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10496867 | Binding of Actinobacillus pleuropneumoniae lipopolysaccharides to glycosphingolipids evaluated by thin-layer chromatography. | The binding profile of Actinobacillus pleuropneumoniae serotypes 1 and 2 to various glycosphingolipids was evaluated by using thin-layer chromatogram overlay. A. pleuropneumoniae whole cells recognized glucosylceramide (Glcbeta1Cer), galactosylceramide (Galbeta1Cer) with hydroxy and nonhydroxy fatty acids, sulfatide (S... |
10493992 | Determination of the enantiomeric purity of S-ropivacaine by capillary electrophoresis with methyl-beta-cyclodextrin as chiral selector using conventional and complete filling techniques. | Capillary electrophoresis (CE) methods based on the conventional and complete filling techniques for determination of the enantiomeric purity of S-ropivacaine are described. The complete filling technique is a separation method which can be used instead of the partial filling technique in order to reduce the total anal... |
10493932 | A modular cinnamoyl ester hydrolase from the anaerobic fungus Piromyces equi acts synergistically with xylanase and is part of a multiprotein cellulose-binding cellulase-hemicellulase complex. | A collection of clones, isolated from a Piromyces equi cDNA expression library by immunoscreening with antibodies raised against affinity purified multienzyme fungal cellulase-hemicellulase complex, included one which expressed cinnamoyl ester hydrolase activity. The P. equi cinnamoyl ester hydrolase gene (estA) compri... |
10490595 | Spliceosomal U snRNP core assembly: Sm proteins assemble onto an Sm site RNA nonanucleotide in a specific and thermodynamically stable manner. | The association of Sm proteins with U small nuclear RNA (snRNA) requires the single-stranded Sm site (PuAU(4-6)GPu) but also is influenced by nonconserved flanking RNA structural elements. Here we demonstrate that a nonameric Sm site RNA oligonucleotide sufficed for sequence-specific assembly of a minimal core ribonucl... |
10488220 | Transmission of an azole-resistant isogenic strain of Candida albicans among human immunodeficiency virus-infected family members with oropharyngeal candidiasis. | We report transmission of an azole-resistant, isogenic strain of Candida albicans in a human immunodeficiency virus (HIV)-infected family of two children with symptomatic oropharyngeal candidiasis and a mother with asymptomatic colonization over a 5-year period. These findings were confirmed by three different molecula... |
10481017 | Plasmid DNA size does not affect the physicochemical properties of lipoplexes but modulates gene transfer efficiency. | Clinical applications of gene therapy mainly depend on the development of efficient gene transfer vectors. Large DNA molecules can only be transfected into cells by using synthetic vectors such as cationic lipids and polymers. The present investigation was therefore designed to explore the physicochemical properties of... |
10482613 | Initial binding of murine leukemia virus particles to cells does not require specific Env-receptor interaction. | The initial step of virus-cell interaction was studied by immunofluorescence microscopy. Single particles of murine leukemia virus (MLV) vectors and human immunodeficiency virus (HIV) were visualized by immunofluorescence. Fluorescent dots representing single virions could be localized by staining of capsid proteins (C... |
10482593 | Activation of cJUN N-terminal kinase by herpes simplex virus type 1 enhances viral replication. | Signal transduction pathways convey signals generated at the cell surface into the cell nucleus in order to initiate a program of gene expression that is characteristic for particular stimuli. Here we present evidence that infection by herpes simplex virus type 1 activated the two terminal kinases, cJUN N-terminal kina... |
10482584 | Proteolytic cleavage of the amino terminus of the U(L)15 gene product of herpes simplex virus type 1 is coupled with maturation of viral DNA into unit-length genomes. | The U(L)15 gene of herpes simplex virus type 1 (HSV-1), like U(L)6, U(L)17, U(L)28, U(L)32, and U(L)33, is required for cleavage of concatameric DNA into genomic lengths and for packaging of cleaved genomes into preformed capsids. A previous study indicated that the U(L)15 gene encodes minor capsid proteins. In the pre... |
10482561 | Adaptation of a CCR5-using, primary human immunodeficiency virus type 1 isolate for CD4-independent replication. | The gp120 envelope glycoprotein of the human immunodeficiency virus type 1 (HIV-1) promotes virus entry by sequentially binding CD4 and chemokine receptors on the target cell. Primary, clinical HIV-1 isolates require interaction with CD4 to allow gp120 to bind the CCR5 chemokine receptor efficiently. We adapted a prima... |
10477900 | Fluorimetric determination of D- and L-lactate derivatized with 4-(N, N-dimethylaminosulfonyl)-7-piperazino-2,1,3-benzoxadiazole (DBD-PZ) by high-performance liquid chromatography. | A highly sensitive method, based on fluorescence derivatization with 4-N,N-dimethylaminosulfonyl-7-piperazino-2,1,3-benzoxadiazol e (DBD-PZ), was developed for the determination of D- and L-lactic acid. High-performance liquid chromatographic separation of the lactic acid derivative was achieved using an octadecylsilic... |
