bluuebunny/crossref_metadata_2025 huggingface dataset:
Plectin scaffolds recruit energy-controlling AMP-activated protein kinase (AMPK) in differentiated myofibres
Authors: Gregor Martin , Zeöld Aniko , Oehler Susanne , Marobela Kerstin Andrä , Fuchs Peter , Weigel Günter , Hardie D. Graham , Wiche Gerhard
Published: April 2006

Plectin, a cytolinker protein greater than 500 kDa in size, has an important role as a mechanical stabiliser of cells. It interlinks the various cytoskeletal filament systems and anchors intermediate filaments to peripheral junctional complexes. In addition, there is increasing evidence that plectin acts as a scaffolding platform that controls the spatial and temporal localisation and interaction of signaling proteins. In this study we show that, in differentiated mouse myotubes, plectin binds to the regulatory γ1 subunit of AMP-activated protein kinase (AMPK), the key regulatory enzyme of energy homeostasis. No interaction was observed in undifferentiated myoblasts, and plectin-deficient myotubes showed altered positioning of γ1-AMPK. In addition we found that plectin affects the subunit composition of AMPK, because isoform α1 of the catalytic subunit decreased in proportion to isoform α2 during in vitro differentiation of plectin-/- myotubes. In plectin-deficient myocytes we could also detect a higher level of activated (Thr172-phosphorylated) AMPK, compared with wild-type cells. Our data suggest a differentiation-dependent association of plectin with AMPK, where plectin selectively stabilises α1-γ1 AMPK complexes by binding to the γ1 regulatory subunit. The distinct plectin expression patterns in different fibre types combined with its involvement in the regulation of isoform compositions of AMPK complexes could provide a mechanism whereby cytoarchitecture influences energy homeostasis.
Caveolin-1 controls cell proliferation and cell death by suppressing expression of the inhibitor of apoptosis protein survivin
Authors: Torres Vicente A. , Tapia Julio C. , Rodríguez Diego A. , Párraga Mario , Lisboa Pamela , Montoya Margarita , Leyton Lisette , Quest Andrew F. G.
Published: April 2006

Caveolin-1 is suggested to act as a tumor suppressor. We tested the hypothesis that caveolin-1 does so by repression of survivin, an Inhibitor of apoptosis protein that regulates cell-cycle progression as well as apoptosis and is commonly overexpressed in human cancers. Ectopic expression of caveolin-1 in HEK293T and ZR75 cells or siRNA-mediated silencing of caveolin-1 in NIH3T3 cells caused downregulation or upregulation of survivin mRNA and protein, respectively. Survivin downregulation in HEK293T cells was paralleled by reduced cell proliferation, increases in G0-G1 and decreases in G2-M phase of the cell cycle. In addition, apoptosis was evident, as judged by several criteria. Importantly, expression of green fluorescent protein-survivin in caveolin-1-transfected HEK293T cells restored cell proliferation and viability. In addition, expression of caveolin-1 inhibited transcriptional activity of a survivin promoter construct in a β-catenin-Tcf/Lef-dependent manner. Furthermore, in HEK293T cells caveolin-1 associated with β-catenin and inhibited Tcf/Lef-dependent transcription. Similar results were obtained upon caveolin-1 expression in DLD1 cells, where APC mutation leads to constitutive activation of β-catenin-Tcf/Lef-mediated transcription of survivin. Taken together, these results suggest that anti-proliferative and pro-apoptotic properties of caveolin-1 may be attributed to reduced survivin expression via a mechanism involving diminished β-catenin-Tcf/Lef-dependent transcription.
NIMA-related kinaseTbNRKC is involved in basal body separation inTrypanosoma brucei
Authors: Pradel Lydie C. , Bonhivers Mélanie , Landrein Nicolas , Robinson Derrick R.
Published: April 2006

The NIMA-related kinase 2 (NEK 2) has important cell cycle functions related to centriole integrity and splitting. Trypanosoma brucei does not possess centrioles, however, cytokinesis is coupled to basal body separation events. Here we report the first functional characterisation of a T. brucei basal body-cytoskeletal NIMA-related kinase (NRK) protein, TbNRKC. The TbNRKC kinase domain has high amino acid identity with the human NEK1 kinase domain (50%) but also shares 42% identity with human NEK2. TbNRKC is expressed in bloodstream and procyclic cells and functions as a bona fide kinase in vitro. Remarkably, RNAi knockdown of TbNRKC and overexpression of kinase-dead TbNRKC in procyclic forms induces the accumulation of cells with four basal bodies, whereas overexpression of active protein produces supernumary basal bodies and blocks cytokinesis. TbNRKC is located on mature and immature basal bodies and is the first T. brucei NRK to be found associated with the basal body cytokinesis pathway.
Phosphorylation of paracellin-1 at Ser217 by protein kinase A is essential for localization in tight junctions
Authors: Ikari Akira , Matsumoto Satomi , Harada Hitoshi , Takagi Kuniaki , Hayashi Hisayoshi , Suzuki Yuichi , Degawa Masakuni , Miwa Masao
Published: April 2006

Although paracellin-1 (PCLN-1) is known to have a crucial role in the control of Mg2+ reabsorption in the kidney, the molecular pathways involved in the regulation of PCLN-1 have not been clarified. We used FLAG-tagged PCLN-1 to investigate these pathways further, and found that PCLN-1 is phosphorylated at Ser217 by protein kinase A (PKA) under physiological conditions in Madin-Darby canine kidney (MDCK) cells. PCLN-1 expression decreased Na+ permeability, resulting in a decrease in the transepithelial electrical resistance (TER). By contrast, PCLN-1 enhanced transepithelial Mg2+ transport. PKA inhibitors, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride (H-89) and myristoylated protein kinase A inhibitor 14-22 amide PKI, and an adenylate cyclase inhibitor, 2′,5′-dideoxy adenosine (DDA), reduced the phosphoserine level of PCLN-1. The inhibitory effect of DDA was rescued by 8-bromoadenosine-3′,5′-cyclic monophosphate (8-Br-cAMP). PKA and adenylate cyclase inhibitors decreased transepithelial Mg2+ transport and TER. Dephosphorylated PCLN-1 moved from detergent-insoluble to soluble fractions and was dissociated from ZO-1. A fusion protein of PCLN-1 with glutathione-S-transferase revealed that Ser217 was phosphorylated by PKA. Phosphorylated PCLN-1 was localized in the tight junction (TJ) along with ZO-1, whereas dephosphorylated PCLN-1 and the S217A mutant were translocated into the lysosome. The degradation of dephosphorylated PCLN-1 and S217A mutant was inhibited by chloroquine, a specific lysosome inhibitor. Thus, the PKA-dependent phosphorylation of Ser217 in PCLN-1 is essential for its localization in the TJ and transepithelial Mg2+ transport.
The inhibitor-of-apoptosis protein Bir1p protects against apoptosis in S. cerevisiae and is a substrate for the yeast homologue of Omi/HtrA2
Authors: Walter David , Wissing Silke , Madeo Frank , Fahrenkrog Birthe
Published: April 2006

