bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical biosensing: Kinetics of protein A‐IGG binding using biolayer interferometry
Authors: Wilson Jo Leanna , Scott Israel M. , McMurry Jonathan L.
Published: November 2010

An undergraduate biochemistry laboratory experiment has been developed using biolayer interferometry (BLI), an optical biosensing technique similar to surface plasmon resonance (SPR), in which students obtain and analyze kinetic data for a protein‐protein interaction. Optical biosensing is a technique of choice to determine kinetic and affinity constants for biomolecular interactions. Measurements can be made in real‐time without labels, making biosensing particularly appropriate for the teaching laboratory. In the described exercise, students investigate the kinetics of Protein A‐human Immunoglobin G binding under conditions that mimic simple 1:1 binding. Students prepare appropriate serial dilutions of IgG and set up a microplate for the experiment by aliquotting biotinylated Protein A, buffer, and IgG solutions. A commercial BLI sensor, the FortéBio Octet QK, is used to measure binding. While data are collected students prepare a spreadsheet with which they will simulate the data to determine kon, koff, and KD. Raw data from the sensor are then exported to the spreadsheets for analysis. Optimized experiment timing, regeneration methods and other parameters are described to increase throughput and reduce cost. The experiment is readily adaptable to other biosensing platforms such as SPR instruments. Biochemistry and Molecular Biology Education Vol. 38, No. 6, pp. 400‐407, 2010
Effects of IMAC specific peptide tags on the stability of recombinant green fluorescent protein
Authors: Widakowich Gabriel , Zhang Chunfang , Harris Simon , Mitri Khosse , Powers Glenn , Troung Kirk‐Ski , Hearn Milton T W
Published: November 2010

Immobilized metal ion affinity chromatography (IMAC) using peptide affinity tags has become a popular tool for protein purification. An important feature dictating the use of a specific affinity tag is whether its structure influences the properties of the target protein to which it is attached. In this work we have studied the influence on protein stability of two novel peptide affinity tags, namely NT1A and HIT2, and compared their effect to the commonly used hexa‐histidine tag, all attached to the C‐terminus of a enhanced green fluorescent protein (eGFP). A comparison of the influence of C‐ or N‐terminal orientation of the tags was also carried out by studying the NT1A tag attached at either terminus of the eGFP. Protein stability was studied utilising guanidine hydrochloride equilibrium unfolding procedures and CD and fluorescence spectroscopy. The novel peptide affinity tags, NT1A and HIT2, and the His6 tag were found to not affect the stability of eGFP. Although these results are protein specific, they highlight, nevertheless, the need to employ suitable characterisation tools if the impact of a specific peptide tag on the folded status or stability of a recombinant tagged protein, purified by immobilized metal ion affinity chromatographic methods, are to be rigorously evaluated and the appropriate choice of peptide tag made. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Historical vignettes of the thyroid gland
Authors: Lydiatt Daniel D. , Bucher Gregory S.
Published: November 2010

Although “glands” in the neck corresponding to the thyroid were known for thousands of years, they were mainly considered pathological when encountered. Recognition of the thyroid gland as an anatomical and physiological entity required human dissection, which began in earnest in the 16th century. Leonardo Da Vinci is generally credited as the first to draw the thyroid gland as an anatomical organ. The drawings were subsequently “lost” to medicine for nearly 260 years. The drawings were probably of a nonhuman specimen. Da Vinci vowed to produce an anatomical atlas, but it was never completed. Michelangelo Buonarroti promised to complete drawings for the anatomical work of Realdus Columbus, De Re Anatomica, but these were also never completed. Andreas Vesalius established the thyroid gland as an anatomical organ with his description and drawings in the Fabrica. The thyroid was still depicted in a nonhuman form during this time. The copper etchings of Bartholomew Eustachius made in the 1560s were obviously of humans, but were not actually published until 1714 with a description by Johannes Maria Lancisius. These etchings also depicted some interesting anatomy, which we describe. The Adenographia by Thomas Wharton in 1656 named the thyroid gland for the first time and more fully described it. The book also attempted to assign a function to the gland. The thyroid gland's interesting history thus touches a number of famous men from diverse backgrounds. Clin. Anat. 24:1–9, 2011. © 2010 Wiley‐Liss, Inc.
H2‐Induced Reconstruction of Supported Pt Clusters: Metal–Support Interaction versus Surface Hydride
Authors: Mager‐Maury Christophe , Bonnard Gaëtan , Chizallet Céline , Sautet Philippe , Raybaud Pascal
Published: December 2010

Platinum nanoparticles supported on γ‐alumina are widely used as highly dispersed heterogeneous catalysts, in particular in the presence of H2. In the present work, an atomic‐scale model for such catalysts is provided, taking into account operating conditions (temperature, hydrogen pressure), thanks to density functional theory calculations coupled to a thermodynamic model. In the absence of hydrogen, Pt13 clusters supported on γ‐Al2O3 preferentially lie in a biplanar (BP) morphology in strong interaction with the support’s surface. This structure has a strong affinity towards hydrogen. The increase of hydrogen coverage above 18 H atoms per cluster (H/Pt>1.4) induces a reconstruction from a BP to a cuboctahedral (CUB) morphology as shown by molecular dynamics. This reconstruction is driven by the ability of the CUB structure to adsorb a significant amount of hydrogen with moderate deformation cost. Electronic analyses reveal that a hydride phase is then obtained, with a partial loss of the metallic nature of the Pt13 edifice. Our model is supported by numerous experimental data (temperature‐programmed desorption, titration experiments, X‐ray absorption spectroscopy). Values higher than 1 for the H/Pt ratio, as measured in previous experimental analyses, are rationalized by the reconstruction process. Moreover, in reaction conditions such as catalytic reforming, the particle remains biplanar with moderate H/Pt ratio and retains its metallic character. The catalytic conditions therefore have a drastic influence on the nature of the catalyst surface.
Hydrogen Peroxide Decomposition over Nanosized La1–XCaXMnO3 (0 ≤ X ≤ 0.6) Perovskite Oxides
Authors: Soleymani M. , Moheb A. , Babakhani D.
Published: November 2010

