bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Novel SOFC's Comprising Thin-Film Nanostructured Electrolyte Layers
Authors: Van Gestel Tim , Sebold Doris , Buchkremer Hans Peter , Stöver Detlev
Published: September 2009

This paper reports a study on the preparation of thin nano-structured 8YSZ membrane films, which can be sintered to full density at a lower temperature (~ 1200{degree sign}C) than currently applied in SOFC manufacturing (> 1400{degree sign}C). For the deposition process, four different coating liquids with varying particle size, covering the range from 85 nm to 6 nm, were prepared. In the first part, it is demonstrated that nano-dispersions with a particle size of e.g. 85 or 60 nm can be used for the formation of dense YSZ membranes with a thickness of 1 - 2 µm on a regular macroporous SOFC anode, but the layers can only be sintered to full density at 1400{degree sign}C. In the second part, ultra-thin YSZ membranes are prepared by sol-gel coating (particle size 35 and 6 nm). These layers show a thickness < 500 nm and a very tight mesoporous or microporous structure in the calcined state (pore size < 5 nm), which allows a sintering treatment in the desired temperature range (~ 1200{degree sign}C).
In-Plane Conductivities of Atomic Layer Deposited Yttria-Stabilized Zirconia Electrolytes for Solid Oxide Fuel Cells
Authors: Chao Cheng-Chieh , Park Joon Seok , Prinz F B.
Published: September 2009

We investigated oxide ion conductivities of ultra-thin (8 nm - 55 nm) yttria-stabilized zirconia (YSZ) films produced by atomic layer deposition (ALD). In-plane oxide ion conductivities were measured as a function of film thickness, temperature, and yttria concentration in the film. We observed higher conductivities for thinner films due to the portion of oxide ion conduction along the surface increased. We also observed changes in conductivities by modifying yttria concentrations near the surfaces, and the optimal concentration near the surface was different from the bulk.
In Situ XPS for Evaluating Ceria Oxidation States in SOFC Anodes
Authors: DeCaluwe Steven C. , Jackson Gregory S. , Farrow Roger , McDaniel Anthony , El Gabaly Farid , McCarty Kevin , Nie Shu , Linne Mark , Bluhm Hendrik , Newberg John , Liu Zhi , Hussain Zahid
Published: September 2009

Ceria is being considered as an electrocatalyst component for fuel-flexible SOFC anodes. With Ce3+ and Ce4+ oxidation states, ceria can function as a mixed ionic-electronic conductor, transporting both O2- ions and electrons. It remains unclear what role these oxidation states play during SOFC operation. This study addresses these issues using ambient-pressure XPS in a single-chamber cell to characterize thin-film CeO2-x electrodes on a YSZ electrolyte during electrochemical oxidation of H2 and reduction of H2O at 620 {degree sign}C. Voltage-current curves for the ceria film electrodes reveal sharp changes in resistance as a function of applied voltage from positive to negative bias. XPS measurements during electrochemical characterization show the extent of near-surface Ce4+ reduction to Ce3+ with increasing cell voltage. Increased oxidation to Ce4+ at large negative voltages correlates with a resistance drop due to H2 oxidation activity. These findings provide insight into how CeO2-x influences electrochemical fuel oxidation or H2O reduction.
First Principles Study on Electronic Structures of Ni/H/ZrO2 Triple Phase Boundary
Authors: Tada Tomofumi , Kasamatsu Syusuke , Watanabe Satoshi
Published: September 2009

We have investigated the electronic structures of Ni/H/ZrO2 triple phase boundary (TPB) from first principles. For this purpose, we constructed a novel computational model for the TPB having a point contact of a Ni-tip and ZrO2(111) surface. We examined several locations of the tip with respect to the ZrO2(111) surface, and found that the fcc location of the Ni-tip is the most stable point contact TPB. The projected density of states (PDOS) of the apex Ni atom of the point contact TPB shows a large and sharp peak at 0.5 eV above the Fermi level. Such a large peak, on the other hand, is not seen in Ni(111) surface without Ni protrusions. We also revealed that the adsorption of hydrogen atom at the Ni-tip leads to a wider peak of PDOS of the apex Ni atom.
Rechargeable Direct Carbon Solid Oxide Fuel Cells with a Gadolinium-doped Ceria (GDC) Anode and a La0.15Sr0.85MnO3/GDC Anode
Authors: Tagawa Yuki , Saito Haruyuki , Ihara Manabu
Published: September 2009

Rechargeable direct carbon solid oxide fuel cells (RDCFCs) with oxide anodes were developed. An RDCFC directly uses solid carbon fuel deposited on the anode surface through pyrolysis of hydrocarbon fuel. High power density and stable power generation of RDCFCs with Ni cermets have been reported previously although Ni is known as a long-term degradation factor. In this research, two oxide anodes, namely, LSM/GDC and GDC, were applied and their electrochemical profiles investigated. With scandia-stabilized-zirconia electrolyte, the maximum power density of an RDCFC with a 65-µm-thick LSM/GDC anode reached 131 mW/cm2 and that of an RDCFC with a 65µm-thick GDC anode reached 95 mW/cm2. Effective anode thickness of the GDC anode for electrochemical reaction was more than 65µm, which was much thicker than that previously reported for a Ni/GDC anode (<12 µm).
Effectiveness of Ga Additive to Sinterability and Electrical Properties on Y-Doped BaZrO3 Proton Conductors Sintered at 1600{degree sign}C
Authors: Iguchi Fumitada , Sata Noriko , Yugami Hiroo
Published: September 2009

