bluuebunny/crossref_metadata_2025 huggingface dataset:
Syntheses, Structures and Electronic Properties of Cationic Hydroxy‐ and Methoxy‐Substituted Tricarbonyl(tetracyclopropylcyclopentadienyl)iron Complexes
Authors: Emme Ingo , Labahn Thomas , de Meijere Armin
Published: October 2005

Tetracyclopropylcyclopentadienone, upon liberation from its previously known tricarbonyliron complex 3, undergoes rapid [4+2] cyclodimerization to the highly congested1,2,4,5,6,7,8,9‐octacyclopropyltricyclo[5.2.1.02,6]deca‐4,8‐diene‐3,10‐dione (6) which was characterized by an X‐ray crystal structure analysis. Upon alkylation of 3 with Me3OBF4 as well as protonation with HBF4 or CF3SO3H, the remarkably stable cationic tricarbonyl(tetracyclopropylcyclopentadienyl)iron complexes 9, 10 and 11, 12, respectively, were obtained in high yields (91, 87 and 74, 79 %, respectively). X‐ray crystal structural data for 11 and 12 as well as NMR‐ and IR spectroscopic evidences for all four new complexes 9–12 indicate that their positive charge predominantly rest on the tricarbonyliron fragments. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Stereoselective Synthesis of 3‐Deoxy‐4‐S‐(1→4)‐Thiodisaccharides and Their Inhibitory Activities Towards β‐Glycoside Hydrolases
Authors: Uhrig María Laura , Manzano Verónica Elena , Varela Oscar
Published: October 2005

The sulfur linkage of β‐(1→4)‐thiodisaccharides was constructed with excellent diastereoselectivity by Michael addition of 2,3,4,6‐tetra‐O‐acetyl‐1‐thio‐β‐D‐galactose (2) or its β‐D‐glucose isomer (3) to sugar‐derived (2S, 6S)‐6‐acetoxymethyl‐2‐(2‐propyloxy)‐2H‐pyran‐3(6H)‐one (1). These reactions led to the per‐O‐acetyl glycosides of 3‐deoxy‐4‐S‐glycopyranosyl‐4‐thiohexopyranosid‐2‐ulose (4 and 5, respectively). Similar conjugated addition to the enone 1 of the isothiouronium salts 6 or 7, precursors in the synthesis of 2 or 3, also afforded the thiodisaccharides 4 or 5, respectively, with exclusive formation of the isomer that has an R configuration for the C‐4 stereocenter of the reducing‐end. The carbonyl function of 4 and 5 was reduced, and the resulting products were O‐deacetylated to give the free 4‐S(1→4)‐thiodisaccharides 10, 11, 14, and 15, which have a deoxy functionality adjacent to the thio group. These compounds were tested as inhibitors of glycoside hydrolases. Thus 11, the 3‐deoxy‐4‐thiomimetic of Galβ(1→4)Gal, proved to be a competitive inhibitor of the β‐galactosidase from E. coli (Ki = 0.16 mM). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
CuI‐Catalyzed Alkyne–Azide “Click” Cycloadditions from a Mechanistic and Synthetic Perspective
Authors: Bock Victoria D. , Hiemstra Henk , van Maarseveen Jan H.
Published: October 2005

CuI‐catalyzed alkyne–azide cycloaddition provides 1,4‐disubstituted 1,2,3‐triazoles with such efficiency and scope that the transformation has been described as “click” chemistry. An overview of the mechanism of this remarkable reaction is presented as a means to explain the myriad of experimental results, particularly the various methods of catalyst generation, solvent and substrate effects, and choice of base or ligand. Both solution‐phase and solid‐phase results are comprehensively examined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Silanediol Protease Inhibitors: From Conception to Validation
Authors: Sieburth Scott McN. , Chen Chien‐An
Published: October 2005

Silanediols are isosteric with the unstable hydrated carbonyl group, but are most commonly associated with polymerization to give silicone polymers. Placement of a silanediol in a dipeptide analogue yields a new kind of nonhydrolyzable transition‐state‐analogue protease inhibitor. Both metallo and aspartic protease inhibitors have been prepared using silanediols, with enzyme inhibition in the low nanomolar range. Structure–activity comparisons with known inhibitors, efficacy in whole cell assays, and a crystal structure of a silanediol inhibitor bound to the thermolysin active site establish these silanediol inhibitors as effective and predictable new protease inhibitor tools. Recent chemistry developments have led to efficient and streamlined preparation of these inhibitors. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
GaCl3 in Organic Synthesis
Authors: Amemiya Ryo , Yamaguchi Masahiko
Published: October 2005

