bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blockade of the OX40 ligand prolongs corneal allograft survival
Authors: Hattori Takaaki , Usui Yoshihiko , Okunuki Yoko , Sonoda Yasushi , Usui Masahiko , Takada Eiko , Mizuguchi Junichiro , Yagita Hideo , Okumura Ko , Akiba Hisaya , Takeuchi Masaru 
Published: November 2007

AbstractAlthough corneal transplantation is one of the most common tissue transplantations and is known to have a high graft acceptance rate, occasional corneal graft rejection remains a cause of blindness. OX40, a member of the TNF receptor superfamily, is expressed on activated T cells, and transmits a costimulatory signal by binding to OX40 ligand (OX40L) expressed on several cells with antigen‐presenting functions. Using a blocking monoclonal antibody (mAb) against murine OX40L, we investigated the role of OX40 in a murine model of corneal transplantation. C3H/He mouse corneas were transplanted to BALB/c mice orthotopically. Administration of anti‐OX40L mAb significantly reduced allograft rejection, and increased graft survival rate to 40% at 8 weeks after transplantation, while all corneas were rejected within 5 weeks in control IgG‐treated mice. Similar reduced rejection was observed when wild‐type donor corneas were transplanted to OX40L‐deficient recipients. In vitro study revealed that the anti‐OX40L mAb treatment reduced proliferative response and IFN‐γ production of draining lymph node cells in response to stimulation with donor alloantigen. These results demonstrate that OX40L blockade is effective for prolongation of corneal allograft survival by inhibiting recipient T cell activation.
More than Steric Effects: Unlocking the Coordination Chemistry of Barium Pyrazolates
Authors: O'Brien Anna Y. , Hitzbleck Julia , Torvisco Ana , Deacon Glen B. , Ruhlandt‐Senge Karin 
Published: November 2007

AbstractTo further our understanding of the coordination chemistry of the heavy alkaline earth metals, we here report on a family of barium pyrazolates bearing various substitution patterns that illustrate the delicate balance between ligand bulk, donor size, stoichiometry, and hapticity, while emphasizing the importance of secondary interactions including π‐bonding, agostic interactions, and hydrogen bonding to stabilize these heavy‐metal complexes. The dimeric compounds [{Ba(Me2pz)2(pmdta)}2] (1), [{Ba(Phpz)2(pmdta)}2] (2), [{Ba(tBupz)2(pmdta)}2] (3), [{Ba(MePhpz)2(tmeda)}2] (5), [{Ba(Ph2pz)2(tmeda)}2]·TMEDA (6), the polymer [{Ba(tBupz)2(NH3)2}n] (4), and the monomer [Ba(Ph2pz)2(tmeda)2]·TMEDA (7), were prepared using a variety of synthetic methods and were characterized spectroscopically and structurally. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Use of (S)‐5‐(2‐Methylpyrrolidin‐2‐yl)‐1H‐tetrazole as a Novel and Enantioselective Organocatalyst for the Aldol Reaction
Authors: Tong Sok‐Teng (Amy) , Harris Paul W. R. , Barker David , Brimble Margaret A. 
Published: November 2007

AbstractThe novel organocatalyst (S)‐5‐(2‐methylpyrrolidin‐2‐yl)‐1H‐tetrazole (4) catalyzes the aldol reaction between acetone and various aldehydes with superior enantioselectivity to the existing organocatalysts (S)‐proline (1) and (S)‐5‐(pyrrolidin‐2‐yl)‐1H‐tetrazole (3). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Disabled‐1 is a large common fragile site gene, inactivated in multiple cancers
Authors: McAvoy Sarah , Zhu Yu , Perez Damon S. , James C. David , Smith David I. 
Published: November 2007

