bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the DiversiLab Repetitive Element PCR System with
spa
Typing and Pulsed-Field Gel Electrophoresis for Clonal Characterization of Methicillin-Resistant Staphylococcus aureus
Authors: Babouee B. , Frei R. , Schultheiss E. , Widmer A. F. , Goldenberger D.
Published: February 2011

The emergence of methicillin-resistant
Staphylococcus aureus
(MRSA) has become an increasing problem worldwide in recent decades. Molecular typing methods have been developed to identify clonality of strains and monitor spread of MRSA. We compared a new commercially available DiversiLab (DL) repetitive element PCR system with
spa
typing,
spa
clonal cluster analysis, and pulsed-field gel electrophoresis (PFGE) in terms of discriminatory power and concordance. A collection of 106 well-defined MRSA strains from our hospital was analyzed, isolated between 1994 and 2006. In addition, we analyzed 6 USA300 strains collected in our institution. DL typing separated the 106 MRSA isolates in 10 distinct clusters and 8 singleton patterns. Clustering analysis into
spa
clonal complexes resulted in 3 clusters:
spa
-CC 067/548,
spa
-CC 008, and
spa
-CC 012. The discriminatory powers (Simpson's index of diversity) were 0.982, 0.950, 0.846, and 0.757 for PFGE,
spa
typing, DL typing, and
spa
clonal clustering, respectively. DL typing and
spa
clonal clustering showed the highest concordance, calculated by adjusted Rand's coefficients. The 6 USA300 isolates grouped homogeneously into distinct PFGE and DL clusters, and all belonged to
spa
type t008 and
spa
-CC 008. Among the three methods, DL proved to be rapid and easy to perform. DL typing qualifies for initial screening during outbreak investigation. However, compared to PFGE and
spa
typing, DL typing has limited discriminatory power and therefore should be complemented by more discriminative methods in isolates that share identical DL patterns.
Detection of Hemagglutinin Variants of the Pandemic Influenza A (H1N1) 2009 Virus by Pyrosequencing
Authors: Levine Marnie , Sheu Tiffany G. , Gubareva Larisa V. , Mishin Vasiliy P.
Published: February 2011

For influenza viruses, pyrosequencing has been successfully applied to the high-throughput detection of resistance markers in genes encoding the drug-targeted M2 protein and neuraminidase. In this study, we expanded the utility of this assay to the detection of multiple receptor binding variants of the hemagglutinin protein of influenza viruses directly in clinical specimens. Specifically, a customized pyrosequencing protocol that permits detection of virus variants with the D, G, N, or E amino acid at position 222 in the hemagglutinin of the 2009 pandemic influenza A (H1N1) virus was developed. This customized pyrosequencing protocol was applied to the analysis of 241 clinical specimens. The use of the optimized nucleotide dispensation order allowed detection of mixtures of variants in 10 samples (4.1%) which the standard cyclic nucleotide dispensation protocol failed to detect. The optimized pyrosequencing protocol is expected to provide a more accurate tool in the analysis of virus variant composition.
Both Nonstructural Proteins NS1 and NS2 of Pneumonia Virus of Mice are Inhibitors of the Interferon Type I and Type III Responses In Vivo
Authors: Heinze Britta , Frey Stefanie , Mordstein Markus , Schmitt-Gräff Anette , Ehl Stephan , Buchholz Ursula J. , Collins Peter L. , Staeheli Peter , Krempl Christine D.
Published: February 2011

Infection of mice with pneumonia virus of mice (PVM) provides a convenient experimental pathogenesis model in a natural host for a human respiratory syncytial virus-related virus. Extending our previous work showing that the PVM nonstructural (NS) proteins were pathogenicity factors in mice, we identify both the NS1 and NS2 proteins as antagonists of alpha/beta interferon (IFN-α/β) and IFN-λ by use of recombinant PVM (rPVM) with single and combined deletions of the NS proteins (ΔNS1, ΔNS2, and ΔNS1 ΔNS2). Wild-type and NS deletion PVMs were evaluated for growth and pathogenesis by infecting knockout mice that lack functional receptors to IFN-α/β, IFN-λ, or both. The absence of the receptor to IFN-α/β (IFNAR) or IFN-λ (interleukin-28 receptor α chain [IL-28Rα]) individually did not reverse the attenuated virulence of the NS deletion viruses although loss of IFNAR partially restored replication efficiency. When both receptors were deleted, replication and virulence were largely rescued for rPVM ΔNS1 and were significantly but not completely rescued for rPVM ΔNS2. As for rPVM ΔNS1 ΔNS2, the effect was mostly limited to partial enhancement of replication. This indicates that both IFN-α/β and IFN-λ contributed to restricting the NS deletion viruses, with the former playing the greater role. Interestingly, the replication and virulence of wild-type PVM were completely unaffected by the presence or absence of functional receptors to IFN-α/β and IFN-λ, indicating that both systems are strongly suppressed during infection. However, pretreatment of mice with IFN-α/β was protective against lethal rPVM challenge, whereas pretreatment with IFN-λ delayed but did not prevent disease and, in some cases, reduced mortality. The fact that virulence of rPVM lacking NS2 was not recovered completely when both interferon receptors were deleted suggests that NS2 may have further functions outside the IFN system.
Restriction of Porcine Endogenous Retrovirus by Porcine APOBEC3 Cytidine Deaminases
Authors: Dörrschuck Eva , Fischer Nicole , Bravo Ignacio G. , Hanschmann Kay-Martin , Kuiper Heidi , Spötter Andreas , Möller Ronny , Cichutek Klaus , Münk Carsten , Tönjes Ralf R.
Published: February 2011