GaCl3 and organogallium compounds generated from GaCl3 possess novel properties that can be used in organic synthesis. This microreview summarizes our studies on the use of GaCl3 as 1) a reagent to generate organogallium compounds, which can carbometalate unactivated unsaturated bonds, and 2) a Lewis acid which can activate organic molecules by interacting with the π‐, n‐, and σ‐electrons. Carbometalation of carbon–carbon triple bonds (carbogallation) is a characteristic reaction of organogallium compounds. Carbogallation of gallioacetylenes occurs at lower temperatures than with silylacetylenes, and addition to 1‐alkynes is slow. The regiochemistry and stereochemistry are in accordance with other carbometalation reactions, giving 1,1‐digallio or 1‐gallio‐1‐silyl intermediates in the cis‐addition mode. Carbogallation of enolates and acetylenes is effective for the α‐ethenylation of ketones, and a catalytic version of the reaction has been developed. When chloroacetylenes are used, α‐ethynylation of ketones proceeds by addition and β‐elimination. Aniline and phenols can be ethenylated or ethynylated at the o‐position of the heteroatom groups. GaCl3 has been used not only for the ethynylation of heteroatom compounds but also hydrocarbons such as 1,4‐enynes or 1,4‐diynes by C–H activation, and triethynylvinylmethanes and tetraethynylmethanes are obtained in one step via nucleophilic propargylgallium intermediates. As a Lewis acid, GaCl3 has the ability to interact with π‐acids such as silylacetylenes. The resulting gallium complexes are sufficiently electrophilic to react with aromatic hydrocarbons, even at –78 °C, to give an organogallium arenium intermediate. Arenium cations or vinyl cations appear to be stabilized in the presence of GaCl3. An unusual orientation has been observed in electrophilic aromatic substitution with GaCl3. GaCl3 activates even cycloalkane C–H bonds at σ‐electrons, and the reaction of cis‐perhydronaphthalene and naphthalene catalytically gives 2‐naphthylated trans‐perhydronaphthalene. Two C–H activation reactions of hydrocarbons with GaCl3 are notable as they generatenucleophilic and electrophilic species. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
The Phospha‐Michael Addition in Organic Synthesis
Authors: Enders Dieter , Saint‐Dizier Alexandre , Lannou Marie‐Isabelle , Lenzen Achim
Published: October 2005

Phosphorus is essential for many reagents in organic synthesis, for ligands of late‐transition metals and for phosphono‐ and phosphanylamino acids, the latter being important isosteres of amino acids. Similar to the Michaelis–Arbuzov and the Michaelis–Becker reaction the phospha‐Michael addition, i. e. the addition of a phosphorus nucleophile to an acceptor‐substituted alkene or alkyne, certainly represents one of the most versatile and powerful tools for the formation of P–C bonds since many different electrophiles and P nucleophiles can be combined with each other. This offers the possibility to access many diversely functionalised products. With this article, we try to give an instructive overview of this reaction. The outline of this review is supposed to be rather general and it is its goal to make the reader familiar with reactivity principles which are common to the different classes of electrophiles and/or P nucleophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Studies on the Synthesis of Apoptolidin: Progress on the Stereocontrolled Assembly of the Pseudo Aglycone of Apoptolidin
Authors: Wu Bin , Liu Qingsong , Jin Bohan , Qu Tao , Sulikowski Gary A.
Published: October 2005

Progress on a stereocontrolled total synthesis of the pseudo aglycone of apoptolidin (2) starting from (S)‐epichlorohydrin is reported. The lower C(12)–C(28) fragment (4) was derived by consecutive stereoselective aldol reactions and extended using a Suzuki cross‐coupling reaction. Studies on glycoyslation of the C9 hydroxy group are also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Regioselective Synthesis of Novel e‐Edge‐[60]fullerenylmethanodihydropyrroles and 1,2‐Dihydromethano[60]fullerenes
Authors: Chaker Leila , Ball Graham E. , Williams James R. , Burley Glenn A. , Hawkins Bill C. , Keller Paul A. , Pyne Stephen G.
Published: October 2005

Treatment of a tethered N‐(diphenylmethylene)glycinate‐malonate derivative with [60]fullerene under Bingel conditions yielded an e‐edge‐[60]fullerenylmethanodihydropyrrole adduct in a regioselective manner. The regiochemical outcome was independent of the order of addition of either the N‐(diphenylmethylene)glycinate or the malonate moieties. This new bis‐adduct was also prepared in 13C‐enriched form allowing for its unequivocal structural characterization by 2D INADEQUATE NMR experiments. Ring opening of the dihydropyrrole functionality of the bis‐adducts under reductive conditions gave exclusively novel dihydromethano[60]fullerene derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Carbonate melting and peperite formation at the intrusive contact between large mafic dykes and clastic sediments of the upper Palaeozoic Saint‐Jules Formation, New‐Carlisle, Quebec
Authors: Jutras P. , Macrae A. , Owen J. V. , Dostal J. , Préda M. , Prichonnet G.
Published: October 2005

The base of an upper Palaeozoic graben‐fill in eastern Canada was affected by mafic dyke intrusions shortly after deposition, resulting in the formation of peperite. Complex magma–sediment interactions occurred as the melts mingled with the wet and poorly consolidated clastic material of this sedimentary basin, which is separated from underlying rocks by the Acadian unconformity (Middle Devonian). As a result of these interactions, the mafic rocks are strongly oxidized, albitized and autobrecciated near and above the unconformity, where blocky juvenile clasts of mafic glass and porphyritic basalt have mingled with molten or fluidized sediments of the upper Palaeozoic Saint‐Jules Formation, forming a peperite zone several metres thick. In contrast to most peperite occurrences, the New‐Carlisle peperites are associated with the tip of dykes rather than with the sides of sills or dykes. We argue that more heat can be concentrated above a dyke than above a sill, as the former provides a more efficient and focused pathway for heated waters to invade the poorly consolidated host sediments. Superheated groundwaters that issued from the sides of the dykes appear to have promoted melting of carbonate components in calcareous sedimentary rock clasts of the Saint‐Jules Formation, locally generating carbonate melts that contributed to the mingling of juvenile and sedimentary clasts in the peperite. Copyright © 2005 John Wiley & Sons, Ltd.
High‐pressure mineral assemblage in granitic rocks from continental units, Alpine Corsica, France
Authors: Malasoma Alessandro , Marroni Michele , Musumeci Giovanni , Pandolfi Luca
Published: October 2005

