bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of insulin release by adenosine A1receptor agonists and antagonists in INS‐1 cells: The possible contribution of86Rb+efflux and45Ca2+uptake
Authors: Töpfer M. , Burbiel C. E. , Müller C. E. , Knittel J. , Verspohl E. J. 
Published: October 2008

AbstractDue to the lack of specific agonists and antagonists the role of adenosine receptor subtypes with respect to their effect on the insulin secretory system is not well investigated. The A1receptor may be linked to different 2nd messenger systems, i.e. cAMP, K+‐ and45Ca2+channel activity. Partial A1receptor agonists are going to be developed in order to improve diabetes (increase in insulin sensitivity, lowering of FFA and triglycerides). In this study newly synthesized selective A1receptor agonists and antagonists were investigated thereby integrating three parameters, insulin release (RIA),45Ca2+uptake and86Rb+efflux (surrogate for K+efflux) of INS‐1 cells, an insulin secretory cell line. The presence of A1‐receptors was demonstrated by Western blotting. The receptor nonselective adenosine analogue NECA (5′‐N‐ethylcarboxyamidoadenosine) at high concentration (10 µM) had no effect on insulin release and45Ca2+uptake which could be interpreted as the sum of effects mediated by mutual antagonistic adenosine receptor subtypes. However, an inhibitory effect mediated by A1receptor agonism was detected at 10 nM NECA and could be confirmed by adding the A1receptor antagonist PSB‐36 (1‐butyl‐8‐(3‐noradamantyl)‐3‐(3‐hydroxy‐propyl)xanthine). NECA inhibited86Rb+efflux which, however, did not fit with the simultaneous inhibition of insulin secretion. The selective A1receptor agonist CHA (N6‐cyclohexyladenosine) inhibited insulin release; the simultaneously increased Ca2+uptake (nifedipine dependent) and inhibition of86Rb+efflux did not fit the insulin release data. The CHA effect (even the maximum effect at 50 µM) can be increased by 10 µM NECA indicating that CHA and NECA have nonspecific and physiologically non‐relevant effects on86Rb+efflux in addition to their A1‐receptor interaction. Since PSB‐36 did not influence the NECA‐induced inhibition of86Rb+efflux, the NECA effect is not mediated by potassium channel‐linked A1receptors. The nonselective adenosine receptor antagonist caffeine increased insulin release which was reversed by CHA as expected when hypothesizing that both act via A1receptors in this case. In conclusion, stimulation of A1receptors by receptor selective and nonselective compounds reduced insulin release which is not coupled to opening of potassium channels (86Rb+efflux experiments) or inhibition of calcium channels (45Ca2+uptake experiments). It may be expected that of all pleiotropic 2nd messengers, the cAMP system (not tested here) is predominant for A1receptor effects and the channel systems (K+and Ca2+) are of minor importance and do not contribute to insulin release though being coupled to the receptor in other tissues. Copyright © 2008 John Wiley & Sons, Ltd.
Pax9 mediated cell survival in oral squamous carcinoma cell enhanced by c‐myb
Authors: Lee Jung‐Chang , Sharma Manju , Lee Young‐Hee , Lee Nan‐Hee , Kim Sun‐Young , Yun Ji‐Soo , Nam Sang‐Yun , Hwang Pyoung‐Han , Jhee Eun‐Chung , Yi Ho‐Keun 
Published: October 2008

AbstractPaired box gene 9 (Pax9) and c‐myb are transcription factors that regulate the expression of the genes involved in mediating cell proliferation, resistance to apoptosis, and migration. However, the function of Pax9 in oral squamous cell carcinoma (OSCC) is virtually unknown. This study examined the anti‐apoptotic roles of Pax9 and c‐myb, and clarified interaction between the two genes in KB cells. Inhibition of Pax9 caused the induction of apoptosis with enhanced cleavage of caspase‐3 and PARP, accelerated Bax, and reduced Bcl‐2 expression. Transducing c‐myb cells with adenovirus c‐myb (Ad/c‐myb) were induced cell growth and inhibited apoptosis, but dominant‐negative myb cells (Ad/DN‐myb) were not affected. Pax9 was upregulated in the Ad/c‐myb cells with simultaneous decrease in the Ad/DN‐myb infection. However, c‐myb remained unaffected in the Pax9 small interfering RNA (siRNA) transfected cells. Moreover, the Pax9 siRNA transfected cells and Ad/DN‐myb infected cells were able to arrest the cell cycle at the G0 phase. This suggests that Pax9 and c‐myb expression in KB cells is essential for cell growth, and survival is enhanced by c‐myb. Disrupting the function of c‐myb and Pax9 could be a potential target for cancer treatment. Copyright © 2008 John Wiley & Sons, Ltd.
Highly Fluorescent Conjugated Pyrenes in Nucleic Acid Probes: (Phenylethynyl)pyrenecarbonyl‐Functionalized Locked Nucleic Acids
Authors: Astakhova Irina V. , Korshun Vladimir A. , Wengel Jesper 
Published: October 2008