AbstractCommon fragile sites (CFS) are large, genomically unstable regions, which are hot‐spots for deletions and other alterations, especially in cancer cells. Several have been shown to contain genes that span large genomic regions, such as FHIT (1.5 Mb), WWOX (1.0 Mb), GRID2 (1.36 Mb), PARK2 (1.3 Mb), and RORA (730 kb). These genes are frequently inactivated in multiple different cancers, and FHIT and WWOX are shown to function as tumor suppressors. The disabled‐1 gene (DAB1) is one of the human homologs of the Drosophila disabled locus, which in mammals is involved in neuronal migration and lamination in the developing cerebral cortex. Mice DAB1 inactivation results in the neurological mutant Scrambler, having similarities to mice with the inactivation of PARK2 (Quaker), GRID2 (Lurcher), and RORA (Staggerer). We were interested in whether DAB1 was another large CFS gene that could have cancer development importance. We demonstrated here that the human DAB1 gene (spanning 1.25 Mb) mapped within FRA1B CFS region on chromosomal band 1p32.2. Real‐time RT‐PCR analysis revealed that the expression level of DAB1 was decreased in many human cancer samples, including primary tumor tissues and cancer‐derived cell lines, from several different cancers, especially in brain and endometrial cancer. Additionally, the introduction of an over‐expression DAB1 plasmid into two different cell lines, having insignificant endogenous DAB1 expression, resulted in decreased cell growth. In summary, DAB1 is another gene that resides within an unstable CFS region and might play a role in human tumorigenesis. These data may provide further linkage between neurological development and cancer. © 2007 Wiley‐Liss, Inc.
Nitration Products of 5‐Amino‐1H‐tetrazole and Methyl‐5‐amino‐1H‐tetrazoles – Structures and Properties of Promising Energetic Materials
Authors: Klapötke Thomas M. , Stierstorfer Jörg 
Published: November 2007

AbstractThe nitration of 5‐amino‐1H‐tetrazole (1), 5‐amino‐1‐methyl‐1H‐tetrazole (3), and 5‐amino‐2‐methyl‐2H‐tetrazole (4) with HNO3 (100%) was undertaken, and the corresponding products 5‐(nitrimino)‐1H‐tetrazole (2), 1‐methyl‐5‐(nitrimino)‐1H‐tetrazole (5), and 2‐methyl‐5‐(nitramino)‐2H‐tetrazole (6) were characterized comprehensively using vibrational (IR and Raman) spectroscopy, multinuclear (1H, 13C, 14N, and 15N) NMR spectroscopy, mass spectrometry, and elemental analysis. The molecular structures in the crystalline state were determined by single‐crystal X‐ray diffraction. The thermodynamic properties and thermal behavior were investigated by using differential scanning calorimetry (DSC), and the heats of formation were determined by bomb calorimetric measurements. Compounds 2, 5, and 6 were all found to be endothermic compounds. The thermal decompositions were investigated by gas‐phase IR spectroscopy as well as DSC experiments. The heats of explosion, the detonation pressures, and velocities were calculated with the software EXPLO5, whereby the calculated values are similar to those of common explosives such as TNT and RDX. In addition, the sensitivities were tested by BAM methods (drophammer and friction) and correlated to the calculated electrostatic potentials. The explosion performance of 5 was investigated by Koenen steel sleeve test, whereby a higher explosion power compared to RDX was reached. Finally, the long‐term stabilities at higher temperatures were tested by thermal safety calorimetry (FlexyTSC). X‐Ray crystallography of monoclinic 2 and 6, and orthorhombic 5 was performed.
Alkaloids from the Fruits of Daphniphyllum macropodum
Authors: Wang Xiao‐Ning , Gan Li‐She , Fan Cheng‐Qi , Yin Sheng , Yue Jian‐Min 
Published: November 2007

AbstractThree new alkaloids, N‐hydroxypaxdaphnine B (1), 21‐O‐acetylpaxdaphnine B (2), and methyl 17‐hydroxyhomodaphniphyllate (3), were isolated from the fresh fruits of Daphniphyllum macropodum, together with six known alkaloids. Their structures were established on the basis of extensive spectroscopic and mass‐spectrometric analyses in combination with chemical transformations.
Alkaloids from the Roots of Stemona cochinchinensis
Authors: Lin Li‐Gen , Dien Pham‐Huu , Tang Chun‐Ping , Ke Chang‐Qiang , Yang Xin‐Zhou , Ye Yang 
Published: November 2007

AbstractPhytochemical investigation of the roots of Stemona cochinchinensis led to the isolation and structure elucidation of a new pyrido[1,2‐a]azepine‐type alkaloid, stemocochinamine (1), and of four new pyrrolo[1,2‐a]azepine‐type alkaloids, bisdehydrostemocochinine (2), isobisdehydrostemocochinine (3), neostemocochinine (4), and isoneostemocochinine (5), together with six known alkaloids. Their structures were established on the basis of extensive 1D‐ and 2D‐NMR analyses in combination with HR‐MS experiments.
Facile and Selective Synthesis of 4‐Methyl‐ and 4‐Phenylthiosemicarbazide (=N‐Methyl‐ and N‐Phenylhydrazinecarbothioamide) Derivatives of Benzil (=1,2‐Diphenylethane‐1,2‐dione)
Authors: Calatayud David G. , Escolar Francisco J. , López‐Torres Elena , Mendiola M. Antonia 
Published: November 2007

