bluuebunny/crossref_metadata_2025_split huggingface dataset:
The A645D Mutation in the Hinge Region of the Human Androgen Receptor (AR) Gene Modulates AR Activity, Depending on the Context of the Polymorphic Glutamine and Glycine Repeats
Authors: Werner Ralf , Holterhus Paul-Martin , Binder Gerhard , Schwarz Hans-Peter , Morlot Michel , Struve Dagmar , Marschke Christine , Hiort Olaf 
Published: June 2006

AbstractBackground: Sufficient androgen receptor (AR) activity is crucial for normal male sexual differentiation. Here we report on two unrelated 46, XY patients suffering from undervirilization and genital malformations. Both patients had a short polyglycine (polyG) repeat of 10 residues and a relatively long polyglutamine (polyQ) repeat of 28 and 30 residues within the transactivation domain of the AR. In addition, they also harbor a rare A645D substitution.Objective: We made a set of AR expression plasmid constructs with varying polyQ and polyG tract sizes in context with or without the A645D substitution and analyzed their in vitro transactivation capacity in transfected CHO cells.Results: We found that a short polyG repeat downmodulated AR activity to approximately 60–65% of the wild-type receptor. This effect was aggravated by A645D in context of a long polyQ repeat to less than 50% activity. In contrast, in the context of a short polyQ and a short polyG repeat, the A645D mutation rescues AR activity to almost wild-type levels, demonstrating a contradictory effect of this mutation, depending on the size of the polymorphic repeats.Conclusions: A combination of a short polyG repeat with a long polyQ repeat and an A645D substitution might contribute to the development of virilization disorders and explain the observed phenotypes of our patients as a form of androgen insensitivity. The whole recreation of AR sequence variations including individual polymorphic repeat sizes could unravel possible interference of mutations and variations on AR activity by in vitro transfection.
Mosaicism of a Thyroid Hormone Receptor-β Gene Mutation in Resistance to Thyroid Hormone
Authors: Mamanasiri Sunee , Yesil Sena , Dumitrescu Alexandra M. , Liao Xiao-Hui , Demir Tevfik , Weiss Roy E. , Refetoff Samuel 
Published: June 2006

Abstract
Context: Heterozygous mutations in thyroid hormone receptor-β (TRβ) gene are the cause of resistance to thyroid hormone (RTH) in more than 85% of families having the syndrome. In 23% of the families, TRβ gene mutations occur de novo. Of the 141 families with RTH investigated by us, 21 (15%) had no TRβ gene mutations detectable by sequencing from genomic DNA (gDNA) or cDNA (non-TR RTH).
Objective: The objective of the study was to investigate the genotype of a family with RTH and correlate it to the phenotype.
Design: The DNA was isolated from different tissues, and the sequence of the TRβ gene was determined. Clinical studies involved the administration of incremental doses of T3.
Setting: The study was conducted at a referral pediatric endocrinology clinic in Turkey and an academic medical center in the United States.
Main Outcome and Measures: Measurement included markers of thyroid hormone action and sequencing of TRβ revealing a R338W mutation.
Patients and Family: We studied two siblings with short stature, panic disorder, psychosis, and high free iodothyronine concentrations with nonsuppressed TSH and their father with similar thyroid function tests without growth or psychiatric abnormalities.
Results: Direct sequencing of gDNA obtained from the father’s leukocytes, buccal mucosa cells, and prostate tissue showed less amplification of the mutant allele (R338W) than the normal allele as confirmed by PCR/restriction fragment length polymorphism analysis. No sequence abnormalities were detected in gDNA from fibroblasts. Similar results were found in mRNA from the leukocytes and fibroblasts. The sensitivity of various tissues to thyroid hormone was not uniform. The progeny had equal amounts of mutant and wild-type gDNA in leukocytes and skin.
Conclusions: The father has a mosaicism for the R338W mutation as it was present in some cell lineages, including his germline, because it was transferred to his children but not in fibroblasts. This indicates that the mutation occurred de novo in early embryonic life. Here is the first report of mosaicism in RTH. The possibility of mosaicism should be considered in subjects with RTH without apparent mutations in the TRβ gene.
Thyroid Function Is Intrinsically Linked to Insulin Sensitivity and Endothelium-Dependent Vasodilation in Healthy Euthyroid Subjects
Authors: Fernández-Real Jose-Manuel , López-Bermejo Abel , Castro Antoni , Casamitjana Roser , Ricart Wifredo 
Published: June 2006