Xenotransplantation of porcine cells, tissues, and organs shows promise to surmount the shortage of human donor materials. Among the barriers to pig-to-human xenotransplantation are porcine endogenous retroviruses (PERV) since functional representatives of the two polytropic classes, PERV-A and PERV-B, are able to infect human embryonic kidney cells
in vitro
, suggesting that a xenozoonosis
in vivo
could occur. To assess the capacity of human and porcine cells to counteract PERV infections, we analyzed human and porcine APOBEC3 (A3) proteins. This multigene family of cytidine deaminases contributes to the cellular intrinsic immunity and act as potent inhibitors of retroviruses and retrotransposons. Our data show that the porcine
A3
gene locus on chromosome 5 consists of the two single-domain genes
A3Z2
and
A3Z3
. The evolutionary relationships of the
A3Z3
genes reflect the evolutionary history of mammals. The two
A3
genes encode at least four different mRNAs: A3Z2, A3Z3, A3Z2-Z3, and A3Z2-Z3 splice variant A (SVA). Porcine and human A3s have been tested toward their antiretroviral activity against PERV and murine leukemia virus (MuLV) using novel single-round reporter viruses. The porcine A3Z2, A3Z3 and A3Z2-Z3 were packaged into PERV particles and inhibited PERV replication in a dose-dependent manner. The antiretroviral effect correlated with editing by the porcine A3s with a trinucleotide preference for 5′ TGC for A3Z2 and A3Z2-Z3 and 5′ CAC for A3Z3. These results strongly imply that human and porcine A3s could inhibit PERV replication
in vivo
, thereby reducing the risk of infection of human cells by PERV in the context of pig-to-human xenotransplantation.
In Vivo
Fitness Associated with High Virulence in a Vertebrate Virus Is a Complex Trait Regulated by Host Entry, Replication, and Shedding
Authors: Wargo Andrew R. , Kurath Gael
Published: February 2011

The relationship between pathogen fitness and virulence is typically examined by quantifying only one or two pathogen fitness traits. More specifically, it is regularly assumed that within-host replication, as a precursor to transmission, is the driving force behind virulence. In reality, many traits contribute to pathogen fitness, and each trait could drive the evolution of virulence in different ways. Here, we independently quantified four viral infection cycle traits, namely, host entry, within-host replication, within-host coinfection fitness, and shedding,
in vivo
, in the vertebrate virus
Infectious hematopoietic necrosis virus
(IHNV). We examined how each of these stages of the viral infection cycle contributes to the fitness of IHNV genotypes that differ in virulence in rainbow trout. This enabled us to determine how infection cycle fitness traits are independently associated with virulence. We found that viral fitness was independently regulated by each of the traits examined, with the largest impact on fitness being provided by within-host replication. Furthermore, the more virulent of the two genotypes of IHNV we used had advantages in all of the traits quantified. Our results are thus congruent with the assumption that virulence and within-host replication are correlated but suggest that infection cycle fitness is complex and that replication is not the only trait associated with virulence.
Epitope-Specific CD8+T Lymphocytes Cross-Recognize Mutant Simian Immunodeficiency Virus (SIV) Sequences but Fail To Contain Very Early Evolution and Eventual Fixation of Epitope Escape Mutations during SIV Infection
Authors: Cale Evan M. , Hraber Peter , Giorgi Elena E. , Fischer Will , Bhattacharya Tanmoy , Leitner Thomas , Yeh Wendy W. , Gleasner Cheryl , Green Lance D. , Han Cliff S. , Korber Bette , Letvin Norman L.
Published: February 2011

Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) evade containment by CD8+T lymphocytes through focused epitope mutations. However, because of limitations in the numbers of viral sequences that can be sampled, traditional sequencing technologies have not provided a true representation of the plasticity of these viruses or the intensity of CD8+T lymphocyte-mediated selection pressure. Moreover, the strategy by which CD8+T lymphocytes contain evolving viral quasispecies has not been characterized fully. In the present study we have employed ultradeep 454 pyrosequencing of virus and simultaneous staining of CD8+T lymphocytes with multiple tetramers in the SIV/rhesus monkey model to explore the coevolution of virus and the cellular immune response during primary infection. We demonstrated that cytotoxic T lymphocyte (CTL)-mediated selection pressure on the infecting virus was manifested by epitope mutations as early as 21 days following infection. We also showed that CD8+T lymphocytes cross-recognized wild-type and mutant epitopes and that these cross-reactive cell populations were present at a time when mutant forms of virus were present at frequencies of as low as 1 in 22,000 sequenced clones. Surprisingly, these cross-reactive cells became enriched in the epitope-specific CD8+T lymphocyte population as viruses with mutant epitope sequences largely replaced those with epitope sequences of the transmitted virus. These studies demonstrate that mutant epitope-specific CD8+T lymphocytes that are present at a time when viral mutant epitope sequences are detected at extremely low frequencies fail to contain the later accumulation and fixation of the mutant epitope sequences in the viral quasispecies.
Human Cytomegalovirus pUS27 G Protein-Coupled Receptor Homologue Is Required for Efficient Spread by the Extracellular Route but Not for Direct Cell-to-Cell Spread
Authors: O'Connor Christine M. , Shenk Thomas
Published: February 2011