La1–XCaXMnO3 (X = 0.0, 0.2, 0.4, and 0.6) perovskite oxides were synthesized using the citrate gel method. Thermogravimetry and differential thermal analyses, x‐ray diffraction, scanning electron microscopy, and specific surface area results were used for characterization of the perovskite powders obtained. Also, the average manganese valence state and δ‐oxygen non‐stoichiometry in series compounds were determined by the chemical analysis. Catalytic activities of these perovskites were examined for the peroxide decomposition reaction. It was observed that the catalytic activity was improved with increasing calcium content in the catalyst and it is suggested that factors such as δ‐oxygen non‐stoichiometry and average manganese valence state were responsible for the catalytic activity of these materials.
Synthesis and Thermal Energy Storage Properties of Erythritol Tetrastearate and Erythritol Tetrapalmitate
Authors: Sari A. , Eroglu R. , Biçer A. , Karaipekli A.
Published: November 2010

Erythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) were synthesized as novel solid‐liquid phase change materials (PCM) by means of the direct esterification reaction of the erythritol with palmitic and stearic acids. The ETP and ETS esters were characterized chemically using FT‐IR and 1H NMR techniques. The energy storage properties of the esters were determined by DSC analysis. The results indicated that the ETP and ETS esters synthesized as novel solid‐liquid PCMs are promising materials for thermal energy storage applications at large scale such as solar energy storage, building heating or cooling, indoor temperature controlling, and production of smart textile and insulation clothing.
Efficiency of Nanoscaled Flow Regulators
Authors: Odeku O. A. , Weber S. , Zimmermann I.
Published: November 2010

In dry powders the particle flow is mainly determined by van der Waals forces. It was proved in systematic studies that in addition to the hydrophilic silica Aerosil® 200 also hydrophobic silicas, various types of carbon black, or precipitated silicas are able to act as flow regulators if these highly aggregated nanomaterials can be broken down into smaller fragments comprising only a few primary particles. To characterize the ability of a given nanomaterial to act as flow regulator, the two terms effectiveness and efficiency were introduced. Effectiveness describes the maximum achievable reduction of the tensile strength by a given concentration of the nanomaterial. The parameter efficiency expresses the mixing time required to achieve the maximum reduction of tensile strength. The efficiency, however, is strongly dependent on the energy brought up by the mixing procedure. This energy is needed to desagglomerate the highly aggregated nanomaterials. Since up to now there is no method to measure these forces directly and methods allowing their indirect determination were looked for.
Enzymatic Racemization of Amines Catalyzed by Enantiocomplementary ω‐Transaminases
Authors: Koszelewski Dominik , Grischek Barbara , Glueck Silvia M. , Kroutil Wolfgang , Faber Kurt
Published: November 2010

A strategy for the biocatalytic racemization of primary α‐chiral amines was developed by employing a pair of stereocomplementary PLP‐dependent ω‐transaminases. The interconversion of amine enantiomers proceeded through reversible transamination by a prochiral ketone intermediate, either catalyzed by a pair of stereocomplementary ω‐transaminases or by a single enzyme possessing low stereoselectivity. To tune the system, the type and concentration of a nonchiral amino acceptor proved to be crucial. Finally, racemization could be achieved by the cross‐transamination of two different amines without a requirement for an external amino acceptor. Several synthetically and industrially important amines could be enzymatically racemized under mild reaction conditions.
Polymorph‐Tuned Synthesis of α‐ and β‐Bi2O3 Nanowires and Determination of Their Growth Direction from Polarized Raman Single Nanowire Microscopy
Authors: In Juneho , Yoon Ilsun , Seo Kwanyong , Park Jeunghee , Choo Jaebum , Lee Yonghoon , Kim Bongsoo
Published: November 2010

We report polymorph‐tuned synthesis of α‐ and β‐Bi2O3 nanowires and their single nanowire micro‐Raman study. The single crystalline Bi2O3 nanowires in different phases (α and β) were selectively synthesized by adjusting the heating temperature of Bi precursor in a vapor transport process. No catalyst was employed. Furthermore, at an identical precursor evaporation temperature, α‐ and β‐ phase Bi2O3 nanowires were simultaneously synthesized along the temperature gradient at a substrate. The growth direction of α‐Bi2O3 nanowires was revealed by polarized Raman single nanowire spectra. For thin β‐Bi2O3 nanowires with a very small diameter, the polarized Raman single nanowire spectrum was strongly influenced by the shape effect.
Synthesis of Biaryl Compounds Using Tandem Ruthenium‐Catalyzed Ring‐Closing Metathesis
Authors: Yoshida Kazuhiro , Shida Hiroaki , Takahashi Hidetoshi , Yanagisawa Akira
Published: November 2010

Tandem ring‐closing enyne metathesis (RCEM)/ring‐closing olefin metathesis (RCM) of tetraenynes with Grubbs second‐generation catalyst, followed by elimination, was found to be a new and efficient synthetic approach to biaryl compounds. A preliminary asymmetric version of this approach, which used homochiral Ru–alkylidene catalysts, is also presented.
Regioisomeric Control Induced by DABCO Coordination to Rotatable Self‐Assembled Bis‐ and Tetraporphyrin α,γ‐Cyclic Octapeptide Dimers
Authors: Hernández‐Eguía Laura P. , Brea Roberto J. , Castedo Luis , Ballester Pablo , Granja Juan R.
Published: December 2010