Gallium and yttrium co-doped BaZrO3 based proton conductors sintered at 1600oC, in which total dopant concentration is fixed at 15mol%, are fabricated using the conventional solid state reaction method. Ga concentration dependence on sinterability and electrical properties is evaluated. Lattice parameter a, relative density and grain size show local maximum at 1mol% Ga concentration, i.e. BaZr0.85Y0.14Ga0.01O2.925 (BZY14Ga1). Relative density of it is over 95%. Also, it is found that grain boundary conductivity of BZY15 is drastically improved by 1mol% Ga additives, although bulk conductivity is slightly lower than that of 15mol% Y-doped BaZrO3. As a result, total conductivity of BZY14Ga1 is highest in the specimens and the value is over 2 x 10-3 Scm-1. On the other hand, 3 and 5mol% Ga-doped specimens show significantly low bulk and grain boundary conductivity. So, the results suggest that the Ga additive is effective for sintering at 1600oC, but the range of concentration is very limited.
Water-Based Soft Chemical Synthesis of Apatite Type Lanthanum Silicate Powder in Nano-Scale
Authors: Kobayshi Kiyoshi , Oyama Yukiko , Miyoshi Shogo , Yamaguchi S. , Nishimura Chikashi
Published: September 2009

The low temperature synthesis route of lanthanum silicate oxyapatite was investigated by x-ray diffraction and by carrying out thermal analyses using a precursor prepared by a water-based sol-gel method. The precursor was heated at 873 K, and it was found to consist of a lanthanum oxycarbonate (type IA-La2O2CO3), which has a layered stacked structure consisting of two-dimensional (La2O2)n2+ and two (CO3)n2- layers, and amorphous silica. Lanthanum silicate oxyapatite was found to be formed both by the in-situ chemical pulverization of La2O2CO3 into a nano-sized La2O3 powder and a solid-state reaction between the nano-sized powders of La2O3 and amorphous SiO2.
SAXS/DSC/WAXD Study of γ-irradiated Polymer Electrolyte for Zn Rechargeable Nanostructured Galvanic Cells
Authors: Turković Aleksandra , Dubček Pavo , Pavlović Mladen , Bernstorff Sigrid
Published: September 2009

(PEO)8ZnCl2 polymer electrolytes and nano-composites were prepared using PEO γ-irradiated to dose of 529 kGy. The effect of γ-radiation from a Co-60 source were studied by small-angle Xray scattering (SAXS) simultaneously recorded with differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) at synchrotron ELETTRA. Above-mentioned treatment largely enhanced the conductivity of polymer electrolyte. Room temperature conductivity increase up to two orders of magnitude was achieved (1).
Functional Distinction Between Visuomovement and Movement Neurons in Macaque Frontal Eye Field During Saccade Countermanding
Authors: Ray Supriya , Pouget Pierre , Schall Jeffrey D.
Published: September 2009

In the previous studies on the neural control of saccade initiation using the countermanding paradigm, movement and visuomovement neurons in the frontal eye field were grouped as movement-related neurons. The activity of both types of neurons was modulated when a saccade was inhibited in response to a stop signal, and this modulation occurred early enough to contribute to the control of the saccade initiation. We now report a functional difference between these two classes of neurons when saccades are produced. Movement neurons exhibited a progressive accumulation of discharge rate following target presentation that triggered a saccade when it reached a threshold. When saccades were inhibited with lower probability in response to a stop signal appearing at longer delays, this accumulating activity was interrupted at levels progressively closer to the threshold. In contrast, visuomovement neurons exhibited a maintained elevated discharge rate following target presentation that was followed by a further enhancement immediately before the saccade initiation. When saccades were inhibited in response to a stop signal, the late enhancement was absent and the maintained activity decayed regardless of stop-signal delay. These results demonstrate that the activity of movement neurons realizes the progressive commitment to the saccade initiation modeled by the activation of the go unit in computational models of countermanding performance. The lack of correspondence of the activity of visuomovement neurons with any elements of these models indicates that visuomovement neurons perform a function other than the saccade preparation such as a corollary discharge to update visual processing.
TrkBT1 Induces Liver Metastasis of Pancreatic Cancer Cells by Sequestering Rho GDP Dissociation Inhibitor and Promoting RhoA Activation
Authors: Li Zhongkui , Chang Zhe , Chiao Lucia J. , Kang Ya'an , Xia Qianghua , Zhu Cihui , Fleming Jason B. , Evans Douglas B. , Chiao Paul J.
Published: September 2009

Many genetic and molecular alterations, such as K-ras mutation and NF-κB activation, have been identified in pancreatic cancer. However, the mechanisms by which pancreatic cancer metastasizes still remain to be determined. Although we previously showed that the tropomyosin-related kinase B (TrkB) was significantly correlated with the development of liver metastasis, its function in pancreatic cancer metastasis remained unresolved. In the present study, we showed that overexpressed TrkB is an alternatively spliced transcript variant of TrkB (TrkBT1) with a unique COOH-terminal 12–amino acid sequence and is mainly localized in the cytoplasm. Our results showed that overexpression of Flag-tagged TrkBT1 but not a Flag-tagged TrkBT1 COOH-terminal deletion mutant (Flag-TrkBT1ΔC) in nonmetastatic pancreatic cancer cells enhanced cell proliferation, promoted formation of colonies in soft agar, stimulated tumor cell invasion, and induced liver metastasis in an orthotopic xenograft mouse model of pancreatic cancer. TrkBT1 interacted with Rho GDP dissociation inhibitor (GDI) in vivo, but Flag-TrkBT1ΔC did not. Furthermore, overexpression of Flag-TrkBT1 and knockdown of RhoGDI expression by RhoGDI short hairpin RNAs promoted RhoA activation, but Flag-TrkBT1ΔC overexpression did not. Therefore, our results showed that TrkBT1 overexpression induces liver metastasis of pancreatic cancer and uncovered a unique signaling mechanism by which TrkBT1 sequesters GDI and activates RhoA signaling. [Cancer Res 2009;69(19):7851–9]
Acting Locally and Globally: Myc's Ever-Expanding Roles on Chromatin
Authors: Varlakhanova Natalia V. , Knoepfler Paul S.
Published: September 2009