Inhibitor-of-apoptosis proteins (IAPs) play a crucial role in the regulation of metazoan apoptosis. IAPs are typically characterized by the presence of one to three baculovirus IAP repeat (BIR) domains that are essential for their anti-apoptotic activity. Bir1p is the sole BIR-protein in yeast and has been shown to participate in chromosome segregation events. Here, we show that Bir1p is a substrate for Nma111p, which is the homologue of the human pro-apoptotic serine protease Omi/HtrA2 and which is known to mediate apoptosis in yeast. Bir1p is a cytoplasmic and nuclear protein, and yeast cells lacking bir1 are more sensitive to apoptosis induced by oxidative stress. Consistently, overexpression of Bir1p reduces apoptosis-like cell death, whereas this protective effect can be antagonized in vivo by simultaneous overexpression of Nma111p. Moreover, chronologically aged cells that constitutively overexpress Bir1p show a delayed onset of cell death. Therefore, Bir1p, like its closest metazoan homologues deterin and survivin, has dual functions: it participates in chromosome segregation events and cytokinesis and exhibits anti-apoptotic activity.
Dynamic microtubules regulate the local concentration of E-cadherin at cell-cell contacts
Authors: Stehbens Samantha J. , Paterson Andrew D. , Crampton Matthew S. , Shewan Annette M. , Ferguson Charles , Akhmanova Anna , Parton Robert G. , Yap Alpha S.
Published: April 2006

In contrast to the well-established relationship between cadherins and the actin cytoskeleton, the potential link between cadherins and microtubules (MTs) has been less extensively investigated. We now identify a pool of MTs that extend radially into cell-cell contacts and are inhibited by manoeuvres that block the dynamic activity of MT plus-ends (e.g. in the presence of low concentrations of nocodazole and following expression of a CLIP-170 mutant). Blocking dynamic MTs perturbed the ability of cells to concentrate and accumulate E-cadherin at cell-cell contacts, as assessed both by quantitative immunofluorescence microscopy and fluorescence recovery after photobleaching (FRAP) analysis, but did not affect either transport of E-cadherin to the plasma membrane or the amount of E-cadherin expressed at the cell surface. This indicated that dynamic MTs allow cells to concentrate E-cadherin at cell-cell contacts by regulating the regional distribution of E-cadherin once it reaches the cell surface. Importantly, dynamic MTs were necessary for myosin II to accumulate and be activated at cadherin adhesive contacts, a mechanism that supports the focal accumulation of E-cadherin. We propose that this population of MTs represents a novel form of cadherin-MT cooperation, where cadherin adhesions recruit dynamic MTs that, in turn, support the local concentration of cadherin molecules by regulating myosin II activity at cell-cell contacts.
Lumenal protein sorting to the constitutive secretory pathway of a regulated secretory cell
Authors: Lara-Lemus Roberto , Liu Ming , Turner Mark D. , Scherer Philipp , Stenbeck Gudrun , Iyengar Puneeth , Arvan Peter
Published: April 2006

Newly synthesized secretory granule content proteins are delivered via the Golgi complex for storage within mature granules, whereas constitutive secretory proteins are not stored. Most soluble proteins traveling anterograde through the trans-Golgi network are not excluded from entering immature secretory granules, whether or not they have granule-targeting signals. However, the `sorting-for-entry' hypothesis suggests that soluble lumenal proteins lacking signals enter transport intermediates for the constitutive secretory pathway. We aimed to investigate how these constitutive secretory proteins are sorted. In a pancreatic β-cell line, we stably expressed two lumenal proteins whose normal sorting information has been deleted: alkaline phosphatase, truncated to eliminate its glycosylphosphatidylinositol membrane anchor (SEAP); and Cab45361, a Golgi lumenal resident, truncated to eliminate its intracellular retention (Cab308Myc). Both truncated proteins are efficiently secreted, but whereas SEAP enters secretory granules, Cab308Myc behaves as a true constitutive marker excluded from granules. Interestingly, upon permeabilization of organelle membranes with saponin, SEAP is extracted as a soluble protein whereas Cab308Myc remains associated with the membrane. These are among the first data to support a model in which association with the lumenal aspect of Golgi and/or post-Golgi membranes can serve as a means for selective sorting of constitutive secretory proteins.
Pax7 and myogenic progression in skeletal muscle satellite cells
Authors: Zammit Peter S. , Relaix Frederic , Nagata Yosuke , Ruiz Ana Pérez , Collins Charlotte A. , Partridge Terence A. , Beauchamp Jonathan R.
Published: April 2006