The Popolasca–Francardo area of northern Corsica contains an assemblage of continental tectonic units affected by an Alpine deformation. In one of these units, Unit II, previously regarded as weakly metamorphosed, a metamorphic mineral assemblage characterized by sodic amphibole, phengite, quartz, albite and epidote has been found in an aplite dyke that cuts the dominant granitoids. Peak‐metamorphic temperature and pressure conditions of 300–370°C and 0.50–0.80 GPa, respectively, have been determined. This finding indicates that a continuous belt of continental slices, characterized by high‐pressure, low‐temperature metamorphism of Tertiary age, extends from the Tenda Massif in the north to the Corte area in the south, thus placing additional constraints on the tectonic evolution of Alpine Corsica. Copyright © 2005 John Wiley & Sons, Ltd.
Hydrodynamic compression of young and adult rat osteoblast‐like cells on titanium fiber mesh
Authors: Walboomers X. F. , Elder S. E. , Bumgardner J. D. , Jansen J. A.
Published: October 2005

Living bone cells are responsive to mechanical loading. Consequently, numerous in vitro models have been developed to examine the application of loading to cells. However, not all systems are suitable for the fibrous and porous three‐dimensional materials, which are preferable for tissue repair purposes, or for the production of tissue engineering scaffolds. For three‐dimensional applications, mechanical loading of cells with either fluid flow systems or hydrodynamic pressure systems has to be considered. Here, we aimed to evaluate the response of osteoblast‐like cells to hydrodynamic compression, while growing in a three‐dimensional titanium fiber mesh scaffolding material. For this purpose, a custom hydrodynamic compression chamber was built. Bone marrow cells were obtained from the femora of young (12‐day‐old) or old (1‐year‐old) rats, and precultured in the presence of dexamethasone and β‐glycerophosphate to achieve an osteoblast‐like phenotype. Subsequently, cells were seeded onto the titanium mesh scaffolds, and subjected to hydrodynamic pressure, alternating between 0.3 to 5.0 MPa at 1 Hz, at 15‐min intervals for a total of 60 min per day for up to 3 days. After pressurization, cell viability was checked. Afterward, DNA levels, alkaline phosphatase (ALP) activity, and extracellular calcium content were measured. Finally, all specimens were observed with scanning electron microscopy. Cell viability studies showed that the applied pressure was not harmful to the cells. Furthermore, we found that cells were able to detect the compression forces, because we did see evident effects on the cell numbers of the cells derived from old animals. However, there were no other changes in the cells under pressure. Finally, it was also noticeable that cells from old animals did not express ALP activity, but did show similar calcified extracellular matrix formation to the cells from young animals. In conclusion, the difference in DNA levels as reaction toward pressure, and the difference in ALP levels, suggest that the osteogenic properties of bone marrow‐derived osteoblast‐like cells are different with respect to the age of the donor. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Surface‐attached PEO in the form of activated pluronic with immobilized factor H reduces both coagulation and complement activation in a whole‐blood model
Authors: Andersson Jonas , Bexborn Fredrik , Klinth Jeanna , Nilsson Bo , Ekdahl Kristina Nilsson
Published: October 2005

In the present work we have bound Pluronic™, a class of triblock copolymers consisting of a block of polypropylene oxide (PPO) surrounded on each side by polyethylene oxide (PEO) blocks, to polystyrene surfaces and investigated the thrombogenicity and complement activation of this construct upon exposure to whole blood. The surface was highly inert towards coagulation, unfortunately at the expense of increased complement activation. We, therefore, as an alternative approach, used End‐Group Activated Pluronic to conjugate factor H, a regulator of complement activation (RCA), to the surface. The bound factor H did not detach from the surface upon incubation with human serum. Furthermore, factor H bound in a physiological conformation could to a significant degree attenuate complement activation at the Pluronic™ surface. Thus, we have created a hybrid surface in which the coagulation‐inert properties of the original Pluronic™ are supplemented with a specific complement‐inhibitory effect. Medical device technology includes numerous potential applications for crosslinkers that are capable of specifically binding biomolecules to surfaces with retained activity. These applications include coupling of functional biomolecules to biomedical devices such as stents and grafts. The biomolecule may be an RCA, antibody, or other beneficial ligand. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
A promoter element of the CD‐RAP gene is required for repression of gene expression in non‐cartilage tissues in vitro and in vivo
Authors: Okazaki Ken , Yu Hua , Davies Sherri R. , Imamura Toshihiro , Sandell Linda J.
Published: October 2005

The cartilage‐derived retinoic acid‐sensitive protein (CD‐RAP) gene is expressed predominately in cartilage. Previous studies in transgenic mice have shown that the DNA promoter segment from −2,251 bp to −2,068 bp of the CD‐RAP gene contains elements critical for gene expression. Subsequent studies revealed both positive and negative regulatory motifs in this 183 bp element. Here we show that this element demonstrates activation or repression of gene expression in vitro and in vivo based on cell type and content of transcription factors. The distribution of Sox (positive) and C/EBP (negative) transcription factors in cell lines and in mouse tissues is consistent with their positive and negative roles. In transgenic mice, when the 183‐bp element was removed from a 3,345‐bp cartilage‐specific CD‐RAP promoter, expression of the reporter gene became widespread, being observed in muscle, bone, lung, and liver in addition to cartilage. In vitro, mutation of the C/EBP site activated the inactive 3,345‐bp CD‐RAP gene promoter in myoblastic cells, suggesting that this site is responsible for (−2,079 bp) repression. These results indicate that the 183‐bp element plays an important role in cartilage‐specific gene expression by acting as a chondrocyte‐regulatory module repressing transcription in non‐chondrocytes and contributing to activation in chondrocytes. This is the first report of a functional DNA element necessary for repression in non‐cartilage tissues in vivo. J. Cell. Biochem. 97: 857–868, 2006. © 2005 Wiley‐Liss, Inc.
SCN− binding to the charged lysines of histones end domains mimics acetylation and shows the major histone–DNA interactions involved in eu and heterochromatin stabilization
Authors: Patrone Eligio , Coradeghini Rosella , Barboro Paola , D'Arrigo Cristina , Mormino Michele , Parodi Silvio , Balbi Cecilia
Published: October 2005

