first step in search for HspA2 function in cancer cells, was to establish its intracellular localization at physiological temperature and during heat shock. First, we used qRT‐PCR and a highly specific antibody to select cell lines with the highest expression of the HspA2 protein, which turned out to be A549 and NCI‐H1299 lines originating from non‐small cell lung carcinoma (NSCLC). Significant expression of the HspA2 was also detected by immunohistochemistry in primary NSCLC specimens. Intracellular localization of the HspA2 was studied using both the specific anti‐HspA2 polyclonal antibody and transfection of cells with fusion proteins HspA2‐EGFP and mRFP‐HspA2. We found that, at physiological temperature, the HspA2 was localized primarily in cytoplasm whereas, during heat shock, localization shifted to nucleus and nucleoli. Moreover, we demonstrate that in heat‐shocked cells HspA2 accumulated in centrosomes. Our results suggest that the HspA2, like Hsp70 protein, can be involved in protecting nucleoli and centrosomes integrity in cancer cells subjected to heat shock and, possibly, other cellular stressors. J. Cell. Biochem. 104: 2193–2206, 2008. © 2008 Wiley‐Liss, Inc.
Epinephrine stimulates esophageal squamous‐cell carcinoma cell proliferation via β‐adrenoceptor‐dependent transactivation of extracellular signal‐regulated kinase/cyclooxygenase‐2 pathway
Authors: Liu Xuan , Wu William K.K. , Yu Le , Sung Joseph J.Y. , Srivastava Gopesh , Zhang Shu T. , Cho Chi H. 
Published: May 2008

AbstractEsophageal cancer is the sixth leading causes of cancer‐related death in the world. It is suggested that β‐adrenoceptor is involved in the control of cell proliferation, but its role in the pathogenesis of esophageal cancer remains unknown. We therefore studied the role of β‐adrenergic signaling in the regulation of growth of an esophageal squamous‐cell carcinoma cell line HKESC‐1. Results showed that both β1‐ and β2‐adrenoceptors were expressed in HKESC‐1 cells. Stimulation of β‐adrenoceptors with epinephrine significantly increased HKESC‐1 cell proliferation accompanied by elevation of intracellular cyclic AMP levels, which were abolished by β1‐ or β2‐selective antagonists. Epinephrine also increased extracellular signal‐regulated kinase‐1/2 (ERK1/2) phosphorylation as well as cyclooxygenase‐2 (COX‐2) and cytosolic phospholipase A2 expression, which were blocked by β1‐ or β2‐selective antagonists. Moreover, epinephrine increased cyclin D1, cyclin E2, cyclin‐dependent kinase (CDK)‐4, CDK‐6, and E2F‐1 expression and retinoblastoma protein phosphorylation at Ser807/811, all of which were abrogated by β1‐adrenoceptor antagonist. Furthermore, epinephrine increased the expression of vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)‐1 and ‐2 in a β2‐adrenoceptor‐, mitogen‐activated protein kinase/ERK kinase (MEK)‐, and COX‐2‐dependent manner. MEK or COX‐2 inhibitor also significantly inhibited HKESC‐1 cell proliferation induced by epinephrine. Collectively, we demonstrate that epinephrine stimulates esophageal squamous‐cell carcinoma cell proliferation via β‐adrenoceptor‐dependent transactivation of ERK/COX‐2 pathway. Stimulation of β1‐ and β2‐adrenoceptors also elicits a differential response on the expression of cell cycle regulators. These novel findings may shed new light on the understanding of β‐adrenergic signaling in the control of esophageal cancer cell growth. J. Cell. Biochem. 105: 53–60, 2008. © 2008 Wiley‐Liss, Inc.
Interactions between integrin ligand density and cytoskeletal integrity regulate BMSC chondrogenesis
Authors: Connelly John T. , García Andrés J. , Levenston Marc E. 
Published: May 2008

AbstractInteractions with the extracellular matrix play important roles in regulating the phenotype and activity of differentiated articular chondrocytes; however, the influences of integrin‐mediated adhesion on the chondrogenesis of mesenchymal progenitors remain unclear. In the present study, agarose hydrogels were modified with synthetic peptides containing the arginine‐glycine‐aspartic acid (RGD) motif to investigate the effects of integrin‐mediated adhesion and cytoskeletal organization on the chondrogenesis of bone marrow stromal cells (BMSCs) within a three‐dimensional culture environment. Interactions with the RGD‐modified hydrogels promoted BMSC spreading in a density‐dependent manner and involved αvβ3 integrin receptors. When cultured with the chondrogenic supplements, TGF‐β1 and dexamethasone, adhesion to the RGD sequence inhibited the stimulation of sulfated‐glycosaminoglycan (sGAG) production in a RGD density‐dependent manner, and this inhibition could be blocked by disrupting the F‐actin cytoskeleton with cytochalasin D. In addition, interactions with the RGD‐modified gels promoted cell migration and aggrecanase‐mediated release of sGAG to the media. While adhesion to the RGD sequence inhibited BMSC chondrogenesis in the presence of TGF‐β1 and dexamethasone, osteocalcin and collagen I gene expression and alkaline phosphatase activity were enhanced by RGD interactions in the presence of serum‐supplemented medium. Overall, the results of this study demonstrate that integrin‐mediated adhesion within a three‐dimensional environment inhibits BMSC chondrogenesis through actin cytoskeleton interactions. Furthermore, the effects of RGD‐adhesion on mesenchymal differentiation are lineage‐specific and depend on the biochemical composition of the cellular microenvironment. J. Cell. Physiol. 217: 145–154, 2008. © 2008 Wiley‐Liss, Inc.
Dynamic assessment of fibroblast mechanical activity during Rac‐induced cell spreading in 3‐D culture
Authors: Petroll W. Matthew , Ma Lisha , Kim Areum , Ly Linda , Vishwanath Mridula 
Published: May 2008