The design and synthesis of two α,γ‐cyclic octapeptides decorated with one and two Zn–porphyrin units in their periphery is described. In nonpolar organic solvents the α,γ‐cyclic octapeptides quantitatively self‐assemble into Zn–bis‐ or –tetraporphyrin architectures that could act as molecular tweezers. The self‐assembly process, however, is not regioselective and affords a mixture of different regioisomers that are involved in chemical exchange processes. The regioisomers with the Zn–porphyrin units positioned in register with respect to each other are proposed to be the less abundant species in the solution mixture. It has been demonstrated that the coordination of 1,4‐diazabicyclo[2.2.2]octane (DABCO) to the supramolecular bis‐ or tetraporphyrin tweezers is an effective way to achieve regioisomeric control of the self‐assembled mixture of dimers. Thus, DABCO functions as an external molecular trigger and, when used under strict stoichiometric control with respect to the Zn–porphyrin units, provokes the exclusive formation of self‐assembled dimers with a cofacial arrangement of Zn–porphyrin units through the formation of sandwich‐type complexes. The use of excess DABCO fragments the sandwich complexes and affords open dimers of high stoichiometry with DABCO molecules axially monocoordinated to the Zn–porphyrin units, probably as a regioisomeric mixture. In the case of Zn–tetraporphyrin tweezers, the ditopic coordination of DABCO at the two binding sites shows a moderate positive cooperativity factor, αP=5. These assemblies have potential applications as light‐induced energy and electron‐transfer switches regulated by DABCO coordination; such applications would require the introduction of additional chromophores in the cyclic peptide scaffold.
Delayed Fluorescent Emission from Pyrene Doped Phenanthrene Nanoparticles Based on Triplet‐triplet Energy Transfer
Authors: Jiang Ziwen , Zhao Yongsheng , Luo Zhixun , Peng Aidong , Wang Hao , Yao Jiannian
Published: November 2010

Doped nanoparticles were prepared from pyrene and phenanthrene using a facile reprecipitation method. The doped nanoparticles presented unique delayed fluorescent emissions of pyrene under the unprotected condition. The ratio of the intensity of delayed fluorescence (IDF) to that of phosphorescence (IP) is about 4:1, which almost keeps unchanged with the decrease of pyrene content at room temperature. The intensity of the delayed fluorescence emissions is dependent on the relative content of pyrene, as well as the aggregation degree of nanoparticles. The delayed emissions are contributed to efficient triplet‐triplet energy transfer from phenanthrene (donor) to pyrene (acceptor). Steady fluorescence measurement have proved that the singlet‐singlet energy transfer process was also existent dominated by the radiation energy transfer mechanism.
Photo Catalytic Degradation of Azo Dyes over Mn2+ Doped TiO2 Catalyst under UV/Solar Light: An Insight to the Route of Electron Transfer in the Mixed Phase of Anatase and Rutile
Authors: Lakshmipathi Naik Gomathi Devi , Kottam Nagaraju , Shivashankar Girish Kumar
Published: November 2010

Mn2+ ion was doped into the TiO2 matrix and its photocatalytic activity was evaluated for the degradation of a mono azo dye methyl orange (MO) and a di‐azo dye brilliant yellow (BY) under UV/solar light. X‐ray diffraction results revealed the phase transformation from anatase to rutile due to the inclusion of Mn2+ ion into the TiO2 matrix. All the doped catalysts showed a red shift in the band gap to the visible region. The degradation reaction of the dyes was found to be dependent on its structure. It was found that mono azo dye degrades faster than di azo dye under UV/solar light. The rate constant under identical conditions calculated for the degradation of MO is 2.4 times (under UV light) and 4.5 times (under solar light) higher compared to BY. Among the photocatalysts studied, Mn2+(0.06 at.%)‐TiO2 showed higher activity under both UV and solar light illumination. The synergestic effect in the bicrystalline framework of anatase and rutile effectively suppresses the charge carrier recombination and enhances the photocatalytic activity. The degradation reaction was followed by UV‐visible spectroscopy and the photoproducts formed were analyzed by GC‐MS techniques.
Synthesis, Crystal Structure, Spectroscopic, Electrochemical and Antimicrobial Properties of Cu(II) Complex with the Mixed Ligands of 2,9‐Dimethyl‐1,10‐phenanthroline and 4‐Hydroxypyridine‐2,6‐dicarboxylic Acid
Authors: Derikvand Zohreh , Talei Gholam Reza , Aghabozorg Hossein , Olmstead Marilyn M. , Azadbakht Azadeh , Nemati Andya , Gharamaleki Jafar Attar
Published: November 2010

A mononuclear Cu(II) complex with mixed ligands, formulated as [Cu(hypydc)(dmp)]·H2O (hypydc=4‐hydroxypyridine‐2,6‐dicarboxylate, dmp=2,9‐dimethyl‐1,10‐phenanthroline), was synthesized and well characterized by single crystal X‐ray diffraction analysis, as well as spectroscopic (IR, UV‐Vis), and electrochemical methods. The Cu(II) atom exhibits a distorted square‐pyramidal geometry. Intermolecular OH···O and CH···O hydrogen bonds, π‐π stacking interactions and CH···π interactions seem to be effective in the stabilization of the crystal structure. The complex was also evaluated for its antimicrobial activity using in vitro microdilution methods. Six standard bacteria and a strain of Candida albicans were used for the antimicrobial activities. There was a very strong activity against Candida albicans and significant activities against Enterococcus fecalis, Listeria monocytogenes, Bacillus cereus and Staphylococcus aureus, indicating important biological activities of the complex.
Spectrofluorimetric Determination and Validation of Biotin in Pure and Dosage Form via Derivatization with 4‐Fluoro‐7‐nitrobenzofurazan
Authors: Sevgi Tatar Ulu
Published: November 2010

A simple and highly sensitive spectrofluorimetric method was developed for the determination of biotin in pure and dosage form. The method is based on the derivatization of biotin with 4‐fluoro‐7‐nitrobenzofurazan in borate buffer of pH 9.0 to yield a yellow, fluorescent product. The various chemical conditions that affected the reaction were studied. The method was validated for specificity, linearity, precision, accuracy, recovery and robustness. At optimized experimental conditions, a linear relationship between the fluorescence intensity of the concentration of biotin is observed in the range 45–450 ng/mL. Limit of detection and quantification were 0.038 and 0.114 ng/mL, respectively. The percentage mean recovery was 99.96. The proposed procedure was successfully applied to the determination of biotin in its dosage form with mean recovery of 101.23±1.22 for biotin tablets. The results obtained were in good agreement with those obtained by the reference method.
Regio‐ and Stereo‐selective Synthesis of Peracetylated Carbohydrate Esters of Aromatic Fatty Acid Using p‐Toluenesulfonic Acid as Catalyst
Authors: Zhu Zhenyuan , Li Shengfeng , Liu Rongqiang , Yuan Jing , Wang Haibiao , Zhang Yongmin , Liu Yang
Published: November 2010