SCN− binds to the charged amino group of lysines, inducing local changes in the electrostatic free energy of histones. We exploited this property to selectively perturb the histone–DNA interactions involved in the stabilization of eu and heterochromatin. Differential scanning calorimetry (DSC) was used as leading technique in combination with trypsin digestion that selectively cleaves the histone end domains. Euchromatin undergoes progressive destabilization with increasing KSCN concentration from 0 to 0.3 M. Trypsin digestion in the presence of 0.2 M KSCN show that the stability of the linker decreases as a consequence of the competitive binding of SCN− to the amino groups located in the C and N‐terminal domain of H1 and H3, respectively; likewise, the release of the N‐terminal domain of H4 induces an appreciable depression in both the temperature and enthalpy of melting of core particle DNA. Unfolding of heterochromatin requires, in addition to further cleavage of H4, extensive digestion of H2A and H2B, strongly suggesting that these histones stabilize the higher order structure by forming a protein network which extends throughout the heterochromatin domain. J. Cell. Biochem. 97: 869–881, 2006. © 2005 Wiley‐Liss, Inc.
Involvement of CSF‐1 in generating a stroma‐independent hematopoietic stem cell line
Authors: Heberlein Christoph , Friel Jutta , Itoh Katsuhiko , Medlock Eugene , Li Luke , Nakayama Naoki , Stocking Carol , Geldmacher Maren , Ostertag Wolfram
Published: October 2005

The hematopoietic stem cell line, Myl‐D7, is maintained by a self‐renewing stem cell population that spontaneously generates myeloid, lymphoid, and erythroid progeny. MS‐5 stromal cells are necessary for the growth of Myl‐D7 cells. One component of the Myl‐D7 cells proliferation activity released by MS‐5 stromal cells was enriched by Q sepharose fractionation and shown to be colony stimulating factor‐1 (CSF‐1) by Western blotting, BAC1.2F5 cell bioassay and inhibition of Myl‐D7 proliferation by CSF‐1 antibody. The requirement of Myl‐D7 cells for CSF‐1 was also demonstrated independently by selecting for rare, stroma‐independent Myl‐D7 mutant clones able to grow without stroma and additional factors. Eighty‐nine stroma‐independent mutant clones were obtained and belonged to two classes. The majority of mutants did not secrete any growth promoting activity. The second, rarer class of mutants releases a factor that stimulates proliferation/survival for up to several months and approximately half of the secretors express high levels of CSF‐1 mRNA. Wild type Myl‐D7 grown with supernatants from the secretor cells retained the stem cell phenotype. These data suggest that CSF‐1 may act as a key factor in stroma‐regulated hematopoiesis and cell–cell interaction. J. Cell. Physiol. 206: 556–562, 2006. © 2005 Wiley‐Liss, Inc.
Multiple genetic and epigenetic interacting mechanisms contribute to clonally selection of drug‐resistant tumors: Current views and new therapeutic prospective
Authors: Roberti Annalisa , Sala Dario La , Cinti Caterina
Published: October 2005

Successful treatment of cancer requires a clear understanding of drug‐resistance mechanism. Cancer patient are often treated with standard protocols without considering individual difference in chemosensitivity, whereas the efficacy of anticancer drug varies widely among individual patients. Since chemosensitivity involves multiple interacting factors, it is not sufficient to investigate a single gene or factor to fix chemoresistance. Along with affecting disease progression, the synergism between genetic and epigenetic abnormalities can contribute to convert a sensible tumor cell in a resistant one. Unlike genetic changes, epigenetic changes are potentially reversible. Therefore, treatment with DNA methylation inhibitors can reactivate the expression of genes improperly methylated and can reverse many aspect of cancer phenotype such as drug resistance. The demethylating agents are used in the treatment of several kind of tumor, but toxicity and the potential outcome on the normal methylation patterns have always been concern of researchers and clinicals. It is necessary to create individual chemosensitivity–chemoresistance maps in order to identify the combination of drugs for optimized treatments. An overview on genetic and epigenetic events contributing to clonally selection of chemotherapeutic‐resistant tumors is discussed. J. Cell. Physiol. © 2005 Wiley‐Liss, Inc.
Expression of the mechanosensitive 2PK+ channel TREK‐1 in human osteoblasts
Authors: Hughes Steven , Magnay Julia , Foreman Megan , Publicover Stephen J. , Dobson Jon P. , El Haj Alicia J.
Published: October 2005

TREK‐1 is a mechanosensitive member of the two‐pore domain potassium channel family (2PK+) that is also sensitive to lipids, free fatty acids (including arachidonic acid), temperature, intracellular pH, and a range of clinically relevant compounds including volatile anaesthetics. TREK‐1 is known to be expressed at high levels in excitable tissues, such as the nervous system, the heart and smooth muscle, where it is believed to play a prominent role in controlling resting cell membrane potential and electrical excitability. In this report, we use RT‐PCR, Western blotting and immunohistochemistry to confirm that human derived osteoblasts and MG63 cells express TREK‐1 mRNA and protein. In addition, we show gene expression of TREK2c and TRAAK channels. Furthermore, whole cell patch clamp electrophysiology demonstrates that these cells express a spontaneously active, outwardly rectifying potassium “background leak” current that shares many similarities to TREK‐1. The outward current is largely insensitive to TEA and Ba2+, and is sensitive to application of lysophosphatidylcholine (LPC). In addition, blocking TREK‐1 channel activity is shown to upregulate bone cell proliferation. It is concluded that human osteoblasts functionally express TREK‐1 and that these channels contribute, at least in part, to the resting membrane potential of human osteoblast cells. We hypothesise a possible role for TREK‐1 in mechanotransduction, leading to bone remodelling. J. Cell. Physiol. © 2005 Wiley‐Liss, Inc.
Normal and transforming functions of RUNX1: A perspective
Authors: Mikhail Fady M. , Sinha Kislay K. , Saunthararajah Yogen , Nucifora Giuseppina
Published: October 2005