Myc regulates key cellular processes including cell cycle, differentiation, and apoptosis. It has long been thought to direct these functions by acting solely as a classic transcription factor regulating expression of a small number of key target genes through discrete chromatin events in their promoters. A recent wave of genomics studies together directly challenge the narrowness of this model. For example, Myc binds to tens of thousands of sites in the human genome. It also regulates histone acetylation at and transcription of a remarkable number of genes, far beyond that expected of a classical transcription factor. The influence of Myc on chromatin also surprisingly extends to both genic and expansive intergenic regions. These studies support an evolving model in which Myc activity on chromatin is far more complex than previously imagined. The ability of Myc to act both locally and globally on chromatin may be responsible for its wide-ranging effects on the biology of stem and tumor cells. [Cancer Res 2009;69(19):7487–90]
Molecular Distinctions between Stasis and Telomere Attrition Senescence Barriers Shown by Long-term Culture of Normal Human Mammary Epithelial Cells
Authors: Garbe James C. , Bhattacharya Sanchita , Merchant Batul , Bassett Ekaterina , Swisshelm Karen , Feiler Heidi S. , Wyrobek Andrew J. , Stampfer Martha R.
Published: September 2009

Normal human epithelial cells in culture have generally shown a limited proliferative potential of ∼10 to 40 population doublings before encountering a stress-associated senescence barrier (stasis) associated with elevated levels of cyclin-dependent kinase inhibitors p16 and/or p21. We now show that simple changes in medium composition can expand the proliferative potential of human mammary epithelial cells (HMEC) initiated as primary cultures to 50 to 60 population doublings followed by p16-positive, senescence-associated β-galactosidase–positive stasis. We compared the properties of growing and senescent pre-stasis HMEC with growing and senescent post-selection HMEC, that is, cells grown in a serum-free medium that overcame stasis via silencing of p16 expression and that display senescence associated with telomere dysfunction. Cultured pre-stasis populations contained cells expressing markers associated with luminal and myoepithelial HMEC lineages in vivo in contrast to the basal-like phenotype of the post-selection HMEC. Gene transcript and protein expression, DNA damage–associated markers, mean telomere restriction fragment length, and genomic stability differed significantly between HMEC populations at the stasis versus telomere dysfunction senescence barriers. Senescent isogenic fibroblasts showed greater similarity to HMEC at stasis than at telomere dysfunction, although their gene transcript profile was distinct from HMEC at both senescence barriers. These studies support our model of the senescence barriers encountered by cultured HMEC in which the first barrier, stasis, is retinoblastoma-mediated and independent of telomere length, whereas a second barrier (agonescence or crisis) results from telomere attrition leading to telomere dysfunction. Additionally, the ability to maintain long-term growth of genomically stable multilineage pre-stasis HMEC populations can greatly enhance experimentation with normal HMEC. [Cancer Res 2009;69(19):7557–68]
Nitrosative Stress–Induced S-Glutathionylation of Protein Disulfide Isomerase Leads to Activation of the Unfolded Protein Response
Authors: Townsend Danyelle M. , Manevich Yefim , He Lin , Xiong Ying , Bowers Robert R. , Hutchens Steven , Tew Kenneth D.
Published: September 2009

The rapid proliferation of cancer cells mandates a high protein turnover. The endoplasmic reticulum (ER) is intimately involved in protein processing. An accumulation of unfolded or misfolded proteins in the ER leads to a cascade of transcriptional and translational events collectively called the unfolded protein response (UPR). Protein disulfide isomerase (PDI) is one of the most abundant ER proteins and maintains a sentinel function in organizing accurate protein folding. Treatment of cells with O2-[2,4-dinitro-5-(N-methyl-N-4-carboxyphenylamino)phenyl]1-(N,N-dimethylamino)diazen-1-ium-1,2-diolate (PABA/NO) resulted in a dose-dependent increase in intracellular nitric oxide that caused S-glutathionylation of various proteins. Within 4 h, PABA/NO activated the UPR and led to translational attenuation as measured by the phosphorylation and activation of the ER transmembrane kinase, pancreatic ER kinase, and its downstream effector eukaryotic initiation factor 2 in human leukemia (HL60) and ovarian cancer cells (SKOV3). Cleavage of the transcription factor X-box protein 1 and transcriptional activation of the ER resident proteins BiP, PDI, GRP94, and ERO1 (5- to 10-fold induction) also occurred. Immunoprecipitation of PDI showed that whereas nitrosylation was undetectable, PABA/NO treatment caused S-glutathionylation of PDI. Mass spectroscopy analysis showed that single cysteine residues within each of the catalytic sites of PDI had a mass increase [+305.3 Da] consistent with S-glutathionylation. Circular dichroism confirmed that S-glutathionylation of PDI results in alterations in the α-helix content of PDI and is concurrent with inhibition of its isomerase activity. Thus, it appears that S-glutathionylation of PDI is an upstream signaling event in the UPR and may be linked with the cytotoxic potential of PABA/NO. [Cancer Res 2009;69(19):7626–34]
MicroRNA-34a Inhibits Glioblastoma Growth by Targeting Multiple Oncogenes
Authors: Li Yunqing , Guessous Fadila , Zhang Ying , DiPierro Charles , Kefas Benjamin , Johnson Elizabeth , Marcinkiewicz Lukasz , Jiang Jinmai , Yang Yanzhi , Schmittgen Thomas D. , Lopes Beatriz , Schiff David , Purow Benjamin , Abounader Roger
Published: September 2009