Abstract
Context: Levels of TSH respond to fluctuations in serum free T4 (fT4) but remain in a very narrow individual range. There exists current controversy regarding the upper limit of normal serum TSH values above which treatment should be indicated.
Objective: We aimed to study whether the individually determined fT4-TSH relationship was associated with plasma lipids, insulin sensitivity, and endothelial dysfunction in healthy subjects with strictly normal thyroid function according to recent recommendations (0.3–3.0 mU/liter).
Design: This was a cross-sectional study.
Setting: The study consisted of a cohort of healthy men from the general population (n = 221).
Main Outcome Measures: Oral glucose tolerance, insulin sensitivity (SI, minimal model), endothelium-dependent vasodilation (high-resolution ultrasound), and plasma lipids were measured in relation to thyroid function tests.
Results: Both serum TSH and fT4·TSH product were positively associated with fasting and postload insulin concentration and negatively with SI. After body mass index stratification, these associations were especially significant among lean subjects. Serum TSH and fT4·TSH product also correlated positively with fasting triglycerides and negatively with high-density lipoprotein cholesterol. In a multiple linear regression analysis, age (P = 0.007) and SI (P = 0.02) but not body mass index, fasting triglycerides, or serum high-density lipoprotein concentration contributed independently to 3.7 and 3.3%, respectively, of the variance in fT4·TSH. Those subjects over the median of fT4·TSH showed reduced endothelium-dependent vasodilation.
Conclusions: Thyroid function tests are intrinsically linked to variables of insulin resistance and endothelial function. It is possible that underlying factors lead simultaneously to increased serum TSH, insulin resistance, ensuing dyslipidemia, and altered endothelial function even within current normal TSH levels.
Development of Electron-Ion Coincidence Spectroscopy for the Study of Surface Dynamics
Authors: Mase Kazuhiko , Nagasono Mitsuru , Urisu Tsuneo , Murata Yoshitada 
Published: June 2006

Abstract
Electron-ion coincidence (EICO) spectroscopy for studying surface dynamics has been developed. The apparatus consists of an electron gun, a cylindrical mirror analyzer (CMA), and a time-of-flight ion mass spectrometer (TOF-MS). A sample surface is excited with an electron beam, and the energy of the emitted electrons is analyzed by the CMA. The TOF spectra of desorbed ions are measured with the TOF-MS and a multichannel scaler, taking the energy-analyzed electron signal as the starting trigger. Those ions coincidently desorbed with electrons give a characteristic peak in the TOF spectrum. The apparatus has been evaluated on the basis of electron-ion coincidence measurements of an F/SrTiO3 (100) surface. The F+ coincidence signal was observed to be enhanced at electron kinetic energies of 650—655 eV, corresponding to the F(KL23L23) Auger transition. The result provides direct evidence of the Auger-stimulated ion-desorption mechanism for an ionically bonded surface (the Knotek–Feibelman (KF) mechanism).
Proposed Mechanism of Ferromagnetic Interaction of Organic Ferromagnets: 4-(Arylmethyleneamino)-2,2,6,6-tetramethylpiperidin-1-oxyls and Related Compounds
Authors: Nogami Takashi , Ishida Takayuki , Yasui Masanori , Iwasaki Fujiko , Takeda Naoya , Ishikawa Masayasu , Kawakami Takashi , Yamaguchi Kizashi 
Published: June 2006