Human cytomegalovirus (HCMV) encodes multiple G protein-coupled receptor (GPCR) homologues, including pUS27, pUS28, pUL33, and pUL78. To explore the function of pUS27, we constructed pUS27-deficient derivates of two clinical isolates of HCMV. BFX-GFP
stop
US27 is a FIX variant with a single base pair change in the US27 open reading frame, generating a stop codon that ablates accumulation of the GPCR homologue, and TB40/E-mCherry
dl
US27 lacks the entire US27 coding region. BFX-GFP
stop
US27 generated 10-fold less extracellular progeny in fibroblasts, and TB40/E-mCherry
dl
US27 exhibited a similar defect in endothelial cells. The pUS27-deficient FIX derivative produced normal quantities of viral DNA and viral proteins tested, and a late virion protein was appropriately localized to the cytoplasmic assembly zone. After infection at a low multiplicity with wild-type FIX virus, neutralizing antibody reduced the accumulation of intracellular viral DNA and intracellular virions, as would be expected if the virus is limited to direct cell-to-cell spread by neutralization of extracellular virus. In contrast, the antibody had little effect on the spread of the BFX-GFP
stop
US27 virus. Further, after infection at a low multiplicity, the pUS27-deficient TB40/E virus exhibited a growth defect in endothelial cells, where the clinical isolate normally generates extracellular virus, but the TB40/E derivative exhibited little defect in epithelial cells, where the wild-type virus does not produce extracellular virus. Thus, mutants lacking pUS27 rely primarily on direct cell-to-cell spread, and we conclude that the viral GCPR homologue acts at a late stage of the HCMV replication cycle to support spread of virus by the extracellular route.
Efficient Rescue of Recombinant Lassa Virus Reveals the Influence of S Segment Noncoding Regions on Virus Replication and Virulence
Authors: Albariño César G. , Bird Brian H. , Chakrabarti Ayan K. , Dodd Kimberly A. , Erickson Bobbie Rae , Nichol Stuart T.
Published: February 2011

Lassa virus (LASV), is a significant cause of severe, often fatal, hemorrhagic fever in humans throughout western Africa, with an estimated 100,000 infections each year. No vaccines are commercially available. We report the development of an efficient reverse genetics system to rescue recombinant LASV and to investigate the contributions of the long 5′ and 3′ noncoding regions (NCRs) of the S genomic segment to
in
vitro
growth and
in
vivo
virulence. This work demonstrates that deletions of large portions of these NCRs confer an attenuated phenotype and are a first step toward further insights into the high virulence of LASV.
An Insertion Mutation That Distorts Antibody Binding Site Architecture Enhances Function of a Human Antibody
Authors: Krause Jens C. , Ekiert Damian C. , Tumpey Terrence M. , Smith Patricia B. , Wilson Ian A. , Crowe James E.
Published: February 2011

The structural and functional significance of somatic insertions and deletions in antibody chains is unclear. Here, we demonstrate that a naturally occurring three-amino-acid insertion within the influenza virus-specific human monoclonal antibody 2D1 heavy-chain variable region reconfigures the antibody-combining site and contributes to its high potency against the 1918 and 2009 pandemic H1N1 influenza viruses. The insertion arose through a series of events, including a somatic point mutation in a predicted hot-spot motif, introduction of a new hot-spot motif, a molecular duplication due to polymerase slippage, a deletion due to misalignment, and additional somatic point mutations. Atomic resolution structures of the wild-type antibody and a variant in which the insertion was removed revealed that the three-amino-acid insertion near the base of heavy-chain complementarity-determining region (CDR) H2 resulted in a bulge in that loop. This enlarged CDR H2 loop impinges on adjacent regions, causing distortion of the CDR H1 architecture and its displacement away from the antigen-combining site. Removal of the insertion restores the canonical structure of CDR H1 and CDR H2, but binding, neutralization activity, and
in vivo
activity were reduced markedly because of steric conflict of CDR H1 with the hemagglutinin antigen.

IMPORTANCE
Antibody diversification through VDJ gene recombination, junctional variation, and somatic hypermutation has clear importance for the generation of mature, high-affinity antibodies. Between 1.3 and 6.5% of antibody variable gene sequences have been reported to contain insertions or deletions, but their structural and functional significance remains less well defined. The pandemic influenza virus hemagglutinin antibody 2D1 data suggest that somatic insertions and deletions in antibody genes contribute important structural and functional features. We predict that such features can be critical for affinity and functional maturation of the human antibody repertoire.
Synthesis and reactions of furocondensed derivatives
Authors: Krutošíková Alžbeta , Kováč Jaroslav , Dandárová Miroslava
Published: February 2011

This paper describes the preparation of furo[2',3' :4,5]pyrollo[1,2-d]-1,2,4-triazolo[3,4-f]-1,2,4-triazines (V) from 4H-furo[3,2-b]pyrolle-5-carboxhydrazide (I, and benzo[b]furo[2',3' :4,5]-pyrrolo[1,2-d]-1,2,4-triazolo[3,4-f]-1,2,4-triazines (VIII) from 1H-benzo[b]furo[3,2-b]pyrrole-2-carboxhydrazide. Compound I reacts with triethyl orthoformate or orthoacetate to give 1,2-dihydro[2',3'-4,5]pyrrolo[1,2-d]-1,2,4-triazin-1-one or its methyl analogue II. Compounds of general formula II afford with phosphorus pentasulfide thiones III; III yields IV with hydrazine. Cyclization of IVwith triethyl orthoformate or orthoacetate furnished compounds V. Similarly, VIgives with hydrazine VII, which, upon reaction with triethyl orthoformate or orthoacetate affords VIII.
Synthesis of some 1,2-unsaturated analogues of androgens with the cyclopropane ring in 4,5-position
Authors: Joska Jiří , Farkaš Jan
Published: February 2011

1,2-Unsaturated analogues of testosterone XI and XVII carrying the cyclopropane ring in position 4,5 were prepared from the corresponding 3-oxo derivatives VIII and XIV viathe enol acetates IX and XV and the bromo ketones X and XVI followed by dehydrohalogenation with sym-collidine. Analogues of androstenedione XXI and testosterone XIX with the epoxide ring in 2β,19-position were prepared from the bromo ketone XVI with potassium methoxide.
Electrostatic effects on ionization equilibria: Solvent dependence
Authors: Kalfus Karel , Friedl Zdeněk , Exner Otto
Published: February 2011