MicroRNA-34a (miR-34a) is a transcriptional target of p53 that is down-regulated in some cancer cell lines. We studied the expression, targets, and functional effects of miR-34a in brain tumor cells and human gliomas. Transfection of miR-34a down-regulated c-Met in human glioma and medulloblastoma cells and Notch-1, Notch-2, and CDK6 protein expressions in glioma cells. miR-34a expression inhibited c-Met reporter activities in glioma and medulloblastoma cells and Notch-1 and Notch-2 3′-untranslated region reporter activities in glioma cells and stem cells. Analysis of human specimens showed that miR-34a expression is down-regulated in glioblastoma tissues as compared with normal brain and in mutant p53 gliomas as compared with wild-type p53 gliomas. miR-34a levels in human gliomas inversely correlated to c-Met levels measured in the same tumors. Transient transfection of miR-34a into glioma and medulloblastoma cell lines strongly inhibited cell proliferation, cell cycle progression, cell survival, and cell invasion, but transfection of miR-34a into human astrocytes did not affect cell survival and cell cycle status. Forced expression of c-Met or Notch-1/Notch-2 transcripts lacking the 3′-untranslated region sequences partially reversed the effects of miR-34a on cell cycle arrest and cell death in glioma cells and stem cells, respectively. Also, transient expression of miR-34a in glioblastoma cells strongly inhibited in vivo glioma xenograft growth. Together, these findings represent the first comprehensive analysis of the role of miR-34a in gliomas. They show that miR-34a suppresses brain tumor growth by targeting c-Met and Notch. The results also suggest that miR-34a could serve as a potential therapeutic agent for brain tumors. [Cancer Res 2009;69(19):7569–76]
Adipocytes Impair Leukemia Treatment in Mice
Authors: Behan James W. , Yun Jason P. , Proektor Marina P. , Ehsanipour Ehsan A. , Arutyunyan Anna , Moses Ara S. , Avramis Vassilios I. , Louie Stan G. , Butturini Anna , Heisterkamp Nora , Mittelman Steven D.
Published: September 2009

Obesity is associated with increased cancer incidence and mortality. We have previously found that obesity in children is associated with a 50% increased recurrence of acute lymphoblastic leukemia (ALL) in high-risk patients. We have therefore developed novel in vivo and in vitro preclinical models to study the mechanism(s) of this association. Obesity increased relapse after monotherapy with vincristine (P = 0.03) in obese mice injected with syngeneic ALL cells. This occurred although the drug was dosed proportionally to body weight, equalizing blood and tissue drug levels. In coculture, 3T3-L1 adipocytes significantly impaired the antileukemia efficacy of vincristine, as well as three other chemotherapies (P < 0.05). Interestingly, this protection was independent of cell-cell contact, and it extended to human leukemia cell lines as well. Adipocytes prevented chemotherapy-induced apoptosis, and this was associated with increased expression of the two prosurvival signals Bcl-2 and Pim-2. These findings highlight the role of the adipocyte in fostering leukemia chemotherapy resistance, and may help explain the increased leukemia relapse rate in obese children and adults. Given the growing prevalence of obesity worldwide, these effects are likely to have increasing importance to cancer treatment. [Cancer Res 2009;69(19):7867–74]
c-Myc and eIF4F Constitute a Feedforward Loop That Regulates Cell Growth: Implications for Anticancer Therapy
Authors: Lin Chen-Ju , Malina Abba , Pelletier Jerry
Published: September 2009

The Myc/Max/Mad family of transcription factors and the eukaryotic initiation factor 4F (4F) complex play fundamental roles in regulating cell growth, proliferation, differentiation, and oncogenic transformation. Recent findings indicate that the role of Myc during cell growth and proliferation is linked to an increase in eIF4F activity in a feedforward relationship, providing a possible molecular mechanism of cell transformation by Myc. Developing therapeutics to inhibit eIF4F and/or Myc could be a potential treatment for a wide range of human cancers. [Cancer Res 2009;69(19):7491–4]
Expression of IFN-β Enhances Both Efficacy and Safety of Oncolytic Vesicular Stomatitis Virus for Therapy of Mesothelioma
Authors: Willmon Candice L. , Saloura Vassiliki , Fridlender Zvi G. , Wongthida Phonphimon , Diaz Rosa Maria , Thompson Jill , Kottke Timothy , Federspiel Mark , Barber Glen , Albelda Steven M. , Vile Richard G.
Published: September 2009

Our preclinical and clinical trials using a replication-defective adenoviral vector expressing IFN-β have shown promising results for the treatment of malignant mesothelioma. Based on the hypotheses that a replication-competent vesicular stomatitis virus (VSV) oncolytic vector would transduce more tumor cells in vivo, that coexpression of the immunostimulatory IFN-β gene would enhance the immune-based effector mechanisms associated both with regression of mesotheliomas and with VSV-mediated virotherapy, and that virus-derived IFN-β would add further safety to the VSV platform, we tested the use of IFN-β as a therapeutic transgene expressed from VSV as a novel treatment for mesothelioma. VSV-IFN-β showed significant therapy against AB12 murine mesotheliomas in the context of both local and locoregional viral delivery. Biologically active IFN-β expressed from VSV added significantly to therapy compared with VSV alone, dependent in part on host CD8+ T-cell responses. Immune monitoring suggested that these antitumor T-cell responses may be due to a generalized T-cell activation rather than the priming of tumor antigen–specific T-cell responses. Finally, IFN-β also added considerable extra safety to the virus by providing protection from off-target viral replication in nontumor tissues and protected severe combined immunodeficient mice from developing lethal neurotoxicity. The enhanced therapeutic index provided by the addition of IFN-β to VSV therefore provides a powerful justification for the development of this virus for future clinical trials. [Cancer Res 2009;69(19):7713–20]
Rearrangements and Amplification of IER3 (IEX-1) Represent a Novel and Recurrent Molecular Abnormality in Myelodysplastic Syndromes
Authors: Steensma David P. , Neiger Jessemy D. , Porcher Julie C. , Keats J. Jonathan , Bergsagel P. Leif , Dennis Thomas R. , Knudson Ryan A. , Jenkins Robert B. , Santana-Davila Rafael , Kumar Rajiv , Ketterling Rhett P.
Published: September 2009