10451557 | Antibody BCF2 against scorpion toxin Cn2 from Centuroides noxius Hoffmann: primary structure and three-dimensional model as free Fv fragment and complexed with its antigen. | The antibody BCF2 generated against the mammal-specific toxin Cn2 of the scorpion Centuroides noxius Hoffmann neutralizes the effect of both the toxin and the venom. We cloned and sequenced the genes coding for the Fv fragment of BCF2. A three-dimensional (3D) model of the Fv fragment was generated using a knowledge-ba... |
32267907 | Luminescence Spectral Properties of CdS Nanoparticles. | We examined the steady state and time resolved luminescence spectral properties of two types of CdS nanoparticles. CdS nanoparticles formed in the presence of an amine-terminated dendrimer showed blue emission. The emission wavelength of these nanoparticles depended on the excitation wavelength. The CdS/dendrimer nanop... |
20651937 | Monofunctionalization of Calix[4]arene Tetracarboxylic Acid at the Upper Rim with Isothiocyanate Group: First Bifunctional Chelating Agent for Alpha-Emitter Ac-225. | A procedure is reported for synthesizing a novel, water-soluble bifunctional chelating agent derived from calix[4]arene. This chelate features tetracarboxylic acid groups at the lower rim as an actinium-225 ionophore, and an isothiocyanate functional group at the upper rim for labeling of the N-terminus of monoclonal a... |
21662886 | Analytical- and preparative-scale isoelectric focusing separation of enantiomers. | Isoelectric focusing has been used to achieve the analytical- and preparative-scale separation of the enantiomers of amphoteric analytes. By considering the simultaneous multiple equilibria involved in the chiral recognition process, a model has been developed to describe the magnitude of the ΔpI value that develops be... |
16118873 | Synthesis of novel polyethers in a geometrically precise conformation. | [reaction: see text] A convergent design for the preparation of a polyoxyethylene-based channel molecule is presented, and the synthesis of the key unit 2 required for the projected construction is described. The essential elements of the design included face to face oriented macrorings spaced by rigid trans-fused oxan... |
10556883 | Erratum | The paper 'Interference of rheumatoid factor activity by aspartame, a dipeptide methyl ester' by Paul A. Ramsland, Bahereh F. Movafagh, Morris Reichlin and Allen B. Edmundson, J. Mol. Recognit. 1999; 12: 249--257, was published without the required colour plates. The publisher would like to apologise for this omission.... |
10508381 | STM Images of Individual Porphyrin Molecules on Cu(100) and Cu(111) Surfaces. | Simply sublime! Samples of monomeric and dimeric zinc porphyrins were sublimed onto a Cu surface under ultrahigh vacuum conditions. Images obtained by scanning tunneling microscopy at room and low temperature (98 K) show features attributed to individual porphyrin molecules with excellent resolution. In the case of the... |
10508359 | Icosahedral Building Blocks: Towards Dendrimers with Twelve Primary Branches? | A convergent point for cluster and supramolecular chemists is provided by the isolation of the per-B-hydroxylated, icosahedral clusters [B(12)(OH)(12)](2-) (shown schematically), [1-H-1-CB(11)(OH)(11)](-), and 1,12-H(2)-1,12-C(2)B(10)(OH)(10) by Hawthorne et al. But will these multifunctionalized clusters, which contai... |
10508352 | Supramolecular Isomerism in Caviplexes. | Stereoisomeric complexes of an open-ended cavitand and its guest molecules (shown schematically) were detected, and complexes within caviplexes were introduced. Some control can be exerted on the stereoisomerism through methylation of the guest. The symbols "0" and "1" represent different ends of the guest molecule. |
10508342 | Supramolecular Organometallic Polymer Chemistry: Self-Assembly of a Novel Poly(ferrocene)-b-polysiloxane-b-poly(ferrocene) Triblock Copolymer in Solution. | Micelles with unprecedented flowerlike arrangements of the poly(ferrocene) cores (shown in the TEM image) are among the supramolecular architectures generated in the self-assembly of a novel organometallic triblock copolymer from silicon-bridged [1]ferrocenophane monomers and [Me(2)SiO](3) in hexane, a solvent selectiv... |
10508333 | Controlled Arrangement of Supramolecular Metal Coordination Arrays on Surfaces. | Metallo-supramolecular systems have been adsorbed in a controlled way onto graphite surfaces and visualized with molecular resolution for the first time. A parallel or orthogonal arrangement of the metal coordination arrays is evident depending on the specific ligands (see picture). Furthermore, simple nanomanipulation... |
10469551 | Removal of Aromatic Hydrocarbon Compounds by Hydroxypropyl-cyclodextrin. | Activated carbon has been used for the recovery and removal of benzene, toluene, and xylenes in air and water for a long time. However, removal of benzene, toluene, and xylenes from soil is very difficult. They can be removed by an increase in the apparent solubility of organic compounds in soil. The apparent solubilit... |
11681523 | Determination of the enantiomerization barrier of chlorthalidone by dynamic electrokinetic chromatography and computer simulation. | Dynamic electrokinetic chromatography (DEKC) and computer simulation have been used to determine the enantiomerization barrier of the drug chlorthalidone, which is commonly employed as a diuretic. The separation of enantiomers was performed in an aqueous 100 mM citric acid/phosphate buffer system at pH 5 containing 12.... |