Apparent dissociation constants of 3-substituted bicyclo[2,2,2]-octane-1-carboxylic acids I-III and of several substituted benzoic acids were measured in four pure solvents. The results - together with numerous literature data concerning dissociation in other solvents and in the gas phase - were compared with the prediction of the electrostatic theory. The theory fails to reproduce the essential features of the solvent dependence as it predicts generally too small effects and does not differentiate between protic and aprotic solvents. The mentioned goal cannot be achieved by any more sophisticated cavity model or by any other theory as far as it characterizes the solvent only through its bulk permittivity.
Azido derivatives of 1,6-anhydro-β-D-hexopyranoses corresponding to 3-deoxy- and 4-deoxy-D-glucosamine
Authors: Černý Ivan , Trnka Tomáš , Černý Miloslav
Published: February 2011

Nucleophilic substitution of the tosyloxy group in 1,6-anhydro-3-deoxy-2-O-p-toluenesulfonyl-β-D-arabino-hexopyranose (II) with lithium azide gave derivative V which was acetolysed and deacetylated to 2-azido-2,3-dideoxy-D-ribo-hexose (IX). The oxirane ring in 1,6 : 2,3-dianhydro-4-deoxy-β-D-lyxo-hexopyranose (XII) was opened using lithium azide and the mixture of 2- and 3-azido derivatives XIII of D-xylo and XIV of D-arabino configuration formed was separated by an extraction procedure after previous selective trimethylsilylation. Azido derivative XIII was converted to 2-azido-2,4-dideoxy-D-xylo-hexose (XIX) on acetolysis and deacetylation. Hydrogenation of azido derivatives IX and XIX on palladium on charcoal and subsequent N-acetylation gave corresponding 3- and 4-deoxy derivatives of D-glucosamine, XI and XXI.
Analysis of the anodic processes of 8-hydroxyquinoline in AcOH-AcONa buffer on mercury
Authors: Muller Carlos , Claret José , Feliu Juan M. , Virgili José
Published: February 2011

Polarographic current-potential characteristics for the anodic behaviour of 8-hydroxyquinoline (QH) in a pH ~ 5 aqueous AcOH-AcONa buffer have been examined in detail at low concentrations. The electrode reaction is 2 Hg + 2 QH ⇋ Hg2Q2 + 2 H+ + 2 e. The study of the polarographic wave has been performed introducing the Frumkin isotherm in the treatment of adsorption. Also, the inhibition of electrode process due to the films formed on electrode surface has been discussed.
The influence of monomer structure on polypropylene modification in emulsion
Authors: Citovický Pavol , Mikulášová Darina , Mejzlík Jiří , Majer Josef , Chrástová Viera , Beniska Jozef
Published: February 2011

Oxidized isotactic polypropylene powder is chemically modified by monomers of widely differing structure, the reaction being carried out at 30 °C in aqueous emulsion in the presence of a ferrous chelate as an activator. Apart from the polymer bonded to the polypropylene carrier also some homopolymer is formed simultaneously during this heterogeneous polymerization initiated by polypropylene peroxides. The mutual proportion and amount of the resulting polymers may be considerably influenced by the properties of the monomer used, such as by its partial or total solubility in water, its polarity and reactivity as well as by the substituent size. Moreover, the chelate and emulsifier type as well as the presence of organic liquid phase in the system play also an important role. The mechanistic discussion is focused to the early initiation stage of the polymerization. This period, together with the active participation of the monomer, is decisive for the formation of both polymer types produced in the system. The results obtained are in accordance with the observed heterogeneous distribution of -O-O- groups in oxidized polypropylene.
Liquid-liquid equilibrium, modelling the temperature dependence of mutual solubility of liquids
Authors: Novák Josef P. , Matouš Jaroslav , Pick Jiří
Published: February 2011

The applicability of the modified Wilson equation to correlation of the temperature dependence of mutual solubility of liquids is demonstrated. The position of the critical point is fixed, and the linear dependence of parameters on temperature is used in calculating. The method was applied with success to the aqueous solutions of 1-butanol, isobutyl alcohol, phenol and 2-butanone and to the nonaqueous system cyclohexane-methanol.
Reaktionen mit 3-Chlorochinoxalin-2-carbaldehyd
Authors: Lippmann Eberhard , Shilov Wladimir
Published: February 2011

Das Chlor im 3-Chlorchinoxalin-2-carbaldehyd(Ia) wird nucleophil substituiert. CH-acide-Verbindungen und N-Nucleophile reagieren an der Formylgruppe. Das Hydrazon und das Oxim von Ia werden unter Ringschlussreaktionen zu 1,2,3-Triazolo[1,5-a]chinoxalin und 3-Cyanochinoxalin-2-(1H)-on (VIII) ubergefuhrt. Mit Thioglykolsaureethylester entsteht aus Ia Thieno[2,3-b]chinoxalin-2-carbonsaureethylester (IX). Die Umsetzung von 2-Chloro-3-methylchinoxalin (IIa) mit nucleophilen Reagenzien wird durchgefuhrt.
The possibilities of polarography in the chemistry of nitroazoles
Authors: Dumanović Dragica , Ćirić Janka , Kosanović Djuro , Jeremić Dragoslav
Published: February 2011