IER3 (formerly IEX-1) encodes a 27-kDa glycoprotein that regulates death receptor–induced apoptosis, interacts with NF-κB pathways, and increases expression rapidly in response to cellular stresses such as irradiation. Animal models, gene expression microarray experiments, and functional studies in cell lines have suggested a potential role for IER3 in oncogenesis, but, to date, no abnormalities of IER3 at the DNA level have been reported in patients with neoplasia. Here, we describe breakpoint cloning of a t(6;9)(p21;q34) translocation from a patient with a myelodysplastic syndrome (MDS), facilitated by conversion technology and array-based comparative genomic hybridization, which revealed a rearrangement translocating the IER3 coding region away from critical flanking/regulatory elements and to a transcript-poor chromosomal region, markedly decreasing expression. Using split-signal and locus-specific fluorescence in situ hybridization (FISH) probes, we analyzed 204 patients with diverse hematological malignancies accompanied by clonal chromosome 6p21 abnormalities, and found 8 additional patients with MDS with IER3 rearrangements (translocations or amplification). Although FISH studies on 157 additional samples from patients with MDS and a normal-karyotype were unrevealing, and sequencing the IER3 coding and proximal promoter regions of 74 MDS patients disclosed no point mutations, reverse transcription-PCR results suggested that dysregulated expression of IER3 is common in MDS (61% >4-fold increase or decrease in expression with decreased expression primarily in early MDS and increased expression primarily in later MDS progressing toward leukemia), consistent with findings in previous microarray experiments. These data support involvement of IER3 in the pathobiology of MDS. [Cancer Res 2009;69(19):7518–23]
Identification of a Small Molecule Inhibitor of the Human DNA Repair Enzyme Polynucleotide Kinase/Phosphatase
Authors: Freschauf Gary K. , Karimi-Busheri Feridoun , Ulaczyk-Lesanko Agnieszka , Mereniuk Todd R. , Ahrens Ashley , Koshy Jonathan M. , Rasouli-Nia Aghdass , Pasarj Phuwadet , Holmes Charles F.B. , Rininsland Frauke , Hall Dennis G. , Weinfeld Michael
Published: September 2009

Human polynucleotide kinase/phosphatase (hPNKP) is a 57.1-kDa enzyme that phosphorylates DNA 5′-termini and dephosphorylates DNA 3′-termini. hPNKP is involved in both single- and double-strand break repair, and cells depleted of hPNKP show a marked sensitivity to ionizing radiation. Therefore, small molecule inhibitors of hPNKP should potentially increase the sensitivity of human tumors to γ-radiation. To identify small molecule inhibitors of hPNKP, we modified a novel fluorescence-based assay to measure the phosphatase activity of the protein, and screened a diverse library of over 200 polysubstituted piperidines. We identified five compounds that significantly inhibited hPNKP phosphatase activity. Further analysis revealed that one of these compounds, 2-(1-hydroxyundecyl)-1-(4-nitrophenylamino)-6-phenyl-6,7a-dihydro-1H-pyrrolo[3,4-b]pyridine-5,7(2H,4aH)-dione (A12B4C3), was the most effective, with an IC50 of 0.06 μmol/L. When tested for its specificity, A12B4C3 displayed no inhibition of two well-known eukaryotic protein phosphatases, calcineurin and protein phosphatase-1, or APTX, another human DNA 3′-phosphatase, and only limited inhibition of the related PNKP from Schizosaccharomyces pombe. At a nontoxic dose (1 μmol/L), A12B4C3 enhanced the radiosensitivity of human A549 lung carcinoma and MDA-MB-231 breast adenocarcinoma cells by a factor of two, which was almost identical to the increased sensitivity resulting from shRNA-mediated depletion of hPNKP. Importantly, A12B4C3 failed to increase the radiosensitivity of the hPNKP-depleted cells, implicating hPNKP as the principal cellular target of A12B4C3 responsible for increasing the response to radiation. A12B4C3 is thus a useful reagent for probing hPNKP cellular function and will serve as the lead compound for further development of PNKP-targeting drugs. [Cancer Res 2009;69(19):7739–46]
Metastamir: The Field of Metastasis-Regulatory microRNA Is Spreading
Authors: Hurst Douglas R. , Edmonds Mick D. , Welch Danny R.
Published: September 2009

Despite advancements in knowledge from more than a century of metastasis research, the genetic programs and molecular mechanisms required for cancer metastasis are still incompletely understood. Genes that specifically regulate the process of metastasis are useful tools to elucidate molecular mechanisms and may become markers and/or targets for antimetastatic therapy. Recently, several noncoding regulatory RNA genes, microRNA (miRNA), were identified, which play roles in various steps of metastasis, some without obvious roles in tumorigenesis. Understanding how these metastasis-associated miRNA, which we term metastamir, are involved in metastasis will help identify possible biomarkers or targets for the most lethal attribute of cancer: metastasis. [Cancer Res 2009;69(19):7495–8]
Combined Bcl-2/Mammalian Target of Rapamycin Inhibition Leads to Enhanced Radiosensitization via Induction of Apoptosis and Autophagy in Non–Small Cell Lung Tumor Xenograft Model
Authors: Kim Kwang Woon , Moretti Luigi , Mitchell Lauren Rhea , Jung Dae Kwang , Lu Bo
Published: September 2009

Purpose: Radiotherapy has a central role in the treatment of non–small cell lung cancer. Effectiveness of this modality, however, is often limited as resistance results from defects in cell death.