10823212 | Catalysis and acceleration of acyl transfer by aminocyclodextrins: a biomimetic system of use in enzyme modeling and drug design. | [formula: see text] Aminocyclodextrins (ACDs), perfunctionalized at the 6-position with amino groups, bind phosphonoformate (PFA) diesters and accelerate acyl transfer reactions with high efficiency at neutral pH. Aminolysis and esterolysis are accelerated and hydrolysis of PFA diesters is catalyzed by ACDs. PFA dieste... |
10777254 | Interference of rheumatoid factor activity by aspartame, a dipeptide methyl ester. | Circulating autoimmune complexes of IgM rheumatoid factors (RF) bound to the Fc portions of normal, polyclonal IgG antibodies are frequently present in humans with rheumatoid arthritis (RA). The sweet tasting methyl ester of L-Asp-L-Phe (aspartame or APM) was found to relieve pain and improve joint mobility in subjects... |
10738550 | Interaction of liposomal and polycationic transfection complexes with pulmonary surfactant. | <h4>Background</h4>The delivery of genes to the airways holds promise for the treatment of lung diseases such as cystic fibrosis and asthma. Current non-viral gene delivery systems lack sufficient transfection efficiency. Pulmonary surfactant has been reported to be a barrier to gene transfer into the airways. Here we ... |
10645172 | Angiogenesis in cancer: the role of endothelin-1. | This review summarises the process of angiogenesis, its role in tumourigenesis and suggests a mechanism by which endothelin-1 may influence these processes. |
10586245 | Schwann cell-derived desert hedgehog signals nerve sheath formation. | Reciprocal signaling between axons and Schwann cells during development is well established. The contribution of Schwann cells to the formation and maintenance of the protective nerve sheaths (endo-, peri-, and epineurium) has been less studied. Although mesenchymal cells contribute to all these structures, only perine... |
10581683 | Molecular recognition of synthetic siderophore analogues: a study with receptor-deficient and fhu(A-B) deletion mutants of Escherichia coli. | The biological activity of six synthetic siderophore analogues (two dihydroxamates, two trihydroxamates, one tetrahydroxamate and one 3-hydroxy-4(1H)pyridinone) has been studied in Escherichia coli, Morganella morganii 13 and Proteus mirabilis 8993 strains by using growth promotion tests. Various transport-deficient mu... |
10573209 | Dendrimer-platinate: a novel approach to cancer chemotherapy. | A polyamidoamine (PAMAM) dendrimer generation 3.5 with a sodium carboxylate surface was conjugated to cisplatin giving a dendrimer-platinate (dendrimer-Pt; 20-25 wt% platinum) which was highly water soluble and released platinum slowly in vitro. In vivo the dendrimer-Pt and cisplatin were equi-active i.p. against i.p. ... |
10566244 | [Preparation and antineoplastic activity of acylhydrazones of R- and S-usnic acid]. | Hydrazones of R- and S-usnic acid were prepared by condensation of the appropriate enantiomer of usnic acid with hydrazides of aromatic acids. Prepared compounds were characterized by spectral methods. Reaction kinetic was studied with capillary electrokinetic chromatography, enantiomeric purity of products was checked... |
10556882 | The ion channel switch biosensor. | A biosensor technology is described which provides a direct measurement for functional molecular interactions, at the surface of a tethered bilayer membrane, through the electrical transduction of chemically modified ion-channels. High sensitivity of analyte detection is achieved due to the large flux of ions transmitt... |
10556881 | Real time in vitro analysis of transcription by RNA polymerase on immobilized DNA fibres. | We have used surface plasmon resonance (SPR) to follow variations in the concentrations of binary complexes as RNA polymerase moves into a transcriptionally competent initiation complex with immobilized DNA fibres containing promoter sequences. The use of SPR to follow complex binding phenomena is described. We have al... |
10556880 | Biosensor analysis of the interleukin-2 receptor complex. | Surface plasmon resonance (SPR) biosensor technology has been a significant addition to the evolution and refinement of methods to study macromolecular interactions. Prior to the advent of SPR, we employed a variety of biochemical and biological techniques to study the interleukin-2/interleukin-2 receptor system (IL-2/... |
10556879 | Exploring buffer space for molecular interactions. | The interaction of two molecules binding to each other is described by two rate parameters, the association rate parameter k(a) and the dissociation rate parameter k(d). Under standardized conditions these kinetic parameters can be determined by analysis of their interaction in an affinity-based biosensor system, such ... |
10556878 | Active concentration measurements of recombinant biomolecules using biosensor technology. | Whereas the concentration of a biomolecule simply refers to the amount of chemical substance per unit of volume, its active concentration refers to a relational parameter that has meaning only with respect to the molecule's ability to interact specifically with one particular ligand. When proteins are studied in a biol... |
10556877 | The influence of transport on the kinetics of binding to surface receptors: application to cells and BIAcore. | Accurate estimation of biomolecular reaction rates from binding data, when ligands in solution bind to receptors on the surfaces of cells or biosensors, requires an understanding of the contributions of both molecular transport and reaction. Efficient estimation of parameters requires relatively simple models. In this ... |