Abstract
A possible mechanism of ferromagnetic coupling of a series of organic radical ferromagnets is presented, based on their crystal structures and molecular-orbital calculations. The investigated radicals are 4-(arylmethyleneamino)-2,2,6,6-tetramethylpiperidin-1-oxyls (abbreviated as Ar–CH=N–TEMPO, where Ar = phenyl, 4-methylthiophenyl, 4-chlorophenyl, 4-biphenylyl, and 4-phenoxyphenyl), and 4-hydroxyimino-TEMPO. All of these radical crystals have characteristic features that oxygen atoms of N–O radical sites of TEMPO moieties always locate near methyl- and/or methylene-hydrogens at β-positions of N–O in the TEMPO moieties of adjacent molecules. A positive spin on the N–O radical induces negative spins on the β-hydrogen atoms due to an intramolecular spin-polarization, ON(↑)–C(↓)–C(↑)–H(↓), which in turn induces a positive spin on the N–O sites of the adjacent molecules. This spin-alternation mechanism of ferromagnetic coupling among N–O sites via hydrogen bridges is also applicable to the case of an organic metamagnet, bis(2,2,6,6-tetramethylpiperidin-1-oxyl-4-yl) 1,6-hexanedicarboxylate. In the case of an organic ferromagnet, 2,4,6,8-tetramethyl-1,5-diazaadamantane-1,5-dioxyl, both the spin-alternation and direct exchange mechanisms seem to be operative.
Structure and Properties of Titanium-Including Complex, Tris(tetramethyltetrathiafulvalene) Di-μ-fluoro-bis[tetrafluorotitanate(IV)], (TMTTF)3Ti2F10
Authors: Akutsu Hiroki , Ozeki Katsunari , Ozaki Takayuki , Nozawa Kiyokazu , Kinoshita Minoru , Kozawa Kozo , Uchida Tokiko 
Published: June 2006

Abstract
A novel molecular complex of tetramethyltetrathiafulvalene (TMTTF) was prepared by the treatment with TiF4. The X-ray analysis reveals the exsistence of a trimer of TMTTF’s and a Ti2F102− anion in a triclinic unit cell of the dimension; a = 10.934(3), b = 12.798(2), c = 8.000(1) Å, α = 103.86(1), β = 107.08(2), γ = 75.02(2)°. All the molecular planes of TMTTF are nearly parallel. The trimers stack parallel to the a axis, and the intertrimer interaction is estimated to be weak. A semiconductive behavior with a relatively large Seebeck coefficient was observed (ρ = 3 × 102 Ω cm, Ea = 0.26 eV, and S = −0.41 mV K−1 along the a axis). Weak electron spin resonance (ESR) absorption was observed to be characteristic of low-dimensional diffusive spin systems.
Order Parameter and Density Effects in the Third-Order Nonlinear Optical Properties of Liquid Crystals
Authors: Terazima Masahide 
Published: June 2006

Abstract
Third-order nonlinear optical effects induced by thermal and photochemical reactions after a real photoexcitation of neat (undoped) liquid crystals (N-(4-methoxybenzylidene)-4-butylaniline (MBBA) and cyanopentylbiphenyl) were investigated by the transient grating method with nanosecond and picosecond pulsed-laser systems. The origins of the effect were clearly separated into the density and order parameter changes by a polarization selection of the probe beam; also, the dynamics (speed of the changes) of both components were investigated. The decrease in the density under the presence of the cis form of MBBA was observed and could be explained in terms of a void volume effect.
Suppression of Growth Instability in Electropolymerization of Pyrrole
Authors: Mogi Iwao , Kamiko Masao 
Published: June 2006

Abstract
The pattern formation of electropolymerized polypyrrole was studied in bulk-solution and thin-layer-solution cells with and without a magnetic field. A diffusion-limited aggregation pattern was observed in the bulk-solution cell in the absence of a magnetic field. The growth instability was found to be suppressed by thinning the solution and the application of the magnetic field.
Multielement Determination of Trace Elements in Coastal Seawater by ICP-MS and ICP-AES after Aluminum Coprecipitation Associated with Magnesium
Authors: Sawatari Hideyuki , Hayashi Toshio , Fujimori Eiji , Hirose Akio , Haraguchi Hiroki 
Published: June 2006