This paper describes an efficient synthesis of carbohydrate fatty acid esters based on a highly stereo‐ and regio‐selective esterification. The suitably protected glycosyl was esterified with stearic acid to give mainly the β‐anomer in good yield using p‐toluenesulfonic acid as catalyst. The structures of these compounds were fully confirmed by 1H, 13C NMR, mass spectra and HRMS.
Application of N,N′‐Diiodo‐N,N′‐1,2‐ethandiylbis(p‐toluene sulfonamide) as a New Reagent for Synthesis of 2‐Arylbenzimidazoles and 2‐Arylbenzothiazoles under Solvent‐free Conditions
Authors: Veisi Hojat , Ghorbani‐Vaghei Ramin , Faraji Alireza , Ozturk Turan
Published: November 2010

N,N′‐Diiodo‐N,N′‐1,2‐ethandiylbis(p‐toluene sulfonamide) (NIBTS) is a good and new reagent for synthesis of 2‐arylbenzimidazoles and 2‐arylbenzothiazoles at room temperature under solvent‐free condition with good to high yield. Absence of solvent, short reaction times, non‐corrosive, operational simplicity and environmentally friendliness are the main advantages of this procedure.
Catalysis by L‐Lysine: A Green Method for the Condensation of Aromatic Aldehydes with Acidic Methylene Compounds in Water at Room Temperature
Authors: Zhang Yan , Sun Cuizhi , Liang Jun , Shang Zhicai
Published: November 2010

The condensation of aromatic aldehydes with acidic methylene compounds such as ethyl benzoylacetate, 2,4‐pentanedione and dimedone proceeded efficiently in pure water in the presence of L‐lysine at room temperature. Interestingly, there are two different reaction mechanisms taking place under the same green catalyst system. This provides a green and mild synthetic method for the preparation of these two classes of compounds.
Synthesis of Fe3O4 Microspheres‐Supported Catalysts for Suzuki Coupling Reaction
Authors: Zhang Yanqi , Wei Xianwen , Yao Zijian
Published: November 2010

Two new Fe3O4 microspheres‐supported semi‐homogeneous catalysts, namely Fe3O4‐G4‐polyaminoamido (PAMAM) dendrimers‐Pd(0) and Fe3O4‐polyethylene glycols (PEGs)‐Pd(0) were synthesized and characterized by X‐ray powder diffraction, infrared spectrum, scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy and thermal gravimetric analysis, which can catalyze Suzuki coupling reactions. The performance of catalysts was tested for the reactions of aryl halides with phenyl boronic acid and compared with a heterogeneous catalyst Fe3O4‐(3‐aminopropyl)triethoxysilane (APTS)‐Pd(0), in which Fe3O4‐G4‐PAMAM dendrimers‐Pd(0) shows the best activity among the three catalysts. The order of the catalytic activities is Fe3O4‐G4‐PAMAM dendrimers‐Pd(0)>Fe3O4‐PEGs‐Pd(0)>Fe3O4‐APTS‐Pd(0). The catalysts can be quickly and completely recovered by simply applying a magnet of 105 mT and the efficiencies remain unaltered even after four recycles.
Isomeric Effect on H/D Exchange of Resveratrol Studied by NMR Spectroscopy
Authors: Jiang Haipeng , Fang Hanjun , Jiang Ling , Zheng Limin , Wang Nian , Zheng Anmin , Deng Feng , Liu Maili
Published: November 2010

Resveratrol (3,5,4′‐trihydroxylstilbene), a phytoalexin in response to injury or fungal attack, is found in grapes and other food products. It has been well documented that the compound has beneficial effects as hypolipidemic, anticancer, antiviral, neuroprotective, antiaging, and anti‐inflammatory natural active principle. It was observed that both trans‐ and cis‐resveratrols undergo hydrogen‐deuterium (H/D) exchange at H‐2,6 and H‐4 positions of the A‐ring. The exchange rates were determined by 1H NMR spectroscopy. The results reveal that the exchange rates are configuration and pH dependent. Derivative of 2‐O‐β‐D‐glucoside can significantly speed up the H/D exchange reactions for both isomers. The trans‐resveratrol experiences faster H/D exchanging than the cis‐resveratrol. Such isomeric effect is possibly due to the factor that the trans‐resveratrol is in favor of forming larger/super conjugative system and has less spatial interference. Theoretical calculation shows that electronegativity at these positions is in the order of H‐2,6>H‐4, which is in consistent with the exchange rates observed by NMR. The results may be of help in understanding the properties of resveratrol, and in analysis of resveratrol in natural products or body fluids using mass spectroscopy that occasionally requires stable deuterium isotope labeling.
A Simple and Sensitive Method for the Detection of Trace Pb(II) and Cd(II) based on Nafion‐coated Antimony Film Electrode
Authors: Xu He , Yang Ping , Zheng Qiaoli , Liu Jianshe , Jin Litong
Published: November 2010