10556876 | Affinity analysis of non-steady-state data obtained under mass transport limited conditions using BIAcore technology. | Binding data obtained with Biacore instrumentation is often evaluated using a kinetic transport model where reaction rate constants and a mass transport coefficient are used to describe the interaction. Here the use of a simplified model, an affinity transport model, for determination of the affinity (K(D)) but not the... |
10556875 | Improving biosensor analysis. | The quality of optical biosensor data must be improved in order to characterize the mechanism and rate constants associated with molecular interactions. Many of the artifacts associated with binding data can be minimized or eliminated by designing the experiment properly, collecting data under optimum conditions and pr... |
10532350 | Nonaqueous capillary electrophoretic separation of basic enantiomers using heptakis(2,3-dimethyl-6-sulfato)-beta-cyclodextrin. | The enantiomers of 40 basic analytes, mostly pharmaceuticals, were separated by nonaqueous capillary electrophoresis in acidic methanol background electrolytes using the sodium salt of heptakis(2,3-dimethyl-6-sulfato)-beta-cyclodextrin (HDMS-beta-CD). The effective mobilities, separation selectivities, and peak resolut... |
10532349 | Separations of enantiomers by preparative capillary isotachophoresis. | The use of capillary isotachophoresis (ITP), operating in a discontinuous fractionation mode, for preparative separations of enantiomers of chiral compounds was studied. The ITP separations were carried out in the column-coupling configuration of the separation unit provided with the preseparation column of a 1.0 mm ID... |
10532348 | Enantiomer separation by pressure-supported electrochromatography using capillaries packed with Chirasil-Dex polymer-coated silica. | Pressure-supported electrochromatography using capillaries packed with permethyl-cyclodextrin covalently linked via an octamethylene spacer to dimethylpolysiloxane and immobilized on silica (Chirasil-Dex silica) has been employed as an efficient and rapid method for the enantiomer separation of various racemic compound... |
10532341 | Stereoselective screening for and confirmation of urinary enantiomers of amphetamine, methamphetamine, designer drugs, methadone and selected metabolites by capillary electrophoresis. | Data presented in this paper demonstrate that a competitive binding, electrokinetic capillary-based immunoassay previously used for screening of urinary amphetamine and analogs cannot be employed to distinguish between the enantiomers of amphetamine and methamphetamine. However, capillary zone electrophoresis with a pH... |
10532340 | Enantiomeric purity determination of propranolol by capillary electrophoresis using dual cyclodextrins and a polyacrylamide-coated capillary. | The use of a chirally selective capillary electrophoresis method is reported for the enantioselective purity determination of propranolol drug substance. The method employed a combination of both charged and neutral cyclodextrin. An internally coated capillary was used to suppress electroosmotic flow and potential peak... |
10532339 | pKa shift-associated effects in enantioseparations by cyclodextrin-mediated capillary zone electrophoresis. | Enantioselective migration of dansylated (Dns) amino acids in the presence of hydroxypropylated-beta-cyclodextrin under acidic conditions near the pI value of the analytes was investigated by means of capillary zone electrophoresis. Based on the migration data, the pH dependence of the complexation constants was evalua... |
10532338 | Some factors affecting enantiomeric impurity determination by capillary electrophoresis using ultraviolet and laser-induced fluorescence detection. | The key factors influencing enantiomer trace determination were investigated; these include resolution capillary diameter, limit of detection, linear range and type of detection. Chiral reagents, (+)- and (-)-1-(9-fluorenyl)ethyl chloroformate (FLEC), were employed as probes to demonstrate the influence of the variable... |
10532337 | Resolution of ephedrine derivatives by means of neutral and sulfated heptakis(2,3-di-O-acetyl)beta-cyclodextrins using capillary electrophoresis and nuclear magnetic resonance spectroscopy. | Beta-cyclodextrin (beta-CD), heptakis(2,3-di-O-acetyl)beta-cyclodextrin (Diac-beta-CD) and heptakis (2,3-di-O-acetyl-6-sulfato)beta-cyclodextrin (HDAS-beta-CD) were tested for their ability to discriminate the enantiomers of ephedrine, pseudoephedrine, norephedrine and methylephedrine. Using capillary electrophoresis (... |
10532336 | Designed combination of chiral selectors for adjustment of enantioseparation selectivity in capillary electrophoresis. | In this study an attempt has been made to explain the reasons for changing the enantioseparation selectivity in some dual cyclodextrin (CD) systems compared to the use of single chiral selectors in capillary electrophoresis (CE). An explanation for selectivity changes is proposed based on the effect of the chiral selec... |
10532335 | Cyclodextrins as chiral selectors in capillary electrophoresis: a comparative study for the enantiomeric separation of some beta-agonists. | A comparative study for the enantiomeric separation of terbutaline, clenbuterol, salbutamol and dobutamine was performed by capillary electrophoresis using cyclodextrins and their derivatives as chiral selectors. Several parameters such as buffer composition and temperature were studied. Simple, fast and reliable enant... |
