bluuebunny/crossref_metadata_2025_split huggingface dataset:
hnRNPs Relocalize to the Cytoplasm following Infection with Vesicular Stomatitis Virus
Authors: Pettit Kneller Elizabeth L. , Connor John H. , Lyles Douglas S. 
Published: November 2008

ABSTRACT
Vesicular stomatitis virus (VSV) matrix protein inhibits nuclear-cytoplasmic mRNA transport. The goal of this work is to determine whether VSV inhibits the nuclear-cytoplasmic transport of heterogeneous ribonucleoproteins (hnRNPs), which are thought to serve as mRNA export factors. Confocal microscopy experiments showed that hnRNPA1, hnRNPK, and hnRNPC1/C2, but not hnRNPB1 or lamin A/C, are relocalized to the cytoplasm during VSV infection. We determined whether protein import is inhibited by VSV by transfecting cells with a plasmid encoding enhanced green fluorescent protein (EGFP) tagged with either the M9 nuclear localization sequence (NLS) or the classical NLS. These experiments revealed that both the M9 NLS and the classical NLS are functional during VSV infection. These data suggest that the inhibition of protein import is not responsible for hnRNP relocalization during VSV infection but that hnRNP export is enhanced. We found that hnRNPA1 relocalization was significantly reduced following the silencing of the mRNA export factor Rae1, indicating that Rae1 is necessary for hnRNP export. In order to determine the role of hnRNPA1 in VSV infection, we silenced hnRNPA1 in HeLa cells and assayed three aspects of the viral life cycle: host protein synthesis shutoff concurrent with the onset of viral protein synthesis, replication by plaque assay, and cell killing. We observed that host shutoff and replication are unaffected by the reduction in hnRNPA1 but that the rate of VSV-induced apoptosis is slower in cells that have reduced hnRNPA1. These data suggest that VSV promotes hnRNPA1 relocalization in a Rae1-dependent manner for apoptotic signaling.
Role of Cellular RNA Processing Factors in Human Immunodeficiency Virus Type 1 mRNA Metabolism, Replication, and Infectivity
Authors: Jablonski Joseph A. , Caputi Massimo 
Published: November 2008

ABSTRACT
Expression of the human immunodeficiency virus type 1 genome requires several cellular factors regulating transcription, alternative splicing, RNA stability, and intracellular localization of the viral transcripts. In vitro and ex vivo approaches have identified SR proteins and hnRNPs of the A/B and H subfamilies as cellular factors that regulate different aspects of viral mRNA metabolism. To understand the role of these protein families within the context of the full replicating virus, we altered the expression levels of hnRNPs H, F, 2H9, GRSF1, A1, A2, and A3 and SR proteins SC35, SF2, and SRp40 in HEK 293 cells transfected with the proviral clone pNL4-3. Quantitative and semiquantitative PCR analyses showed that overexpression as well as downregulation of these proteins disrupted the balance of alternatively spliced viral mRNAs and may alter viral transcription. Furthermore, expression of hnRNPs H, F, 2H9, A1, and A2 and SR proteins SF2 and SRp40 increased nuclear localization of the unspliced Gag/Pol mRNA, while the same factors increased the cytoplasmic localization of the partially spliced Env mRNA. We also report that overexpression of hnRNPs A1 and A2 and SR proteins SF2, SC35, and SRp40 causes a dramatic decrease in virion production. Finally, utilizing a reporter TZM-bl cell line, we show that virion infectivity may be also impacted by deregulation of expression of most SR proteins and hnRNPs. This work demonstrates that cellular factors regulating mRNA processing have wide-ranging effects on human immunodeficiency virus type 1 replication and should be considered novel therapeutic targets.
Effects of Simultaneous Deletion of pUL11 and Glycoprotein M on Virion Maturation of Herpes Simplex Virus Type 1
Authors: Leege Tobias , Fuchs Walter , Granzow Harald , Kopp Martina , Klupp Barbara G. , Mettenleiter Thomas C. 
Published: November 2008