Skeletal muscle growth and regeneration are attributed to satellite cells - muscle stem cells resident beneath the basal lamina that surrounds each myofibre. Quiescent satellite cells express the transcription factor Pax7 and when activated, coexpress Pax7 with MyoD. Most then proliferate, downregulate Pax7 and differentiate. By contrast, others maintain Pax7 but lose MyoD and return to a state resembling quiescence. Here we show that Pax7 is able to drive transcription in quiescent and activated satellite cells, and continues to do so in those cells that subsequently cease proliferation and withdraw from immediate differentiation. We found that constitutive expression of Pax7 in satellite-cell-derived myoblasts did not affect MyoD expression or proliferation. Although maintained expression of Pax7 delayed the onset of myogenin expression it did not prevent, and was compatible with, myogenic differentiation. Constitutive Pax7 expression in a Pax7-null C2C12 subclone increased the proportion of cells expressing MyoD, showing that Pax7 can act genetically upstream of MyoD. However these Pax7-null cells were unable to differentiate into normal myotubes in the presence of Pax7. Therefore Pax7 may be involved in maintaining proliferation and preventing precocious differentiation, but does not promote quiescence.
Photoinduced Cleavage of the C–C Bonds of 9-Alkyl-10-methyl-9,10-dihydroacridines by Perchloric Acid
Authors: Fukuzumi Shunichi , Tokuda Yoshihiro , Fujita Morifumi
Published: April 2006

The C–C single bonds of 9-alkyl-10-methyl-9,10-dihydroacridines [AcrHR: R = 1-naphthylmethyl, diphenylmethyl, and AcrH (dimer)] are readily cleaved by perchloric acid in acetonitrile under irradiation of the absorption band of AcrHR to yield the corresponding alkane (RH) and 10-methylacridinium ion (AcrH+).
Autocatalytic Reduction of Nitric Acid by an Acid-Stable NADH Analogue
Authors: Fukuzumi Shunichi , Yorisue Tomohiro
Published: April 2006

The reduction of nitric acid to nitrous acid by an acid-stable NADH analogue proceeds autocatalytically in the presence of perchloric acid in acetonitrile via novel chain reactions where the reduction of one nitrous acid in the presence of nitric acid eventually results in the formation of two nitrous acid.
New Oxidative Aromatization of α,β-Unsaturated Cyclohexenones with Iodine–Cerium(IV) Ammonium Nitrate in Alcohol
Authors: Horiuchi C Akira , Fukunishi Hirotada , Kajita Mika , Yamaguchi Akihisa , Kiyomiya Hiroshi , Kiji Shinji
Published: April 2006

The reaction of 2-cyclohexen-1-one derivatives with iodine–cerium(IV) ammonium nitrate in alcohols (methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol) under refluxing, gave the corresponding alkyl phenyl ethers in good yields. In the case of diol (ethylene glycol, 1,3-propanediol, and 1,4-butanediol), phenoxyalkanol derivatives were obtained. The present method was also applicable to oxidative rearrangement of isophorone.
Atomic Force Microscopic Study of Vesicles of Synthetic Surfactant, Vesicles of Thylakoid Membrane, and Whole Cells of Bacteria
Authors: Azumi Reiko , Matsumoto Mutsuyoshi , Kawabata Yasujiro , Ichimura Toshiaki , Mizuno Takafumi , Miyamoto Hiroshi
Published: April 2006

Surface images of vesicles of synthetic surfactant, vesicles of thylakoid membrane isolated from thermophilic cyanobacteria, and whole cells of bacteria, E. coli were obtained using atomic force microscopy (AFM). The AFM proved itself to be useful in direct observations for molecular assemblies of biological interest.
Synthesis and Characterization of a Novel Dimer of Di(μ-oxo)manganese Dimers with Two Coordinated Water Molecules in (III,IV,III,IV) Oxidation State
Authors: Suzuki Masatatsu , Hayashi Yoshihito , Munezawa Kazutoshi , Suenaga Machiko , Senda Hitoshi , Uehara Akira
Published: April 2006

A dimer of di(μ-oxo)dimanganese(III,IV) dimers with two coordinated water molecules, [{Mn2(tmdp)(O)2(H2O)}2] (CF3SO3)4·6H2O, was prepared, where Htmdp is 1,5-bis[bis(2-pyridylmethyl)amino]-3-pentanol, and its crystal structure was determined by X-ray structure analysis. The complex cation consists of two di(μ-oxo)Mn2(III,IV) dimers which are linked by two tmdps to form a dimer of dimers with a bilayered structure.
Ethyl Cyanoformate/Hydrogen Peroxide and Related Combination Systems, Novel Epoxidizing Systems of Olefins
Authors: Masaki Yukio , Miura Tsuyoshi , Mukai Isao , Itoh Akichika , Oda Hirohisa
Published: April 2006

A combination system of ethyl cyanoformate and hydrogen peroxide was found to epoxidize olefins in a stereospecific manner at room temperature. Asymmetric epoxidation was observed with menthyl cyanoformate/hydrogen peroxide system.
Structure and Electrical Properties of θ- and κ-Type BEDT-TSeF Salts with Bromomercurate Anions
Authors: Naito Toshio , Miyamoto Akihito , Kobayashi Hayao , Kato Reizo , Kobayashi Akiko
Published: April 2006

Four types of the crystals of BEDT-TSeF (“BETS”) salts with bromomercurate anions were synthesized electrochemically. The salts with θ- and κ-type molecular arrangements retain high conductivity down to 4 K.
Dimethylgold(III) Aryloxides and Alkoxides Having a Triphenylphosphine Ligand
Authors: Sone Takuo , Iwata Minor , Kasuga Noriko , Komiya Sanshiro
Published: April 2006

Cis-dimethyl(aryloxo or alkoxo)(triphenylphosphine)gold(III), cis-AuMe2(OR)(PPh3) (R = Ph, tol, CH2CF3, CH(CF3)2) were isolated by the reaction of cis-AuMe2[(PPh3) with corresponding potassium aryloxides or alkoxides. Nucleophilic phenoxogold(III) smoothly traps phenol by hydrogen bond and can abstract a proton from methyl cyanoacetate, malononitrile and phenyl acetylene to give corresponding cis-dimethyl(organo)(triphenylphosphine)gold(III) complexes, cis-AuMe2(R′)(PPh3).
Useful Syntheses of (3S)-2,3,4,5-Tetrahydropyridazine-3-carboxylic Acid and Its Dehydrotetrapeptide Derivatives
Authors: Nakamura Yutaka , Shin Chung-gi
Published: April 2006