Converging studies from many investigators indicate that RUNX1 has a critical role in the correct maintenance of essential cellular functions during embryonic development and after birth. The discovery that this gene is also frequently mutated in human leukemia has increased the interest in the role that RUNX1 plays in both normal and transforming pathways. Here, we provide an overview of the many roles of RUNX1 in hematopoietic self‐renewal and differentiation and summarize the information that is currently available on the many mechanisms of RUNX1 deregulation in human leukemia. J. Cell. Physiol. © 2005 Wiley‐Liss, Inc.
Nectin‐2 expression in testicular cells is controlled via the functional cooperation between transcription factors of the Sp1, CREB, and AP‐1 families
Authors: Lui Wing‐Yee , Sze Kit‐Ling , Lee Will M.
Published: October 2005

Nectin‐2, a major protein component of the adherens junctions (AJs), is found between Sertoli cells and germ cells in the seminiferous epithelium. Recent studies have shown that the expression of nectin‐2 gene in testis is crucial to maintain normal spermatogenesis since male knockout mice lacking nectin‐2 gene are sterile and possess morphologically abnormal spermatozoa. However, the molecular mechanisms governing its basal transcription remain poorly understood. By the use of Sertoli and germ cell‐lines (TM4 and GC‐2spd(ts) cells, respectively) in transient transfection studies, we showed that the minimal mouse nectin‐2 promoter was located between nucleotides −316 and −211 (relative to the translation start site). Two putative Sp1 motifs and one each of the CRE, AP1, and AP2 motifs were identified within this region. Mutational studies showed that these two Sp1 motifs cooperated synergistically with the CRE motif, but not the AP1 and AP2 motifs, to regulate nectin‐2 gene transcription in both TM4 and GC‐2spd(ts) cells. By EMSAs, we found that an AP‐1 consensus sequence was able to inhibit DNA–protein complex formation with the CRE motif, suggesting an interaction between the AP‐1 transcription factor (c‐Jun) and CREB within the CRE motif. Overexpressions of CREB and c‐Jun, but not c‐Fos, also significantly increased the promoter activity, which suggests that CREB and c‐Jun are the crucial transcription factors involved in regulating nectin‐2 gene transcription. Chromatin immunoprecipitation assay has shown that, in vivo, CREB, c‐Jun, and Sp1 family proteins are bound to the mouse nectin‐2 promoter. Analysis of the staged tubules has confirmed that the cyclic expressions of CREB and nectin‐2 coincide with the event of adherens junction restructuring between Sertoli cells and germ cells. The cross‐talk between CREB, c‐Jun, and Sp1 family protein is believed to be a major transcription machinery to drive nectin‐2 expression in Sertoli cells. J. Cell. Physiol. 207: 144–157, 2006. © 2005 Wiley‐Liss, Inc.
A two‐step supercritical fluid extraction of polycyclic aromatic hydrocarbons from roadside soil samples
Authors: Lojková Lea , Sedláková Jitka , Kubáň Vlastimil
Published: October 2005

A two‐step procedure for the supercritical fluid extraction (SFE) of polycyclic aromatic hydrocarbons from soil samples was developed. The procedure consists of a static supercritical fluid treatment in a closed extraction cell at a high temperature (T = 250 or 340°C for 20 min) and an SFE with a solvent trapping. During the static phase, the sample is exposed to a supercritical organic solvent (methanol, toluene, dichloromethane, ACN, acetone, and hexane). The solvent penetrates particles of the matrix to substitute strongly bonded molecules and dissolves the analytes in the supercritical phase. At ambient temperature, supercritical fluids became liquid and lost their solvation abilities. Most of the analytes condense on the surface of the particles or on the extraction cell walls without forming strong bonds or penetrating deep into the matrix. Thus, the pretreatment liberates the analytes and they behave similar to those in freshly spiked samples. The common SFE with toluene‐modified CO2 as an extraction fluid follows the static phase. With the use of the most suitable extraction phases (toluene, ACN), the extraction efficiency of the combined procedure is much higher (∼︁100%). The results of the combined procedure are compared to the SFE procedure of the same untreated sample (difference less than 5%) and to the Soxhlet extraction. The extracts were analyzed using a GC with the flame ionization detection.
Liquid chromatography of polymers under limiting conditions of adsorption: III. Role of experimental variables
Authors: Šnauko Marián , Berek Dušan
Published: October 2005

LC of polymers under limiting conditions of adsorption (LC LCA) is a novel method based on different mobility of (pore excluded) macromolecules compared to (pore permeating) solvent molecules. Polymer sample is injected in a solvent preventing its adsorption within the column. Eluent promotes sample adsorption. Under these conditions, macromolecules cannot leave its initial solvent and elute from the column independently of their molar mass. In contrast, a less interactive simultaneously injected polymer leaves its initial solvent zone and is eluted in the size exclusion mode. As a result, chemically different polymer species can be discriminated. The effect of selected experimental conditions was studied on the LC LCA behavior of poly(methyl methacrylate)s eluted from bare silica gel columns. The parameters were packing pore diameter, injected sample volume and concentration, as well as column temperature. The size independent elution was only little affected by the above parameters and LC LCA produced well‐focused peaks. The LC LCA mechanism was operative even at a very large sample of both volume and concentration. This makes LC LCA a robust and user‐friendly method, likely suitable also for characterization of minor components of polymer mixtures.
Electrochemical preparation of composite polyaniline coating and its application in the determination of bisphenol A, 4‐n‐nonylphenol, 4‐tert‐octylphenol using direct solid phase microextraction coupled with high performance liquid chromatography
Authors: Huang Minjia , Jiang Guibin , Cai Yaqi
Published: October 2005