Abstract
An analytical method for multielement determination of trace and ultratrace elements in seawater has been investigated by using ICP-MS. Trace and ultratrace elements were preconcentrated by 10- or 20-times with addition of aluminum into seawater and then the elements were determined by ICP-MS. In this procedure, aluminum was added as the carrier for coprecipitation; it precipitated together with magnesium in seawater. Some trace elements were also measured by ICP-AES after coprecipitation. In addition, major and minor elements in seawater were determined by ICP-AES after dilution with acidified water. As the result, 37 elements in total could be determined in coastal seawater. The present results are compared with the concentrations of the elements in open seawater.
Coordination of 2,5-Dihydroxy-p-benzoquinone to Nickel(II) Ion
Authors: Miyoshi Hirokazu , Mihara Hiroki , Kanda Seiichi 
Published: June 2006

Abstract
2,5-Dihydroxy-p-benzoquinonatonickel(II) [dhqNi(II)] coordination polymer was carefully prepared from 2,5-dihydroxy-p-benzoquinone (L) and anhydrous nickel(II) chloride. The elemental and thermal analyses indicate two coordinated and one additive water molecules in the dhqNi(II) complex. A strong peak in IR spectrum at 3330 cm−1 and a shoulder at 1660 cm−1attributed to O–H stretching vibration were detected. The paramagnetic moment of the complex, μeff = 2.94 μB, was calculated from the observed susceptibility. Consequently, dhqNi(II) coordination polymer seemed to be D4h structure, where Ni was coordinated by two ligand water molecules and four oxygen atoms from two ligand (dhq2−) molecules.
Synthesis and Characterization of Monomeric (Aryloxo)iron Complexes: [FeIIL(OAr)] and [FeIIIL(OAr)2] {L = BH(3,5-Pri2pz)3−}
Authors: Ito Masami , Amagai Hironobu , Fukui Hideno , Kitajima Nobumasa , Moro-oka Yoshihiko 
Published: June 2006

Abstract
A series of (aryloxo)iron(II) complexes [Fe{BH(3,5-Pri2pz3}(OAr)] (Ar = C6H5 (4); C6H4-p-Cl (5); C6H4-p-F (6); C6H4-p-Me (7); C6H3-2,6-Cl2 (8); C6F5 (9)) were synthesized by the anion ligand replacement of [Fe(Cl){BH(3,5-Pri2pz)3}] (1) with NaOAr. Crystallography was performed for 1 and 9. All these tetrahedral (aryloxo)iron(II) complexes react with dioxygen readily, to afford the bis(aryloxo)iron(III) complexes [Fe{BH(3,5-Pri2pz)3}(OAr)2] (Ar = C6H5 (10); C6H4-p-Cl (11); C6H4-p-F (12); C6H4-p-Me (13); C6H3-2,6-Cl2 (14); C6F5 (16)) as sole isolable products (the maximum yield based on the iron(II) complex was ca. 50%). The MeCN adduct of 13 was structurally characterized by X-ray crystallography.
Detection Method Based on a Surface Plasmon Resonance and Its Application to Flow Injection Analysis and Liquid Chromatography
Authors: Wu Xing-Zheng , Nakagawa Masamitsu , Nagamori Chiaki , Uchiyama Katsumi , Hobo Toshiyuki 
Published: June 2006

Abstract
A simple surface plasmon resonance (SPR) experimental set-up has been made for investigating further applications of the SPR detection method in analytical chemistry. In the home-made SPR experimental set-up, a Ag film with a thickness about 50 nm was deposited on the flat surface of a hemicyclindrical prism, and a flow cell was attached directly to the flat surface of the prism. It has been confirmed that SPR occurred in the experimental setup using model samples of water and alcohols. The SPR detection modes, based on changes in the coupling angle and reflectivity at a fixed angle, were investigated both theoretically and experimentally. It has been shown that the SPR detection mode based on the reflectivity change is much more sensitive than that based on a change in the coupling angle, for the SPR experimental set-up. A preliminary investigation indicates that the SPR method can be used as a universal detector for HPLC or FIA or other analytical methods. Its problems, improvements, and future applications in analytical chemistry are also discussed.
Preparation and Resolution of a Series of Cobalt(III) Complexes Containing 2,2′-Biimidazole and Ethylenediamine
Authors: Kanno Hideaki , Manriki Satoru , Yamazaki Emiko , Utsuno Shunji , Fujita Junnosuke 
Published: June 2006

