bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of NUP98 abnormalities in acute leukemia: JARID1A (12p13) as a new partner gene
Authors: van Zutven Laura J. C. M. , Önen Emine , Velthuizen Sandra C. J. M. , van Drunen Ellen , von Bergh Anne R. M. , van den Heuvel‐Eibrink Marry M. , Veronese Angelo , Mecucci Cristina , Negrini Massimo , de Greef Georgine E. , Beverloo H. Berna
Published: January 2006

Chromosome rearrangements are found in many acute leukemias. As a result, genes at the breakpoints can be disrupted, forming fusion genes. One of the genes involved in several chromosome aberrations in hematological malignancies is NUP98 (11p15). As NUP98 is close to the 11p telomere, small translocations might easily be missed. Using a NUP98‐specific split‐signal fluorescence in situ hybridization (FISH) probe combination, we analyzed 84 patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia, or myelodysplastic syndrome with either normal karyotypes or 11p abnormalities to investigate whether there are unidentified 11p15 rearrangements. Neither NUP98 translocations nor deletions were identified in cases with normal karyotypes, indicating these aberrations may be very rare in this group. However, NUP98 deletions were observed in four cases with unbalanced 11p aberrations, indicating that the breakpoint is centromeric of NUP98. Rearrangements of NUP98 were identified in two patients, both showing 11p abnormalities in the diagnostic karyotype: a t(4;11)(q1?3;p15) with expression of the NUP98–RAP1GDS1 fusion product detected in a 60‐year‐old woman with AML‐M0, and an add(11)(p15) with a der(21)t(11;21)(p15;p13) observed cytogenetically in a 1‐year‐old boy with AML‐M7. JARID1A was identified as the fusion partner of NUP98 using 3′ RACE, RT‐PCR, and FISH. JARID1A, at 12p13, codes for retinoblastoma binding protein 2, a protein implicated in transcriptional regulation. This is the first report of JARID1A as a partner gene in leukemia. © 2006 Wiley‐Liss, Inc.
Spatiotemporal gene control by the Cre‐ERT2 system in melanocytes
Authors: Yajima Ichiro , Belloir Elodie , Bourgeois Yveline , Kumasaka Mayuko , Delmas Véronique , Larue Lionel
Published: January 2006

The organ‐specific and temporal control of gene activation/inactivation is a key issue in the understanding of protein function during normal and pathological development and during oncogenesis. We generated transgenic mice bearing a tamoxifen‐dependent Cre recombinase (Tyr::Cre‐ERT2) gene expressed under the control of a 6.1 kb murine tyrosinase promoter in order to facilitate targeted spatiotemporally controlled somatic recombination in melanoblasts/melanocytes. Cre‐ERT2 production was detected in tissues containing melanocytes. After tamoxifen induction at various times during embryogenesis and adulthood in a Cre‐responsive reporter mouse strain, genetic recombination was detected in the melanoblasts and melanocytes of the skin. Thus, the Tyr::Cre‐ERT2 transgenic mice provides a valuable tool for following this cell lineage and for investigating gene function in melanocyte development and transformation. genesis 44:34–43, 2006. © 2006 Wiley‐Liss, Inc.
On the reversible O2 binding of the Fe–porphyrin complex
Authors: Nakashima Hiroyuki , Hasegawa Jun‐Ya , Nakatsuji Hiroshi
Published: January 2006

Electronic mechanism of the reversible O2 binding by heme was studied by using Density Functional Theory calculations. The ground state of oxyheme was calculated to be open singlet state [Fe(S =1/2) + O2(S = 1/2)]. The potential energy surface for singlet state is associative, while that for triplet state is dissociative. Because the ground state of the O2+ deoxyheme system is triplet in the dissociation limit [Fe(S = 2) + O2(S = 1)], the O2 binding process requires relativistic spin‐orbit interaction to accomplish the intersystem crossing from triplet to singlet states. Owing to the singlet‐triplet crossing, the activation energies for both O2 binding and dissociation become moderate, and hence reversible. We also found that the deviation of the Fe atom from the porphyrin plane is also important reaction coordinate for O2 binding. The potential surface is associative/dissociative when the Fe atom locates in‐plane/out‐of‐plane. © 2006 Wiley Periodicals, Inc. J Comput Chem 4: 426–433, 2006
HMGB1 expression and release by bone cells
Authors: Charoonpatrapong Kanokwan , Shah Rita , Robling Alexander G. , Alvarez Marta , Clapp D. Wade , Chen Shi , Kopp Ryan P. , Pavalko Fredrick M. , Yu Jun , Bidwell Joseph P.
Published: January 2006

