bluuebunny/crossref_metadata_2025 huggingface dataset:
A Mutation in the Latency-Related Gene of Bovine Herpesvirus 1 Leads to Impaired Ocular Shedding in Acutely Infected Calves
Authors: Inman Melissa , Lovato Luciane , Doster Alan , Jones Clinton
Published: July 2002

Bovine herpesvirus 1 (BHV-1) is an important pathogen of cattle, and infection is usually initiated in the ocular or nasal cavity. Like other alphaherpesviruses, BHV-1 establishes latency in sensory neurons but has the potential of reactivating from latency and spreading. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA, which is alternatively spliced in trigeminal ganglia during acute infection (L. R. Devireddy and C. Jones, J. Virol. 72:7294–7301, 1998). LR gene products inhibit cell cycle progression (Y. Jiang, A. Hossain, M. T. Winkler, T. Holt, A. Doster, and C. Jones, J. Virol. 72:8133–8142, 1998) and chemically induced apoptosis (J. Ciacci-Zannela, M. Stone, G. Henderson, and C. Jones. J. Virol. 73:9734–9740, 1999). Although these studies suggest that LR gene products play an important role in the latency/pathogenesis of BHV-1, construction of a mutant is necessary to test this hypothesis. Because the bICP0 gene overlaps and is antisense to the LR gene, it was necessary to mutate the LR gene without altering bICP0 expression. This was accomplished by inserting three stop codons near the beginning of the LR RNA, thus interfering with expression of proteins expressed by the LR RNA. The LR mutant virus grew with wild-type (WT) efficiency in bovine kidney (MDBK) cells and expressed bICP0 at least as efficiently as WT BHV-1 or the LR rescued virus. When calves were infected with the LR mutant, we observed a dramatic decrease (3 to 4 log units) in ocular shedding during acute infection relative to WT or the LR rescued virus. In contrast, shedding of the LR mutant from the nasal cavity was not significantly different from that of the WT or the LR rescued virus. Calves infected with the LR mutant exhibited mild clinical symptoms, but they seroconverted. Neutralizing antibody titers were lower in calves infected with the LR mutant, confirming reduced growth. In summary, this study suggests that an LR protein promotes ocular shedding during acute infection of calves.
Identification of a Novel Element Involved in Regulation of the Lytic Switch BZLF1 Gene Promoter of Epstein-Barr Virus
Authors: Kraus Richard J. , Mirocha Sarah J. , Stephany Heather M. , Puchalski Joel R. , Mertz Janet E.
Published: July 2002

Epstein-Barr virus (EBV) is a human herpesvirus capable of establishing a latent state in B lymphocytes. EBV's BZLF1 gene product plays a central role in regulating the switch from latency to productive infection. Here, we identify a sequence element, 5′-CAGGTA-3′, called ZV, located at nucleotides −17 to −12 relative to the transcription initiation site of the BZLF1 promoter. ZV sequence-specifically binds a cellular nuclear factor(s), ZVR. ZVR DNA-binding activity was present in the EBV-negative B-lymphocytic cell line DG75, the EBV-positive B-lymphocytic cell lines GG68 and 721, the cervical cell line C33A, and the kidney cell line CV-1 but not in the breast carcinoma cell line MCF-7. Mutations in ZV that relieve binding of ZVR lead to a two- to fourfold increase in basal expression of the BZLF1 promoter in DG75, C33A, and CV-1 cells. The same mutants exhibited a 40- to 180-fold increase in tetradecanoyl phorbol acetate-ionomycin-induced expression in DG75 cells and a 22-fold increase in C33A cells. Thus, ZVR functions as a regulator of the BZLF1 promoter, repressing transcription when bound to the ZV site in the absence of inducers. No differences in basal or induced transcription between wild-type and ZV mutant BZLF1 promoters were observed in ZVR-negative MCF-7 cells. ZVR failed to bind any of the previously identified negative regulatory elements within the BZLF1 promoter. We conclude that ZV functions as an important regulatory element of the BZLF1 promoter, with ZVR likely playing important roles in the maintenance of latency and reactivation of EBV.
Structure and Assembly of Intracellular Mature Vaccinia Virus: Isolated-Particle Analysis
Authors: Griffiths Gareth , Wepf Roger , Wendt Thomas , Locker Jacomine Krijnse , Cyrklaff Marek , Roos Norbert
Published: July 2002

In a series of papers, we have provided evidence that during its assembly vaccinia virus is enveloped by a membrane cisterna that originates from a specialized, virally modified, smooth-membraned domain of the endoplasmic reticulum (ER). Recently, however, Hollinshead et al. (M. Hollinshead, A. Vanderplasschen, G. I. Smith, and D. J. Vaux, J. Virol. 73:1503–1517, 1999) argued against this hypothesis, based on their interpretations of thin-sectioned material. The present article is the first in a series of papers that describe a comprehensive electron microscopy (EM) analysis of the vaccinia Intracellular Mature Virus (IMV) and the process of its assembly in HeLa cells. In this first study, we analyzed the IMV by on-grid staining, cryo-scanning EM (SEM), and cryo-transmission EM. We focused on the structure of the IMV particle, both after isolation and in the context of viral entry. For the latter, we used high-resolution cryo-SEM combined with cryofixation, as well as a novel approach we developed for investigating vaccinia IMV bound to plasma membrane fragments adsorbed onto EM grids. Our analysis revealed that the IMV is made up of interconnected cisternal and tubular domains that fold upon themselves via a complex topology that includes an S-shaped fold. The viral tubules appear to be eviscerated from the particle during viral infection. Since the structure of the IMV is the result of a complex assembly process, we also provide a working model to explain how a specialized smooth-ER domain can be modulated to form the IMV. We also present theoretical arguments for why it is highly unlikely that the IMV is surrounded by only a single membrane.
Epstein-Barr Virus Nuclear Protein 2 Has at Least Two N-Terminal Domains That Mediate Self-Association
Authors: Harada Shizuko , Yalamanchili Ramana , Kieff Elliott
Published: July 2002