The stereoselective synthesis of (3S)-2,3,4,5-tetrahydropyridazine-3-carboxylic acid (Pya), which is a cyclic α-amino acid at center of antrimycins (1), was successful. Moreover, the synthesis of the C-terminal dehydrotetrapeptide of 1 containing Pya residue at N-terminus is described.
Phenylselenoazidation of Conjugated Enals. Allylic Rearrangement of 2-Alkylidene-3-azidopropanals and Propionic Acids
Authors: Huot Jean-François , Outurquin Francis , Paulmier Claude
Published: April 2006

β-Azido α-phenylseleno aldehydes were isolated as adducts of PhSeN3 on conjugated enals bearing an α-alkyl substituent. Their oxidation leads to 2-alkylidene-3-azido propanals and propionic acids. An allylic rearrangement of the azido group was observed.
Asymmetric Aggregative Activation. A New Useful Concept for Asymmetric Reduction
Authors: Lalloz Lucien , Vanderesse Régis , Mayesky Bertrand , Caubere Paul
Published: April 2006

Reduction of arylketones with a Complex Reducing Agent containing 2 equivalents of Zn° and 4 equivalents of sodium chiraldate in a mixture of THF and methylcyclohexane for 1 equivalent of arylketone took place with a chiral induction from 56 to 89% of enantiomeric excess.
Reactions of Aryliminodimagnesium with Some N,N-Dimethylcarboxamides and Benzonitriles Affording Various Types of Amidines. Correction of Previous Results on Formamidine Formation from N,N-Dimethylformamide
Authors: Okubo Masao , Tanaka Mikio , Murata Yuri , Tsurusaki Nobuyuki , Omote Yasumasa , Ikubo Yukinobu , Matsuo Koji
Published: April 2006

Some symmetrical and unsymmetrical form- and benzamidines were prepared by the reaction of ArN(MgBr)2 with Ar’CN, HCONMe2 and related compounds in tetrahydrofurn.
Thermal Properties and Ferroelectric Like Behavior of Liquid-Crystalline Ionic Polyethylenimine Derivative
Authors: Ujiie Seiji , Iimura Kazuyoshi
Published: April 2006

Liquid-crystalline ionic polyethylenimine derivatives have been synthesized, and their thermal properties and dielectric behavior have been studied. They exhibited thermotropic smectic phases. The ferroelectric like behavior was confirmed by dielectric measurement and observation of the hysteresis loop with the Sawyer-Tower circuit.
Synthesis and Physical Properties of 6,8-Bis(phenylthio)-7H-benzocycloheptene-1,4,7-trione. A Novel D-s-A-s-D Molecular Unit Directed toward Organic Conductors
Authors: Kato Masahiko , Amatatsu Yoshimasa , Tada Hitoshi , Tanaka Shigeru , Furuichi Kimiaki , Hashimoto Masao , Matsumoto Shuji
Published: April 2006

The title compound was prepared via a route involving dehydrogenative phenylsulfidation. The NMR and electronic spectra and reduction potential were discussed in comparisons with those of the unsubstituted and monosubstituted analogs. The structure was examined by X-ray crystallography.
Evidences for Bromo-Bridged One-Dimensional Chain Structure of the Mixed-Valence Gold Complexes with the Empirical Formulas, [AuBr2(DBS)] and [AuBrCl(DBS)] (DBS = dibenzyl sulfide)
Authors: Takahashi Kazuhiro , Tanino Hiroshi
Published: April 2006

The bromo-bridged one-dimensional chain structure of [AuBr2(DBS)] is revealed by X-ray analysis. The bromo-bridged skeleton of the one-dimensional chain of [AuBrCl(DBS)] is identified by comparing its unit cell parameters, visible absorption spectrum on nujol mull, and Br K near-edge X-ray absorption spectra with those of [AuBr2(DBS)].
Preparation and Characterization of New Misfit Layer Selenides SnVSe3 and SnNb2 Se5
Authors: Hernan Lourdes , Morales Julián , Pattanayak Jayasree , Tirado José L
Published: April 2006

New “SnVSe3” and “SnNb2Se5” phases have been synthesized from the corresponding elements. The structure of these compounds may be described as a mixed sandwiched layered type where one [SnSe] slab alternates with one [VSe2] slab for SnVSe3 and with two [NbSe2] slabs for SnNb2Se5.
The Formation of Ground-State Nonfluorescent Complex between Chlorophyll a and Methylviologen in Methanol Solution
Authors: Kusumoto Yoshihumi , Uchikoba Michiko
Published: April 2006

An enhanced quenching of fluorescence of chlorophyll a by methylviologen in methanol solution was found to proceed via both dynamic and static processes. It was shown that the formation of a ground-state “dark” complex between the reactants is responsible for the latter process.
Utility of Acyloxypyridines and Acylazoles for the Lipasecatalyzed Enantioselective Acylation of 1-Phenylethanol
Authors: Keumi Takashi , Hiraoka Yasumasa , Ban Takashi , Takahashi Ichiro , Kitajima Hidehiko
Published: April 2006

3-Acyloxypyridines and 4-acetyl-1,2,4-triazole were found to react enantioselectively with (RS)-1-phenylethanol to give (R)-1-phenethyl carboxylates in high purity, catalyzed by lipase P (from Pseudomonas fluorescens).
Palladium(0)-Catalyzed Carbonylation of 1-Alkyl-2-trialkylsilyl-2-propenyl Carbonates
Authors: Wang Shu-Zhong , Yamamoto Keiji
Published: April 2006

Pd(0)-catalyzed carbonylation of methyl 1-alkyl-2-trialkylsilyl-2-propenyl carbonates required forcing conditions [CO (60 atm), 70 °C] to give respective methyl (E)-3-trialkylsilyl-3-alkenoate as a major product along with the (Z)-isomer as well as an unusual regioisomeric product, methyl 2-alkyl-3-trialkylsilyl-3-butenoate to various extent.
Regio- and Stereo-Selective [2π + 2π] Photocycloaddition of Electron-Deficient Alkenes to Naphthalene Ring Bearing Si- and Ge-Containing Substituents
Authors: Mizuno Kazuhiko , Nakanishi Kazuhisa , Yasueda Masahiro , Miyata Hideki , Otsuji Yoshio
Published: April 2006