10532334 | Potential of flow-counterbalanced capillary electrophoresis for analytical and micropreparative separations. | The potential of flow-counterbalanced capillary electrophoresis (FCCE) in chiral and achiral separations was investigated in this work. Unlimited increase of the separation selectivity can be achieved for binary mixtures using FCCE. This was shown for the enantioseparation of (+/-)-chlorpheniramine (CHL) with carboxyme... |
10532333 | Binding constant dependency of amphetamines with various commercial methylated beta-cyclodextrins. | Cyclodextrins play an important role in enantioselective separations. They represent the major class of chiral selectors used by capillary electrophoresis. Unfortunately, the purity of commercial cyclodextrins is often not well characterized, and similar selectors sold by various suppliers may show totally different en... |
10532332 | When a truck becomes a motorcycle: the impact of sample load on a chiral capillary electrophoresis separation using mixtures of neutral and sulfated cyclodextrins. | Chiral capillary electrophoresis (CE) separations are useful for monitoring the presence of a minor isomer at low levels (e.g., <0.5%) in the presence of the major form. In order to quantitate these low levels, it is necessary to inject large amounts of sample. Separations which appear to have more than enough resoluti... |
10532331 | Enantioseparation of beta-blockers with two chiral centers by capillary electrophoresis using sulfated beta-cyclodextrins. | Capillary electrophoresis methods for the enantioresolution of two beta-blockers possessing two chiral centers--labetalol and nadolol--were developed using electrokinetic chromatography. These methods were based on the addition of sulfated beta-cyclodextrins (S-betaCD) as chiral selectors to the background electrolyte ... |
10532330 | Comparison of highly sulfated alpha-, beta-, and gamma-cyclodextrins and 18-crown-6-tetracarboxylic acid for the enantiomeric separation of some amino acids and derivatives by capillary electrophoresis. | 18-Crown-6-tetracarboxylic acid (18C6H4) and highly sulfated cyclodextrins (HS-alpha-, beta-, gamma-CDs) are highly selective chiral selectors for the enantioseparation of solutes bearing the primary amino function. Excellent resolutions were obtained for all solutes on HS-gamma-CD and on 18C6H4. The former, however, i... |
10532329 | Application of sulfobutylether-beta-cyclodextrin with specific degrees of substitution for the enantioseparation of pharmaceutical mixtures by capillary electrophoresis. | In this research the separation of the enantiomers of the basic drug bidisomide (SC-40230) from five closely related known process impurities was investigated using several neutral and anionic sulfobutylether beta-cyclodextrins (SBE-beta-CDs) as isomer selectors. Several novel sulfobutylether derivative mixtures and pu... |
10532328 | Comparison of sulfobutylether- and sulfated-beta-cyclodextrins as additives for the chiral separation of basic spirobenzopyrans by capillary electrophoresis. | Three charged substituted beta-cyclodextrins (beta-CDs), sulfobutylether-beta-(SBE-beta-CD), degree of substitution (DS) 4 and 7), and sulfated-beta-(S-beta-CD) cyclodextrins, were compared as chiral additives in capillary electrophoresis for the enantiomeric separation of basic spirobenzopyran derivatives (pKa 9.9) wh... |
10532327 | Histamine-modified cationic beta-cyclodextrins as chiral selectors for the enantiomeric separation of hydroxy acids and carboxylic acids by capillary electrophoresis. | The enantiomeric separation of alpha-hydroxy acids and carboxylic acids was successfully performed by using 6-deoxy-6-N-histamino-beta-cyclodextrin (CD-hm), a monosubstituted positively charged beta-cyclodextrin (beta-CD) bearing a histamine moiety linked to the C6 of a glucose unit in the upper CD rim via the amino gr... |
10532326 | Vinylpyrrolidine-beta-cyclodextrin copolymer: a novel chiral selector for capillary electrophoresis. | The synthesis and characterization of a novel polymer consisting of an alkyl backbone and pendant beta-cyclodextrin units, obtained by radical copolymerization of vinylpyrrolidone and methacryloyl-beta-cyclodextrin (PVP-beta-CD), was reported. The ability of this copolymer to act as a capillary electrophoresis (CE) chi... |
10532325 | Enantiomeric separation by capillary electrophoresis using a crown ether as chiral selector. | This paper reviews chiral separations of primary amines by capillary electrophoresis and crown ether as chiral selector. Two possible mechanisms of chiral recognition by host-guest complexation are discussed: (i) The substituents of the crown ether act as barriers for the guest compounds, and (ii) lateral electrostatic... |
10526576 | Novel approaches to the treatment of small-cell lung cancer. | Small-cell lung cancer (SCLC) is characterized by its initial responsiveness to chemotherapy and the appearance of early metastases. Although combination chemotherapy, in some instances together with radiation, has improved the prognosis of this disease, in most patients SCLC ultimately recurs in a drug-resistant form.... |
10526569 | Interferons as a paradigm for cytokine signal transduction. | Characterization of the ability of interferons to induce immediate early genes led to the identification of the signal transducer and activators of transcription (STAT) signaling paradigm, where a single protein transduces signals directly from the receptor to the nucleus. Subsequent studies have determined that all cy... |