For SPME‐HPLC, metal wires with better mechanical strength are preferred over the fused silica fibers. In this article, a novel composite polyaniline (CPANI) doped with PEG and polydimethylsiloxane coating (CPANI fiber) was prepared on a stainless steel wire by a three‐electrode system: the fiber was used as the work electrode, a calomel electrode and a platinum electrode were used as the reference and the counter electrodes, respectively. To evaluate the new CPANI coating, the coating was used to extract three kinds of phenols (bisphenol A, 4‐n‐nonylphenol, and 4‐tert‐octylphenol) in water samples by direct‐SPME mode and then desorbed in commercial SPME‐HPLC interface to separation. The extraction procedure was also optimized. Five real water samples were investigated. Good recoveries were gained when environmental samples were analyzed.
Novel nonaqueous capillary electrophoresis separation and determination of bioactive flavone derivatives in Chinese herbs
Authors: Qi Shengda , Li Yuqin , Wu Shuixian , Chen Xingguo , Hu Zhide
Published: October 2005

Nonaqueous CE (NACE) coupled to UV detection is described for the separation and determination of bioactive flavone derivatives in Chinese herbs extraction. After optimization of electrophoresis parameters, including the electrolyte nature and the organic solvent composition, a reliable separation of the analytes in an ACN/methanol (60 : 40, v/v) mixture containing 80 mM Tris and 10 mM sodium cholate was performed. The detection was performed at 254 nm. Method performances, including migration time and peak area reproducibility, linearity, sensitivity, and accuracy, were evaluated. The method was applied to determine bioactive flavone derivatives in seven Chinese herbs.
Separation and determination of anthraquinones in Cassia obtusifolia (Leguminosae) by micellar electrokinetic capillary electrophoresis
Authors: Jiang Ting‐Fu , Lv Zhi‐Hua , Wang Yuan‐Hong
Published: October 2005

An MEKC method was developed for the determination of the five pharmaceutically important anthraquinones: chrysophanol (1), physcion (2), emodin (3), aloe‐emodinin (4), and rhein (5) in Cassia obtusifolia (Leguminosae). A buffer solution (pH 9.00) composed of 20 mM sodium borate, 20 mM sodium deoxycholate (DOC), and 15% ACN was found to be the most suitable electrolyte for this separation. Regression equations revealed linear relationships (correlation coefficients: 0.9993, 0.9992, 0.9996, 0.9989, and 0.9991) between the peak area of each compound (1, 2, 3, 4, and 5) and its concentration. The RSDs of migration times and peak areas were <1.23 and 2.72% within 1 day, respectively. The effects of pH value, surfactant (DOC) concentration, and organic modifier on the migration were also studied. By this way, the contents of five anthraquinones in the extracts of the seed of C. obtusifolia (Leguminosae) from different sources were successfully determined within 14 min.
Characterization of N‐ and O‐glycopeptides of recombinant human erythropoietins as potential biomarkers for doping analysis by means of microscale sample purification combined with MALDI‐TOF and quadrupole IT/RTOF mass spectrometry
Authors: Stübiger Gerald , Marchetti Martina , Nagano Marietta , Grimm Rudolf , Gmeiner Günter , Reichel Christian , Allmaier Günter
Published: October 2005

See original 2005, vol. 28, issue 14, pp. 1764–1778. DOI 10.1002/jssc.200500148
The influence of some steric and electron effects on the mechanism of aromatic nucleophilic substitution (SNAr) reactions in nonpolar solvent
Authors: Emokpae Thomas A. , Atasie Nkechi V.
Published: October 2005

Kinetic studies are reported for the reactions with aniline in benzene of a series of X‐phenyl 2,4,6‐trinitrophenyl ethers [X = H; 2‐, 3‐, 4‐CH3; 2,4‐, or 2,6‐(CH3)2] a–f, and the results compared with those of the corresponding nitro derivatives. In the methyl series, kinetic data show that increasing substitution reduces drastically the rates of reactions indicative of the operation of some kind of steric effect. The unfavorable steric congestion at the reaction center appears to be unimportant in determining the kinetic order of the reactions. In general, the second‐order rate constants kA depend linearly on the square of nucleophile concentration. The change in the kinetic form observed in the nitro derivatives may be largely due to the electron‐withdrawing effect of the group. With the 2,6‐dinitro derivative, however, the uncatalyzed pathway k2 takes all the reaction flux. Steric hindrance to intermolecular proton transfer from base to the ethereal oxygen of the intermediate is sufficient to make the base‐catalyzed pathway insignificant relative to the k2 pathway. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 744–750, 2005
Kinetics and mechanism of oxidation of iodide with a (μ‐oxo)diiron(III,III) complex in weakly acidic media
Authors: Mukherjee Ritam , Dhar Basab Bijayi , Banerjee Rupendranath
Published: October 2005