Irradiation of benzene solutions of 1- and 2-naphthylmethyltrimethylsilanes or their germane and disilane analogues in the presence of electron deficient alkenes afforded [2π + 2π] photocycloadducts with high regio- and stereo-selectivities.
Electroreductive Acylation of Benzyl Chlorides with Acid Anhydrides. Stereoselective Formation of (E)-Enol Esters from Benzyl Alkyl Ketones
Authors: Nishiguchi Ikuzo , Oki Tsuneo , Hirashima Tsuneaki , Shiokawa Jiro
Published: April 2006

Electroreduction of benzyl chlorides in the presence of acid anhydrides brought about stereoselective formation of (E)-enol esters of the corresponding benzyl alkyl ketones, the initial acylated products, in good to moderate yields.
Selective Isomerization of Glycidates and Their Analogues with Triphenylsilyl Perchlorate or Electrogenerated Acid
Authors: Inokuchi Tsutomu , Kusumoto Masahiko , Matsumoto Sigeaki , Okada Hiroyuki , Torii Sigeru
Published: April 2006

Isomerization of glycidic esters and nitriles to the corresponding 2-hydroxy-3-alkenoates and their nitrile derivatives occurred on treatment with triphenylsilyl perchlorate or electrogenerated acid (EG acid). The cyanohydrin moiety of the nitriles 4 was transformed to a formyl group, giving the corresponding enals on treatment with weak base.
Model Compounds for Purple Lipoxygenase
Authors: Nishida Yuzo , Akamatsu Tetsuya
Published: April 2006

We have found that some iron(III) compounds with tripodal-like ligands react with t-butyl hydroperoxide to yield a purple species, whose spectroscopic properties are very similar to those observed for the purple lipoxygenase. Based on these facts the origin of the purple color in the native enzyme was discussed.
Nickel(0)-Catalyzed Reduction of Aryl Triflates with Zinc Powder and Methanol
Authors: Sasaki Ken , Sakai Mutsuji , Sakakibara Yasumasa , Takagi Kentaro
Published: April 2006

Deoxygenative reduction of aryl Inflates was attained by using nickel(0)-dppp/PPh3 catalyst with zinc powder and methanol as a hydrogen donor.
Rapid Unidentate–Chelate Equilibrium of Acetate Ligands on the Ruthenium-Analog of the Hemerythrin Active Center and the Crystal Structure of [Ru2(μ-O)(μ-CH3COO)2(CH3COO)2(H2O)(CH3OH)(P(C6H5)3)2]·H2O Having Unidentate Acetates
Authors: Ochi Takashi , Sasaki Yoichi , Yamaguchi Tadashi , Ito Tasuku
Published: April 2006

[Ru2(O)(CH3COO)4(H2O)(CH3OH)(PPh3)2], has an Ru2(μ-O)(μ-CH3COO)2 core and unidentate acetates with H2O and CH3OH coordinated to the trans positions to the oxide bridge as determined by the X-ray structural analysis. This is in contrast to the recent report of the chelatiftg acetate on the similarlly prepared complex. 1H NMR spectra in CDCl3 revealed that the complex undergoes rapid unidentate-chelate equilibrium of acetates between the bis(chelate) and mono(chelate)mono(unidentate) forms.
NiCl2(PPh3)2–Zn Promoted Deallyloxycarbonylative Directed Aldo Reaction of Allyl β-Keto Carboxylates with Aldehydes to β-Hydroxy Ketones
Authors: Nokami Junzo , Konishi Haruhisa , Matsuura Hiroyuki
Published: April 2006

Regie- and chemospecific deallyloxycarbonylative aldol reaction of allyl(or -lie) α,α-disubstituted β-keto carboxylate with aldehyde was effectively promoted by Ni0 (NiCl2(PPh3)2–Zn), in which the allyloxycarbonyl group (–COOCH2CH=CH2) was replaced to 1-hydroxyalkyl group(–CH(OH)R, R = alkyl, vinyl, aryl) under mild reaction conditions.
New Metallochromic and Fluorescence Compounds Obtained from the Reaction of 5,8-Quinolinedione with 2-[3-(Dimethylamino)phenyl]propene
Authors: Yoshida Katsuhira , Miyatake Osamu , Okamoto Juri , Tokuda Hiroaki , Kubo Yuji
Published: April 2006

The reaction of 5,8-quinolinedione with 2-[3-(dimethylamino)phenyl]propene was initiated by HC1 to give 6-[4-(dimethylamino)-2-(2-propenyl)phenyl]quinoline-5,8-dione, which subsequently underwent intramolecular cyclization to produce new compounds with remarkable metallochromism and intense fluorescence.
Ferromagnetically Coupled Binuclear Iron(III) Complexes and Antiferromagnetically Coupled Binuclear Copper(II) Complexes. The Importance of the Metal-O-Metal Angle
Authors: Mikuriya Masahiro , Kakuta Yoshihisa , Kawano Kouichi , Tokii Tadashi
Published: April 2006

Binuclear iron(III) and copper(II) complexes with N-salicylidene-2-hydroxy-5-chloro(or bromo)benzylamine (H2L), [Fe2(L)2(CH3COO)2]·2THF (THF = tetrahydrofuran) and [Cu2(L)2(DMSO)2]·2DMSO (DMSO = dimethyl sulfoxide) have been prepared and characterized by X-ray structure analysis and magnetic susceptibilities (80–300 K).
Synthesis and Spectroscopic Properties of Water-Soluble Cerium(III) or Praseodymium(III) Mono[tetra(4-pyridyl)-porphyrinate] and Cerium(IV) Bis[tetra(4-pyridyl)-porphyrinate]
Authors: Jiang Jianzhuang , Machida Ken-ichi , Yamamoto Eiji , Adachi Gin-ya
Published: April 2006

Water-soluble lanthanoid mono- and bisporphyrins, Ln(TPyP)acac (Ln = Ce, Pr) and Ln(TPyP)2 (Ln = Ce) [TPyP = tetra(4-pyridyl)-porphyrin, acac = acetylacetone] were synthesized by refluxing Ln(acac)3·nH2O (Ln = Ce, Pr) and H2TPyP in 1,2,4-trichlorobenzene. The complexes were characterized based on UV/vis absorption and 1H-NMR spectra, respectively.
Controlled Formation of CdS Particles in Multibilayer Cast Films of Amphiphilic Cyclams
Authors: Kimizuka Nobuo , Miyoshi Takanori , Ichinose Izumi , Kunitake Toyoki
Published: April 2006