Experimental Design: We investigated whether simultaneous up-regulation of apoptosis, via Bcl-2 inhibitor ABT-737, and autophagy, via mammalian target of rapamycin inhibitor rapamycin, can be used to enhance radiosensitivity of H460 cells in vitro and growth delay in a xenograft model.

Results: In vitro studies confirmed that ABT-737 and rapamycin induce apoptosis and autophagy, respectively. ABT-737 induced cleaved caspase-3, a marker of apoptosis, and rapamycin correlated with an increase in punctate localization of green fluorescent protein-LC3, characteristic of autophagy. The combination ABT-737/rapamycin markedly enhanced sensitivity of H460 cells to radiation (dose enhancement ratio = 2.47; P = 0.002) in clonogenic assay. In addition, the combination ABT-737/rapamycin/radiation showed a dramatic tumor growth delay in a mouse xenograft model. In vivo immunohistochemistry staining showed that combination therapy yielded over a 100% increase in caspase-3 activity (apoptosis) and a 6-fold decrease in p62 protein level (indicative of autophagic flux) compared with radiation alone control group. Moreover, cell proliferation (Ki-67 staining) was reduced by 77% (P = 0.001) and vascular density (von Willebrand factor staining) by 67.5% (P = 0.09) compared with radiation alone. Additional in vitro studies in human umbilical vein endothelial cells indicated that combined therapy also significantly decreases tubule formation.

Conclusion: These results suggest that concurrent induction of apoptosis and autophagy enhances radiation therapy both in vitro and in lung cancer xenograft models. Further investigations are warranted to assess the clinical potential of such strategy in lung cancer patients. (Clin Cancer Res 2009;15(19):6096–105)
Synergistic Effects of Oncolytic Reovirus and Cisplatin Chemotherapy in Murine Malignant Melanoma
Authors: Pandha Hardev S. , Heinemann Lucy , Simpson Guy R. , Melcher Alan , Prestwich Robin , Errington Fiona , Coffey Matt , Harrington Kevin J. , Morgan Richard
Published: September 2009

Purpose: To test combination treatment schedules of reovirus and cisplatin chemotherapy in human and murine melanoma cell lines and murine models of melanoma and to investigate the possible mechanisms of synergistic antitumor effects.

Experimental Design: The effects of reovirus ± chemotherapy on in vitro cytotoxicity and viral replication were assessed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay and plaque assay. Interactions between agents were assessed by combination index analysis. Mode of cell death was assessed by Annexin V/propidium iodide fluorescence-activated cell sorting–based assays; gene expression profiling of single versus combination treatments was completed using the Agilent microarray system. Single agent and combination therapy effects were tested in vivo in two immunocompetent models of murine melanoma.

Results: Variable degrees of synergistic cytotoxicity between live reovirus and several chemotherapy agents were observed in B16.F10 mouse melanoma cells, most significantly with cisplatin (combination index of 0.42 ± 0.03 at ED50). Combination of cisplatin and reovirus exposure led to increased late apoptotic/necrotic cell populations. Cisplatin almost completely abrogated the inflammatory cytokine gene up-regulation induced by reovirus. Combination therapy led to significantly delayed tumor growth and improved survival in vivo (P < 0.0001 and P = 0.0003, respectively). Cisplatin had no effect on the humoral response to reovirus in mice. However, cisplatin treatment suppressed the cytokine and chemokine response to reovirus in vitro and in vivo.

Conclusion: The combination of reovirus and several chemotherapeutic agents synergistically enhanced cytotoxicity in human and murine melanoma cell lines in vitro and murine tumors in vivo. The data support the current reovirus/chemotherapy combination phase I clinical studies currently ongoing in the clinic. (Clin Cancer Res 2009;15(19):6158–66)
Recent Natural Selection Identifies a Genetic Variant in a Regulatory Subunit of Protein Phosphatase 2A that Associates with Altered Cancer Risk and Survival
Authors: Grochola Lukasz F. , Vazquez Alexei , Bond Elisabeth E. , Würl Peter , Taubert Helge , Müller Thomas H. , Levine Arnold J. , Bond Gareth L.
Published: September 2009

Purpose: A regulated p53-dependent stress response is crucial in suppressing tumor formation and mediating the response to commonly used cancer therapeutics. However, little is known about the human, inherited genetics of this important signaling pathway.

Experimental Design: Studies of human genetic variants in the p53 tumor suppressor gene and MDM2 oncogene have shown that single nucleotide polymorphisms (SNP) can affect p53 signaling, confer cancer risk, and alter outcome, and also suggest that the pathway is under evolutionary selective pressure. Here, we attempt to accelerate the identification of functional p53 pathway SNPs by incorporating these characteristics into an analysis of 142 genes that are known to affect p53 signaling.

Results: We report that a genomic scan for recent natural selection denotes that of the 142 genes studied, the PPP2R5E gene that encodes a regulatory subunit of the tumor suppressing protein phosphatase 2A resides in a naturally selected genomic region. We go on to show that a selected SNP in PPP2R5E (ϵ-SNP2) associates with significant allelic differences in the onset (up to 19.2 years; P = 0.0002) and risk (odds ratio, up to 8.1; P = 0.0009) of soft tissue sarcoma development, as well as overall survival (relative risk, up to 3.04; P = 0.026).