ABSTRACT

The conserved membrane-associated tegument protein pUL11 and envelope glycoprotein M (gM) are involved in secondary envelopment of herpesvirus nucleocapsids in the cytoplasm. Although deletion of either gene had only moderate effects on replication of the related alphaherpesviruses herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PrV) in cell culture, simultaneous deletion of both genes resulted in a severe impairment in virion morphogenesis of PrV coinciding with the formation of huge inclusions in the cytoplasm containing nucleocapsids embedded in tegument (M. Kopp, H. Granzow, W. Fuchs, B. G. Klupp, and T. C. Mettenleiter, J. Virol. 78:3024-3034, 2004). To test whether a similar phenotype occurs in HSV-1, a gM and pUL11 double deletion mutant was generated based on a newly established bacterial artificial chromosome clone of HSV-1 strain KOS. Since gM-negative HSV-1 has not been thoroughly investigated ultrastructurally and different phenotypes have been ascribed to pUL11-negative HSV-1, single gene deletion mutants were also constructed and analyzed. On monkey kidney (Vero) cells, deletion of either pUL11 or gM resulted in ca.-fivefold-reduced titers and 40- to 50%-reduced plaque diameters compared to those of wild-type HSV-1 KOS, while on rabbit kidney (RK13) cells the defects were more pronounced, resulting in ca.-50-fold titer and 70% plaque size reduction for either mutant. Electron microscopy revealed that in the absence of either pUL11 or gM virion formation in the cytoplasm was inhibited, whereas nuclear stages were not visibly affected, which is in line with the phenotypes of corresponding PrV mutants. Simultaneous deletion of pUL11 and gM led to additive growth defects and, in RK13 cells, to the formation of large intracytoplasmic inclusions of capsids and tegument material, comparable to those in PrV-ΔUL11/gM-infected RK13 cells. The defects of HSV-1ΔUL11 and HSV-1ΔUL11/gM could be partially corrected in
trans
by pUL11 of PrV. Thus, our data indicate that PrV and HSV-1 pUL11 and gM exhibit similar functions in cytoplasmic steps of virion assembly.
The Human Papillomavirus Type 8 E2 Tethering Protein Targets the Ribosomal DNA Loci of Host Mitotic Chromosomes
Authors: Poddar Atasi , Reed Shawna C. , McPhillips Maria G. , Spindler Jonathan E. , McBride Alison A. 
Published: November 2008

ABSTRACT
For many papillomaviruses, the viral protein E2 tethers the viral genome to the host mitotic chromosomes to ensure persistent, long-term maintenance of the genome during cell division. Our previous studies of E2 proteins from different genera of papillomaviruses have shown that they bind to different regions of the host chromosomes during mitosis. For example, bovine papillomavirus type 1 (BPV-1) E2 binds to all chromosomes as small speckles in complex with the cellular protein Brd4. In contrast, the human papillomavirus type 8 (HPV-8) E2 protein binds as large speckles at the pericentromeric regions of chromosomes. Here we show that these speckles do not contain Brd4, and unlike that of BPV-1, the N-terminal Brd4-interacting domain of HPV-8 E2 is not required for chromosome binding. In contrast to BPV-1 E2, the HPV-8 E2 protein targets the short arms of acrocentric mitotic chromosomes. Furthermore, the E2 protein interacts with the repeated ribosomal DNA genes found in this location and colocalizes with UBF, the RNA polymerase I transcription factor. Therefore, HPV-8 E2 genome tethering occurs by a Brd4-independent mechanism through a novel interaction with specific regions of mitotic chromosomes. Thus, a wide range of viruses have adopted the strategy of linking their genomes to host chromosomes, but individual viruses use different chromosomal targets. Characterization of these targets will enable the development of antiviral therapies to eliminate the viral genomes from infected cells.
Analysis of Neutralization Specificities in Polyclonal Sera Derived from Human Immunodeficiency Virus Type 1-Infected Individuals
Authors: Li Yuxing , Svehla Krisha , Louder Mark K. , Wycuff Diane , Phogat Sanjay , Tang Min , Migueles Stephen A. , Wu Xueling , Phogat Adhuna , Shaw George M. , Connors Mark , Hoxie James , Mascola John R. , Wyatt Richard 
Published: November 2008