Based on systematic investigation of mononitroimidazoles, selective polarographic and spectrophotometric methods for determination of nitrazole compounds in reaction mixture are proposed. It was proved that the selectivity is based on the different properties of the nitro group due to the effects of the nitro group position in the ring, the type and position of the other substituents and on the fact whether the compound is N-substituted or not. The proposed methods can be successfully used for monitoring the synthetic procedures and decreasing the number of experiments for optimization. Based on the anticipated and proved behaviour of the nitro compounds of pyrazole, novel mononitropyrazole derivatives were synthetized in a new way and with high yields. Applying the polarographic method it was discovered that during N-substitution of tautomeric mononitroimidazole and mononitropyrazole substrates other byproducts were obtained besides the main products and undesired isomers. The products were identified and then a correct and more complete N-substitution scheme could be given. Following quantitatively these N-substitution processes conclusions which directly concern the mechanism of reactions were drawn.
Alkaloids of Gloriosa superba L.
Authors: Dvoráčková Svatava , Sedmera Petr , Potěšilová Helena , Šantavý František , Šimánek Vilím
Published: February 2011

From the corms and seeds of Indian Gloriosa superba L., 19 tropolone and 3 non-tropolone alkaloids were isolated. Of these, cornigerine, (S)-(+)-floramultine (bechuanine), 1,12-dihydroxy-2,10,11-trimethoxyhomoaporphine, colchicamide, 2-demethylcolchifoline, 3-demethylcolchifoline, colchicoside, and isoperlolyrine are reported for the first time from this plant. The new alkaloid isoperlolyrine has been assigned the structure III. This is the first alkaloid of carboline type found in the subfamily Wurmbaeoideae.
Spectroscopic study of thiamine-phenylcarbamate complexes possessing local anaesthetic effect
Authors: Remko Milan , Liptaj Tibor , Veselovská Juliana , Čižmárik Jozef
Published: February 2011

UV and 1H NMR spectroscopy were used to study the interaction of thiamine with 1(2-(4-methoxyphenylcarbamoyl)ethyl) piperidinium chloride, a local anaesthetic drug. UV spectroscopy did not bring a direct evidence of the existence of a local anaesthetic-thiamine omplex. On the contrary, the upfield shifts of certain protons in the mixtures local anaesthetic with thiamine were interpreted as a result of a π-complex formation between the aromatic nucleus and the pyrimidine ring of thiamine
Semisynthetic cephalosporines. Synthesis of some substituted tetrazolyl acetic and propionic acids
Authors: Janda Ľubomír , Votický Zdeno , Jakubcová Jozefína , Světlík Jan , Grimová Jaroslava , Maturová Eva
Published: February 2011

The N-alkylation of 5-[5-(substituted phenyl)-2-furyl]-1H-tetrazoles with ethyl bromoacetate or ethyl 3-bromopropionate afforded a mixture of 5-substituted ethyl 1- and 2-tetrazoyl acetates or propionates, which were separated and hydrolyzed to the corresponding 1- and 2-acetic or propionic acids, and used as intermediates for the synthesis of semisynthetic cephalosporine antibiotics. The prepared tetrazolyl acetic acids exhibited antiinflammatory activity.
Thioxanthene derivatives with neurotropic activity; synthesis of 9-(3-dimethylaminopropylidene)-2-(methylthiomethyl)thioxanthene and of some related compounds
Authors: Kmoníček Vojtěch , Bártl Václav , Protiva Miroslav
Published: February 2011

A reaction of 2-(bromomethyl)thioxanthone with sodium methanethiolate with sodium methanethiolate gave 2-(methylthiomethyl)thioxanthone (II) which was transformed by treatment with 3-dimethylaminopropylmagnesium chloride to the tertiary alcohol IV. Its dehydration by heating with dilute sulfuric acid afforded the title compound I. An attempt at preparing the analogous 2-(methoxymethyl) derivative proceeded similarly but failed in the stage of the acid-catalyzed dehydration of the tertiary alcohol V. Acids VIII-XII and the nitrile XIII were prepared as potential intermediates. Compound I has properties of a tranquilizer with a weak cataleptic activity.
11-(4-Piperidylidene)-6,11-dihydrodibenzo[b,e]thiepins as potential antipsychotic agents; Synthesis and pharmacology
Authors: Bártl Václav , Dlabač Antonín , Valchář Martin , Protiva Miroslav
Published: February 2011

The secondary amine VIIIb, prepared by demethylation of 2-chloro-11-(1-methyl-4-piperidylidene)-6,11-dihydrodibenzo[b,e]thiepin (IVb), afforded by alkylation with 2-bromoethanol the amino alcohol Vb which was esterified to the decanoate VIb. A reaction of 5-fluorophthalide with the sodium salt of 4-chlorothiophenol in boiling 1-butanol gave the acid X which afforded by cyclization 2-chloro-8-fluorodibenzo[b,e]thiepin-11(6H)-one (XII). Treatment with 1-methyl-4-piperidylmagnesium chloride resulted in the tertiary alcohol IXc which was transformed by an acid catalyzed dehydration to the desired unsaturated amine IVc. While compounds Vb and IVc showed properties of mild tranquillizers, the ester VIb, surprisingly, brought about a mild dopaminomimetic activity (it potentiates the action of apomorphine, has anticataleptic activity and lowers the homovanillic acid level in the striatum of rat brain.
Post-proline endopeptidase, further characterization of the enzyme from pig kidneys
Authors: Hauzer Karel , Barth Tomislav , Servítová Linda , Jošt Karel
Published: February 2011

A post-proline endopeptidase (EC 3.4.21.26) was isolated from pig kidneys using a modified method described earlier. The enzyme was further purified by ion exchange chromatography on DEAE-Sephacel. The final product contained about 95% of post-proline endopeptidase. The enzyme molecule consisted of one peptide chain with a relative molecular mass of 65 600 to 70 000, containing a large proportion of acidic and alifatic amino acids (glutamic acid, aspartic acid and leucine) and the N-terminus was formed by aspartic acid or asparagine. In order to prevent losses of enzyme activity, thiol compounds has to be added.
A supersensitive spectrophotometric method for the determination of uranium(VI) with eriochromazurol B in the presence of tensides
Authors: Pištělka Milan , Stojek Bohumil , Havel Josef
Published: February 2011