AbstractIn recent years, fluorescently labeled oligonucleotides have become a widely used tool in diagnostics, DNA sequencing, and nanotechnology. The recently developed (phenylethynyl)pyrenes are attractive dyes for nucleic acid labeling, with the advantages of long‐wave emission relative to the parent pyrene, high fluorescence quantum yields, and the ability to form excimers. Herein, the synthesis of six (phenylethynyl)pyrene‐functionalized locked nucleic acid (LNA) monomers M1–M6 and their incorporation into DNA oligomers is described. Multilabeled duplexes display higher thermal stabilities than singly modified analogues. An increase in the number of phenylethynyl substituents attached to the pyrene results in decreased binding affinity towards complementary DNA and RNA and remarkable bathochromic shifts of absorption/emission maxima relative to the parent pyrene fluorochrome. This bathochromic shift leads to the bright fluorescence colors of the probes, which differ drastically from the blue emission of unsubstituted pyrene. The formation of intra‐ and interstrand excimers was observed for duplexes that have monomers M1–M6 in both complementary strands and in numerous single‐stranded probes. If more phenylethynyl groups are inserted, the detected excimer signals become more intense. In addition, (phenylethynyl)pyrenecarbonyl–LNA monomers M4, M5, and M6 proved highly useful for the detection of single mismatches in DNA/RNA targets.
Heterometal Alkoxides as Precursors for the Preparation of Porous Fe– and Mn–TiO2 Photocatalysts with High Efficiencies
Authors: Zou Xiao‐Xin , Li Guo‐Dong , Guo Ming‐Yi , Li Xin‐Hao , Liu Da‐Peng , Su Juan , Chen Jie‐Sheng 
Published: October 2008

AbstractTransition‐metal‐doped titanium glycolates (M–TG, with M=Fe, Mn), which are the first non‐stoichiometric heterometal alkoxides, have been synthesised through a solvothermal doping approach. X‐ray diffraction, UV/Vis diffuse reflectance and ESR spectroscopy revealed that the dopant ion (Fe3+ or Mn2+) is substituted for Ti4+ in the TG lattice. Fe3+ prolongs the crystallisation time of Fe–TG, whereas Mn2+ has a smaller effect on the crystallisation time in comparison with Fe3+. The as‐synthesised M–TG materials were used directly as single‐source precursors for the preparation of metal‐doped titania (M–TiO2) through a simple thermal treatment process. The as‐prepared M–TiO2 materials maintain the rod‐like morphology of the precursors and possess a mesoporous structure with high crystallinity. It has been proved that the dopant ions are incorporated into the TiO2 lattice at the Ti4+ positions. The photocatalytic activities of the M–TiO2 materials obtained were evaluated by testing the degradation of phenol under UV irradiation. From the photocatalytic results, it was concluded that high crystallinity, a large surface area and appropriate transition‐metal‐doping are all beneficial to the enhancement of the photocatalytic performance of the doped TiO2 material. In addition, it was noted that in comparison with Mn–TiO2, Fe–TiO2 shows higher photocatalytic activity due to the better inhibition effect of Fe3+ on recombination of photogenerated electron–hole pairs. In contrast to the conventional nanosized TiO2 photocatalyst, the micrometre‐sized M–TiO2 particles we obtained can be easily separated and recovered after the photocatalytic reactions.
Total Synthesis and Biological Activity of Neopeltolide and Analogues
Authors: Vintonyak Viktor V. , Kunze Brigitte , Sasse Florenz , Maier Martin E. 
Published: October 2008