ABSTRACT
During human immunodeficiency virus type 1 (HIV-1) infection, patients develop various levels of neutralizing antibody (NAb) responses. In some cases, patient sera can potently neutralize diverse strains of HIV-1, but the antibody specificities that mediate this broad neutralization are not known, and their elucidation remains a formidable challenge. Due to variable and nonneutralizing determinants on the exterior envelope glycoprotein (Env), nonnative Env protein released from cells, and the glycan shielding that assembles in the context of the quaternary structure of the functional spike, HIV-1 Env elicits a myriad of binding antibodies. However, few of these antibodies can neutralize circulating viruses. We present a systematic analysis of the NAb specificities of a panel of HIV-1-positive sera, using methodologies that identify both conformational and continuous neutralization determinants on the HIV-1 Env protein. Characterization of sera included selective adsorption with native gp120 and specific point mutant variants, chimeric virus analysis, and peptide inhibition of viral neutralization. The gp120 protein was the major neutralizing determinant for most sera, although not all neutralization activity against all viruses could be identified. In some broadly neutralizing sera, the gp120-directed neutralization mapped to the CD4 binding region of gp120. In addition, we found evidence that regions of the gp120 coreceptor binding site may also be a target of neutralizing activity. Sera displaying limited neutralization breadth were mapped to the immunogenic V3 region of gp120. In a subset of sera, we also identified NAbs directed against the conserved, membrane-proximal external region of gp41. These data allow a more detailed understanding of the humoral responses to the HIV-1 Env protein and provide insights regarding the most relevant targets for HIV-1 vaccine design.
Gazing at Cirrus Clouds for 25 Years through a Split Window. Part I: Methodology
Authors: Heidinger Andrew K. , Pavolonis Michael J. 
Published: November 2008

Abstract
This paper demonstrates that the split-window approach for estimating cloud properties can improve upon the methods commonly used for generating cloud temperature and emissivity climatologies from satellite imagers. Because the split-window method provides cloud properties that are consistent for day and night, it is ideally suited for the generation of a cloud climatology from the Advanced Very High Resolution Radiometer (AVHRR), which provides sampling roughly four times per day. While the split-window approach is applicable to all clouds, this paper focuses on its application to cirrus (high semitransparent ice clouds), where this approach is most powerful. An optimal estimation framework is used to extract estimates of cloud temperature, cloud emissivity, and cloud microphysics from the AVHRR split-window observations. The performance of the split-window approach is illustrated through the diagnostic quantities generated by the optimal estimation approach. An objective assessment of the performance of the algorithm cloud products from the recently launched space lidar [Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation/Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO/CALIOP)] is used to characterize the performance of the AVHRR results and also to provide the constraints needed for the optimal estimation approach.
How Do Outer Spiral Rainbands Affect Tropical Cyclone Structure and Intensity?*
Authors: Wang Yuqing 
Published: November 2008