Nafion‐coated antimony film electrode (NCAFE) was prepared in situ by simultaneously plated antimony with analytes, and applied to the determination of trace Pb(II) and Cd(II) in non‐deaerated solutions by differential pulse anodic stripping voltammetry (DPASV). Various experimental parameters, which influenced the response of the NCAFE to those metals, were thoroughly optimized and discussed. The results indicated that the sensitivity and resistance to surfactants at the NCAFE were remarkably improved with relative to the antimony film electrode (AFE). In the presence of 5 mg·L−1 gelatin, the peak heights at the NCAFE showed 4‐fold enhancement for Pb and a 9‐fold enhancement for Cd over a bare AFE. Reproducibility of the sensor was satisfactory, and the relative standard deviations were 4.8% for 20 μg·L−1 Pb and 3.2% for 25 μg·L−1 Cd (n=15) with preconcentration time of 180 s. The determination limits (S/N=3) of this sensor were determined to be 0.15 μg·L−1 for Pb and 0.30 μg·L−1 for Cd with accumulation time of 300 s. The NCAFE was successfully applied to determining Pb(II) and Cd(II) in vegetable and water samples with satisfactory results.
Development of High Performance Liquid Chromatography Method for Costunolide and Dehydrocostuslactone in Mice Plasma and Tissues: Application to Pharmacokinetic Study
Authors: Hu Fangdi , Feng Shilan , Wu Yuqiong , Bi Yingyan , Cui Fang , Li Yongjie , Wang Chunming
Published: November 2010

A simple and sensitive high performance liquid chromatographic (HPLC) method for simultaneous determination of costunolide and dehydrocostuslactone in mice plasma and tissues was developed and validated. Costunolide and dehydrocostuslactone were extracted into acetonitrile and separated using an isocratic mobile phase, on a Hypersil ODS C18 column. The effluent was monitored by UV detector at 210 nm and at a flow rate of 1.0 mL· min−1 and 25°C. The linearity ranges of proposed method were 0.223–8.920 µg·mL−1 for costunolide and 0.227–9.080 µg·mL−1 for dehydrocostuslactone. The intra‐day and inter‐day RSD of the assay method for the two components were less than 5%, and mean recovery was within the 86.5% to 101.8% range. The method was found to be precise, accurate, and specific during the study. The method was successfully applied for pharmacokinetic study of costunolide and dehydrocostuslactone after application of ethanol extraction of Muxiang (EEM) in mice.
Shape‐controlled Synthesis of Nanostructure Ramsdellite‐type Manganese Oxide at Atmospheric Pressure
Authors: Qiu Guohong , Wang Jun , Zhao Wei , Feng Xionghan , Tan Wenfeng , Zhang Qin , Liu Fan
Published: November 2010

Ramsdellite (R‐MnO2) was prepared by oxidizing bivalent manganese salts, such as MnCl2, MnSO4 and Mn(NO3)2, with NaClO solution using a refluxing process at atmospheric pressure. The products were characterized by X‐ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy and flame photometry. R‐MnO2 microstructure and morphology were controlled by adjusting reaction temperature, the amount of hydrochloric acid (HCl) and anions of bivalent manganese salts. Ramsdellite grain was formed with three different bivalent manganese salts oxidized by NaClO solution at 60°C, and increased with the increase of reflux temperature. R‐MnO2 nanorod and nanowire crystals were obtained when MnCl2 and MnSO4 were used as bivalent manganese salts at 100°C respectively. Nanosized flake of R‐MnO2 came into being when Mn(NO3)2 was applied at 80°C. When 30 mmol MnCl2 was oxidized by 60 mmol NaClO solution with adding 20 mmol HCl in refluxing solution, specific surface area of R‐MnO2 grain obtained at 60°C was greater than 140 m2/g, and the self‐assembly of nanorod bundles into interesting flowerlike architectures was achieved at 100°C. The process of dissolution‐precipitation equilibrium might be the primary cause for the morphology transformation.
How to assess cytotoxicity of (iron oxide‐based) nanoparticles. A technical note using cationic magnetoliposomes
Authors: Soenen Stefaan J.H. , De Cuyper Marcel
Published: December 2010

The range of different types of nanoparticles and their biomedical applications is rapidly growing, creating a need to thoroughly examine the effects these particles have on biological entities. One of the most commonly used nanoparticle types is iron oxide nanoparticles, which can be used as MRI contrast agents. The main research topic is the in vitro labeling of cells with iron oxide nanoparticles to render the cells detectable for MRI upon in vivo transplantation. For the correct evaluation of cell function and behavior in vivo, any effects of the nanoparticles on the cells must be completely ruled out. The present work provides a technical note where a detailed overview is given of several assays that could be useful to determine nanoparticle toxicity. The assays described focus on (i) nanoparticle internalization, (ii) immediate cell toxicity, (iii) cell proliferation, (iv) cell morphology, (v) cell functionality and (vi) cell physiology. Potential pitfalls, appropriate controls and advantages/disadvantages of the different assays are given. The main focus of this work is to provide a detailed guide to help other researchers in the field interested in setting up nanoparticle‐toxicity studies. Copyright © 2010 John Wiley & Sons, Ltd.
A phase 2 study of irinotecan, cisplatin, and simvastatin for untreated extensive‐disease small cell lung cancer
Authors: Han Ji‐Youn , Lim Kun Young , Yu Sun Young , Yun Tak , Kim Heung Tae , Lee Jin Soo
Published: November 2010

BACKGROUND:

The objective of this study was to investigate the efficacy of simvastatin in combination with irinotecan and cisplatin in chemotherapy‐naive patients with extensive‐disease small‐cell lung cancer (ED‐SCLC).

METHODS:

In this phase 2 study, 61 patients received treatment with irinotecan (65 mg/m2) and cisplatin (30 mg/m2) on Days 1 and 8 every 3 weeks until either death or disease progression occurred. Patients also received oral simvastatin (40 mg daily) during the course of chemotherapy. The primary endpoint was 1‐year survival. Secondary endpoints included the response rate (RR), progression‐free survival (PFS), and toxicity.

RESULTS:

The 1‐year survival rate was 39.3%. The median overall survival (OS) was 11 months, and the median PFS was 6.1 months. Overall, the RR was 75%. The most common grade 3/4 toxicity was neutropenia (67%). Efficacy of the treatment was associated significantly with smoking status. Compared with never‐smokers, ever‐smokers had a better RR (40% vs 78%; P = .01), a longer PFS (2.5 months vs 6.4 months; P = .018), and had a trend toward an improved OS (9.0 months vs 11.2 months; P = .095). The effect of smoking on survival was apparent when ever‐smokers were subdivided according to pack‐years (PY) of smoking. Ever‐smokers who had smoked >65 PY had a significantly longer OS compared with ever‐smokers who had smoked ≤65 PY or never‐smokers (20.6 months vs 10.6 months vs 9.0 months, respectively; log‐rank P = 0.032). In multivariate analysis, PY >65 was predictive of longer survival (hazard ratio, 0.280; 95% confidence interval, 0.113‐0.694).