10521330 | Influence of temperature and membrane lipid composition on the osmotic water permeability of teleost gills. | Osmotic water uptake was measured gravimetrically in isolated, ligated gill arches from trout (acclimated to and incubated at 5 degrees and 20 degrees C) and tilapia (21.5 degrees and 33 degrees C). For both species, incubation of arches at the higher temperature led to 1.5- to 3-fold greater measures of water weight g... |
10522482 | [Nerve biopsy]. | Nerve biopsy, if undertaken at centres with appropriate expertise, may be a valuable diagnostic procedure in selected patients with peripheral neuropathy. Sural nerve biopsy and skin biopsy for evaluation of epidermal nerves are described. Indications, surgical procedure, preparation and transport are reviewed. Usually... |
10519104 | Rapid development of the enantiomeric separation of beta-blockers by capillary electrophoresis using an experimental design approach. | A rapid method for determining the separation conditions for chiral resolution of eleven beta-blocking drug substances by capillary electrophoresis is described, using an experimental design approach. An acidic phosphate-triethanolamine buffer and an uncoated fused-silica capillary were used for all experiments. Severa... |
10519101 | Electrospray mass spectrometry and supercritical fluid chromatography of methylated beta-cyclodextrins. | Five commercial dimethylated beta-cyclodextrin (DM-beta-CD) samples were analysed by electrospray (or ionspray) mass spectrometry (ESI-MS) and supercritical fluid chromatography (SFC) with evaporative light scattering detection. A silica and a nitro-bonded silica were selected using CO2-methanol-acetonitrile-water and ... |
10518954 | An NMR investigation of solution aggregation reactions preceding the misassembly of acid-denatured cold shock protein A into fibrils. | At pH 2.0, acid-denatured CspA undergoes a slow self-assembly process, which results in the formation of insoluble fibrils. 1H-15N HSQC, 3D HSQC-NOESY, and 15N T2 NMR experiments have been used to characterize the soluble components of this reaction. The kinetics of self-assembly show a lag phase followed by an exponen... |
10518058 | [Multicenter evaluation on different analyzers of three methods for direct HDL-cholesterol assay]. | Most frequently, in routine laboratories, C-HDL is measured in the supernatant after precipitation of apolipoprotein B-containing lipoproteins by the sodium phosphotungstate/magnesium chloride reagent (PTA). This method involves precipitation, centrifugation and decantation steps which prevent full automation of the me... |
10517155 | Extending the concept of template-assembled synthetic proteins. | The creation of native-like macromolecules in copying nature's way represents a fascinating challenge in protein chemistry today. In the absence of a detailed knowledge of the complex folding pathway the ultimate goal in protein de novo design, the construction of artificial proteins with predetermined three-dimensiona... |
10514997 | Capillary electrophoresis separation and permanganate chemiluminescence on-line detection of some alkaloids with beta-cyclodextrin as an additive. | Capillary electrophoresis has been used in combination with on-line permanganate chemiluminescence detection for the simultaneous determination of morphine, 6-monoacetylmorphine and heroin. It was found that beta-cyclodextrins could improve the separation efficiency and enhance the chemiluminescence signal. Improved se... |
10512989 | Improved extraction and assay of mycobacterial ATP for rapid drug susceptibility testing. | The firefly luciferase assay of ATP is a rapid and convenient technique for monitoring growth of mycobacteria. The time needed to obtain a drug susceptibility pattern can be reduced to less than 1 week as compared to 4 weeks with conventional methods. The ATP assay is simple and reliable. However, the extraction of bac... |
10515460 | Reciprocal enhancement of gene transfer by combinatorial adenovirus transduction and plasmid DNA transfection in vitro and in vivo. | The addition of replication-defective recombinant adenovirus to plasmid transfection (termed here "adenofection") has been shown to increase plasmid transgene expression in limited studies. Similarly, the addition of cationic liposomes to adenovirus increases adenovirus-mediated gene transduction (termed here "lipoduct... |
10511816 | [Nucleic acid syntheses and molecular recognition]. | Syntheses of nucleic acids are of importance not only in the natural product chemistry but also in the molecular recognition study in biology. This review describes syntheses of RNA and DNA, which were found to be related each other. Deoxyinosine probes were developed for cloning genes with degenerated codons. Syntheti... |
10512237 | Evaluation of the substantia nigra in patients with Parkinsonian syndrome accomplished using multishot diffusion-weighted MR imaging. | <h4>Background and purpose</h4>Although it is important to evaluate the substantia nigra in patients with parkinsonian syndrome, it is difficult to depict its anatomy, even by MR imaging. Using anatomic studies of the direction of nerve fibers around the substantia nigra, we attempted to depict this entity with multish... |
10508445 | Synthesis and structure-activity relationships of phenylenebis(methylene)-linked bis-azamacrocycles that inhibit HIV-1 and HIV-2 replication by antagonism of the chemokine receptor CXCR4. | Bis-tetraazamacrocycles such as the bicyclam AMD3100 are a class of potent and selective anti-HIV-1 and HIV-2 agents that inhibit virus replication by binding to the chemokine receptor CXCR4, the co-receptor for entry of X4 viruses. With the aim of optimizing the anti-HIV-1 and HIV-2 activity of bis-azamacrocycles, a s... |