Abstract
A long-standing issue on how outer spiral rainbands affect the structure and intensity of tropical cyclones is studied through a series of numerical experiments using the cloud-resolving tropical cyclone model TCM4. Because diabatic heating due to phase changes is the main driving force of outer spiral rainbands, their effect on the tropical cyclone structure and intensity is evaluated by artificially modifying the heating and cooling rate due to cloud microphysical processes in the model. The view proposed here is that the effect of diabatic heating in outer spiral rainbands on the storm structure and intensity results mainly from hydrostatic adjustment; that is, heating (cooling) of an atmospheric column decreases (increases) the surface pressure underneath the column. The change in surface pressure due to heating in the outer spiral rainbands is significant on the inward side of the rainbands where the inertial stability is generally high. Outside the rainbands in the far field, where the inertial stability is low and internal atmospheric heating is mostly lost to gravity wave radiation and little is left to warm the atmospheric column and lower the local surface pressure, the change in surface pressure is relatively small. This strong radially dependent response reduces the horizontal pressure gradient across the radius of maximum wind and thus the storm intensity in terms of the maximum low-level tangential wind while increasing the inner-core size of the storm.
The numerical results show that cooling in the outer spiral rainbands maintains both the intensity of a tropical cyclone and the compactness of its inner core, whereas heating in the outer spiral rainbands decreases the intensity but increases the size of a tropical cyclone. Overall, the presence of strong outer spiral rainbands limits the intensity of a tropical cyclone. Because heating or cooling in the outer spiral rainbands depends strongly on the relative humidity in the near-core environment, the results have implications for the formation of the annular hurricane structure, the development of concentric eyewalls, and the size change in tropical cyclones.
Observations of MI Values During Neonatal Cardiac Ultrasound Scanning
Authors: Verma Prashant K. 
Published: November 2008

Aim: The on-screen Mechanical Index (MI), was recorded from eight diagnostic ultrasound machines used for cardiac scanning of neonates. The objective of the study was to compare values of MI used in neonatal cardiac scanning with those recommended by the British Medical Ultrasound Society safety guidelines. Methods: The eight scanners were based at Sheffield Teaching Hospitals NHS Trust (STH), Sheffield Children's Hospitals NHS Trust (SCH) and Leeds Teaching Hospitals NHS Trust (LTH). Two methods of recording the MI value were used. At the Sheffield sites the on-screen safety index was obtained from archived patient studies saved on the Trust PACS. At the Leeds site the on-screen safety index was recorded from the scanner when it was switched on to its default neonatal or paediatric pre-sets with the appropriate transducer connected. Results: Data from clinical examinations at the Sheffield sites show that on average the MI values, for cardiac scanning, in B-mode and colour/pulsed wave Doppler mode were 1·1±0·3 and 1·3±0·3 respectively. The maximum values of MI recorded during clinical cardiac examinations were 1·6 for B-mode and 1·7 for colour/pulsed wave Doppler mode. Data from the Leeds site recorded default MI values, using appropriate transducers with neonatal and paediatric presets. One scanner from the Leeds site defaulted to an MI value of 1·9 in colour/pulsed Doppler mode with a neonatal preset. All the MI values are well above BMUS guideline recommendations for neonates when lung tissue is present within the ultrasound beam. Conclusions: The implication of these results is that neonates undergoing cardiac ultrasound examinations, were regularly exposed to MI values at least four to six times that recommended by BMUS guidelines (MI<0·3).
Complete eradication of human B-cell lymphoma xenografts using rituximab in combination with the immunocytokine L19-IL2
Authors: Schliemann Christoph , Palumbo Alessandro , Zuberbühler Kathrin , Villa Alessandra , Kaspar Manuela , Trachsel Eveline , Klapper Wolfram , Menssen Hans Dietrich , Neri Dario 
Published: November 2008