AbstractThe goal of this study was to determine the morphological and sub‐cellular mechanical effects of Rac activation on fibroblasts within 3‐D collagen matrices. Corneal fibroblasts were plated at low density inside 100 µm thick fibrillar collagen matrices and cultured for 1–2 days in serum‐free media. Time‐lapse imaging was then performed using Nomarski DIC. After an acclimation period, perfusion was switched to media containing PDGF. In some experiments, Y‐27632 or blebbistatin were used to inhibit Rho‐kinase (ROCK) or myosin II, respectively. PDGF activated Rac and induced cell spreading, which resulted in an increase in cell length, cell area, and the number of pseudopodial processes. Tractional forces were generated by extending pseudopodia, as indicated by centripetal displacement and realignment of collagen fibrils. Interestingly, the pattern of pseudopodial extension and local collagen fibril realignment was highly dependent upon the initial orientation of fibrils at the leading edge. Following ROCK or myosin II inhibition, significant ECM relaxation was observed, but small displacements of collagen fibrils continued to be detected at the tips of pseudopodia. Taken together, the data suggests that during Rac‐induced cell spreading within 3‐D matrices, there is a shift in the distribution of forces from the center to the periphery of corneal fibroblasts. ROCK mediates the generation of large myosin II‐based tractional forces during cell spreading within 3‐D collagen matrices, however residual forces can be generated at the tips of extending pseudopodia that are both ROCK and myosin II‐independent. J. Cell. Physiol. 217: 162–171, 2008. © 2008 Wiley‐Liss, Inc.
Sentinel lymph node micrometastasis may predict non‐sentinel involvement in cutaneous melanoma patients
Authors: Glumac Nebojsa , Hocevar Marko , Zadnik Vesna , Snoj Marko 
Published: May 2008

AbstractBackground and objectivesCutaneous melanoma patients with positive sentinel lymph node biopsy (SLNB) are being treated with completion lymph node dissection (CLND). The aim of our study was to determine the predictive value of sentinel lymph node (SLN) micrometastases (metastases less than 2 mm in diameter) in assessing further lymph node involvement in CLND.MethodsBetween 2001 and 2005, we performed 476 SLNB in patients with stages I and II melanoma; 74 had metastases in SLN. We evaluated retrospectively the metastases in SLN according to their size and number. The presence of additional metastases in non‐sentinel lymph nodes after CLND was evaluated.ResultsThirty‐nine patients had micrometastases, 22 of them were solitary, 3 were double, and 14 patients had multiple micrometastases in SLN. Out of 22 solitary micrometastases, no patient had additional metastases in non‐sentinel lymph nodes. From 3 patients with double micrometastases, 1 patient had further metastases in non‐sentinel lymph nodes after CLND. Out of 14 patients with multiple micrometastases, 2 had additional metastases in CLND.ConclusionsNo patient with a single SLN micrometastasis had further metastases after CLND in our series. CLND may not be beneficial after detecting a single micrometastasis in SLN. J. Surg. Oncol. 2008;98:46–48. © 2008 Wiley‐Liss, Inc.
Toward the synthesis of strongly photoluminescing polyesters by entropically driven ring‐opening polymerizations
Authors: Williams Richard T. , Hodge Philip , Yeates Stephen G. 
Published: May 2008

AbstractA range of strongly fluorescent polyesters incorporating distyrylarylene moieties have been prepared. The polyesters have the potential to be prepared from the corresponding macrocyclic oligomers (MCOs) by entropically driven ring‐opening polymerizations (ED‐ROP). This reactive macrocyclic oligomer approach to the polymers has the advantage of allowing the deposition of conjugated materials by solution deposition techniques, such as ink‐jet, since the macrocycles after deposition can be converted directly on the substrate, in the absence of any external initiator, into solvent intractable thin polymeric films. Copyright © 2008 John Wiley & Sons, Ltd.
Delays in diagnosis and treatment among children and adolescents with cancer in Canada
Authors: Dang‐Tan Tam , Trottier Helen , Mery Leslie S. , Morrison Howard I. , Barr Ronald D. , Greenberg Mark L. , Franco Eduardo L. 
Published: May 2008