Conclusions: The PPP2R5E gene is identified as harboring genetic variants that can affect human cancer and are possibly under evolutionary selection pressure. (Clin Cancer Res 2009;15(19):6301–8)
FADS Gene Cluster Polymorphisms: Important Modulators of Fatty Acid Levels and Their Impact on Atopic Diseases
Authors: Lattka Eva , Illig Thomas , Heinrich Joachim , Koletzko Berthold
Published: September 2009

Long-chain polyunsaturated fatty acids (LC-PUFAs) play an important role in several physiological processes and their concentration in phospholipids has been associated with several complex diseases, such as atopic disease. The level and composition of LC-PUFAs in the human body is highly dependent on their intake in the diet or on the intake of fatty acid precursors, which are endogenously elongated and desaturated to physiologically active LC-PUFAs. The most important enzymes in this reaction cascade are the Δ5 and Δ6 desaturase. Several studies in the last few years have revealed that single nucleotide polymorphisms (SNPs) in the 2 desaturase encoding genes (FADS1 and FADS2) are highly associated with the concentration of ω–6 and ω–3 fatty acids, showing that beside nutrition, genetic factors also play an important role in the regulation of LC-PUFAs. This review focuses on current knowledge of the impact of genetic polymorphisms on LC-PUFA metabolism and on their potential role in the development of atopic diseases.
ω–3 Fatty Acids, Genetic Variants in COX-2 and Prostate Cancer
Authors: Reese Adam C. , Fradet Vincent , Witte John S.
Published: September 2009

Dietary intake of fish and ω–3 polyunsaturated fatty acids (ω–3 PUFAs) may decrease the risk of prostate cancer development and progression to advanced stage disease. This could reflect the anti-inflammatory effects of PUFAs, possibly through mediation of cyclooxygenase (COX), a key enzyme in fatty acid metabolism and inflammation. Despite promising experimental evidence, epidemiological studies have reported somewhat conflicting results regarding the effects of fish/PUFAs on prostate cancer development and progression. The literature suggests that fish, and particularly long-chain ω–3 PUFAs, may have a more pronounced protective effect on biologically aggressive tumors or on their progression, and less on early steps of carcinogenesis. Moreover, the impact of LC ω–3 PUFAs may be modified by variation of the COX-2 gene. Overall, results to date support the hypothesis that long-chain ω–3 PUFAs may impact prostate inflammation and carcinogenesis via the COX-2 enzymatic pathway.
Prenatal Diagnosis of Oral Cyst Caused by Foregut Duplication
Authors: Aviram Rami , Yaffe Daniel , Kidron Dvora , Tepper Ronnie , Regev Rivka
Published: September 2009

Prenatal diagnosis of oral cystic lesions is rare but is reported more frequently. The diagnosis of sublingual cyst is important because of the potential for airway obstruction. A rare case of a foregut duplication cyst associated with unilateral sclerocorneal microphthalmia is reported. The differential diagnosis and the limitations of the prenatal ultrasound and the postnatal MRI are discussed.
Changes in Alcohol-Related Harm after Alcohol Policy Changes in Denmark
Authors: Bloomfield Kim , Rossow Ingeborg , Norström Thor
Published: September 2009

Objectives: This paper examines changes in alcohol-related harm in Denmark between 2003 and 2005 after changes in alcohol policies were introduced between 2003 and 2005. Methods: Interrupted time series analysis was performed with data on violent assaults and hospitalisations for acute alcohol intoxication from 2003 through 2005. Results: A 26% increase in the number of acute alcohol intoxication hospitalisations among people aged 15 years and younger was detected after the tax reduction on spirits. No significant increase in violent assaults and acute intoxication among adults was found. Conclusions: Even modest alcohol price policies can affect more vulnerable population sub-groups such as under-age youth. Policy makers should consider such consequences when forming economic policies that also have public health implications.
Bioinformatic Analyses of Transmembrane Transport: Novel Software for Deducing Protein Phylogeny, Topology, and Evolution
Authors: Yen Ming Ren , Choi Jeehye , Saier Jr. Milton H.
Published: September 2009

During the past decade, we have experienced a revolution in the biological sciences resulting from the flux of information generated by genome-sequencing efforts. Our understanding of living organisms, the metabolic processes they catalyze, the genetic systems encoding cellular protein and stable RNA constituents, and the pathological conditions caused by some of these organisms has greatly benefited from the availability of complete genomic sequences and the establishment of comprehensive databases. Many research institutes around the world are now devoting their efforts largely to genome sequencing, data collection and data analysis. In this review, we summarize tools that are in routine use in our laboratory for characterizing transmembrane transport systems. Applications of these tools to specific transporter families are presented. Many of the computational approaches described should be applicable to virtually all classes of proteins and RNA molecules.
Cardiac Autonomic Regulation under Hypnosis Assessed by Heart Rate Variability: Spectral Analysis and Fractal Complexity
Authors: Aubert André E. , Verheyden Bart , Beckers Frank , Tack Jan , Vandenberghe Joris
Published: September 2009

Objective: This study examined the effects of hypnosis on autonomic cardiac control. We hypothesized a modification of autonomic modulation of the heart rate with an enhanced vagal tone during hypnosis compared to baseline. Methods: In 12 healthy subjects (6 men and 6 women, 22.2 ± 1.0 years of age) ECG was recorded at baseline and during hypnosis. Heart rate variability parameters were obtained in the frequency domain (LFnu: low frequency normalized units, and HFnu: high frequency normalized units) and from nonlinear analysis methods (detrended fluctuation analysis, DFA). Results: Compared to the control condition, hypnosis showed a significantly decreased LFnu, a significantly increased HFnu, and a significantly decreased LF/HF. DFA showed a significantly decreased short-range similarity. Heart rate remained unchanged. Conclusion: Autonomic cardiac tone is significantly modified during hypnosis by shifting the balance of the sympathovagal interaction toward an enhanced parasympathetic modulation, accompanied by a reduction of the sympathetic tone and a decreased short-range similarity but without a concomitant change in heart rate. Central and secondary autonomous nervous system changes induced by hypnosis are a possible explanation for our results. Another highly probable explanation is given by a variation in the depth of respiration. Hypnosis appears to prevent the autonomic responses expected during neutral stimulation.
Postnatal Synthesis of Adult and Fetal Hemoglobin in Infants with Congenital Cyanotic Heart Disease
Authors: Bard Harry
Published: September 2009