The complex ion [FeIII2(μ‐O)(phen)4(H2O)2]4+ (1) (phen = 1,10‐phenanthroline) and its hydrolytic derivatives [FeIII2(μ‐O)(phen)4(H2O)(OH)]3+ (1a) and [FeIII2(μ‐O)(phen)4‐ (OH)2]2+ (2a) coexist in rapid equilibria in the range pH 4.23–5.35 in the presence of excess phenanthroline (pKa1 = 3.71±0.03, pKa2 = 5.28± 0.07). The solution reacts quantitatively with I− to produce [Fe(phen)3]2+ and I2. Only 1 but none of its hydrolytic derivatives is kinetically active. Both inner and outer sphere pathways operate. The observed rate constants show second‐order dependence on the concentration of iodide, while the dependence on [H+] is complex in nature. Added Cl− inhibits the formation of adduct with I− and thus retards the rate of inner sphere path, leading to a rate saturation at high [Cl−], where only the outer sphere mechanism is active. Kinetic data indicate that simultaneous presence of two I− in the vicinity of diiron core is necessary for the reduction of 1. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 737–743, 2005
Quantum yield for hydrogen atom formation from H2O2 photolysis in the range 193–240 nm
Authors: Nakayama Tomoki , Takahashi Kenshi , Matsumi Yutaka
Published: October 2005

Photodissociation processes of H2O2 in the range 193–240 nm have been studied by pulsed laser photolysis and laser‐induced fluorescence detection of H atom fragments at 121.56 nm. The quantum yield values for H atom formation at 295 ± 2 K have been determined to be 0.20 ± 0.03, 0.038 ± 0.008, 0.029 ± 0.003, 0.015 ± 0.006, 0.007 ± 0.002 at 193, 207, 210, 220, and 230 nm, respectively. At 240 nm, only the upper limit value of <0.002 has been obtained. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 751–754, 2005
Gas‐phase reaction of dichlorvos, carbaryl, chlordimeform, and 2,4‐D butyl ester with OH radicals
Authors: Sun F. , Zhu T. , Shang J. , Han L.
Published: October 2005

Widespread use of pesticides has caused serious environmental concern. In order to evaluate the fate of organic pesticides in the atmosphere, rate constants for gas phase reactions of OH radicals with dichlorvos, carbaryl, chlordimeform, and 2,4‐D butyl ester were measured using the relative rate method at ambient temperature and 101 kPa total pressure. On‐line FTIR spectroscopy was used to monitor the concentrations of pesticides as a function of time. The reaction rate constants with OH radicals (in units of cm3 molecule−1 s−1) have been determined as (2.0 ± 0.4) ×  10−11 for dichlorvos, (3.3 ± 0.5) ×  10−11 for carbaryl, (3.0 ± 0.7) ×  10−10 for chlordimeform, and (1.5 ± 0.2) ×  10−11 for 2,4‐D butyl ester. These rate constants agree well with those estimated based on the structure–activity relationship. The group rate constant for NC group (k(NC)) was estimated as 2.7 × 10−10 cm3 molecule−1 s−1. Dimethyl phosphite has been tentatively identified as a product of the reaction of dichlorvos with OH radicals. Atmospheric lifetimes due to the reactions with OH radicals were also estimated (in units of h): 14 ± 3 for dichlorvos, 8 ± 1 for carbaryl, 1.0 ± 0.3 for chlordimeform, and 19 ± 3 for 2,4‐D butyl ester. These short atmospheric lifetimes indicate that the four organic pesticides degrade rapidly in the atmosphere, and they themselves are unlikely to cause persistent pollution. Further studies are needed to identify the potential hazard of their degradation products. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 755–762, 2005
Photophysics and kinetics of naphthopyran derivatives, part 2: Analysis of diarylnaphthopyran kinetics. Degeneracy of the kinetic solution
Authors: Maafi M. , Brown R. G.
Published: October 2005

The photocoloring and fading kinetics of the photochromic 3,3‐diphenyl‐3H‐naphtho[2,1‐b]pyran (NPY) have been analyzed using a kinetic treatment for three related species recently developed by us (Int J Chem Kinet 2005, 37(3), 162). The concepts of identifiability and distinguishability are developed with respect to the elucidation of the NPY kinetics. We find that neither set of kinetic data on its own, nor the two data sets combined, allow the true mechanism to be distinguished. In addition, even for a chosen mechanism, there exist degenerate sets of parameters i.e. the solutions are also unidentifiable. A discussion of the limits and uniqueness of the results' interpretation is presented. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 717–727, 2005
Cover Picture: Macromol. Chem. Phys. 21/2005
Authors: Jin Ren‐Hua , Yuan Jian‐Jun
Published: October 2005

Cover: The figure shows silicas with tunable micrometer‐scale shapes and hierarchical structures. They can be obtained through facile adjustment of media compositions in which poly(ethyleneimine)s pre‐organize. All the silicas deposited instantly at ambient conditions without extra catalyst. Further details can be found in the Full Paper by R.‐H. Jin* and J.‐J. Yuan on page 2160.
Cover Picture: Macromol. Rapid Commun. 21/2005
Authors: Khelfallah Nawel , Gunari Nikhil , Fischer Karl , Gkogkas Giorgos , Hadjichristidis Nikos , Schmidt Manfred
Published: October 2005

Cover: The AFM picture shows a micelle formed in water by seven “cylindrical brush”‐coil blockcopolymers. The core consists of the hydrophobic polystyrene coils which are surrounded by the corona of water‐soluble cylindrical brush blocks with polyacrylic acid side chains. Further details can be found in the Communication by N. Khelfallah, N. Gunari, K. Fischer, G. Gkogkas, N. Hadjichristidis, and M. Schmidt* on page 1693.
Action fluency in Parkinson's disease: A follow‐up study
Authors: Signorini Matteo , Volpato Chiara
Published: October 2005