Abstract
The antibody-mediated delivery of therapeutic agents to sites of angiogenesis is an attractive strategy for anticancer therapy, but is largely unexplored in hematologic malignancies. In the present study, we show that the extra domain B (EDB) of fibronectin, a marker of angiogenesis, is expressed in B-cell non-Hodgkin lymphoma (NHL) and that the human monoclonal anti-EDB antibody L19 can selectively localize to the lymphoma-associated subendothelial extracellular matrix. In vivo, the preferential accumulation of the antibody at the tumor site was confirmed by quantitative biodistribution analyses with radioiodinated antibody preparations. The fusion protein L19-IL2, which mediates the delivery of interleukin-2 (IL-2) to the neovasculature, displayed a superior antilymphoma activity compared with unconjugated IL-2 in localized and systemic xenograft models of NHL. When coadministered with rituximab, L19-IL2 induced complete remissions of established localized lymphomas and provided long-lasting protection from disseminated lymphoma. The combined use of rituximab and L19-IL2, which dramatically increases the infiltration of immune effector cells in lymphomas, may deserve clinical investigations, facilitated by the fact that L19-IL2 is currently being studied in phase II clinical trials in patients with solid tumors.
Recent Developments of Boryl Anions: Boron Analogues of Carbanion
Authors: Yamashita Makoto , Nozaki Kyoko 
Published: November 2008

Abstract
This account reviews the chemistry of “boryl anion.” Boryl anions can be classified with their metallic counterpart, such as Li, Mg, Cu, and Zn in a similar manner to the classification of carbanions. The early attempts to generate boryl anions by reductive dehalogenation of haloboranes with alkali metal or photolysis of tetraphenylborate compounds had no modern spectroscopic identification of the reactive “boryl anion.” Recent developments of base-stabilized boryl anion, base–BH2−M+ (base = NEt3 or PCy3, M=K or Li), and generation of borylcopper species, “pinBCuL,” have opened a new area of organoboron chemistry. Recently, we have synthesized a lithium salt of boryl anion, boryllithium, which reacted with electrophiles as a boron nucleophile. Based on the high reactivity of boryllithium, transmetallation to other metals enables synthesis of a series of borylmetals, such as borylmagnesium, borylcopper, and borylzinc species. All of these compounds were isolated and structurally characterized to have an sp2 boron atom. Reactivity with organic electrophiles could confirm that they behaved as boron nucleophiles.
Reactions and Mechanistic Studies of Rhenium-Catalyzed Insertion of α,β-Unsaturated Carbonyl Compounds into a C–H Bond
Authors: Kuninobu Yoichiro , Nishina Yuta , Okaguchi Kayo , Shouho Makoto , Takai Kazuhiko 
Published: November 2008

Abstract
A rhenium complex, [ReBr(CO)3(thf)]2, catalyzes the insertion of α,β-unsaturated carbonyl compounds into a C–H bond of aromatic compounds having nitrogen-containing directing groups. In this reaction, Re2(CO)10 can also be used as a catalyst. When imines are employed as the aromatic substrates, sequential cyclization proceeds and indene derivatives are obtained in good to excellent yields. This reactivity is in contrast to those of ruthenium and rhodium complexes, which are usually used as catalysts in the insertion reactions of unsaturated molecules into a C–H bond. Investigations on the reaction mechanism indicate that the rhenium catalyst promotes C–H bond activation of aromatic compounds, the insertion of α,β-unsaturated carbonyl compounds into a Re–C bond, and intramolecular nucleophilic cyclization followed by reductive elimination and the elimination of an amine.
Synthesis and Structural Characterization of a Dinuclear Palladium(II) Complex with N,N',N'',N'''-Tetrakis(2-p-toluenesulfonamidoethyl)cyclam
Authors: Wada Shusaku , Kotera Takanori , Mikuriya Masahiro 
Published: November 2008

Abstract
Dinuclear palladium(II) complex with 1,4,8,11-tetrakis(2-p-toluenesulfonamidoethyl)-1,4,8,11-tetraazacyclotetradecane (H4tstaec), [Pd2(tstaec)], was synthesized and characterized by elemental analysis and IR and UV–vis spectroscopies. The crystal structures of H4tstaec and [Pd2(tstaec)] were determined by single-crystal X-ray diffraction method. In the former ligand, the cyclam ring moiety takes a trans IV conformation with the tosyl arms pointing away from each other, whereas each palladium atom is bound by two nitrogen atoms of the cyclam moiety and two nitrogen atoms of the tosyl arms with Pd···Pd distance of 5.617(1) Å intervening the trans IV cyclam ring in the latter complex. DFT calculations were performed based on these crystal structures.
Microsphere vs. Microbelt Morphology of Ionic Palladium(II) Complexes
Authors: Noh Tae Hwan , Chun In Sung , Lee Young-A , Ahn Sungho , Hong Jongki , Jung Ok-Sang 
Published: November 2008