Abstract
A new series of cobalt(III) complexes of the type [Co(H2biim)n(en)3−n]3+ (H2biim = 2,2′-biimidazole; n = 1—3) was obtained. All of the complexes were resolved into their antipodes by SP-Sephadex column chromatography. The absorption, circular dichroism, and 1H NMR spectra of the complexes in aqueous solutions were dependent on the pH due to deprotonation of the imino protons of H2biim. The pKa1 and pKa2 values for [Co(H2biim)(en)2]3+ were obtained as 5.9 and 9.9, respectively, from the absorption spectra in aqueous solutions. The optically active deprotonated complexes, (−)589-[Co(Hbiim)3]·2H2O and (−)589-Ba1.5[Co(biim)3]·2H2O, were also isolated from weakly and strongly basic aqueous solutions, respectively, of (−)589-[Co(H2biim)3](NO3)3·H2O.
Comparison of the Electrochemical and Enzymic Oxidation of 1,3,7-Trimethyluric Acid at Solid Electrodes
Authors: Goyal Rajendra Nath , Jain Ajay Kumar , Jain Neena 
Published: June 2006

Abstract
The electrochemical oxidation of 1,3,7-trimethyluric acid has been studied in phosphate buffers in the pH range 2.1—10.2 at solid electrodes. In cyclic voltammetry a single, well defined, pH-dependent oxidation peak was obtained at all of the three electrodes used. However, the reduction behavior of the oxidation product was different at pyrolytic graphite, glassy carbon (GCE), and platinum due to adsorption at PGE and GCE. The nature of the electrode reaction was established as EC, in which a charge transfer is followed by competitive chemical reactions. The formation of the same UV-absorbing intermediate and products and identical rate constants for the decay of the UV-absorbing intermediate indicated that the electrochemical oxidation of 1,3,7-trimethyluric acid proceeds by an identical mechanism at PGE, GCE, and Pt. The results of a peroxidase-catalyzed oxidation of 1,3,7-trimethyluric acid were compared with the electrochemical oxidation; it is concluded that both of the oxidations follow a similar pathway.
Facile Synthesis of Functionalized Nitroenamines. III. Aminolysis of 1-Methyl-5-nitropyrimidin-2(1H)-one
Authors: Nishiwaki Nagatoshi , Tohda Yasuo , Ariga Masahiro 
Published: June 2006

Abstract
The aminolysis of 1-methyl-5-nitropyrimidin-2(1H)-one furnished diimines of nitromalonaldehyde in good yields. One of the imino groups of the diimines was readily hydrolyzed on silica gel to give nitroenamines possessing a formyl group. These reagents behaved as the synthetic equivalent of unstable nitromalonaldehyde, affording azaheterocycles upon a treatment with hydrazines or diamines.
Electronic Structures and Oxidation Potentials of Some Azulene Derivatives
Authors: Kurihara Teruo , Suzuki Takanori , Wakabayashi Hidetsugu , Ishikawa Sumio , Shindo Kimio , Shimada Yuji , Chiba Hiroshi , Miyashi Tsutomu , Yasunami Masafumi , Nozoe Tetsuo 
Published: June 2006