10508403 | Membrane cholesterol modulates galanin-GalR2 interaction. | The neuropeptide galanin mediates a number of diverse physiological and pathophysiological actions via interaction with membrane-bound receptors. The role that membrane cholesterol plays in modulating the interaction between galanin and one of the three cloned galanin receptor subtypes (GalR2) expressed in Chinese hams... |
10509920 | Combinatorial search of substituted beta-cyclodextrins for phosphatase-like activity. | Thirteen per-6-akylamino-6-deoxy-beta-cyclodextrin libraries (beta-CD libraries) were generated by a solution-phase combinatorial synthesis starting from per-6-iodo-6-deoxy-beta-CD and different combinations of eleven individual amine nucleophiles. Certain libraries showed the ability to hydrolyzep-nitrophenyl phosphat... |
10502352 | DNA complexing with polyamidoamine dendrimers: implications for transfection. | DNA and polyamidamine (PAMAM) dendrimers form complexes on the basis of the electrostatic interactions between negatively charged phosphate groups of the nucleic acid and protonated (positively charged) amino groups of the polymers. Charge neutralization of both components and subsequent increases of the net positive c... |
10502345 | Human serum albumin incorporating Tetrakis(o-pivalamido) phenylporphinatoiron(II) derivative as a totally synthetic O2-carrying hemoprotein. | 2-[8-{N-(2-Methylimidazolyl)}octanoyloxymethyl]-5,10,15, 20-tetrakis(o-pivalamido)phenylporphinatoiron(II)s (FePs) were incorporated into hydrophobic cavities of recombinant human serum albumin (rHSA), providing a totally synthetic O(2)-carrying hemoprotein (rHSA-FeP). An rHSA host absorbs maximally eight FeP molecules... |
10500183 | Autoproteolysis in nucleoporin biogenesis. | We have molecularly characterized a proteolytic cleavage in conserved nuclear pore complex proteins. This cleavage, previously demonstrated to be essential for the biogenesis of two nuclear pore complex proteins in mammals (Nup98 and Nup96) and yeast (Nup145-N and Nup145-C), occurs between Phe and Ser residues within a... |
10500156 | De novo amyloid proteins from designed combinatorial libraries. | Amyloid deposits are associated with several neurodegenerative diseases, including Alzheimer's disease and the prion diseases. The amyloid fibrils isolated from these different diseases share similar structural features. However, the protein sequences that assemble into these fibrils differ substantially from one disea... |
10500119 | Chaperone rings in protein folding and degradation. | Chaperone rings play a vital role in the opposing ATP-mediated processes of folding and degradation of many cellular proteins, but the mechanisms by which they assist these life and death actions are only beginning to be understood. Ring structures present an advantage to both processes, providing for compartmentalizat... |
10500487 | Microfabricated capillary electrophoresis amino acid chirality analyzer for extraterrestrial exploration. | Chiral separations of fluorescein isothiocyanate-labeled amino acids have been performed on a microfabricated capillary electrophoresis chip to explore the feasibility of using such devices to analyze for extinct or extant life signs in extraterrestrial environments. The test system consists of a folded electrophoresis... |
10498834 | Recovery of dopamine neuronal transporter but lack of change of its mRNA in substantia nigra after inactivation by a new irreversible inhibitor characterized in vitro and ex vivo in the rat. | 1. In vitro, the ability of DEEP-NCS {1-[2-(diphenylmethoxy)ethyl]-4-[2-(4-isothiocyanatophenyl)ethyl]- piperazine} to inhibit [3H]-dopamine uptake by rat striatal synaptosomes was concentration-dependent and inversely related to the protein concentration. This inhibition was irreversible and resulted from changes in V... |
10498832 | Sulphonic acid derivatives as probes of pore properties of volume-regulated anion channels in endothelial cells. | 1. We have used the whole-cell patch-clamp technique to study the effects of 4-sulphonic-calixarenes and some other poly-sulphonic acid agents, such as suramin and basilen blue, on volume-regulated anion channel (VRAC) currents in cultured endothelial cells (CPAE cells). 2. The 4-sulphonic-calixarenes induced a fast in... |
10499581 | A metal complex that binds alpha-amino acids with high and predictable stereospecificity. | Molecular recognition is the key step in a wide range of controlled separation and chemical transformation processes, with enzymes performing this task with an unsurpassed degree of selectivity. Enzymes contain only 20 simple amino acids, yet it remains difficult to rationalize or even predict these stereospecific reco... |
10499336 | Optical isomer separation of potential analgesic drug candidates by using capillary electrophoresis. | Using cyclodextrin capillary zone electrophoresis (CD-CZE), baseline separation of synthetic potential analgesic drug diastereoisomer candidates 6,11-dimethyl-1,2,3,4,5,6-hexahydro-3-[(2'-methoxycarbonyl-2'-phenylc yclopropyl)methyl]-2,6-methano-3-benzazocin-8-ol (MPCB) and 6,11-dimethyl-1,2,3,4,5,6-hexahydro-3-[[2'-me... |
10499335 | Enantioseparation of thalidomide and its hydroxylated metabolites using capillary electrophoresis with various cyclodextrins and their combinations as chiral buffer additives. | The separation of thalidomide (TD) and its hydroxylated metabolites including their simultaneous enantioseparation was studied in capillary electrophoresis (CE) using four different randomly substituted charged cyclodextrin (CD) derivatives, the combinations of some of them with each other, and beta-CD. TD, as well as ... |