Immune and bone cells are functionally coupled by pro‐inflammatory cytokine intercellular signaling networks common to both tissues and their crosstalk may contribute to the etiologies of some immune‐associated bone pathologies. For example, the receptor activator of NF‐κB ligand (RANKL)/osteoprotegerin (OPG)/receptor activator of NF‐κB (RANK) signaling axis plays a critical role in dendritic cell (DC) function as well as bone remodeling. The expression of RANKL by immune cells may contribute to bone loss in periodontitis, arthritis, and multiple myeloma. A recent discovery reveals that DCs release the chromatin protein high mobility group box 1 (HMGB1) as a potent immunomodulatory cytokine mediating the interaction between DCs and T‐cells, via HMGB1 binding to the membrane receptor for advanced glycation end products (RAGE). To determine whether osteoblasts or osteoclasts express and/or release HMGB1 into the bone microenvironment, we analyzed tissue, cells, and culture media for the presence of this molecule. Our immunohistochemical and immunocytochemical analyses demonstrate HMGB1 expression in primary osteoblasts and osteoclasts and that both cells express RAGE. HMGB1 is recoverable in the media of primary osteoblast cultures and cultures of isolated osteoclast precursors and osteoclasts. Parathyroid hormone (PTH), a regulator of bone remodeling, attenuates HMGB1 release in cultures of primary osteoblasts and MC3T3‐E1 osteoblast‐like cells but augments this release in the rat osteosarcoma cell line UMR 106‐01, both responses primarily via activation of adenylyl cyclase. PTH‐induced HMGB1 discharge by UMR cells exhibits similar release kinetics as reported for activated macrophages. These data confirm the presence of the HMGB1/RAGE signaling axis in bone. J. Cell. Physiol. 207: 480–490, 2006. © 2006 Wiley‐Liss, Inc.
S100B stimulates myoblast proliferation and inhibits myoblast differentiation by independently stimulating ERK1/2 and inhibiting p38 MAPK
Authors: Riuzzi Francesca , Sorci Guglielmo , Donato Rosario
Published: January 2006

The Ca2+‐modulated protein of the EF‐hand type, S100B, was shown to inhibit rat L6 myoblast differentiation and myotube formation by interacting with a high affinity with an unidentified receptor (Sorci et al., 2003). We show here that S100B independently inhibits the MKK6‐p38 MAPK pathway and stimulates the Ras‐MEK‐ERK1/2 pathway. The inhibitory effect of S100B on p38 MAPK translates into a defective induction of the muscle‐specific transcription factor myogenin and the antiproliferative factor p21WAF1, while S100B's stimulatory effect on ERK1/2 results in stimulation of myoblast proliferation via cyclin D1 induction and Rb phosphorylation and protection against apoptosis via activation of NF‐κB transcriptional activity. Also, the S100B's effects that are mediated by the Ras‐MEK‐ERK1/2 pathway that is, stimulation of proliferation and protection against apoptosis, depend on reactive oxygen species production, being inhibited by antioxidants, while the S100B inhibitory effect on the MKK6‐p38 MAPK pathway is not. We propose that S100B might participate in the regulation of myoblast differentiation by stimulating myoblast proliferation, protecting myoblasts against apoptosis, and modulating myotube formation. J. Cell. Physiol. 207: 461–470, 2006. © 2006 Wiley‐Liss, Inc.
Intraocular injection of an aptamer that binds PDGF‐B: A potential treatment for proliferative retinopathies
Authors: Akiyama Hideo , Kachi Shu , E Silva Raquel Lima , Umeda Naoyasu , Hackett Sean F. , McCauley Dilara , McCauley Thomas , Zoltoski Anna , Epstein David M. , Campochiaro Peter A.
Published: January 2006

Platelet‐derived growth factor‐B (PDGF‐B) has been implicated in the pathogenesis of proliferative retinopathies and other scarring disorders in the eye. In this study, we sought to test the therapeutic potential of an aptamer that selectively binds PDGF‐B, ARC126, and its PEGylated derivative, ARC127. Both ARC126 and ARC127 blocked PDGF‐B‐induced proliferation of cultured fibroblasts with an IC50 of 4 nM. Pharmacokinetic studies in rabbits showed similar peak vitreous concentrations of approximately 110 µM after intravitreous injection of 1 mg of either ARC126 or ARC127, but the terminal half‐life was longer for ARC127 (98 versus 43 h). Efficacy was tested in rho/PDGF‐B transgenic mice that express PDGF‐B in photoreceptors and develop severe proliferative retinopathy resulting in retinal detachment. Compared to eyes injected with 20 µg of scrambled aptamer in which five of six developed detachments (three total and two partial), eyes injected with ARC126 (no detachment in five of six and one partial detachment), or ARC127 (no detachment in six of six) had significantly fewer retinal detachments. They also showed a significant reduction in epiretinal membrane formation. These data demonstrate that a single intravitreous injection of an aptamer that specifically binds PDGF‐B is able to significantly reduce epiretinal membrane formation and retinal detachment in rho/PDGF‐B mice. These striking effects in an aggressive model of proliferative retinopathy suggest that ARC126 and ARC127 should be considered for treatment of diseases in which PDGF‐B has been implicated, including ischemic retinopathies such as proliferative diabetic retinopathy, proliferative vitreoretinopathy (PVR), and choroidal neovascularization. J. Cell. Physiol. 207: 407–412, 2006. © 2006 Wiley‐Liss, Inc.
Protein kinase C theta co‐operates with calcineurin in the activation of slow muscle genes in cultured myogenic cells
Authors: D'Andrea M. , Pisaniello A. , Serra C. , Senni M.I. , Castaldi L. , Molinaro M. , Bouché M.
Published: January 2006