Quantum sized cadmium sulfide particles were prepared by reaction of H2S gas with Cd2+-cyclam complexes preorganized in cast multibilayer films. The particle size was affected by the chemical structure of the bilayer component as well as by phase transition characteristics.
Novel Conversion of Selenium-containing Five-membered Aromatics to Nitrogen-containing Six-membered Aromatics via Hetero Diels–Alder Reaction with Acetylenic Dienophiles
Authors: Takikawa Yuji , Hikage Shigeki , Matsuda Youichi , Higashiyama Kazuyuki , Takeishi Yoshiyuki , Shimada Kazuaki
Published: April 2006

Treatment of selenium-containing five-membered heteroaromatics with acetylenic dienophiles afforded several nitrogen heterocycles in good to moderate yields by using thermal reaction conditions. These reactions were thought to proceed through sequential [4+2] cycloaddition-selenium extrusion pathway.
Transition Metal Complexes of 1,1′-Bis(2-pyridyl)ferrocene. A Cationic Rhodium(I) and a Silver(I) Complex. Preparation and Structure
Authors: Tani Kazuhide , Mihana Takeshi , Yamagata Tsuneaki , Saito Taro
Published: April 2006

The first transition metal complexes of 1,1′-bis(2-pyridyl)ferrocene (1), a cationic rhodium(I) complex, [Rh(cod)(1)]ClO4, (cod = cycloocta-1,5-diene) and a silver(I) complex, [Ag(1)ClO4]2, were prepared and characterized. X-Ray crystallographic analysis of the silver complex revealed that the complex is a dinuclear highly distorted five-coordinate Ag(I) complex with bridging perchlorate ligands, one of rare examples of five-coordinate Ag(I) complexes.
Participation of the Lowest Excited Singlet States of 9-Bromoanthracene and 9,10-Dibromoanthracene for Their Photochemical Debrominations by Amine (Triethylamine or N,N-Dimethylani1ine) in Acetonitrile
Authors: Nagamura Toshihiko , Nakayama Toshihiro , Hamanoue Kumao
Published: April 2006

From measurements of fluorescence and triplet-triplet absorption spectra of bromoanthracenes in acetonitrile-amines, it is concluded that bromoanthracene radical anions produced by a reaction of the lowest singlet states of bromoanthracenes with amines are the intermediates for the debrominations.
Structures and Dynamics of Alkali Ion-exchanged ZSM-5 as Investigated by Molecular Dynamics and Computer Graphics
Authors: Miyamoto Akira , Matsuba Katsuhiko , Kubo Momoji , Kawamura Katsuyuki , Inui Tomoyuki
Published: April 2006

Molecular dynamics method using a simple two-body interatomic potential was found to be effective for reproducing the structures of silicalite with the MFI structure and CaNaA zeolite. This method was also effective for estimating the cation position in alkali ion-exchanged ZSM-5.
Reactivities of Carbonyl Compounds in Acid-Catalyzed Hydride Transfer vs. Electron Transfer
Authors: Fukuzumi Shunichi , Fujita Morifumi
Published: April 2006

Rate constants for acid-catalyzed hydride-transfer reactions from triethylsilane to a series of carbonyl compounds are compared with those for acid-catalyzed electron transfer from the excited state of [Ru(bpy)3]2+ to the same series of carbonyl compounds in the presence of HClO4 in acetonitrile at 298 K.
Cyclization of 4-Hydroxy-4-methyl-1-pentyl p-Toluenesulfonate as a Model to Evaluate Inherent Medium Effect on SN2 Solvolysis
Authors: Shimizu Nobujiro , Tsutsumi Toru , Tsuno Yuho
Published: April 2006

Solvent effect on the cyclization of 4-hydroxy-4-methyl-1-pentyl p-toluenesulfonate, a mechanistic equivalent to the SN2 solvolysis, was successfully analyzed by the Taft LSER equation as log k = 3.2π* + 1.4α + 1.9β − 8.36, indicating that three independent factors are operative, i.e., solvent polarity and H-bond donor ability which promote ionization, and H-bond acceptor ability which enhances nucleophilicity of the internal OH group.
Solid Electrolyte CO2 Sensor Using NASICON and Li-based Binary Carbonate Electrode
Authors: Yao Sheng , Hosohara Sachio , Shimizu Youichi , Miura Norio , Futata Hozumi , Yamazoe Noboru
Published: April 2006

A solid electrolyte CO2 sensor was developed by combining an Na+ conductor and a Li-based binary carbonate auxiliary electrode represented by Li2CO3–CaCO3 (1.8 : 1 in molar ratio: eutectic mixture). It responded to CO2 quickly and reversibly, following a Nernst equation excellently in the CO2 concentration range 102–105 ppm. In addition, Li2CO3–CaCO3 electrode was found to be stable to deliquescence even when kept under a highly humid condition at 30 °C for more than 700 h.
Selective Mono-Alkylation and Arylation of Dichlorobenzenes by Palladium-Catalyzed Grignard Cross-Coupling
Authors: Katayama Tatsuo , Umeno Masayuki
Published: April 2006

Palladium(II)–phosphine complexes, especially PdCl2(dppf) where dppf stands for 1,1′-bis(diphenylphosphino)ferrocene, are effective catalysts for the cross-coupling of Grignard reagents with dichlorobenzenes to produce selectively mono-alkylated and arylated benzenes. The addition of ligands is also effective for the cross-coupling of Grignard reagents containing a β-hydrogen(s).
Rabies and antirabies immunization in South Western Nigeria: knowledge, attitude and practice
Authors: Opaleye O O , Adesiji Y O , Olowe O A , Fagbami A H
Published: April 2006