Abstract
A series of palladium(II) complexes containing bis[(4-isonicotinoyloxy)phenyl]sulfide (L), [PdII(L)(tmen)]2X4 (tmen = N,N,N',N'-tetramethylethane-1,2-diamine; X=NO3 and ClO4) were prepared and characterized. Reaction of [Pd(tmen)](NO3)2 with L in a mixture of water and acetone affords microspheres whereas reaction of [Pd(tmen)](ClO4)2 with L produces microbelts. The solubility of the products is a significant factor for the formation of morphology. The spherical sizes can be controlled by the evaporation rate of solvents. An array of ≈300 nm and ≈4 μm bimodal spheres was carried out via sonication.
Preparation, Crystal Structures, and Properties of New Conjugated π-Electron Systems with 3-Guaiazulenyl and 4-(Dimethylamino)phenyl Groups
Authors: Takekuma Shin-ichi , Hori Seiki , Minematsu Toshie , Takekuma Hideko 
Published: November 2008

Abstract
Reaction of guaiazulene with 1,2-bis[4-(dimethylamino)phenyl]-1,2-ethanediol in methanol in the presence of hydrochloric acid at 60 °C for 3 h gives 1,1-bis[4-(dimethylamino)phenyl]-2-(3-guaiazulenyl)ethylene, in 81% yield, via pinacol rearrangement and further Wittig reaction of 3-formylguaiazulene with [4-(dimethylamino)benzyl]triphenylphosphonium bromide in ethanol containing NaOEt at 25 °C for 24 h under argon affords (E)-2-[4-(dimethylamino)phenyl]-1-(3-guaiazulenyl)ethylene in 12% yield. Crystal structures as well as spectroscopic and electrochemical properties of the products, with a view to comparative study, are reported. Moreover, reactions of the products with 2 equiv of tetracyanoethylene (TCNE) in benzene at 25 °C for 24 h under argon give 1,1,2,2,11,11,12,12-octacyano-3,3-bis[4-(dimethylamino)phenyl]-8-isopropyl-5,10-dimethyl-1,2,3,6,9,10a-hexahydro-6,9-ethanobenz[a]azulene and 1,1,2,2,11,11,12,12-octacyano-3-[4-(dimethylamino)phenyl]-8-isopropyl-5,10-dimethyl-1,2,3,6,9,10a-hexahydro-6,9-ethanobenz[a]azulene in 74 and 41% yields. A plausible reaction pathway for the formation of the unique products, possessing interesting structures, is submitted.
Electrochemical Oxidation of 4-Methylcatechol in the Presence of β-Diketones
Authors: Nematollahi Davood , Rafiee Mohammad , Khavasi Hamid Reza 
Published: November 2008

Abstract
Electrochemical oxidation of 4-methylcatechol (1) in the presence of, benzoylacetone (2), dibenzoylmethane (3), 3-hydroxy-1H-phenalen-1-one (4), acetylacetone (5), dimedone (6), and 2-acetylcyclohexanone (7) as nucleophiles has been studied in detail by cyclic voltammetry and controlled-potential coulometry. The results indicate that the electrochemically generated quinone participates in Michael addition reaction with 2–7 via various mechanisms to produce new organic compounds. Furthermore, our studies show that the structure of intermediates play a crucial role in product selectivity under controlled-potential conditions. Various types of products were also obtained through the selective oxidation at the surface of a carbon electrode in an undivided cell.