AbstractCombining the core structure of neopeltolide, lactone 16 a, with the oxazole‐containing side chain 23 via a Mitsunobu reaction provided the cytotoxic natural product neopeltolide (2). The side chain 23 was prepared from oxazolone 24 via the corresponding triflate. Key steps in the preparation of 23 were a Sonogashira coupling, an enamine alkylation, and a Still–Gennari Horner–Emmons reaction. By changing the Leighton reagent in the allylation step, the 11‐epimer of lactone 16 a, compound 50 was prepared. This led to 11‐epi‐neopeltolide 51. The 5‐epimer of neopeltolide, compound 52, could be obtained from the minor isomer of the Prins cyclization. Furthermore, a range of analogues with modifications in the side chain were prepared. All derivatives were checked for toxicity effects on mammalian cell cultures and inhibitory effects on NADH oxidation in submitochondrial particles of bovine heart. Modifications in the lactone part are tolerated to some degree. On the other hand, shortening the distance between the oxazole and the lactone causes a significant drop in activity. Analogue 65 with an additional double bond is equally or even more active than neopeltolide itself.
Structural Principles of Polyhedral Allotropes of Phosphorus
Authors: Karttunen Antti J. , Linnolahti Mikko , Pakkanen Tapani A. 
Published: October 2008

AbstractWe derive the structural principles of polyhedral allotropes of phosphorus, introducing three distinct families of black phosphorus nanostructures. The predicted tetrahedral, octahedral, and icosahedral phosphorus cages can also be considered as phosphorus fullerenes. Phosphorus cages up to P888 are systematically investigated by quantum chemical methods, and their thermodynamic stabilities are compared with the experimentally known allotropic forms of phosphorus. The tetrahedral cages are thermodynamically favored over the octahedral and icosahedral structures, although large octahedral structures become nearly as stable as the tetrahedral ones. The stability trends of the studied polyhedral families can be rationalized on the basis of their structural characteristics. The phosphorus polyhedra can be further stabilized by fitting smaller structures inside larger ones, resulting in multilayered, bulk‐like cages. The synthesis of the predicted black phosphorus nanostructures is suggested to be viable from the thermodynamic point of view, and several approaches for their experimental preparation can be envisaged.
Flexible Solar Cells
Authors: Pagliaro Mario , Ciriminna Rosaria , Palmisano Giovanni 
Published: October 2008

AbstractThin‐film flexible photovoltaics are paving the way to low‐cost electricity. Organic, inorganic and organic–inorganic solar cells are deposited over flexible substrates by high‐throughput (often roll‐to‐roll printing) technologies to afford lightweight, economic solar modules that can be integrated into, not installed on, various surfaces. Current conversion efficiencies under standard conditions are in the 3–15 % range, but in real applications the overall productivity is high. These new photovoltaic technologies are ready to provide cheap, clean electricity to the 2 billion people who lack access to the grid as well as to energy‐eager companies and families in the developed world facing the increasing costs of electricity generated using fossil fuel resources. This Review focuses on recent achievements in the area of flexible solar cells, highlights the principles behind the main technologies, and discusses future challenges in this area.
Epithelial‐mesenchymal crosstalk in Wolffian duct and fetal testis cord development
Authors: Archambeault Denise R. , Tomaszewski Jessica , Joseph Avenel , Hinton Barry T. , Yao Humphrey Hung‐Chang 
Published: October 2008

AbstractInteractions between adjacent epithelial and mesenchymal tissues represent a highly conserved mechanism in embryonic organogenesis. In particular, the ability of the mesenchyme to instruct cellular differentiation of the epithelium is a fundamental requirement for the morphogenesis of tubular structures such as those found in the kidneys, lungs, and the developing male reproductive system. Once the tubular structure has formed, it receives signals from the mesenchyme, which can control proliferation, patterning, and differentiation of the epithelium inside the tube. However, the epithelium is not a “silent partner” in this process, and epithelium‐derived factors are often required for proper maintenance of the mesenchymal compartment. Although much emphasis has been placed on the characterization of mesenchymally‐derived signals required for epithelial differentiation, it is important to note that epithelial‐mesenchymal interactions are a two‐way street wherein each compartment requires the presence of the other for proper tubule morphogenesis and function. In this review, we discuss epithelial‐mesenchymal interactions in the processes of Wolffian duct and fetaltestis cord development using the mouse as a model organism and propose inhibin beta A as a conserved mesenchyme‐derived regulator in these two male‐specific tubular structures. genesis 47:40–48, 2009. © 2008 Wiley‐Liss, Inc.
Can NK cells be a therapeutic target in human diseases?
Authors: Chan Christopher J. , Andrews Daniel M. , Smyth Mark J. 
Published: October 2008