Adult skeletal muscle fibers can be divided into fast and slow twitch subtypes on the basis of specific contractile and metabolic properties, and on distinctive patterns of muscle gene expression. The calcium, calmodulin‐dependent protein phosphatase, calcineurin, stimulates slow fiber‐specific genes (myoglobin (Mb), troponin I slow) in cultured skeletal muscle cells, as well as in transgenic mice, through the co‐operation of peroxisome‐proliferation‐activator receptor γ co‐activator 1α (PGC1α) myocyte enhancer factor 2 (MEF2), and nuclear factor of activated T cells (NFAT) transcription factors. Specific protein kinase C isoforms have been shown to functionally co‐operate with calcineurin in different cellular models. We investigated whether specific protein kinase C isoforms are involved in calcineurin‐induced slow skeletal muscle gene expression. By pharmacological inhibition or exogenous expression of mutant forms, we show that protein kinase C theta (the protein kinase C isoform predominantly expressed in skeletal muscle) is required and co‐operates with calcineurin in the activation of the Mb promoter, as well as in the induction of slow isoforms of myosin and troponin I expression, in cultured muscle cells. This co‐operation acts primarily regulating MEF2 activity, as shown by using reporter gene expression driven by the Mb promoter mutated in the specific binding sites. MEF2 activity on the Mb promoter is known to be dependent on both PGC1α and inactivation of histone deacetylases (HDACs) activity. We show in this study that protein kinase C theta is required for, even though it does not co‐operate in, PGC1α‐dependent Mb activation. Importantly, protein kinase C theta regulates the HDAC5 nucleus/cytoplasm location. We conclude that protein kinase C theta ensures maximal activation of MEF2, by regulating both MEF2 transcriptional complex formation and HDACs nuclear export. J. Cell. Physiol. 207: 379–388, 2006. © 2006 Wiley‐Liss, Inc.
The MEK/MAPK pathway is involved in the resistance of breast cancer cells to the EGFR tyrosine kinase inhibitor gefitinib
Authors: Normanno Nicola , Luca Antonella De , Maiello Monica R. , Campiglio Manuela , Napolitano Maria , Mancino Mario , Carotenuto Adele , Viglietto Giuseppe , Menard Sylvie
Published: January 2006

We investigated the role of the MEK/MAPK pathway in the sensitivity/resistance of breast carcinoma cells to the EGFR tyrosine kinase inhibitor gefitinib (IRESSA). We assessed the effects of gefitinib on the growth of three breast cancer cell lines that showed high (SK‐Br‐3; IC50 4 µM), intermediate (MDA‐MB‐361; IC50 5.3 µM), and low (MDA‐MB‐468; IC50 6.8 µM) sensitivity to the drug. Although treatment with gefitinib inhibited EGFR activation in the three cell lines in a similar fashion, significant reduction of both p42/p44‐MAPK and AKT phosphorylation was observed in SK‐Br‐3 and MDA‐MB‐361, but not in MDA‐MB‐468 cells. The growth of MDA‐MB‐468 cells was significantly inhibited by treatment with either the PI3K‐inhibitor LY294002 or the MEK‐inhibitor PD98059. In agreement with these findings, treatment of MDA‐MB‐468 cells with a combination of PD98059 and gefitinib produced a synergistic anti‐tumor effect, whereas this combination was only additive in SK‐Br‐3 and MDA‐MB‐361 cells. The combination of gefitinib and PD98059 also produced a significant increase in the levels of apoptosis in MDA‐MB‐468 cells as compared with treatment with a single agent. This phenomenon was associated with a profound decrease in MAPK activation, reduction of BAD (ser112) phosphorylation and a paradoxical increase in the levels of AKT activation. Finally, overexpression of a constitutively activated form of p42‐MAPK in MCF‐10A non‐transformed human mammary epithelial cells resulted in a two‐ to three‐fold increase in the IC50 to gefitinib. Taken together, these data strongly support the role of the MEK/MAPK pathway in the resistance to gefitinib, and provide the rationale for novel therapeutic approaches based on combinations of signal transduction inhibitors. J. Cell. Physiol. 207: 420–427, 2006. © 2006 Wiley‐Liss, Inc.
From the “Modern Synthesis” to cybernetics: Ivan Ivanovich Schmalhausen (1884–1963) and his research program for a synthesis of evolutionary and developmental biology
Authors: Levit Georgy S. , Hossfeld Uwe , Olsson Lennart
Published: January 2006

Ivan I. Schmalhausen was one of the central figures in the Russian development of the “Modern Synthesis” in evolutionary biology. He is widely cited internationally even today. Schmalhausen developed the main principles of his theory facing the danger of death in the totalitarian Soviet Union. His great services to evolutionary and theoretical biology are indisputable. However, the received view of Schmalhausen's contributions to evolutionary biology makes an unbiased reading of his texts difficult. Here we show that taking all of his works into consideration (including those only available in Russian) paints a much more dynamic and exciting picture of what he tried to achieve. Schmalhausen pioneered the integration of a developmental perspective into evolutionary thinking. A main tool for achieving this was his approach to living objects as complex multi‐level self‐regulating systems. Schmalhausen put enormous effort into bringing this idea into fruition during the final stages of his career by combining evolutionary theory with cybernetics. His results and ideas remain thought‐provoking, and his texts are of more than just historical interest. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
Application of flow nephelometry to the analysis of the influence of carbohydrates on protein–tannin interactions
Authors: Carvalho Elisabete , Póvoas Maria João , Mateus Nuno , de Freitas Victor
Published: January 2006

The flow nephelometric technique was recently introduced to study the interaction between tannins and proteins. This technique was employed here to study the ability of the polysaccharides xanthan, dextran and gum arabic to disrupt the interactions between condensed tannin fractions from grape seed and bovine serum albumin (BSA). Xanthan was shown to have a higher ability to inhibit the aggregate formation of tannins and BSA than the other polysaccharides. Xanthan's ability to inhibit protein‐tannin complex formation was higher for condensed tannin fractions of smaller size and lower complexity. Copyright © 2006 Society of Chemical Industry
Tea, obesity, and diabetes
Authors: Kao Yung‐Hsi , Chang Hsin‐Huei , Lee Meng‐Jung , Chen Chia‐Lin
Published: January 2006