The influence of various tensides on the sensitivity of the reaction of uranyl with chromatographically pure Eriochromazurol B (2'',6''-dichloro-3,3'-dimethyl-4-hydroxyfuchsone-5,5'-dicarboxylic acid) was studied and considerable bathochromic and hyperchromic effects were observed. The reaction is most sensitive in the presence of cetyltrimethylammonium or certylpyridinium bromide. Based on the study of the equlibria and optimization of the conditions, a method is suggested for the determination of uranium traces in waters consisting in the measurement of absorbance at 624 nm at pH 5. With the molar absorptivity value of 136 000, the method ranks among the most sensitive spectrophotometric methods of determination of uranium in general. The uranium traces in waters can conveniently be extracted with tri-n-octylamine and reextracted into an aqueous phase. For 10 ml samples, the detection limit is 0.025 ppm uranium. The results obtained are evaluated statistically.
Kinetics and mechanism of methanolysis of benzoyl derivatives of substituted phenylureas and phenylthioureas
Authors: Kaválek Jaromír , El Bahaie Said , Štěrba Vojeslav
Published: February 2011

The methanolysis rate constants and dissociation constants have been measured of benzoyl derivatives of substituted phenylureas and phenylthioureas. The dissociation constants of the thio derivatives are higher by 1 order of magnitude and the rate constants are higher by 2 orders of magnitude than the respective values of the oxygen analogues. Logarithms of the rate and dissociation constants have been correlated with the Hammet σ constant; the ρ constant of the methanolysis of the oxygen derivatives is almost 2x higher than that of the thio derivatives, which is explained by a change in the rate-limiting step. Methylation of the phenyl nitrogen atom increases the acidity by almost 2 orders of magnitude. This effect is due obviously to steric hindrance to the conjugation with the adjacent carbonyl or thiocarbonyl group.
The crystal and molecular structure of the copper(II) bis(dialyldithiocarbamate) complex
Authors: Kellö Eleonóra , Kettmann Victor , Garaj Ján
Published: February 2011

The crystal structure of {Cu[S2CN(C3H5)2]2}2 was solved by the single crystal method of X-ray structural analysis. The substance crystallized as a dimer in the triclinic system with space group of PI and latice parameters a = 1.0161 (4), b =0.9294(4), c = 1.0518(3) nm, α = 77.46(3), β = 77.10(3), γ = 89.02(3)°. The structure was refined by the least squares method to a final value of R = 4.9% using all the 1 713 observed reflections. The crystal structure consists of dimeric molecules, where each pair of centrosymmetrically dependent Cu atoms lies at a distance of 0.3742 nm. The coordination polyhedron of the Cu atom is a tetragonal pyramid, where the four sulphur atoms lie at distances of Cu-S1 0.2314, Cu-S2 0.2309, Cu-S3 0.2324, Cu-S4 0.2328 and are approximately in a place from which the Cu atoms lies at a distance of 0.026 nm. The fifth, longer bond, Cu-S'4 0.2888 nm forms the apex of the tetragonal pyramid. In the streochemistry of the dithiocarbamate ligands of the studied substances there are no marked differences in the bond lengths and corresponding angles compared with the values for the solvent structures of the other dialkyl-dtc complexes. The lengths of the sulphur-carbon bonds lie in the range from 0.170 to 0.173 nm and both lengths of the C(sp)2 - N(sp2) bonds equal to 0.134 and 0.133 nm indicate marked double bond character of the C-N bond. The S2CN ligand fragment is planar. In the alyl part of the ligand, the N-C bond lengths lie in the range 0.147-0.149 nm, the average C-C bond length is 0.149 nm and C=C bond length is 0.132 nm.
Synthesis and properties of 4-amino-5-(5-X-2-furyl)thiazole derivatives
Authors: Krapivin Gennadii D. , Jurášek Adolf , Kováč Jaroslav , Kul'nevich Vladimír G.
Published: February 2011

Reaction of dipotassium cyanimidodithiocarbonate ((KS)2C=N-CN) with 5-X-furfuryl halogenides (X=NO2, CHO) and 4-nitrobenzyl bromide gives the substituted esters which, in alkali medium, gives the carbanions undergoing cyclization to 4-amino-5-(5-X-2-furyl)thiazoles and 4-amino-5-(4-nitrophenyl)-2-(4-nitrobenzylthio)thiazole, respectively. Reaction of 5-X-furfuryl halogenides or 4-nitrobenzyl bromide with potassium methyl cyanimidodithiocarbonate (KSC(SCH3)=N-CN) gives the esters which are cyclized to 4-amino-2-methylthio-5-substituted thiazoles. The starting esters with X = COOCH3 give no carbanion and undergo no cyclization under the same conditions. The 4-amino group in the thiazole is easily acylated and diazotized, but it does not undergo alkylation. 1H NMR, UV, and IR spectra of the compounds prepared are discussed.
Evolution thermique de N-oxydes D'ω-dialkylamino alcanols-1
Authors: Barbry Didier , Hasiak Bruno
Published: February 2011

The thermolysis of ω-dimethylamino-1-alkanol N-oxides affords ω-hydroxy-1-alkenes with dimethylhydroxylamine in good yields. The other basic products ( amino alcohol and isoxazolidine) involve oxidation-reduction process between the tertiary amine N-oxide and dimethylhydroxylamine, followed by 1,3-dipolar cycloaddition reaction. Pyrolysis of 5-piperidino-1-pentanol N-oxide proceeds on a path similar to the N-dimethyl compounds. The elimination of an hydrogen atom of the heterocycle does not occur: the preferred planar transition state cannot be attained because of the steric requirements of the ring.
Transformations of 3-(methylene)dihydro-2(3H)-furanone derivatives
Authors: Mazal Ctibor , Jurka Zdeněk , Jonas Jaroslav
Published: February 2011