Factors responsible for the continued endemicity of rabies in Nigeria were determined by carrying out a knowledge, attitude and practice study among residents of Osun State. Structured questionnaires were administered to 679 individuals comprising students, traders and civil servants. Only 33.4% of the respondents knew rabies could be prevented by vaccination, while 38.7% believed that the infection could be treated with herbs. Of the 387 victims of dog bite, 240 (62%) never sought prophylactic postexposure treatment. Of the 10 people who received postexposure treatment, only one received the appropriate treatment consisting of washing, disinfection of wounds, tetanus toxoid and complete antirabies immunization.
Cotrimoxazole prophylaxis for HIV-positive TB patients in developing countries
Authors: Zachariah R , Massaquoi M
Published: April 2006

Despite provisional recommendations from the World Health Organization and UNAIDS that cotrimoxazole (CTX) prophylaxis be offered to all individuals living with AIDS, including HIV-positive patients with TB, its routine use in developing countries particularly Africa has been minimal. Concerns were expressed regarding its effectiveness in areas of high bacterial resistance, that its widespread use might substantially increase bacterial cross-resistance in the community and that this intervention might promote resistance of malaria parasites to sulphadoxine-pyrimethamine. We review the current evidence on the above concerns and highlight the main operational considerations related to implementing CTX prophylaxis as a basic component of care for HIV-positive TB patients in developing countries.
Pattern of presentation of primary open-angle glaucoma in Benin City, Nigeria
Authors: Omoti A E , Osahon A I , Waziri-Erameh M J M
Published: April 2006

Late presentation is a major problem in the management of patients with primary open-angle glaucoma. The aim of this study was to determine the clinical features and the degree of visual disability of glaucoma patients at initial presentation. This was a prospective study of new patients with a diagnosis of primary open-angle glaucoma seen between January 2001 and August 2002 at the University of Benin Teaching Hospital, Nigeria. The patients were analysed in the context of age, gender, geographical abode, educational and socioeconomic status and clinical presentation. The patients were examined using the Snellen's chart, pen torch, slit lamp biomicroscopy, ophthalmoscopy, tonometry, perimetry and gonioscopy. Over a 20-month period 154 patients were studied; the mean age was 52.73 years (standard deviation ± 15.98) and the highest incidence was in the seventh decade. The male to female ratio was 2.1:1. In all, 119 patients (77.3%) presented with subjective visual loss in one or both eyes, while 57.1% dated the onset of their symptoms to 1-5 years before presentation. Overall, 38 patients (24.7%) were blind when using visual acuity as the criteria, while 87 patients (56.5%) were blind when using visual fields as the criteria. The problem of late presentation has not improved over the last two and a half decades. More measures towards early detection by extensive health education, screening programmes and training of more eye care providers need to be put in place.
Risk factors of postpartum depression and EPDS scores in a group of Nigerian women
Authors: Owoeye A O , Aina O F , Morakinyo O
Published: April 2006

A sample of 252 women was studied for postpartum depression (PPD) in a 68-bed maternity hospital in Lagos, Nigeria. After obtaining consent, they were assessed using: (1) a questionnaire on socio-demographic profile and risk factors of PPD; (2) the Edinburgh Postnatal Depression Scale (EPDS), and when necessary with (3) the depressive module of International Classification of Diseases, 10th edition (ICD-10).

The cohort was predominantly young (mean age 28.5 - 5.26 years). About one-quarter (23%) scored -12, (the cut-off score) on EPDS assessment; with majority of these depressed on further evaluation with ICD-10. The risk factors for PPD were found to be mainly psychosocial, including unwanted pregnancy, unemployment and marital conflict. It is concluded that PPD is a major complication of childbirth in Nigeria, which can be minimized by improving both the citizens' socioeconomic condition and providing cheaper and more efficient health-care services.
The risk factors for relapse among patients with African trypanosomiasis in Daloa, Cote d'Ivoire
Authors: Cross Pamela , Doua Felix , Jaffar Shabbar
Published: April 2006

We describe rates of follow-up and the risk factors for relapse in a cohort of adult patients treated for Trypanosoma brucei gambiense African trypanosomiasis. 812 patients were discharged from hospital between 6 January 1983 and 16 January 1992. The numbers who did not attend a scheduled follow-up appointment at 6,12,18 and 24 months were 383 (47%), 467 (58%), 536 (66%) and 533 (66%), respectively. Thirty-two patients relapsed over the 2 years follow-up: 24 (75%) before the 12-month follow-up appointment. The presence of antibody to trypanosomes in the cerebrospinal fluid (CSF) at discharge from hospital was associated significantly with the risk of relapse at any time. When the analysis was restricted to a follow-up of 1 year, a protein level in the CSF above the median and the presence of antibody in the CSF (both at discharge) were associated in univariate analysis with relapse. A high number of patients were lost to follow-up, which may have resulted in bias. From the data available, the majority of the relapses were recorded within 12 months and the presence of antibody in the CSF at hospital discharge was identified as an independent predictor of future relapse at any time.
Parotid TB
Authors:   Chintamani, Daniel R , Manu S , Bhushan V , Gupta K
Published: April 2006

TB of the parotid is rare and only about 100 cases have been reported in the world literature. Often the diagnosis is made only after the surgery performed for a suspected neoplasm. We describe three patients with diffuse form of parotidTB without any evidence of tubercular focus elsewhere. Fine needle aspiration cytology confirmed the diagnosis in two cases, while the third case was diagnosed only after surgery.
Rate, pattern and barriers of HIV serostatus disclosure in a resource-limited setting in the Niger delta of Nigeria
Authors: Akani C I , Erhabor O
Published: April 2006