Tea has been found to possess widespread biological functions based on a variety of laboratory data. The effects of tea on obesity and diabetes have received increasing attention. This paper reviews the evidence for the connections among tea catechins, and obesity and diabetes. Tea catechins, especially (–)‐epigallocatechin gallate (EGCG), appear to have antiobesity and antidiabetic effects. While few epidemiological and clinical studies show the health benefits of EGCG on obesity and diabetes, the mechanisms of its actions are emerging based on the various laboratory data. These mechanisms may be related to certain pathways, such as through the modulations of energy balance, endocrine systems, food intake, lipid and carbohydrate metabolism, the redox status, and activities of different types of cells (i. e., fat, liver, muscle, and β‐pancreatic cells). Because the EGCG receptor, the so‐called 67‐kDa laminin receptor (LR), has been discovered with colocalization of other types of LR and cytoskeleton in both cancer cells and normal cells, this may explain that EGCG possesses numerous actions. The mechanistic results of this review may possibly be utilized in the treatment of obesity, diabetes, and other related diseases using tea‐ and EGCG‐based folk medicines.
Recent progress in high resolution lithography
Authors: Bratton Daniel , Yang Da , Dai Junyan , Ober Christopher K.
Published: January 2006

The nanotechnology revolution of the past decade owes much to the science of lithography, an umbrella term which encompasses everything from conventional photolithography to “unconventional” soft lithography and the self‐assembly of block polymers. In this review, some of the recent advances in lithography are summarized with special reference to the microelectronics industry. The next generation photolithography, two‐photon lithography, step‐and‐flash imprint lithography and nanofabrication using block copolymers are covered, in an attempt to describe more recent work in this vibrant and active field of research. Copyright © 2006 John Wiley & Sons, Ltd.
Photoinitiators with functional groups. IX. Hydrophilic bisacylphosphine oxides for acidic aqueous formulations
Authors: Ullrich G. , Ganster B. , Salz U. , Moszner N. , Liska R.
Published: January 2006

Because of the poor photoreactivity of camphorquinone–amine‐based photoinitiator systems in dental acidic aqueous primer formulations, we were interested to evaluate a commercially available bisacylphosphine oxide as photoinitiator. Because of the promising results on photoreactivity and storage stability, new oligo(ethylene glycol)‐substituted bisacylphosphine oxides were synthesized and investigated. Beside good solubility and significantly increased reactivity in aqueous acidic formulations, sufficient storage stability was found. Additionally, the influence of the type of substitution on the photopolymerization behavior in aqueous, hydrophilic, and hydrophobic resins is discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1686–1700, 2006
Computational study of the synthesis of benzoin derivatives from benzil
Authors: Topal Kevser Göçmen , Unaleroglu Canan , Aviyente Viktorya
Published: January 2006

Benzil (1,2‐diphenylethane‐1,2‐dione) undergoes cyanide catalyzed condensation with benzaldehyde to yield O‐benzoylated benzoin (2‐benzoyl‐1,2‐diphenylethanone). In this study, the experimentally suggested mechanism has been modeled with PM3 and verified with B3LYP. The effect of the substituent on the reaction yield has been rationalized by considering two benzil derivatives; 1,2‐bis(2‐chlorophenyl)ethane‐1,2‐dione and 1,2‐bis(2‐fluorophenyl)ethane‐1,2‐dione and three benzaldehyde derivatives; o‐fluorobenzaldehyde, o‐methylbenzaldehyde and 2‐pyridinecarboxaldehyde. The effect of the solvent has been modeled by using the isodensity‐surface polarizable continuum (IPCM) model. Reactivity descriptors have been used to justify the reactivity differences of the various substituents. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Theoretical study of the magnetic exchange coupling behavior substituting Cr(III) with Mo(III) in cyano‐bridged transition metal complexes
Authors: Zhang Yi‐Quan , Luo Cheng‐Lin
Published: January 2006

Molecular magnetism in a series of cyano‐bridged first and second transition metal complexes has been investigated using density functional theory (DFT) combined with the broken‐symmetry (BS) approach. Several exchange‐correlation (XC) functionals in the ADF package were used to investigate complexes I [−(Me3tacn)2(cyclam)NiMo2(CN)6]2+, II [−(Me3tacn)2(cyclam)Ni‐Cr2(CN)6]2+, III [(Me3tacn)6MnMo6(CN)18]2+, and IV [(Me3tacn)6MnCr6(CN)18]2+ (Me3tacn = N,N′,N‴‐trimethyl‐1,4,7‐triazacyclononane). For models A (the molded structure of complex I) and B (the modeled structure of complex II), all the XCs given qualitatively reasonable results and predict ferromagnetic coupling character between M (M = MoIII for A or CrIII for B) and NiII in coincidence with the experimental results (see Tables I and II). The calculated using Operdew, OPBE, O3LYP, and B3LYP functionals and experimental J values show that substituting CrIII with MoIII will enhance the ferromagnetic exchange coupling interactions. But VWN, PW91, PBE, VSXC, and tau‐HCTH functionals have no way to differentiate the relative strength of the intramolecular magnetic exchange coupling interactions of A and B correctly. For models C (the modeled structure of complex III) and D (the modeled structure of complex IV), all the XCs in ADF and B3LYP in Gaussian 03 with several basis sets show that substituting CrIII with MoIII will enhance the antiferromagnetic exchange coupling interactions. From the above calculations, the substitution of CrIII by MoIII will enhance the magnetic coupling interactions, whether the magnetic coupling interactions are ferro‐ or antiferromagnetic. Moreover, Kahn's model was applied to investigate the above facts. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Looking for high‐energy density compounds among hexaazaadamantane derivatives with CN, NC, and ONO2 groups
Authors: Xu Xiao Juan , Xiao He Ming , Ma Xiu Fang , Ju Xue Hai
Published: January 2006