Studies were carried out during the postnatal period on infants with severe congenital cyanotic heart disease to measure the proportion of fetal and adult hemoglobin being synthesized between 0–2 and 6–8 weeks of age. These values were compared to those obtained from normal infants at the same ages. There was no significant difference between the proportions of adult and fetal hemoglobin being synthesized at 0–2 and 6–8 weeks of age between the infants with congenital cyanotic heart disease and the normal controls. Hypoxia during early postnatal life had no effect on the switchover from fetal to adult hemoglobin synthesis.
Postnatal Decline of Maternally Acquired Antibodies in the Rat
Authors: Cloonan M.J. , Shortland Gillian M.
Published: September 2009

The decline (half-life) of maternally acquired antibodies of two different specificities (diphtheria and tetanus) was studied in rats. Essentially similar half-lives for antibody of each specificity were found in young rats from the same litter. In contrast, half-lives varied from 2 to 10 days in individuals of different litters. Significant differences in half-lives were demonstrated in young rats possessing markedly different initial titres of antibodies of the two specificities. It was established that there was a relationship between the half-life and the initial titre of antibody of each specificity which could be described by a rectangular hyperbola. These findings are in close agreement with previous studies in human infants.
Nasal Continuous Positive Airway Pressure
Authors: Harris Howard , Wilson Sue , Brans Yves , Wirtschafter David , Cassady George
Published: September 2009

Continuous positive airway pressure (CPAP) was employed using nasal prongs in 30 neonates with hyaline membrane disease (HMD). There was a significant improvement in mean Pa02 (from 47 to 80 mmHg; p < 0.001) with no significant change in PaCO2 or pH within a mean 36 min of therapy. Use of the technique allowed reduction of FiO2 to < 0.60 in < 20 h in 18 infants. Infants treated within 24 h of birth had significantly greater improvements in PaO2. Complications were infrequent and only 3 of 30 babies developed a pneumothorax while on nasal CPAP. Only 1 of the 23 survivors required mechanical ventilation in addition to nasal CPAP.
Effect of Diet on Renal Response to Salt Challenge in Neonatal Piglets
Authors: Kaskel Frederick J. , Kleinman Leonard I.
Published: September 2009

In piglets 14–40 days of age, blood pressure and glomerular filtration rate increased significantly with age and were lower than those reported for adult pigs. There was no effect of dietary salt on the maturation of these parameters and on tubular sodium reabsorption, although the piglets on a low salt diet had lower inulin space than piglets receiving higher dietary salt. After the completion of a 24-hour salt challenge there was little evidence of sodium retention and there was no effect of previous dietary salt intake on sodium excretion. However, salt challenge resulted in higher blood pressure and elevated serum sodium only in piglets on a low sodium diet. These results suggest that in contrast to puppies and infants, the renal response to salt challenge is physiologically adequate in piglets at 14–40 days although glomerular function is still immature. Dietary salt history appears to have little effect on the degree of sodium excretion during salt challenge in this age range.
Preceding Pregnancy Loss as an Index of Risk of Stillbirth or Neonatal Death in the Present Pregnancy
Authors: Fedrick Jean , Adelstein Philippa
Published: September 2009

Details of 9,311 singleton births born to multiparae in the first week of March 1958 were compared with 3,707 singleton cases of stillbirth and neonatal death delivered in the 3-month period March–May, with respect to the outcome of the preceding delivery. It was shown that the risk of death was raised some 66% if the preceding delivery had been an abortion and by a factor of nearly 3 if the preceding delivery had itself been a stillbirth or neonatal death (SBND). The increased risk was especially pronounced for macerated stillbirths. Analysis because of death revealed very significant increases in the incidence of congenital defects, asphyxia and ‘no major lesion’ when the preceding delivery had been either an abortion or an SBND. It was shown that, in general, a woman who had had a preceding SBND was over 3 times more likely to deliver by 35 weeks than on whose preceding delivery had ended in either an abortion or a survivor.
The Development of Glycolytic and Pentose Phosphate Shunt Enzymes in Human Brain
Authors: Bennett M.J. , Timperley W.R. , Taylor C.B. , Hill A.S.
Published: September 2009

A quantitative enzyme analysis of 32 fetal human brains of 6–42 weeks gestational age range was carried out for the major glycolytic and pentose phosphate shunt enzymes. A critical period of raised enzyme levels was observed at 14 weeks. The glycolytic rate was probably controlled by the activities of hexokinase and phosphofructokinase which appear from the development patterns to have independent genetic sites. A rise in most enzyme activities was experienced in the final weeks of gestation towards levels consistent with those of adult tissues. Pentose phosphate shunt enzyme levels remained virtually unchanged during gestation after 14 weeks.
Multiple Forms of Thymidine Kinase during Human Development
Authors: Bernard B. , Preston B. , Beaupre P. , Elliott K. , Sadava D.
Published: September 2009

The developmental progression of thymidine kinase from the electrophoretically slow-migrating ‘fetal’ forms to the fast-migrating ‘adult’ form was examined in human serum and fetal liver. In fetal liver, only the fetal forms of the enzyme were present at 17 weeks’ gestation. A transitional period followed in that both enzyme forms were identified and by 24 weeks only the adult form was detected in fetal liver. This same enzyme changeover pattern – fetal to transitional to adult – occurred at a later time in human serum as it took place between 30 and 40 weeks’ gestation.