AbstractA selective synthesis of 4‐methylthiosemicarbazide (=N‐methylhydrazinecarbothioamide; 4a) derivatives by reaction with benzil (=1,2‐diphenylethane‐1,2‐dione; 3) is described. The reaction conditions determined the condensation product formed. The most important factor was the acid used: in the presence of conc. HCl solution, the open‐chain 2 : 1 compound 1a was exclusively obtained, whereas in the presence of 2M HCl, the cyclic 1 : 1 condensation product 2a was formed. The alcohol used, the presence of H2O, and the time of heating were additional crucial factors. The new cyclic compound 2a with a MeO group was exclusively formed when working under high‐dilution conditions. The reaction with the 4‐phenyl derivative 4b gave new cyclic compounds as the major products under all conditions used (Scheme).
A Novel Norlignan and a Novel Phenylpropanoid from Peperomia tetraphylla
Authors: Li Yun‐Zhi , Huang Jing , Gong Zhen , Tian Xiang‐Qing 
Published: November 2007

AbstractA novel cyclobutane‐type norlignan, peperotetraphin (=methyl rel‐(1R,2S,3S)‐2,3‐bis(7‐methoxy‐1,3‐benzodioxol‐5‐yl)cyclobutanecarboxylate; 1), and a novel phenylpropanoid, i.e., methyl (2E)‐3‐(7‐methoxy‐1,3‐benzodioxol‐5‐yl)prop‐2‐enoate (2), along with three known compounds, α‐asarone (=1,2,4‐trimethoxy‐5‐[(1E)‐prop‐1‐en‐1‐yl]benzene), vanillic acid (=4‐hydroxy‐3‐methoxybenzoic acid), and veratric acid (=3,4‐dimethoxybenzoic acid), were isolated from the EtOH extract of the whole plant of Peperomia tetraphylla. Their structures were determined by spectroscopic methods, especially 1D‐ and 2D‐NMR techniques. This is the first report of naturally occurring cyclobutane‐type norlignans.
Cyclic acetal hydrogel system for bone marrow stromal cell encapsulation and osteodifferentiation
Authors: Betz Martha W. , Modi Parth C. , Caccamese John F. , Coletti Domenick P. , Sauk John J. , Fisher John P. 
Published: November 2007

AbstractMany systems have been proposed for the encapsulation of bone marrow stromal cells (BMSCs) within degradable hydrogels. Here, we use a novel cyclic acetal‐based biomaterial formed from 5‐ethyl‐5‐(hydroxymethyl)‐β,β‐dimethyl‐1,3‐dioxane‐2‐ethanol diacrylate (EHD) and poly(ethylene glycol) diacrylate (PEGDA). A cyclic acetal‐based hydrogel may be preferred as cyclic acetals hydrolytically degraded into diols and carbonyls as primary degradation products, which may not affect local acidity, unlike other widely investigated polymers. The EHD monomer and PEGDA polymer may be fabricated into a EH‐PEG hydrogel by radical polymerization initiated by the ammonium persulfate (APS) and N,N,N′,N′‐tetramethylethylenediamine (TEMED) system. The objective of this work is to determine whether the components utilized in the fabrication of EH‐PEG hydrogels as well as the EH‐PEG hydrogels permit BMSC viability, metabolic activity, and osteodifferentiation. Cell viability and metabolic activity were assessed after 30 min, 1 h, and 3 h of exposure to pertinent concentrations of the initiator system (10–20 mM). Osteodifferentiation was assessed by alkaline phosphatase and osteocalcin expression after a short exposure to the initiator system to simulate the encapsulation process. Lastly, cell viability was assessed immediately after encapsulation and after 7 days of culture within the EH‐PEG hydrogels. Results indicate that the metabolic activity and viability of BMSCs are minimally affected, and that osteodifferentiation is not significantly affected by the APS‐TEMED initiator system. Also, encapsulated BMSCs maintained viability within EH‐PEG hydrogels for 7 days. This work demonstrates that the EH‐PEG hydrogel is a viable option for the encapsulation and osteodifferentiation of BMSCs. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Glutamate accelerates RPE cell proliferation through ERK1/2 activation via distinct receptor‐specific mechanisms
Authors: García Sofía , López Edith , López‐Colomé Ana María 
Published: November 2007