The disclosure of HIV serostatus is a difficult emotional task creating opportunity for both support and rejection. In this study, we evaluated the rate, patterns and barriers to HIV serostatus disclosure. A pre-tested interviewer-administered questionnaire from 187 HIV infected people residing in a resource-limited setting in the Niger Delta of Nigeria was analysed. Of the 187 HIV seropositive patients studied, 144 (77.0%) had disclosed their HIV-serostatus while 43 (23.0%) had not. Results showed that the patients had disclosed their HIV-serostatus to: parents (22.3%), siblings (9.7%), pastors (27.8%), friends (6.3%), family members (10.4%) and sexual partners (23.6%) ( P = 0.004). Females were more likely (59.7%) to disclose their HIV serostatus compared with males (40.3%) ( P = 0.003). Mothers were twice as likely (65.6%) to be confided in compared with fathers. Barriers to HIV serostatus disclosure included fear of stigmatization, victimization, fear of confidants spreading the news of their serostatus and fear of accusation of infidelity and abandonment ( P = 0.002). Married respondents were more likely to disclose their status. Better-educated respondents with tertiary education were more likely to disclose their HIV-serostatus. Expectation of economic, spiritual, emotional and social support was the major reason for disclosure. The ratio of disclosure to non-disclosure among patients with non-formal education was (2.6:1.0), primary education (2.3:1.0), secondary education (3.3:1.0) and tertiary education (10.0:1.0). Disclosure of HIV serostatus can foster economic social and economic support. There is need for the re-intensification of interventional measure that combines provider, patients and community education particularly in the aspect of anti-stigma campaign, partner notification and skill building to facilitate appropriate HIV serostatus disclosure.
Antiretroviral therapy and TB
Authors: Swaminathan Soumya , Luetkemeyer Annie , Srikantiah Padmini , Lin Royce , Charlebois Edwin , Havlir Diane V
Published: April 2006

With the expansion and convergence of the HIV and TB epidemics worldwide, clinicians will increasingly will be called to manage and treat co-infected patients. TB and HIV medications have overlapping and additive toxicities that can complicate therapy. Additional clinical challenges include choice of optimal first and second line antiretroviral therapy, appropriate timing of antiretroviral initiation, management of immune reconstitution disease, and TB diagnosed after initiation of HIV therapy. Despite the complexities presented by co-infection, many programmes have integrated care and are successfully treating patients with both HIV and TB.
HIV-TB: epidemiology, clinical features and diagnosis of smear-negativeTB
Authors: Keshinro Babajide , Diul Mukadi Ya
Published: April 2006

TB remains an important public health problem in the world that has been exacerbated by the HIV epidemic. In 2000, while 9% of new TB infections worldwide were attributable to HIV, in Sub-Saharan Africa - a region with higher HIV prevalence - about 31% of newTB cases were attributable to HIV.

Clinical presentation of TB in HIV-infected individuals depends on the severity of the suppression of immunological functions. In patients in early stages of HIV infection, TB clinical presentation resembles that of HIV-negative individuals with more pulmonary involvement and localized lesions. With the progressive suppression of immunological functions, TB tends to be more generalized affecting more than one organ. Classic TB symptoms are non-specific and may result in delayed diagnosis or misdiagnosis.

Diagnosis of smear negative pulmonary TB is based on clinical and radiological features. Sputum culture and rapid diagnostic tests based on polymerase chain reaction can be used where available.
Percutaneous needle pleural biopsies in pleural effusion of uncertain aetiology in a Nigerian teaching hospital
Authors: Ezemba N , Eze J C , Anyanwu C H
Published: April 2006

Clinical observation shows that most of the patients with pleural effusion of undetermined aetiology in a Nigerian teaching hospital receive antiTB drug trials. This observation prompted the authors to evaluate the role of percutaneous needle pleural biopsy as a diagnostic tool in effusions of uncertain aetiology.

Thirty-seven patients with pleural effusion of uncertain aetiology were investigated by percutaneous pleural biopsies using Abrams pleural biopsy needle over an 18-month period. In 34, the aetiology was established giving a sensitivity of 92%.

Non-specific pleurisy/empyema remains the commonest cause of effusion (41%), followed closely by malignancies (29.4%) and TB pleurisy (22%), respectively. Percutaneous needle pleural biopsies establish diagnosis of malignancy in 91% of the cases with 72% of the malignancies originating from the lung. There is a significant association between malignancy and pleural effusion of uncertain aetiology in patients above 40 years of age ( P = 0.022).

The empirical use of antiTB drugs in the absence of investigative results suggestive of the diagnoses should be discouraged. Instead concerted effort should be made to establish the cause of such effusion.
Cardiopulmonary manifestations of typhoid fever: a prospective analysis of 65 cases in Iran
Authors: Esmailpour Negin , Rasoolinejad Mehrnaz , Abdolbaghi Mahboobeh Haji
Published: April 2006

For an evaluation of cardiopulmonary manifestations in typhoid in Iran, we studied 65 patients with positive blood or bone marrow culture for Salmonella typhi during a 2-year period.

Cardiac complications were seen in 4.6% (myocarditis, pericarditis, pulmonary emboli) and pulmonary complications in 6.2%.
Oral health in rural South African type 2 diabetic patients
Authors: Peck Thabit , Price Caroline , English Paddy , Gill Geoff
Published: April 2006

Diabetes increases the risk of periodontal disease, but information from the tropics is lacking, and the relationship between periodontal disease and glycaemic control is uncertain. We examined 23 type 2 diabetic patients in a rural and resource-poor area of South Africa. Mean age was 59 ± 10 (1SD) years, and diabetes duration 6 ± 6 years. In all,11 were 'well controlled' (glycosylated haemoglobin (HbA1c) <8.0%, mean 6.5%), and 12 'poorly controlled' (HbA1c >8.0%, mean 13.0%). Periodontal disease was more common in the poorly controlled group (42% versus18%, P <0.002). We conclude that dental health is poor in type 2 diabetic patients in rural Africa, and that periodontal disease is closely related to glycaemic control. Improved dental and diabetes care is needed in such communities.
The aetiology of angular deformities of the lower limb in children in Malawi: a review of 35 patients
Authors: Brueton Richard N
Published: April 2006

The aetiology of 35 Malawian children with angular deformities of the lower limb, including 18 with varus,13 with valgus and four with windswept deformities, was assessed prior to surgical correction by proximal tibial or distal femoral osteotomies. Among the varus limbs, the aetiologies were ligamentous laxity of the knee (7), lesions of the medial tibial metaphysis (3), bowing of the femora and tibiae (3), and there were two girls with the end stage of Blount's disease. Among the valgus patients, eight had extremes of physiological knock knee and five had valgus bowing of the femora or tibiae.