CONCLUSIONS:

The current results indicated that simvastatin in combination with irinotecan and cisplatin did not improve the survival of patients with ED‐SCLC. Although the subgroup analysis by smoking status was exploratory, the addition of simvastatin to irinotecan and cisplatin may improve the outcome of heavy smokers with ED‐SCLC. Cancer 2011. © 2010 American Cancer Society.
KIT gene mutation and amplification in dysgerminoma of the ovary
Authors: Cheng Liang , Roth Lawrence M. , Zhang Shaobo , Wang Mingsheng , Morton Michael J. , Zheng Wenxin , Abdul Karim Fadi W. , Montironi Rodolfo , Lopez‐Beltran Antonio
Published: November 2010

BACKGROUND:

Dysgerminoma, the ovarian counterpart of seminoma, is the most common type of malignant ovarian germ cell tumor. The role of KIT mutation and amplification in the development of dysgerminoma is not currently established. The purpose of this study was to analyze alterations of the KIT gene in a large series of dysgerminomas and correlate the findings with clinicopathological parameters.

METHODS:

Dysgerminoma cells from 22 patients were analyzed for KIT mutations at exon 17 codon 816. KIT amplification and chromosome 12p anomalies were investigated by way of dual color fluorescence in situ hybridization. KIT protein expression was also examined by way of immunohistochemistry.

RESULTS:

KIT exon 17 codon 816 mutations and KIT amplification were each detected in 6 cases of dysgerminoma (27%); however, there was no correlation between these 2 factors. KIT expression was detected in 87% of dysgerminomas. The KIT mutation was associated with advanced pathological stage (P < .05), and KIT amplification was associated with elevated KIT protein expression (P < .05). Chromosome 12p anomalies were found in 82% of the dysgerminomas and did not correlate with KIT abnormalities.

CONCLUSIONS:

KIT mutations occur in approximately one‐third of cases of dysgerminomas and are associated with advanced stage at presentation. KIT is a potential therapeutic target for those dysgerminomas that have the mutation. Cancer 2011. © 2010 American Cancer Society.
Differential structural plasticity of corticostriatal and thalamostriatal axo‐spinous synapses in MPTP‐treated parkinsonian monkeys
Authors: Villalba Rosa M. , Smith Yoland
Published: December 2010

Striatal spine loss is a key pathological feature of Parkinson's disease (PD). Knowing that striatal glutamatergic afferents target dendritic spines, these data appear difficult to reconcile with evidence for an increased expression of the vesicular glutamate transporter 1 (vGluT1) in the striatum of PD patients and 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐treated monkeys, as well as in some electrophysiological studies showing overactivity of the corticostriatal glutamatergic system in models of parkinsonism. To address the possibility that structural changes in glutamatergic afferents may underlie these discrepancies, we undertook an ultrastructural analysis of vGluT1‐positive (i.e., corticostriatal) and vGluT2‐positive (i.e., mostly thalamostriatal) axo‐spinous glutamatergic synapses using a 3D electron microscopic approach in normal and MPTP‐treated monkeys. Three main conclusions can be drawn: 1) spines contacted by vGluT1‐containing terminals have larger volume and harbor significantly larger postsynaptic densities (PSDs) than those contacted by vGluT2‐immunoreactive boutons; 2) a subset of vGluT2‐, but not vGluT1‐immunoreactive, terminals display a pattern of multisynaptic connectivity in normal and MPTP‐treated monkeys; and 3) VGluT1‐ and vGluT2‐positive axo‐spinous synapses undergo ultrastructural changes (larger spine volume, larger PSDs, increased PSD perforations, larger presynaptic terminal) indicative of increased synaptic activity in parkinsonian animals. Furthermore, spines contacted by cortical terminals display an increased volume of their spine apparatus in MPTP‐treated monkeys, suggesting an increased protein synthesis at corticostriatal synapses. These findings demonstrate that corticostriatal and thalamostriatal glutamatergic axo‐spinous synapses display significantly different ultrastructural features, and that both systems undergo complex morphological changes that could underlie the pathophysiology of corticostriatal and thalamostriatal systems in PD. J. Comp. Neurol. 519:989–1005, 2011. © 2010 Wiley‐Liss, Inc.
Mediation of Secretory Cell Function by G Protein—Coupled Receptors
Authors: Lledo Pierre‐Marie , Zorec Robert , Rupnik Marjan , Mason W. T.
Published: November 2010

The sections in this article are:

The Impact of Molecular Biology on Cell Physiology

Secretory Cell Physiology

Mechanisms of Action of Antisense Oligonucleotides

Lifetimes of Antisense Probes in Living Cells

Antisense Sites of Action

The Whole Cell Patch—Clamp Technique and Loading Cells with Antisense Oligonucleotide Probes

Antisense Oligonucleotides Assign G Protein Subtypes in The Coupling of Dopamine Receptors to Ionic Channels

Models for The Study of Regulated Secretory Events

Packaging and Storage in Different Secretory Organelles

Membrane Capacitance Reveals Exocytotic and Endocytotic Activities

Homeostasis of The Intracellular‐Free Calcium Concentration

The Exocytotic Machinery is Regulated by Intracellular Calcium Concentration

The Role of Small Gtp‐Binding Proteins in Exocytosis

Identification of Specific G Proteins Controlling Ionic Channel Activities

Use of Pertussis Toxin to Identify a Role For G Proteins in Cell Function

Use of Antisense Oligonucleotides to Study αO‐Mediated Calcium Current Responses to Dopamine in Lactotroph Cells