Abstract
The electronic structures of azulene (1) and its alkylated derivatives were investigated on the basis of MO calculations by MNDO and PM3 method. There results were experimentally evaluated by measuring the oxidation potentials (Eox) of 1 and its alkylated derivatives, from which the additive property on Eox was suggested as shown by Eox(Az.subst) = Eox(AZ) − 0.10n1,3 + 0.06n2 − 0.02n4,8 − 0.11n5,7 − 0.01n6. Thus, the alkyl groups at the 1,3- and 5,7-positions lower the Eox values by ca. 0.1 V, and stronger donating properties were observed for 3-methylguaiazulene (Eox = +0.53 V) and 3,3′-biguaiazulene (Eox = +0.40 V). The redox properties of guaiazulenyl sulfides which were prepared from guaiazulene via a phenylsulfonylthio derivative were also studied. Unlike the alkylated azulenes they underwent reversible one-electron oxidations and exhibited stronger donating properties (Eox = +0.40 – +0.44).
Generation and Reactions of 2-(1-Adamantyl)adamantene. Rearrangement to 3-(1-Adamantyl)-4-protoadamantylidene
Authors: Okazaki Takao , Isobe Hiroshi , Kitagawa Toshikazu , Takeuchi Ken’ichi 
Published: June 2006

Abstract
The SN1 methanolysis of (1-adamantyl)(3-noradamantyl)methyl heptafluorobutyrate at 100 °C yielded (1-adamantyl)(3-noradamantyl)methyl methyl ether (17), 2-(1-adamantyl)-1-methoxyadamantane (18), and 4-(1-adamantyl)-3-methoxyprotoadamantane (19) in a 2 : 65 : 33 ratio. The methanolysis of (1-adamantyl)(3-noradamantyl)diazomethane (7) at 0 °C also yielded 17, 18, and 19 in a 4 : 33 : 63 ratio. On the other hand, the photolysis of 7 in 99 : 1 (v/v) hexane–methanol gave 17, 18, 2-(1-adamantyl)-2-methoxyadamantane (25), and 2-(1-adamantyl)-2,4-didehydroadamantane (20) in a 30 : 9 : 36 : 25 ratio. Presence of triethylamine decreased the yields of ethers 17, 18, and 25, and increased the yield of 20 to 46%. The formation of a considerable amount of 17 and the absence of 19 in the photolysis products indicate the generation of (1-adamantyl)(3-noradamantyl)methylidene (8). The formation of 25 and 20 suggests that the generated carbene 8 rearranges to 2-(1-adamantyl)adamantene (3b) and then gives 3-(1-adamantyl)-4-protoadamantylildene by the subsequent retro-insertion. An attempt to isolate 3b in the photolysis of 7 in cyclohexane failed, and the sole isolated product was 20.
Palladium-Catalyzed Double and Single Carbonylations of β-Amino Alcohols. Selective Synthesis of Morpholine-2,3-diones and Oxazolidin-2-ones and Applications for Synthesis of α-Oxo Carboxylic Acids
Authors: Imada Yasushi , Mitsue Yo , Ike Kazuo , Washizuka Ken-ichi , Murahashi Shun-Ichi 
Published: June 2006

Abstract
Catalytic cross double carbonylation of secondary amines and alcohols proceeds in the presence of [PdCl2(MeCN)2] and CuI under carbon monoxide (80 atm) and oxygen (5 atm). Catalytic intramolecular double carbonylation of β-amino alcohols gives morpholine-2,3-diones, which are excellent protecting compounds of amino alcohols and important precursors for biologically active nitrogen compounds. In contrast, catalytic single carbonylation of β-amino alcohols under a mixture (1 : 1) of carbon monoxide and oxygen (1.0 atm) proceeds to give oxazolidin-2-ones selectively. The reaction can be explained by assuming a mechanism which includes intramolecular nucleophilic attack of the hydroxy group of (hydroxyethyl)aminocarbonyl ligands on the CO ligand of the carbamoylpalladium(II) complexes, followed by reductive elimination to give morpholine-2,3-diones. In contrast, direct nucleophilic attack of the hydroxy group to the carbamoyl group affords oxazolidin-2-ones. As a common intermediate for the double and single carbonylations, carbamoylpalladium(II) complex has been isolated by the reaction of [PdCl2(PMe3)2] with β-amino alcohol under CO.
The present double carbonylation of amino alcohols provides a novel and convenient method for synthesis of α-oxo carboxylic acids. Thus, the morpholine-2,3-diones obtained undergo reaction with Grignard reagents chemoselectively at the ester positions to give 2-substituted 2-hydroxymorpholin-3-ones, which undergo acid hydrolysis to give α-oxo carboxylic acids.