AbstractThe proliferation and migration of Retinal Pigment Epithelium cells resulting from an epithelial‐mesenchymal transition plays a key role in proliferative vitreoretinopathy, which leads to retinal detachment and the loss of vision. In neurons, glutamate has been shown to activate the Ras/Raf/MEK/ERK cascade, which participates in the regulation of proliferation, differentiation, and survival processes. Although glutamate‐stimulation and the activation of ERK1/2 by different stimuli have been shown to promote RPE cell proliferation, the signaling pathway(s) linking these effects has not been established. We analyzed the molecular mechanisms leading to glutamate‐induced proliferation by determining ERK1/2 and CREB phoshporylation in chick RPE cells in primary culture and the human‐derived RPE cell line ARPE‐19. This study shows for the first time, that glutamate promotes RPE cell proliferation by activating two distinct signaling pathways linked to selective glutamate receptor subtypes. Results demonstrate that glutamate stimulates RPE cell proliferation as well as ERK and CREB phosphorylation. These effects were mimicked by the mGluR agonist ACPD and by NMDA, and were prevented by the respective receptor inhibitors MCPG and MK‐801, indicating a cause‐effect relationship between these processes. Whereas mGluR promoted proliferation by activating the MEK/ERK/CREB cascade, NMDA stimulated proliferation through the MEK‐independent activation of Ca2+/calmodulin‐dependent kinases. The blockage of both signaling pathways to proliferation by KN‐62 suggests the involvement of CaMKs in the control of glutamate‐induced proliferation at a common step, downstream of CREB, possibly the regulation of cell cycle progression. Based on these findings, the participation of glutamate in the development of PVR can be considered. J. Cell. Biochem. 104: 377–390, 2008. © 2007 Wiley‐Liss, Inc.
Small tumor antigen of polyomaviruses: Role in viral life cycle and cell transformation
Authors: Khalili Kamel , Sariyer Ilker Kudret , Safak Mahmut 
Published: November 2007

AbstractThe regulatory proteins of polyomaviruses, including small and large T antigens, play important roles, not only in the viral life cycle but also in virus‐induced cell transformation. Unlike many other tumor viruses, the transforming proteins of polyomaviruses have no cellular homologs but rather exert their effects mostly by interacting with cellular proteins that control fundamental processes in the regulation of cell proliferation and the cell cycle. Thus, they have proven to be valuable tools to identify specific signaling pathways involved in tumor progression. Elucidation of these pathways using polyomavirus transforming proteins as tools is critically important in understanding fundamental regulatory mechanisms and hence to develop effective therapeutic strategies against cancer. In this short review, we will focus on the structural and functional features of one polyomavirus transforming protein, that is, the small t‐antigen of the human neurotropic JC virus (JCV) and the simian virus, SV40. J. Cell. Physiol. 215: 309–319, 2008. © 2007 Wiley‐Liss, Inc.
The transient expression of mRNA coding for Rep protein from AAV facilitates targeted plasmid integration
Authors: Howden S. E. , Voullaire L. , Vadolas J. 
Published: November 2007

AbstractBackgroundThere is a risk of insertional mutagenesis when techniques that facilitate random integration of exogenous DNA into the human genome are used for gene therapy. Wild‐type adeno‐associated virus (AAV) integrates preferentially into a specific site on human chromosome 19 (AAVS1). This is mediated by the interaction of the viral Rep68/78 proteins with Rep‐binding elements in the AAV genome and AAVS1. This specificity is often lost when AAV is used as a gene therapy vector due to removal of the sequences coding for Rep.MethodsMessenger RNA coding for the Rep68/78 proteins was prepared in vitro and co‐transfected with a 21 kb DNA plasmid containing the P5 integration efficiency element (P5IEE) from AAV. Single cells were seeded in plates to establish clonal cell lines that were subsequently analysed by dual colour fluorescent in situ hybridisation (FISH) to determine whether site‐specific plasmid integration had occurred on chromosome 19.ResultsThe co‐transfection of plasmid DNA with Rep68/78 mRNA gave a 2.5‐fold increase in DNA integration when compared to transfection of cells with plasmid DNA alone. Rep68/78 mRNA expression facilitated site‐specific plasmid integration to chromosome 19 in 30% (14/44) of all analysed integration sites, while no targeted integration events were observed following transfection of cells with plasmid DNA alone.ConclusionsThese results demonstrate that transient expression of Rep protein using transfected mRNA facilitates site‐specific integration of plasmid DNA. This approach allows expression of Rep for only a short time, and may circumvent the toxicity and chromosome instability associated with long‐term expression of Rep. Copyright © 2007 John Wiley & Sons, Ltd.
Evaluation of enzymatic treatment of peach juice using response surface methodology
Authors: Santin Márcia M , Treichel Helen , Valduga Eunice , Cabral Lourdes MC , Di Luccio Marco 
Published: November 2007