AbstractOur current knowledge of NK‐cell recognition and effector function suggests that it will be possible to design various new NK‐cell‐based immunotherapies against human cancer. The application of NK cells is already showing promise using HLA‐mismatched haematopoietic stem cell transplantation for treatment of haematological malignancies. A better understanding of NK‐cell heterogeneity and function will only broaden the applications for human cancer. Here we review the key developments that will propel this field.
Viral inhibitors of NKG2D ligands: Friends or foes of immune surveillance?
Authors: Jonjić Stipan , Polić Bojan , Krmpotić Astrid 
Published: October 2008

AbstractNKG2D is a potent activating receptor on NK cells and a co‐stimulatory receptor on CD8+ T cells. Through its ability to recognize a panel of ligands inducible by stress or infection, it plays an important role in the control of viral infections. The viruses have evolved robust mechanisms to counteract NKG2D‐dependent immune response. The functions of these viral inhibitors are well characterized during the early days post‐infection but less so during the chronic viral infection.
Functionally distinct NK‐cell subsets: Developmental origins and biological implications
Authors: Di Santo James P. 
Published: October 2008

AbstractNK cells were initially identified based on their capacity to destroy susceptible target cells via granule‐mediated cytotoxicity. Subsequently, NK‐cell cytokine production (IFN‐γ, TNF‐α) was shown to be critical in restricting pathogen infection, defining a non‐cytotoxic role for NK cells in host defense. Recently, specialized NK‐cell subsets with biased effector functions have been described in mice and man. This overview will consider the developmental origins and biological implications of this NK‐cell diversification.
Tumor cell recognition by the NK cell activating receptor NKG2D
Authors: Bryceson Yenan T. , Ljunggren Hans‐Gustaf 
Published: October 2008

AbstractEvidence for increased tumor incidence in NKG2D‐deficient mice has set NKG2D as the first innate immune receptor implicated in immunosurveillance of tumors. In this viewpoint article, we discuss recent genetic insight into NKG2D‐mediated suppression of spontaneous tumor development in the context of NKG2D signaling properties. Moreover, we identify unresolved issues and consider how an understanding of NKG2D‐receptor and ‐ligand biology can facilitate successful therapeutic intervention of human cancer.
NK cells: New issues and challenges
Authors: Colonna Marco 
Published: October 2008

AbstractNK cells are innate lymphocytes crucial for surveillance against pathogens and tumors. Although the basic mechanisms through which NK cells operate have been established, many questions are still unresolved. Are all NK cells equal or can we identify subsets with distinct developmental origin and function? How do NK cells interact with other components of the immune system, such as DC, effector T cells, and Treg cells to elicit effective immune responses? How do NK cells become tolerant to self and preclude autoimmunity? Finally, can we design novel therapeutic avenues for cancer treatment based on NK cells? The editorial team of the European Journal of Immunology asked the opinion of some of the leading experts in the NK‐cell field regarding the new challenges and opportunities facing this area of research and the thoughts of the experts are presented in this viewpoint series. This introduction to the series brings together some of the novel concepts emerging from the experts' discussions.
Stereoselective Synthesis of Chiral 2,3‐Disubstituted 2,3‐Dihydro‐4(1H)‐pyridones
Authors: Etayo Pablo , Badorrey Ramón , Díaz‐de‐Villegas María D. , Gálvez José A. 
Published: October 2008

AbstractThe alkylation at C‐3 of the easily accessible (R)‐2‐[(S)‐1,2‐bis(benzyloxy)ethyl]‐1‐[(S)‐1‐phenylethyl]‐2,3‐dihydro‐4(1H)‐pyridone with different electrophiles took place with totaltransdiastereoselectivity to afford the corresponding (2R,3S)‐2,3‐disubstituted 2,3‐dihydro‐4(1H)‐pyridones in enantiomerically pure form. The configuration at C‐3 can be inverted by deprotonation and subsequent reprotonation to yield the corresponding (2R,3R)‐2,3‐disubstituted 2,3‐dihydro‐4(1H)‐pyridones in a highly diastereoselective manner.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Thiols in Ugi‐ and Passerini–Smiles‐Type Couplings
Authors: Barthelon Anaëlle , El Kaïm Laurent , Gizolme Marie , Grimaud Laurence 
Published: October 2008