The impairment in action fluency task present in Parkinson's disease (PD) patients has been previously interpreted as an indicator of conversion from PD to PD with dementia or as a grammatical deficit for verbs and ascribed to a frontostriatal loop pathophysiology. In the present study, 20 patients with PD without dementia were longitudinally tested with overall cognitive decline scales and semantic, letter, and action fluency tasks in a 24‐month follow‐up study. In comparison with healthy age‐matched controls, PD patients showed a stable and consistent impairment on action fluency without any sign of cognitive decline. Our findings suggest that action fluency task may be an early sign of impairment of frontostriatal circuits in PD and it cannot be considered an indicator of conversion from PD to PD with dementia. © 2005 Movement Disorder Society
Movement disorders fellowship training program at Columbia University Medical Center in 2001–2002
Authors: Portera‐Cailliau Carlos , Victor Daryl , Frucht Steven , Fahn Stanley
Published: October 2005

Data regarding the clinical experience of movement disorders subspecialty training are currently not available. In order to provide information to help design a well‐rounded clinical experience, we reviewed the number and types of patients seen by all clinical movement disorders fellows over the course of 1 year at Columbia University Medical Center (CUMC). We conducted a retrospective analysis of all patients seen by four full‐time clinical fellows and one part‐time fellow during the 2001–2002 academic year, using billing records to tabulate all clinic visits and patient charts to certify diagnosis. One thousand six hundred sixty‐two patients (1,132 new and 530 follow‐ups) were seen by five fellows. Each full‐time fellow evaluated and treated a mean of 263 new patients, 116 follow‐up patients, and 15 in‐patient consultations. The part‐time clinical fellow evaluated and treated 81 new patients and 65 follow‐up patients. Approximately half of the new patients had idiopathic Parkinson's disease. Full‐time fellows saw equivalent numbers of patients but they evaluated few patients with uncommon movement disorders. Weekly video rounds allowed all fellows to see many more patients, aiding the recognition of movement phenomenology and enhancing understanding of diagnoses and treatment strategies. Thus, CUMC fellows evaluate a large number of patients with a wide range of diagnoses within a 1‐year period. Video rounds allow greater exposure to uncommon diagnoses. Similar data from other movement disorder training programs are needed to help create guidelines for formal accreditation and to improve clinical training in this subspecialty. © 2005 Movement Disorder Society
Acute reversible parkinsonism in Epstein–Bbarr virus–related encephalitis lethargica‐like illness
Authors: Dimova Petia S. , Bojinova Veneta , Georgiev Dimitar , Milanov Ivan
Published: October 2005

A 10‐year‐old boy presented with fever, headache, vomiting, and hypersomnolence. An akinetic–rigid syndrome with tremor, dysphagia, dysphonia, and sialorrhea, as well as pyramidal signs, developed. Slightly elevated protein content was found in the cerebrospinal fluid and serological investigations were suggestive of a primary Epstein–Barr virus infection. Magnetic resonance imaging (MRI) showed massive bilateral hyperintense striatal and punctiform periventricular lesions. After 2‐month treatment with steroids and antiparkinsonian drugs, all features resolved without sequelae. Control MRI demonstrated only minimal residual lesions in both putamina. Strongly resembling the encephalitis lethargica‐like syndrome, this case is an unusual presentation of parainfectious acute disseminated encephalitis. © 2005 Movement Disorder Society
Corticomuscular coherence is increased in the small postural tremor of Parkinson's disease
Authors: Caviness John N. , Shill Holly A. , Sabbagh Marwan N. , Evidente Virgilio G.H. , Hernandez Jose L. , Adler Charles H.
Published: October 2005

The mechanisms and electrophysiological characteristics of the postural tremor in Parkinson's disease (PD) have not been defined. We hypothesized that PD subjects with small amplitude postural tremor would show increased corticomuscular coherence at certain frequencies compared to PD subjects without visible tremor. Four groups of participants were studied: (1) Control without postural tremor, (2) Control with small amplitude postural tremor, (3) PD without postural tremor, and (4) PD with small amplitude postural tremor. Accelerometry and electroencephalography–electromyography fast‐fourier transform and corticomuscular coherence spectra were generated. Findings showed (1) elevated corticomuscular coherence centered at 12–18 Hz in PD with small amplitude postural tremor; (2) 5–12 Hz accelerometer frequency peaks that did not shift with increasing weight loads in some individuals; and (3) 5–8 Hz accelerometer peaks that shifted frequency with increasing weight loads, consistent with a peripheral‐mechanical oscillator in all groups. The small amplitude postural tremor in PD arises from heterogeneous oscillator mechanisms. The discovery of increased corticomuscular coupling shows cortical involvement in the small amplitude postural tremor of PD. © 2005 Movement Disorder Society
Association between restless legs syndrome and essential tremor
Authors: Ondo William G. , Lai Dejian
Published: October 2005

After observing that several families with essential tremor (ET) clinically cosegregated with restless legs syndrome (RLS), we prospectively evaluated for the presence of RLS in 100 patients presenting to the Baylor College of Medicine with ET and prospectively examined all patients presenting with RLS for the presence of tremor during the same time frame. Of 100 consecutive ET patients (60 women and 75 with a family history of ET) seen over 19 weeks (current age, 65.2 ± 16.3 years; age at tremor onset, 37.8 ± 19.9 years) 33 met all criteria for RLS, of which 25 had never been diagnosed previously. A family history of RLS was reported in 57.6% of these 33 patients and was the only significant predictor of RLS in the ET population. Their International Restless Legs Syndrome Rating Scale score was 16.6 ± 8.1. Over 19 weeks, we also examined 68 consecutive RLS patients (63.2% women and 54.4% with a family history of RLS) for the presence of tremor. Their current age was 55.8 ± 14.4 years, and age at RLS onset was 33.7 ± 19.5 years. Overtly pathological tremor was rare, but trace tremor was very common. Overall, we found a very high rate of undiagnosed RLS in patients presenting for tremor, but unlike other “secondary” forms of RLS, this finding was also associated with a high familial history of RLS, suggesting that they share some genetic similarities. © 2005 Movement Disorder Society