Density functional theory (DFT) was employed to evaluate the heats of formation (HOFs) for hexaazaadamantane (HAA) derivatives with CN, NC, and ONO2 groups, respectively. This was done by designing isodesmic reactions at the B3LYP/6‐31G* level of theory, where the HAA cage skeletons were kept unbroken to produce more accurate results, and all HOFs for the required reference compounds, NH2CN, NH2NC, NH2ONO2, and (CH2NH)3, were derived from the G3 theory calculation based on the atomization energies. The calculation results show that the HOFs of HAA derivatives are mainly affected by the number and the position of substituent groups, all the obtained HOFs are positive, and the NC derivatives have the most HOFs among the three types of derivatives with the same number of substituent groups. The detonation velocity (D) and detonation pressure (P) were obtained from the empirical Kamlet–Jacobs equations. All the NC and CN derivatives of HAA have lower densities (ρ), heats of explosion (Q), D, and P. However, these properties of ONO2 derivatives are rather high and vary with the number of ONO2 groups. Considering the easiness for synthesis and relative stability, 2,4,6,8‐hexaazaadamantanenitrate is finally recommended as a potential candidate of a high‐energy density compound (HEDC). © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Theoretical study of electric field‐induced intramolecular electron transfer in donor–acceptor pairs via the rigid space and their suitability as molecular electronic devices
Authors: Lu Shen‐Zhuang
Published: January 2006

The geometries of two reaction systems have been optimized under the constraint of C2ν symmetry, using the UHF/6‐31G method. The potential energy surfaces (PES) of the two systems in different external electric field have been constructed using a linear reaction coordinate. It is concluded that the reorganization energies and electron transfer matrix elements for both systems are almost independent of the external electric field. However, the standard Gibbs energy difference changes remarkably with the change of the external electric field. Hence, the applied electric field leads to the variation of rate constant of electron transfer reaction. The threshold field, where the electron transfer becomes barrier free, is obtained to be 0.0015 a.u. for the anion system 1, and 0.00097 a.u. for the anion system 2. The threshold field for modified system 1, in which the hydrogen atoms linking to benzene rings are replaced by fluorine atom, is 0.0018 a.u. The calculations show that the best way to adjust the threshold field is to adjust the dipole moment of the reaction system by changing the length of the bridge. As the rate constant in field‐free case is taken into account, neither reaction systems could be used as molecular electronic device. But if the bridge consists of three or four HCTDs, the rate constant and threshold field will satisfy the practical demand. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Comprehensive mechanistic study of ion pair SN2 reactions of lithium isocyanate and methyl halides
Authors: Sun Ying‐Xin , Ren Yi , Wong Ning‐Bew , Chu San‐Yan , Xue Ying
Published: January 2006

The anionic SN2 reactions NCO− + CH3X and ion pair SN2 reactions LiNCO + CH3X (X = F, Cl, Br, and I) at saturated carbon with inversion and retention mechanisms were investigated at the level of MP2/6‐311+G(d,p). There are two possible reaction pathways in the anionic SN2 reactions, but eight in the ion pair SN2 reactions. Calculated results suggest that the previously reported T‐shaped isomer of lithium isocyanate does not exist. All the retention pathways are not favorable based on the analysis of transition structures. Two possible competitive reaction pathways proceed via two six‐member ring inversion transition structures. It is found that there are two steps in the most favorable pathway, in which less stable lithium cyanate should be formed through the isomerization of lithium isocyanate and nucleophilic site (N) subsequently attacks methyl halides from the backside. The thermodynamically and kinetically favorable methyl isocyanate is predicted as major product both in the gas phase anionic and the ion pair SN2 reactions. In addition, good correlations between the overall barriers relative to separated reactants, ΔH , with geometrical looseness parameter %L≠ and the heterolytic cleavage energies of the CX and LiN (or LiO) bonds are observed for the anionic and ion pair SN2 reactions. The trend of variation of the overall barriers predicts the leaving ability of X increase in the order: F < Cl < Br < I. The polarized continuum model (PCM) has been used to evaluate the solvent effects on the two inversion pathways with six‐member transition structures for the reactions of LiNCO + CH3X. The calculations in solution indicate that solvent effects will retard the rate of reactions and the predicted product, methyl isocyanate, is same as the one in the gas phase. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Theoretical studies on the reaction mechanism of CH2CH radical with HNCO
Authors: Li Lai‐Cai , Zheng Yan , Zha Dong , Tian An‐Min , Xu Ming‐Hou
Published: January 2006