AbstractThe use of the Smiles rearrangement in Ugi‐type couplings with aromatic mercaptans allows for the straightforward, multicomponent formation of α‐arylamino thiocarboxamides. The scope of this new four‐component coupling is further broadened with the use of heterocyclic mercapto derivatives that afford thioamides of high biological interest in one step. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Thermodynamic, Equilibrium and Kinetic Study of the Biosorption of Basic Blue 41 using Bacillus maceran
Authors: Atar N. , Olgun A. , Çolak F. 
Published: October 2008

AbstractThermodynamic, kinetic and equilibrium studies during the biosorption of Basic blue 41(BB 41) from aqueous solution using Bacillus macerans were carried out with a focus on pH, contact time, temperature, biomass dosage and initial dye concentration. The maximum adsorption capacity was found to be 89.2 mg/g under optimal conditions of pH (10.0) and temperature (25 °C). The biosorption rates obtained were consistent with the pseudo‐second order kinetic models. The equilibrium data were analyzed using linearized forms of Langmuir and Freundlich isotherms, and the Langmuir isotherm was found to provide the best correlation of the experimental data for the biosorption of BB 41. The equilibrium time for the removal of BB  41 by the biomass was attained within 90 min. Thermodynamic parameters such as free energy (<$>\Delta G<$>), enthalpy (<$>\Delta H<$>), and entropy (<$>\Delta S<$>) were also calculated. The results indicate that biosorption is spontaneous and exothermic in nature. The negative value of entropy confirms the decreased randomness at the solid‐liquid interface during the adsorption of BB 41 onto Bacillus macerans.
A polygenic model for integration of linkage and pathway information
Authors: Lebrec J.J.P. , Nishchenko I. , van der Wijk H.J. , Huizinga T.W. , van Houwelingen H.C. 
Published: October 2008

AbstractWe introduce an approximate model for linkage curves which accommodates the polygenic structure of complex diseases and accounts for the simultaneous action of closely located genes. The model is extended so that information on biological pathways can be integrated. Using data on rheumatoid arthritis, we describe some of the many applications which the model allows: it can be used to test for residual linkage in the presence of already established loci, to derive a global test for linkage, to test for the relevance of a gene list in terms of linkage and to help in candidate gene prioritization by integration of gene‐pathway annotation data. Genet. Epidemiol. 2009. © 2008 Wiley‐Liss, Inc.
The impact of newly identified loci on coronary heart disease, stroke and total mortality in the MORGAM prospective cohorts
Authors: Karvanen Juha , Silander Kaisa , Kee Frank , Tiret Laurence , Salomaa Veikko , Kuulasmaa Kari , Wiklund Per‐Gunnar , Virtamo Jarmo , Saarela Olli , Perret Claire , Perola Markus , Peltonen Leena , Cambien Francois , Erdmann Jeanette , Samani Nilesh J. , Schunkert Heribert , Evans Alun 
Published: October 2008

AbstractRecently, genome wide association studies (GWAS) have identified a number of single nucleotide polymorphisms (SNPs) as being associated with coronary heart disease (CHD). We estimated the effect of these SNPs on incident CHD, stroke and total mortality in the prospective cohorts of the MORGAM Project. We studied cohorts from Finland, Sweden, France and Northern Ireland (total N=33,282, including 1,436 incident CHD events and 571 incident stroke events). The lead SNPs at seven loci identified thus far and additional SNPs (in total 42) were genotyped using a case‐cohort design. We estimated the effect of the SNPs on disease history at baseline, disease events during follow‐up and classic risk factors. Multiple testing was taken into account using false discovery rate (FDR) analysis. SNP rs1333049 on chromosome 9p21.3 was associated with both CHD and stroke (HR=1.20, 95% CI 1.08–1.34 for incident CHD events and 1.15, 0.99–1.34 for incident stroke). SNP rs11670734 (19q12) was associated with total mortality and stroke. SNP rs2146807 (10q11.21) showed some association with the fatality of acute coronary event. SNP rs2943634 (2q36.3) was associated with high density lipoprotein (HDL) cholesterol and SNPs rs599839, rs4970834 (1p13.3) and rs17228212 (15q22.23) were associated with non‐HDL cholesterol. SNPs rs2943634 (2q36.3) and rs12525353 (6q25.1) were associated with blood pressure. These findings underline the need for replication studies in prospective settings and confirm the candidacy of several SNPs that may play a role in the etiology of cardiovascular disease. Genet. Epidemiol. 2009. © 2008 Wiley‐Liss, Inc.