AbstractBACKGROUND: This work aimed to assess peach juice clarification using enzymatic treatment. The enzymatic hydrolysis was performed to reduce the juice viscosity and pulp content, and consequently to increase juice extraction. The hydrolysis conditions were optimized by the response surface methodology, where the influence of temperature, amount and type of enzyme and time of reaction were investigated.RESULTS: Two commercial pectinase preparations (AFP L3 and ULTRA SP WOP from Novozymes) as well as a cellulase (R10 from Onozuka) were tested. The hydrolysis using Pectinex AFP L3 (Novozymes) at 25 °C for 60 min presented the best results of pulp (48%) and viscosity (68%) reduction.CONCLUSION: Physical and chemical analyses showed that the enzymatic treatment is effective for reduction of peach pulp viscosity, pulp content and turbidity and does not influence other juice parameters such as pH, total acidity, vitamin C and soluble solids. Copyright © 2007 Society of Chemical Industry
Method of fast trace microanalysis of the chiral pesticides epoxiconazole and novaluron in soil samples using off‐line flow‐through extraction and on‐column direct large volume injection in reversed‐phase high performance liquid chromatography
Authors: Rybár Ivan , Góra Robert , Hutta Milan 
Published: November 2007

AbstractAn analytical method combining off‐line flow‐through extraction of a soil micro‐sample (mass around 100 mg, packed into a short HPLC glass column) and direct on‐column large‐volume injection (LVI up to 1.00 mL) of a methanol–water soil extract onto a conventional C18 RP HPLC column enabled fast (within 3.5 minutes) trace micro‐analysis of the relatively new chiral pesticides epoxiconazole (E) and novaluron (N), respectively. Linear calibration curves were evaluated from UV detection (230 nm) data in the range from 0.1 to 5 mg/kg in three most abundant Slovak agricultural soils. LOD (confidence band) at the levels 0.08–0.11 mg/kg and LOQ 0.4–0.6 mg/kg and LOD (S/N = 3) at the levels 0.007–0.018 mg/kg and LOQ (S/N = 10) 0.024–0.060 mg/kg, respectively, of dry soil were achieved. Recovery of pesticides in the overall LVI method including flow‐through 130–200 mg soil micro‐sample extraction was: for epoxiconazole from 74 to 85% and from 56% to 90% for novaluron with reproducibility within ± 6% RSD. This fast (30 min) and simple method consists of just three steps which are short column filling with a solid micro‐sample; flow‐through liquid extraction and direct large‐volume injection RP HPLC DAD analysis. The method is prepared for automation and further analysis of enantiomers of both investigated pesticides by achiral‐chiral column switching techniques.
Comparison between effects of 3‐isobutyl‐1‐methylxanthine and FSH on gap junctional communication, LH‐receptor expression, and meiotic maturation of cumulus–oocyte complexes in pigs
Authors: Ozawa Manabu , Nagai Takashi , Somfai Tamás , Nakai Michiko , Maedomari Naoki , Fahrudin Mokhamad , Karja Ni Wayan Kurniani , Kaneko Hiroyuki , Noguchi Junko , Ohnuma Katsuhiko , Yoshimi Noriko , Miyazaki Hitoshi , Kikuchi Kazuhiro 
Published: November 2007

AbstractWe investigated cAMP content, gap junctional communications (GJCs) status, and LH‐receptor (LH‐R) expression in porcine cumulus–oocyte complexes (COCs) during in vitro maturation treated with the phosphodiesterase (PDE) inhibitor 3‐isobutyl‐1‐methylxanthine (IBMX) or with FSH. COCs were cultured for 20 hr (1st culture) in M199 containing 10% FBS (basic medium, BM group) or BM supplemented with FSH (FSH group) or IBMX (IBMX group). Each COC was then transferred into BM containing both FSH and LH and cultured for an additional 24 hr (2nd culture). The proportions of metaphase‐II (M‐II) oocytes at the end of the 2nd culture did not differ between the FSH (75.7%) and IBMX (68.2%) groups, whereas only 10.1% of oocytes in the BM group reached the M‐II stage. During the 1st culture, the cAMP content of COCs and oocytes became significantly higher in the FSH and IBMX groups than in the BM group; the FSH group had a far greater increment than did the IBMX group. GJCs in the FSH and BM groups gradually closed with increasing duration of the 1st culture, whereas a significantly higher proportion of COCs in the IBMX group still had open GJCs than in the other two groups. Furthermore, LH‐R mRNA expression significantly increased in both the FSH and IBMX groups compared with the BM group. These results suggest that inhibition of PDEs in porcine COCs make the oocyte ready for release from meiotic arrest, and that maintenance of a moderate cAMP content may prolong GJCs and stimulate LH‐R expression. Mol. Reprod. Dev. 75: 857–866, 2008. © 2007 Wiley‐Liss, Inc.