The reaction mechanism of CH2CH radical with HNCO has been investigated systematically by density functional theory (DFT). The geometries and harmonic frequencies of reactants, intermediates, transition states, and products have been optimized with the B3LYP at different levels. At the same time, AIM is performed to calculate the charge density of some bonding critical points and the charges of some atoms. Nine feasible reaction pathways have been investigated. The results indicated that the main pathway is CH2CH + HNCO → IMA1 → TSA1 → CH2CH2 + NCO, which is characterized by hydrogen atom transferring. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Binding of 3O2 and 1O2 to dyes used in photodynamic therapy in gas phase and aqueous media
Authors: Kushwaha P. S. , Mishra P. C.
Published: January 2006

Density functional theory (DFT) was employed at the B3LYP/6‐31+G* level to study complexes of 1O2 and 3O2 with the dye molecules proflavine, methylene blue, and acridine orange, which are useful in photodynamic therapy. It was found that the most stable complex between 1O2 and proflavine are formed when 1O2 is located above the central ring, while the most stable complex between 1O2 and methylene blue is formed when 1O2 is located above the molecular plane, but not above any of the rings, near the sulfur atom. 1O2 can make a stable complex with acridine orange, as it is located above the outer ring of the dye. The binding energies of the complexes of 1O2 with all three dyes are enhanced considerably in going from gas phase to aqueous media. The complexes of 3O2 with the dyes will be unstable in all cases, while those of 1O2 with the same will be quite stable and will not be dissociated due to thermal fluctuations at room temperature. In the complexes of 1O2 and 3O2 with the dyes, charge transfer occurs from the dyes to the O2 moiety, the amount of charge transfer being much more to 1O2 than to 3O2 in each case. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
F + H2 → FH + H potential energy surface: Construction of the reference configuration state function space and MR‐ACPF‐2 results
Authors: Cardoen Wim , Simons Jack , Gdanitz Robert J.
Published: January 2006

A new electronic configuration reference space (subsequently used in multi‐reference averaged coupled pair functional (MR‐ACPF) or multi‐reference configuration interaction singles and doubles [MR‐CI(SD)] level treatments of electron correlation) is determined using the aug‐cc‐pVQZ basis set as a step toward constructing a new potential energy surface (PES) for the F + H2 → FH + H reaction. We use our new reference space to calculate several chemically important properties (e.g., barriers, exothermicity, van der Waals wells) of the F + H2 PES. We obtain nonrelativistic barrier heights of 1.32 kcal/mol−1 (bent) and 1.67 kcal/mol−1 (collinear) that are ∼0.2–0.3 kcal/mol−1 lower than those obtained from the current best PES. Our nonrelativistic value for the exothermicity is 32.45 kcal/mol−1, which is 0.7–1.1 kcal/mol−1 higher than the values obtained from some other PESs and 0.45 kcal/mol−1 higher than the experimental value. The van der Waals wells we find are slightly deeper (0.05 kcal/mol−1) than the wells on the other PES. The ≈1‐kcal/mol−1 magnitude of the differences among barrier heights, exothermicities, and well depths, obtained in our work and using the most reliable current PESs suggest that to obtain a three‐dimensional (3D) PES for the F + H2 → FH + H accurate to 0.2 kcal/mol−1, we will have to use even higher‐level methods (e.g., explicitly correlated wave functions) and include relativistic corrections. We intend to do so in the next phase of this effort that is currently under way. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Vibrational–rotational energies of all H2 isotopomers using Monte Carlo methods
Authors: Alexander S. A. , Coldwell R. L.
Published: January 2006

Using variational Monte Carlo techniques, we have computed several of the lowest rotational–vibrational energies of all the hydrogen molecule isotopomers (H2, HD, HT, D2, DT, and T2). These calculations do not require the excited states to be explicitly orthogonalized. We have examined both the usual Gaussian wave function form as well as a rapidly convergent Padé form. The high‐quality potential energy surfaces used in these calculations are taken from our earlier work and include the Born–Oppenheimer energy, the diagonal correction to the Born–Oppenheimer approximation, and the lowest‐order relativistic corrections at 24 internuclear points. Our energies are in good agreement with those determined by other methods. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Quantum mechanical predictions of chiroptical vibrational properties
Authors: Polavarapu Prasad L.
Published: January 2006

The developments in quantum mechanical calculations of vibrational circular dichroism, vibrational Raman optical activity, and vibrational contributions to optical rotation are summarized. Further developments needed in each of these areas are pointed out. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Simple, sensitive and rapid liquid chromatography/atmospheric pressure chemical ionization mass spectrometric method for the quantitation of Ranolazine in rat plasma
Authors: Liang Yan , Xie Lin , Liu Xiao‐Dong , Chen Wei‐Dong , Lu Tong , Xiong Ye , Wang Guang‐Ji
Published: January 2006

A sensitive and specific method using liquid chromatography with atmospheric pressure chemical ionization mass spectrometry (LC/APCI‐MS) has been developed and validated for the identification and quantification of Ranolazine in rat plasma. A simple liquid–liquid extraction procedure was followed by injection of the extracts onto a C18 column with isocratic elution and detection using a single quadrupole mass spectrometer in selected ion monitoring (SIM) mode. The method was tested using six different batches of blank plasma. Linearity was established for the concentration range 0.02–10.0 µg/mL, with a coefficient of determination (r) of 0.9998 and good back‐calculated accuracy and precision. The intra‐ and inter‐day precision (relative standard deviation (RSD) %) was lower than 10%, and accuracy ranged from 85 to 115%. The lower limit of quantification was reproducible at 0.01 µg/mL with 20 µL plasma. The proposed method enables the unambiguous identification and quantification of Ranolazine for pre‐clinical and clinical studies. Copyright © 2006 John Wiley & Sons, Ltd.
Development of a multi‐residue method for the determination of 18 carbamates in tobacco by high‐performance liquid chromatography/positive electrospray ionisation tandem mass spectrometry
Authors: Mayer‐Helm B. , Hofbauer L. , Müller J.
Published: January 2006