Time Dependence of Antisense Action in Single‐Cell Studies

Use of Antisense Oligonucleotides to Establish a Role for RAB3B Small GTP‐Binding Protein in Calcium‐Induced Exocytosis of Anterior Pituitary Cells

Discussion
General Introduction: Reminiscences and Reflections on Fifty Years of the Endocrine Pancreas
Authors: Randle Philip J.
Published: November 2010

The sections in this article are:

Beginnings

Endocrine Nature of the Pancreas

Action Mechanisms

Landmarks in Protein Phosphorylation: Mechanism of Action of Glucagon

Insulin

Early Development of Ideas About the Mechanism of Action of Insulin

Insulin Secretion and Biosynthesis

Fuels: Consumption and Selection—The Glucose Fatty Acid Cycle and the Role of the PDH Complex

Fuel Consumption and Selection

The Glucose Fatty Acid Cycle

Role of the Pyruvate Dehydrogenase Complex

Physiopathological Significance of Pyruvate Dehydrogenase Kinase Regulation in Humans

The Thrifty Phenotype Hypothesis in Relation to Insulin Secretion, Insulin Insensitivity, and the Origins of Non‐Insulin‐Dependent Diabetes Mellitus

Where Next?
Regulation of Ketogenesis in Liver
Authors: Zammit Victor A.
Published: November 2010

The sections in this article are:

Roles of Insulin and Glucagon in Substrate Supply for Hepatic Ketogenesis

Effects of Ketones on the Endocrine Pancreas and Adipose Tissue

Intrahepatic Partitioning of Fatty Acids Between Oxidation and Esterification

Pancreatic Hormone Effects on Enzyme Substrate Availability

Expression of Enzyme Activity

Role of Malonyl CoA

Role of Carnitine Palmitoyltransferase I Membrane Topology and Membrane‐Protein Interactions

Control of Carnitine Palmitoyltransferase I over Ketogenesis: Effects of Altered Insulin Status

In Vivo Monitoring of Hepatic Acyl‐CoA Partitioning

Intramitochondrial Regulation of Ketogenesis

Modulation of Mitochondrial 3‐Hydroxy‐3‐Methylglutaryl‐CoA Synthase Activity

Examples of Physiological Conditions Involving Pancreatic Hormone Regulation of Ketogenesis

General Comments
Molecular and Physiological Aspects of Angiotensin I Converting Enzyme
Authors: Alhenc‐Gelas Francois , Corvol Pierre
Published: December 2010

The sections in this article are:

Distribution

Somatic Angiotensin‐Converting Enzyme

Germinal Angiotensin‐Converting Enzyme

Catalytic Properties

Angiotensin‐Converting Enzyme Is a Zinc Metallopeptidase

Substrate Specificity

Anion Activation

Molecular Structure of Angiotensin‐Converting Enzyme

Somatic Angiotensin‐Converting Enzyme

Germinal Angiotensin‐Converting Enzyme

Two Angiotensin‐Converting Enzyme Active Sites: Identification of Essential Residues

Differences in the Characteristics of the N and C domains

Chloride Activation

Substrate Specificity

Angiotensin‐Converting Enzyme Inhibitors

Structure of the Angiotensin‐Converting Enzyme Gene

Mechanism of Angiotensin‐Converting Enzyme Anchorage and Solubilization

Regulation of Angiotensin‐Converting Enzyme Gene Expression in Somatic And Germinal Cells

Induction of Angiotensin‐Converting Enzyme Gene Expression in Physiological and Pathological Situations

Genetic Polymorphism of Angiotensin‐Converting Enzyme Levels in Humans

Association of the Genetic Polymorphism of Angiotensin‐Converting Enzyme Levels with Disease

Physiological Role of Angiotensin‐Converting Enzyme
Antidiuretic Hormone: Synthesis and Release
Authors: Sladek Celia D.
Published: December 2010

The sections in this article are:

Morphology of Vasopressinergic Neurons

Localization

Cellular Morphology

Glial–Neuronal Interactions

Posterior Pituitary Morphology

Synthesis of Vasopressin

Vasopressin Gene

Regulation of Vasopressin mRNA

Processing, Packaging, and Transport to the Neural Lobe

Release of Antidiuretic Hormone

Electrophysiological Characteristics of Vasopressin Neurons

Stimulus–Secretion Coupling in the Neural Lobe

Dendritic Release

Regulation of Vasopressin Secretion

Afferents to Magnocellular Vasopressin Neurons

Neurochemicals Regulating Secretion

Neuropeptides in Afferent Pathways

Osmoregulatory Pathways and Mechanisms

Pressure/Volume‐Regulatory Pathways

Other Ascending Pathways

Other Physiological Regulators

Steroid hormones
Endocrine Control of Water Balance
Authors: Andreoli Thomas E. , Reeves W. Brian , Bichet Daniel G.
Published: December 2010

The sections in this article are:

The Water‐Repletion Reaction

Cell‐Volume Regulation

The Neurohypophysis

Structure

Hormone Biosynthesis, Transport, and Metabolism

Control of Antidiuretic Hormone Release

Osmotic Regulation

Nonosmotic Regulation

Chemical Mediators

Intranuclear Secretion

Oxytocin

Thirst

Osmotic Regulation

Volume‐Mediated Thirst

Satiation of Thirst

Renal Contribution to Osmotic Homeostasis

Renal Countercurrent Mechanisms

Effects of Filtration Rate and Solute Excretion

Collecting Tubule

Medullary Thick Ascending Limb of Henle

Integration of Antidiuretic Hormone Actions with the Urinary Concentrating Mechanism

Selected Clinical Derangements of Water Balance

Hypertonic Syndromes

Hypotonic Syndromes
Parathyroid Hormone and Polyhormones: Production and Export
Authors: Diaz Ruben , Fuleihan Ghada El‐Hajj , Brown Edward M.
Published: December 2010

The sections in this article are:

Role of Extracellular Calcium–Sensing and Extracellular Calcium–Regulated Parathyroid Hormone Secretion in Mineral ion Homeostasis

The G Protein–Coupled, Extracellular Calcium–Sensing Receptor

Structure and Function

Inherited Diseases Resulting from Receptor Mutations

Mice with Targeted Disruption of the Receptor

Are There Additional Receptors or Other Ion‐Sensing Receptors?