10499334 | Stereoselective analysis of acid herbicides in natural waters by capillary electrophoresis. | A capillary electrophoretic method for the stereoselective analysis of aryloxypropionic and aryloxyphenoxypropionic acidic herbicides in ground water and river water was performed. Vancomycin and gamma-cyclodextrin were added to the background electrolyte (BGE) as chiral selectors. Water sample preconcentration was acc... |
10499321 | Recent innovations in enantiomer separation by electrochromatography utilizing modified cyclodextrins as stationary phases. | Enantiomer separation by electrochromatography employing modified cyclodextrins as stationary phases is performed in two ways. (i) Polysiloxane-linked permethylated beta-cyclodextrin (Chirasil-Dex 1) or related selectors are coated and immobilized onto the inner surface of a capillary column. Enantiomer separation is p... |
10496657 | A new specific enzyme immunoassay allowing an efficient pharmacokinetic evaluation of gamma-cyclodextrin after intravenous administration to rats. | <h4>Purpose</h4>Because of its ability to form complexes with drugs, gamma-cyclodextrin is of great potential value in pharmaceutical formulations. The biological fate of y-cyclodextrin must therefore be considered in safety evaluation, using sensitive and specific methods applicable to biological fluids.<h4>Methods</h... |
10496596 | Muscular cushions of the vessel wall at the periphery of thyroid nodules. | Insufficient vascular compliance might be the cause of regressive changes commonly observed within long-standing thyroid nodules. This hypothesis induced us to study the morphology of vessels at the periphery of nodular thyroid lesions. A series of 104 consecutive nodular goiters and 10 follicular adenomas were collect... |
10496367 | Cellular uptake, cytotoxicity and DNA-binding studies of the novel imidazoacridinone antineoplastic agent C1311. | C1311 is a novel therapeutic agent with potent activity against experimental colorectal cancer that has been selected for entry into clinical trial. The compound has previously been shown to have DNA-binding properties and to inhibit the catalytic activity of topoisomerase II. In this study, cellular uptake and mechani... |
10496345 | Ca2+-induced changes in energy metabolism and viability of melanoma cells. | Cancer cells are characterized by a high rate of glycolysis, which is their primary energy source. We show here that a rise in intracellular-free calcium ion (Ca2+), induced by Ca2+-ionophore A23187, exerted a deleterious effect on glycolysis and viability of B16 melanoma cells. Ca2+-ionophore caused a dose-dependent d... |
10491120 | Mapping of an epitope recognized by a neutralizing monoclonal antibody specific to toxin Cn2 from the scorpion Centruroides noxius, using discontinuous synthetic peptides. | The Na+-channel-affecting toxin Cn2 represents the major and one of the most toxic components of the venom of the Mexican scorpion Centruroides noxius Hoffmann. A monoclonal antibody BCF2 raised against Cn2 has been shown previously to be able to neutralize the toxic effect of Cn2 and of the whole venom of C. noxius. I... |
10491073 | Scorpion toxins specific for Na+-channels. | Na+-channel specific scorpion toxins are peptides of 60-76 amino acid residues in length, tightly bound by four disulfide bridges. The complete amino acid sequence of 85 distinct peptides are presently known. For some toxins, the three-dimensional structure has been solved by X-ray diffraction and NMR spectroscopy. A c... |
10493590 | Histidine placement in de novo-designed heme proteins. | The effects of histidine residue placement in a de novo-designed four-alpha-helix bundle are investigated by placement of histidine residues at coiled coil heptad a positions in two distinct heptads and at each position within a single heptad repeat of our prototype heme protein maquette, [H10H24]2 [[Ac-CGGGELWKL x HEE... |
10493583 | Functional analyses of AmpC beta-lactamase through differential stability. | Despite decades of intense study, the complementarity of beta-lactams for beta-lactamases and penicillin binding proteins is poorly understood. For most of these enzymes, beta-lactam binding involves rapid formation of a covalent intermediate. This makes measuring the equilibrium between bound and free beta-lactam diff... |
10493575 | Structural changes in the C-terminus of Ca2+-bound rat S100B (beta beta) upon binding to a peptide derived from the C-terminal regulatory domain of p53. | S100B(beta beta) is a dimeric Ca2+-binding protein that interacts with p53, inhibits its phosphorylation by protein kinase C (PKC) and promotes disassembly of the p53 tetramer. Likewise, a 22 residue peptide derived from the C-terminal regulatory domain of p53 has been shown to interact with S100B(beta beta) in a Ca2+-... |
10489532 | Examination of ionic liquids and their interaction with molecules, when used as stationary phases in gas chromatography. | Stable room-temperature ionic liquids (RTILs) have been used as novel reaction solvents. They can solubilize complex polar molecules such as cyclodextrins and glycopeptides. Their wetting ability and viscosity allow them to be coated onto fused silica capillaries. Thus, 1-butyl-3-methylimidazolium hexafluorophosphate a... |
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