A multi‐residue method for the determination of carbamates in tobacco was developed by high‐performance liquid chromatography (HPLC) triple quadrupole mass spectrometry (MS). A rapid sample preparation consisted of an extraction step with methanol, centrifugation and 1:1 dilution with aqueous 10 mM ammonium acetate. After filtration these extracts were directly analysed by reversed‐phase HPLC coupled to positive electrospray ionisation tandem mass spectrometry operated in the multiple reaction monitoring mode. Capillary voltage and dwell times were optimised to reduce matrix effects and to increase sensitivity. The method was validated for the determination of 18 carbamates in three main types of raw tobacco and three tobacco products. The interday accuracy ranged between 80 and 110% with a relative standard deviation (RSD) of <30%. The limits of quantification (LOQs) ranged between 0.01 and 0.04 ppm for almost all carbamates, except aldicarb sulfone, carbofuran, and pebulate, with LOQs between 0.10 and 0.20 ppm. These LOQs were clearly below the guidance residue levels defined by the Agrochemical Advisory Committee of CORESTA, an association of organisations having scientific research relative to tobacco. Copyright © 2006 John Wiley & Sons, Ltd.
Hypothesized and found mechanisms for potentiation of bradykinin actions
Authors: Mueller Sylvia , Paegelow Inge , Reissmann Siegmund
Published: January 2006

Potentiation of hormone actions can occur by different mechanisms, including inhibition of degrading enzymes, interaction with the hormone receptor leading to stabilization of bioactive conformation or leading to receptor homo‐ and hetero‐oligomerization, receptor phosphorylation and dephosphorylation or can occur by directly influencing the signal transduction and ion channels. In this review the potentiation of bradykinin actions in different systems by certain compounds will be reviewed. Despite many long years of experimental research and investigation the mechanisms of potentiating action remain not fully understood. One of the most contradictory findings are the distinct differences between the inhibition of the angiotensin I‐converting enzyme and the potentiation of the bradykinin induced smooth muscle reaction. Contradictory findings and hypothesized mechanisms in the literature are discussed in this review and in some cases compared to own results. Investigation of potentiating actions was extended from hypotension, smooth muscle reaction and cellular actions to activation of immunocompetent cells. In our opinion the potentiation of bradykinin action can occur by different mechanisms, depending on the system and the applied potentiating factor used.
Autism following a history of newborn encephalopathy: more than a coincidence?
Authors: Badawi Nadia , Dixon Gleny S , Felix Janine F , Keogh John M , Petterson Beverly , Stanley Fiona J , Kurinczuk Jennifer J
Published: January 2006

Between June 1993 and December 1996, 276 term newborn infants with encephalopathy and 564 randomly selected term controls were enrolled in a population‐based study of moderate and severe term newborn encephalopathy (NE) in Western Australia. During comprehensive neurobehavioural and cognitive follow‐up of all patients and controls at 3 years and again at 5 years of age we found an unexpected but strong association between NE and autism spectrum disorders (ASDs). A diagnosis of ASD by age 5 years was reached using criteria according of the Diagnostic Statistical Manual, 4th edition. Linking records to the Western Australian Disability Services Commission Register ensured that no child in the study with ASD was missed. By age 5 years, 37 (13.4%) infants with NE and one (0.2%) control had died. Among the 239 survivors of NE, 12 (5%) were diagnosed with an ASD. Of these, 10 (4.2%) met the full criteria for autism, one had pervasive developmental disorder‐not otherwise specified, and one had Asperger syndrome. Among the 563 surviving controls, five (0.8%) were diagnosed with an ASD: three with autism, one with autism/possible Asperger syndrome, and one with Asperger syndrome. Compared with the controls, the children who had experienced NE were 5.9 times (95% confidence interval 2.0–16.9) more likely to have been diagnosed with an ASD.
Long‐term survival for a cohort of adults with cerebral palsy
Authors: Hemming Karla , Hutton Jane L , Pharoah Peter O D
Published: January 2006

The aim of this study was to investigate long‐term survival and examine causes of death in adult patients with cerebral palsy (CP). A 1940–1950 birth cohort based on paediatric case referral allows for long‐term survival follow‐up. Survival is analyzed by birth characteristics and severity of disability from age 20 years (and age 2y for a subset of the data). Survival outcome compared with that expected in the general population based on English life tables. The main cohort consisted of 341 individuals, with 193 males and 148 females. Conditional on surviving to age 20 years, almost 85% of the cohort survived to age 50 years (a comparable estimate for the general population is 96%). Very few deaths were attributed to CP for those people dying over 20 years of age. Females survived better than males. However, females faced a greater increase in risk relative to the general population than did males. We conclude that survival outlook is good though lower than in the general population. The relative risk of death compared with the UK population decreases with age, although it shows some indication of rising again after age 50 years. Many more deaths were caused by diseases of the respiratory system among those dying in their 20s and 30s than would be expected in the general population. Many fewer deaths than expected in this age group are caused by injuries and accidents. For those people who die in their 40s and 50s, an increase in deaths due to diseases of the circulatory system and neoplasms is observed. More deaths than expected in this age group are due to diseases of the nervous system.
Transient dystonic toe‐walking: differentiation from cerebral palsy and a rare explanation for some unexplained cases of idiopathic toe‐walking
Authors: Newman Christopher J , Ziegler Anne‐Lise , Jeannet Pierre‐Yves , Eliane Roulet‐Perez MD;  , Deonna Thierry W
Published: January 2006