Anatomy and Physiology of the Parathyroid Cell

Morphology

Secretory Pathway

Physiological Control of Parathyroid Hormone Secretion by Extracellular Calcium and Other Factors

Acute Regulation

Additional Ionic Agonists Regulating Parathyroid Hormone Secretion via the Extracellular Calcium‐Sensing Receptor

Other Ions Modulating Parathyroid Hormone secretion

Rapid Actions of Vitamin D on Parathyroid Cells

Regulation of Parathyroid Hormone Secretion by Catecholamines and Other Biogenic Amines

Regulation of Parathyroid Hormone Secretion by Lipid Metabolites

Regulation of Parathyroid Hormone Secretion by Peptides and Peptide Hormones

Miscellaneous Factors Regulating Parathyroid Hormone Secretion

Mechanisms Underlying the Acute Regulation of Parathyroid Hormone Secretion by Extracellular Calcium

Regulation of Intracellular Degradation of Parathyroid Hormone

Regulation of Parathyroid Hormone Gene Expression

Chromosomal Localization and Organization of the Parathyroid Hormone Gene

Effects of Extracellular Calcium

Effects of Extracellular Phosphate

Effects of Vitamin D Metabolites

Parathyroid Hormone Regulation of Gene Expression by Steroids and Other Hormones

Regulation of Parathyroid Hormone Gene Expression by Agents that Increase Intracellular Cyclic Adenosine Monophosphate

Regulation of Overall Biosynthetic Activity of the Parathyroid Cell

Regulation of Parathyroid Cellular Proliferation

Effects of Extracellular Calcium

Effects of Vitamin D Metabolites

Effect of Extracellular Phosphate

Effect of Growth Factors

Circadian and Pulsatile Control of Parathyroid Hormone Secretion

Circadian Variation

Pulsatility

Alterations in Circadian Rhythm and Pulsatility in Patients with Abnormal Parathyroid Function

Secretion of Factors Other Than Parathyroid Hormone: Possible Autocrine/ Paracrine Regulation of Parathyroid Hormone Secretion

Evidence for Autocrine Control of Parathyroid Function

Secretion of Parathyroid Hormone–Related Protein

Secretion of Chromogranin A‐Derived Peptides

Secretion of Other Peptides

Secretion of Prostaglandins
Roles of Parathyroid Hormone and Parathyroid Hormone–Related Peptide in Calcium Metabolism and Bone Biology: Biological Actions and Receptors
Authors: Jüppner Harald , Jr. Potts John T.
Published: December 2010

The sections in this article are:

Parathyroid Hormone

Chemistry

Peripheral Metabolism

Actions in Kidney and Bone

Parathyroid Hormone‐Related Peptide

Chemistry: Role of the Amino‐terminal Portion in Calcium Metabolism

Biological Role in Bone Development

Receptors That Mediate Analogous and Distinct Molecular Actions of Parathyroid Hormone and Parathyroid Hormone–Related Peptide

The Parathyroid Hormone/Parathyroid Hormone–Related Peptide Receptor

The Type 2 Parathyroid Hormone Receptor

Additional Receptors

Structure‐Based Design of Analogues
Chronic Stress and Energy Balance: Role of the Hypothalamo‐Pituitary‐Adrenal Axis
Authors: Dallman Mary F. , Bhatnagar Seema
Published: December 2010

The sections in this article are:

Regulation of Function in the Hypothalamo‐Pituitary‐Adrenal Axis

Corticosteroid Receptors: Feedback Control of the Hypothalamo‐Pituitary‐Adrenal Axis by Exogenous Corticosteroid Treatment

Stressor‐Induced Endogenous Corticosteroid Secretion and Feedback Control

Chronic or Repeated Stressors Induce Facilitated Responses

Diurnal Rhythms and Responsivity

Acute Versus Chronic Stressors: Effects on Activity in the Hypothalamo‐Pituitary‐Adrenal Axis

Acute Responses to Stress

Adaptations to Intermittent Stimuli

Adaption to Chronic, Sustained Stimuli

Corticosteroids, Stress, and Energy Balance

Energy Acquisition

Energy Disposition

Chronic Stress in Humans
Interactions Between the Hypothalamic‐Pituitary‐Adrenal Axis and Immune System During Viral Infection: Pathways for Environmental Effects on Disease Expression
Authors: Miller Andrew H. , Pearce Bradley D. , Ruzek Melanie C. , Biron Christine A.
Published: December 2010

The sections in this article are:

Immune Responses to Viral Infection

Early Innate Immunity

Late Adaptive Immunity

Pathology During Viral Infection

Cell‐Mediated Pathology

Cytokine‐Mediated Pathology

Cytokine Pathways for Glucocorticoid Induction During Viral Infection [“Starting the Loop”]

Glucocorticoid Induction during Viral Infection

Cytokines and Glucocorticoid Induction during Viral Infection

Central Nervous System/Neuroendocrine Pathways for Glucocorticoid Induction During Viral Infection (“Making the Connection”)

Pathways by which Peripheral Cytokine Signals Reach the Brain

Cytokine Network in the Central Nervous System

Cytokines and Behavior

Viral Infection, Glucocorticoid Availability, and Glucocorticoid Receptor Expression and Function (“Delivering and Receiving The Signal”)

Corticosteroid‐Binding Globulin and 11β‐Hydroxysteroid Dehydrogenase

Glucocorticoid Receptor Changes during Viral Infection

Cytokines as Potential Mediators of Glucocorticoid Receptor Changes during Viral Infection

Endogenous Glucocorticoids and Host Responses to Viral Infection (“Shaping The Response, Protection, and Closing the Loop”)

Impact of Stress on Immune Responses to Viral Infection

Glucocorticoids as the Mediator of Stress Effects on Viral Immunity