AbstractBackgroundFew studies have investigated delays in diagnosis and treatment among children and adolescents with cancer, especially from the perspective of an entire country. Detailed understanding of delays along the continuum of cancer patient care is important in order to establish appropriate benchmarks for timely oncological care. Our objective was to characterise the different components of delay in 2,896 Canadian children and adolescents (aged 0–19 years) with cancer that were enrolled in the Treatment and Outcome Surveillance component of the Canadian Childhood Cancer Surveillance and Control Program from 1995 to 2000.ProcedureWe examined median and standardised means concerning the distribution of delay times across categories of pertinent variables and over time. The word “delay” was used simply to represent a time interval, measured in days, without implying whether this interval exceeded a particular threshold of clinical acceptability.ResultsThe median times (and inter‐quartile ranges) for patient, diagnosis and healthcare system delays for all cancers were 9 (1–31), 30 (13–69) and 12 (4–35) days, respectively. The median total delay was 34 (16–76) days.ConclusionsPatient and referral delays were the longest time segments influencing timely diagnosis. Differences in delays were observed across age groups, cancer types and geographical regions. There was a significant trend for decreasing delays to diagnosis and treatment. Pediatr Blood Cancer 2008;51:468–474. © 2008 Wiley‐Liss, Inc.
Drug‐induced torsades de pointes: a review of the Swedish pharmacovigilance database
Authors: Åström‐Lilja Cecilia , Odeberg Johanna Mercke , Ekman Elisabet , Hägg Staffan 
Published: May 2008

AbstractAimTo describe spontaneously reported cases of torsades de pointes (TdP) in Sweden and to investigate if this adverse drug reaction (ADR) was labelled in the summary of product characteristics (SPC) for the drugs implicated.MethodsReported cases of TdP 1991–2006 were identified and evaluated with regard to drug use and other possible risk factor.ResultsAmong a total of 61 788 ADRs, 88 cases of TdP were identified. In these cases, 27 different suspected drugs were implicated. Cardiac drugs were involved in most reports (74%; 65/88), with sotalol being the most frequently suspected drug (57%, 58/88). In addition to drug treatment two or more established risk factors were present in 85% of the cases (75/88). Heart disease (90%; 79/88) was the most common risk factor followed by age over 65 years (72%; 63/88) and female gender (70%; 62/88). TdP or QT prolongation were labelled in the SPC for 33% (9/27) of the drugs implicated in the 88 cases. However, supporting evidence for an association was found elsewhere in 56% (15/27) for the different drugs implicated in the reports. Although citalopram was the third most common suspected drug in the reports (10%; 9/88), TdP was not listed in the SPC.ConclusionTdP is a rarely reported ADR. Several risk factors are often present. In two thirds of the drugs implicated in the reports neither TdP nor QT prolongation was labelled in the SPC. Further investigations are needed regarding the association between citalopram and TdP. Copyright © 2008 John Wiley & Sons, Ltd.
A cross‐species quantitative proteomic study of salt adaptation in a halotolerant environmental isolate using 15N metabolic labelling
Authors: Pandhal Jagroop , Snijders Ambrosius P. L. , Wright Phillip C. , Biggs Catherine A. 
Published: May 2008

AbstractWe examine differential protein expression in Euhalothece sp. BAA001, an extremely halotolerant and unsequenced cyanobacterium, under adaptation to low (0% w/v), medium (3% w/v), high (6% w/v) and very high (9% w/v) salt concentrations using cross‐species protein identification tools. We combine stable isotope labelling with 1‐D SDS‐PAGE, and MASCOT protein identification software with MS‐driven BLAST searches, to produce an accurate method for protein identification and quantitation. The use of metabolic labelling to improve the confidence in identification of proteins in cross‐species proteomics is demonstrated. Three hundred and eighty‐three unique proteins were identified, and 72 were deemed to be differentially expressed (average CV for quantitations was 0.10 ± 0.08), belonging to 24 functional groups. Responses to low salt as well as high salt are discussed in terms of adaptation and evidence shows that Euhalothece cells display ‘stress’ responses in nonsaline conditions as well as higher salt environments.
Metal hydroxystannates as flame retardants and smoke suppressants for semirigid poly(vinyl chloride)
Authors: Qu Hongqiang , Wu Weihong , Wei Haiying , Xu Jianzhong 
Published: May 2008

AbstractMetal hydroxystannates were studied as flame retardants and smoke suppressants for semirigid poly(vinyl chloride) (PVC). The flame‐retardant and smoke‐suppression mechanisms were investigated by using limiting oxygen index (LOI), smoke density rating (SDR), the solid yield test (SY), scanning electron microscopy (SEM), thermogravimetry, differential thermogravimetry, and differential thermal analysis. Results showed that semirigid PVC treated with the flame retardants had a higher LOI, and solid yield, but a lower SDR and maximum smoke density, thereby indicating that the flame‐retardance and smoke‐suppression properties of the treated PVC were improved and that the hydroxystannate compounds could be used as highly effective flame retardants. The tin compounds may exert their action in both the condensed and vapor phases, but mainly in the condensed phase as Lewis acids. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.