(E) and (Z)-3-(4-toluenesulfonyloxymethylene)dihydro-2(3H)-furanones ((E)-I) and ((Z-I) react with piperidine, pyrrolidine, morpholine, butanethiol, 4-toluenethiol, and 2-naphthalenethiol to give (E)-isomers of the corresponding enamines II-IV and thiomethylene derivatives V-VII in high yields. As has been shown, the reactions proceed with retention of configuration; the initially formed (Z)-II, (Z)-III, (Z)-IV, and (Z)-V isomerize rapidly to the thermodynamicaly more stable (E)-isomers. Ether IX was obtained by reaction of (E)-I with the (E)-isomer of sodium salt of 3-(hydroxymethylene)dihydro-2(3H)-furanone ((E)-VIII) and a mixture of ethers IX and X resulted from reaction of (Z)-I with sodium salt of (E)-VIII. Compounds (E)-I and (Z)-I afforded the corresponding azides(E)-XI and (Z)-XI upon treatment with sodium azide, and hydroxybutanoic acids (E)-XII and (Z)-XII with sodium hydroxide in aqueous acetone. Chloride (E)-XIII, prepared by reacting (E)-I with methanolic hydrogen chloride, furnished with piperdine, pyrrolidine, morpholine, or 2-naphthalenethiol the corresponding (E)-II, (E)-III, (E)-IV, and (E)-VII. Potassium cyanide reacted with (E)-I in dimethylsulfoxide to yield nitrile (E)-XIV. Cycloaddition of the azide (E)-XI to isobutyl vinyl ether or cyclohexyl vinyl ether proceeds quantitatively to give the respective triazolines (E)-XV and (E)-XVI. Alkaline hydrolysis of IX afforded the acid XVII. reduction of (E)-I, (Z)-I, and (E)-VII with chloralane gave the respective butanediols (E)-XVIII, (Z)-XVIII, and (E)-XIX, respectively. Configurations of these substances were elucidated by 1H NMR spectrometry.
13C, 15N, and 19F NMR spectra of 2-phenylhydrazonopropanedinitriles and methyl 2-phenyl hydrazonocyanoacetates
Authors: Lyčka Antonín
Published: February 2011

13C, 15N, and 19F NMR spectra of the azo coupling products obtained from 4-X-benzenediazonium salts (X = H, F, NO2) and propanedinitrile (I) or methyl cyanoacetate (II) and of their 15N isotopomers have been measured. The 13C chemical shifts of cyano groups have been assigned unambiguously on the basis of the 2J(15Nβ13C) coupling constants, and mutual comparison of the 15N chemical shifts in compounds I and II enabled also the assignment of the15N chemical shifts of these groups. The 13C chemical shifts of cyano groups in cis position with respect to free electron pair at Nβ nitrogen atom are shifted downfield, whereas δ(15N) of the same groups exhibit upfield shifts as compared with the cyano in trans position. The azo coupling products of benzenediazonium salts and methyl cyanoacetate contain predominantly the E isomer even after long-term standing in hexadeuteriodimethyl sulphoxide.
Square-wave cathodic adsorptive stripping voltammetry of risperidone
Authors: Taşdemir Ibrahim Hüdai , Çakirer Orhan , Erk Nevin , Kiliç Esma
Published: February 2011

Electrochemical properties and diffusion-adsorption behavior of risperidone (RPN), an antiphyscotic drug, on hanging mercury drop electrode (HMDE) were carried out in Britton–Robinson (BR) buffer. Some electrochemical parameters such as diffusion coefficient, number of transferred electrons and proton participated to its reduction mechanism and surface coverage coefficient were calculated from the results of cyclic voltammetry, square-wave voltammetry and constant potential electrolysis. RPN was found to be reduced with single two-electron/two-proton quasi-reversible mechanism controlled mainly by adsorption with some diffusion contribution at the potential about –1.58 V (vs Ag|AgCl electrode). Experimental parameters were optimized to develop a new, accurate, rapid, selective and simple square-wave cathodic adsorptive stripping voltammetric (SWCAdSV) method for direct determination of RPN in pharmaceutical dosage forms, spiked human urine and human serum samples without time-consuming steps prior to drug assay. This method was based on the relation between the peak current and the concentration of RPN and it was recognized that peak current of reduction wave linearly changes with the concentration of RPN in the concentration range of 1.5–150 nM, when optimum preconcentration potential –0.65 V and optimum preconcentration time 60 s were applied. In this method, limit of detection (LOD) was found as 5.18 nM (2.12 ppb). The method was successfully applied to determine the RPN content of commercial pharmaceutical preparations, spiked human serum and spiked human urine. The method was found to be highly accurate and precise, having a relative standard deviation of less than 4.80% for all applications.
Adenomyoepithelioma of the breast: a review stressing its propensity for malignant transformation
Authors: Hayes Malcolm M
Published: February 2011

This review describes the classification, clinical presentation, pathological features and clinical behaviour of adenomyoepithelioma (AME) of the breast. It is based on an extensive review of the literature and study of a collection of cases built up over a 17-year period at the British Columbia Cancer Agency. The diversity of the morphology encountered in both benign and malignant AME is described. The behaviour of malignant AME seems to be related to the grade of the malignant component.
Evidence for two different broad-specificity oligopeptide transporters in intestinal cell line Caco-2 and colonic cell line CCD841
Authors: Chothe Paresh , Singh Nagendra , Ganapathy Vadivel
Published: February 2011