We report on seven children (five males, two females) who presented with marked, often asymmetrical, toe‐walking from onset of independent walking, associated with abnormal foot postures and increased tone at the ankles with characteristics of dystonia. Most of the children had presented with unusual pre‐walking locomotion and a mild delay in independent walking. They did not fit into the usual categories of ‘habitual’ toe‐walking or congenital short tendo calcaneus but nor did they have the clinical signs of spastic diplegia or of a peripheral neuromuscular disease. Normalization occurred progressively in the second to fourth years of life. The children were re‐examined several years later (1 to 11y) and were normal. We believe that their persistent toe‐walking corresponded to a variant of ‘transient focal dystonia of infancy’. Knowledge of its existence may justify a period of observation without special investigations, surgery, or casting.
Drooling in children with cerebral palsy: effect of salivary flow reduction on daily life and care
Authors: Van der Burg Jan J W , Jongerius Peter H , Van Hulst Karen , Van Limbeek Jacques , Rotteveel Jan J
Published: January 2006

The purpose of this study was to investigate the effect of salivary flow reduction on daily life and provision of care in children with cerebral palsy (CP). Parents of children with CP were asked to fill in a questionnaire on the impact of drooling on the daily life of their children and their families and the data were then analyzed. Forty‐five children with severe drooling (28 males, 17 females; mean age 9y 5mo [SD 3y 7mo]; range 3 to 16y) were monitored before and after receiving medication (scopolamine and botulinum toxin) to reduce salivary flow. Type of CP included hypotonia (n=1), spastic paresis (n=27), and mixed motor disorders with spastic and dyskinetic paresis (n=17). Eight children were independently ambulant and 37 children were wheelchair users. Thirty‐four children had learning disability* with a developmental age of below 6 years. Six participants dropped out of the study; data on 39 children were analyzed. Results showed that anticholinergic agents effectively reduced salivary flow. Drooling diminished substantially and this was accompanied by a significant reduction in care needs, making daily care less demanding. The amount of reported damage to communication devices and computers decreased. In addition to the evaluation of primary variables, such as the salivary flow rate, investigation of impact of drooling on daily life provides useful information about the outcome of treatment for reduction in drooling.
Post‐varicella intracranial haemorrhage in a child
Authors: Danchaivijitr Nasuda , Miravet Elena , Saunders Dawn E , Cox Tim , Ganesan Vijeya
Published: January 2006

We report a case of a 7‐month‐old male with primary intracranial haemorrhage 2 months after infection with varicella zoster virus (VZV). His initial clinical course was complicated by seizures and right hemiparesis; when last seen at 22 months the only positive finding was of left hand preference. Although the literature has recently established the association of arterial ischaemic stroke and VZV infection, primary intracranial haemorrhage has been reported only in one case. The child reported here had anterior interhemispheric haemorrhage due to a focal arteritis of the left anterior cerebral artery. The vascular abnormality was transient and had radiological features compatible with either a focal arteritis or vasospasm as a direct result of blood surrounding the vessels. We postulate that direct invasion of VZV caused extensive inflammation of the vessel wall and aggressive tissue penetration resulting in necrotizing angiitis and intracranial haemorrhage. We suggest that VZV infection should be considered a potential risk factor for intracranial haemorrhage in children.
A systematic review of the self‐concept of children with cerebral palsy compared with children without disability
Authors: Shields Nora , Murdoch Alison , Loy Yijun , Dodd Karen J , Taylor Nicholas F
Published: January 2006

Young people with cerebral palsy (CP) are often assumed to have low self‐concept, in other words, they do not feel good about themselves. We systematically searched the literature to determine whether this assumption was supported by empirical research. Relevant trials were identified by searching electronic databases, and this was supplemented by citation tracking. Of 1355 papers initially identified, six met the criteria for review. Results showed that adolescent females with CP have a lower self‐concept than females without disability in the domains of physical appearance (d=‐1.16;95% confidence interval [CI] −2.06 to −0.26); social acceptance (d=‐1.24; 95% CI −2.15 to −0.33); athletic competence (d=‐0.93; 95% CI −1.79 to −0.07); and scholastic competence (d=‐0.86; 95% CI, −1.71 to −0.01). Adolescent females with CP may be an at‐risk group owing to their vulnerable self‐concept. Clinicians may need to monitor and implement appropriate intervention strategies with this group. There was insufficient evidence to conclude that children with CP, in general, have a lower global self‐concept compared with those without disability.
Heloise, Abelard and the Ordination of Abbesses
Authors: MACY GARY
Published: January 2006

Abelard discussed the status and history of the ordo sanctimonialium in several of his works. In them he identified abbesses as the successors to the ancient order of deaconesses and thus sacramentally ordained and equal to any male order. This understanding followed a venerable tradition that stood in stark contrast to the more recent claims of the Glossa ordinaria, Gratian and Peter the Lombard that the only true sacramental orders were the subdiaconate, the diaconate and the presbyterate. Abelard's work then can be understood in part as a response to these claims and a defence of the older tradition.