Recently the existence of two different Na+-coupled oligopeptide transport systems has been described in mammalian cells. These transport systems are distinct from the previously known H+/peptide cotransporters PEPT1 and PEPT2, which transport only dipeptides and tripeptides. To date, the only peptide transport system known to exist in the intestine is PEPT1. Here we investigated the expression of the Na+-coupled oligopeptide transporters in intestinal cell lines, using the hydrolysis-resistant synthetic oligopeptides deltorphin II and [d-Ala2,d-Leu5]enkephalin (DADLE) as model substrates. Caco-2 cells and CCD841 cells, both representing epithelial cells from human intestinal tract, were able to take up these oligopeptides. Uptake of deltorphin II was mostly Na+ dependent, with more than 2 Na+ involved in the uptake process. In contrast, DADLE uptake was only partially Na+ dependent. The uptake of both peptides was also influenced by H+ and Cl−, although to a varying degree. The processes responsible for the uptake of deltorphin II and DADLE could be differentiated not only by their Na+ dependence but also by their modulation by small peptides. Several dipeptides and tripeptides stimulated deltorphin II uptake but inhibited DADLE uptake. These modulating small peptides were, however, not transportable substrates for the transport systems that mediate deltorphin II or DADLE uptake. These two oligopeptide transport systems were also able to take up several nonopioid oligopeptides, consisting of 9–17 amino acids. This represents the first report on the existence of transport systems in intestinal cells that are distinct from PEPT1 and capable of transporting oligopeptides consisting of five or more amino acids.
Live pancreatic acinar imaging of exocytosis using syncollin-pHluorin
Authors: Fernandez Nestor A. , Liang Tao , Gaisano Herbert Y.
Published: February 2011

In this report, a novel live acinar exocytosis imaging technique is described. An adenovirus was engineered, encoding for an endogenous zymogen granule (ZG) protein (syncollin) fused to pHluorin, a pH-dependent green fluorescent protein (GFP). Short-term culture of mouse acini infected with this virus permits exogenous adenoviral protein expression while retaining acinar secretory competence and cell polarity. The syncollin-pHluorin fusion protein was shown to be correctly localized to ZGs, and the pH-dependent fluorescence of pHluorin was retained. Coupled with the use of a spinning disk confocal microscope, the syncollin-pHluorin fusion protein exploits the ZG luminal pH changes that occur during exocytosis to visualize exocytic events of live acinar cells in real-time with high spatial resolution in three dimensions. Apical and basolateral exocytic events were observed on stimulation of acinar cells with maximal and supramaximal cholecystokinin concentrations, respectively. Sequential exocytic events were also observed. Coupled with the use of transgenic mice and/or adenovirus-mediated protein expression, this syncollin-pHluorin imaging method offers a superior approach to studying pancreatic acinar exocytosis. This assay can also be applied to acinar disease models to elucidate the mechanisms implicated in pancreatitis.
Sucrose self-administration and CNS activation in the rat
Authors: Figlewicz Dianne P. , Bennett-Jay Jennifer L. , Kittleson Sepideh , Sipols Alfred J. , Zavosh Aryana
Published: February 2011

We have previously reported that administration of insulin into the arcuate nucleus of the hypothalamus decreases motivation for sucrose, assessed by a self-administration task, in rats. Because the pattern of central nervous system (CNS) activation in association with sucrose self-administration has not been evaluated, in the present study, we measured expression of c-Fos as an index of neuronal activation. We trained rats to bar-press for sucrose, according to a fixed-ratio (FR) or progressive-ratio (PR) schedule and mapped expression of c-Fos immunoreactivity in the CNS, compared with c-Fos expression in handled controls. We observed a unique expression of c-Fos in the medial hypothalamus (the arcuate, paraventricular, retrochiasmatic, dorsomedial, and ventromedial nuclei) in association with the onset of PR performance, and expression of c-Fos in the lateral hypothalamus and the bed nucleus of stria terminalis in association with the onset of FR performance. c-Fos expression was increased in the nucleus accumbens of both FR and PR rats. Our study emphasizes the importance of both hypothalamic energy homeostasis circuitry and limbic circuitry in the performance of a food reward task. Given the role of the medial hypothalamus in regulation of energy balance, our study suggests that this circuitry may contribute to reward regulation within the larger context of energy homeostasis.
Effects of increasing doses of glucagon-like peptide-1 on insulin-releasing phases during intravenous glucose administration in mice
Authors: Chan Hui Min , Jain Ritesh , Ahrén Bo , Pacini Giovanni , D'Argenio David Z.
Published: February 2011

The increase in insulin secretion caused by glucagon-like peptide-1 (GLP-1) and GLP-1 mimetics observed during an intravenous glucose test (IVGTT) has been reported in both normal and disease animal models, as well as in humans. In this study, a hierarchical population modeling approach is used, together with a previously reported model relating glucose to insulin appearance, to determine quantitative in vivo dose-response relationships between GLP-1 dose level and both first- and second-phase insulin release. Parameters of the insulin kinetic model were estimated from the complete set of glucose and insulin data collected in 219 anesthetized nonfasted NMR-imaged mice after intravenous injection of glucose (1 g/kg) alone or with GLP-1 (0.03–100 nmol/kg). The resulting dose-response curves indicate a difference in GLP-1 effect on the two release phases, as is also evident from the different ED50 parameter values (0.107 vs. 6.65 nmol/kg for phase 1 vs. phase 2 insulin release parameters). The first phase of insulin release is gradually augmented with increasing GLP-1 dose, reaching saturation at a dose of ∼1 nmol/kg, while the second-phase release changes more abruptly at GLP-1 doses between 3 and 10 nmol/kg and shows a more pronounced 100-fold increase between control and the high GLP-1 dose of 100 nmol/kg Moreover, separate disposition indices calculated for phase 1 and 2 insulin release, show a different pattern of increase with increasing GLP-1 dose.