Previous genetic and biochemical analyses have indicated that the Epstein-Barr virus EBNA-2 amino terminus is important for primary B-lymphocyte growth transformation and may be involved in self-association. We now report that EBNA-2 has at least two domains, amino acids 1 to 60 and 96 to 210, which independently mediate homotypic association, 1 to 60 with 1 to 60 and 96 to 210 with 96 to 210. EBNA-2 self-association is likely to be critical to the ability of EBNA-2 to interact simultaneously with multiple cellular transcription factors, coactivators, and histone acetyltransferases through its RBPJκ binding and acidic activating domains.
Envelope Gene of the Human Endogenous Retrovirus HERV-W Encodes a Functional Retrovirus Envelope
Authors: An Dong Sung , Xie Yi-ming , Chen Irvin S. Y.
Published: July 2002

A member of the human endogenous retrovirus (HERV) family termed HERV-W encodes a highly fusogenic membrane glycoprotein that appears to be expressed specifically in the placenta. It is unclear whether the glycoproteins of the HERVs can serve as functional retrovirus envelope proteins to confer infectivity on retrovirus particles. We found that the HERV-W envelope glycoprotein can form pseudotypes with human immunodeficiency virus type 1 virions and confers tropism for CD4-negative cells. Thus, the HERV-W
env
gene represents the first HERV
env
gene demonstrated to encode the functional properties of a retrovirus envelope glycoprotein.
CD4+T-Cell Effectors Inhibit Epstein-Barr Virus-Induced B-Cell Proliferation
Authors: Nikiforow Sarah , Bottomly Kim , Miller George
Published: July 2002

In immunodeficient hosts, Epstein-Barr virus (EBV) often induces extensive B-cell lymphoproliferative disease and lymphoma. Without effective in vitro immune surveillance, B cells infected by the virus readily form immortalized cell lines. In the regression assay, memory T cells inhibit the formation of foci of EBV-transformed B cells that follows recent in vitro infection by EBV. No one has yet addressed which T cell regulates the early proliferative phase of B cells newly infected by EBV. Using new quantitative methods, we analyzed T-cell surveillance of EBV-mediated B-cell proliferation. We found that CD4+T cells play a significant role in limiting proliferation of newly infected, activated CD23+B cells. In the absence of T cells, EBV-infected CD23+B cells divided rapidly during the first 3 weeks after infection. Removal of CD4+but not CD8+T cells also abrogated immune control. Purified CD4+T cells eliminated outgrowth when added to EBV-infected B cells. Thus, unlike the killing of EBV-infected lymphoblastoid cell lines, in which CD8+cytolytic T cells play an essential role, prevention of early-phase EBV-induced B-cell proliferation requires CD4+effector T cells.
Selection of Apoptosis-Deficient Adenovirus E4orf4 Mutants in
Saccharomyces cerevisiae
Authors: Afifi Rana , Sharf Rakefet , Shtrichman Ronit , Kleinberger Tamar
Published: July 2002

Adenovirus E4orf4 protein has been shown to induce p53-independent, protein phosphatase 2A (PP2A)-dependent apoptosis in transformed cells. Furthermore, E4orf4 also induces toxicity in
Saccharomyces cerevisiae
in a PP2A-dependent manner (D. Kornitzer and T. Kleinberger, submitted for publication). In this work, we utilized yeast cells to select for nonapoptotic E4orf4 mutants which, in turn, were shown to possess a diminished ability to bind PP2A. The success of this selection system will provide additional apoptosis-relevant mutants for E4orf4 research and strongly supports the relevance of E4orf4-induced toxicity in
S. cerevisiae
to E4orf4-induced apoptosis in mammalian cells.
The Interacting UL31 and UL34 Gene Products of Pseudorabies Virus Are Involved in Egress from the Host-Cell Nucleus and Represent Components of Primary Enveloped but Not Mature Virions
Authors: Fuchs Walter , Klupp Barbara G. , Granzow Harald , Osterrieder Nikolaus , Mettenleiter Thomas C.
Published: July 2002

A 2.6-kbp fragment of the pseudorabies virus (PrV) genome was sequenced and shown to contain the homologues of the highly conserved herpesvirus genes UL31 and UL32. By use of a monospecific antiserum, the UL31 gene product was identified as a nuclear protein with an apparent molecular mass of 29 kDa. For functional analysis, UL31 was deleted by mutagenesis in
Escherichia coli
of an infectious full-length clone of the PrV genome. The resulting virus mutants were deficient in plaque formation, and titers were reduced more than 100-fold from those of wild-type PrV. Ultrastructural analyses demonstrated that capsid maturation and DNA packaging were not affected. However, neither budding at the inner nuclear membrane nor cytoplasmic or extracellular virus particles were observed. These replication defects were similar to those of a UL34 deletion mutant (B. G. Klupp, H. Granzow, and T. C. Mettenleiter, J. Virol. 74:10063–10073, 2000) and could be completely repaired in a cell line which constitutively expresses the UL31 protein. Yeast two-hybrid studies revealed that a UL31 fusion protein specifically interacts with plasmids of a PrV genome library expressing the N-terminal part of UL34. Vice versa, UL34 selected UL31-encoding plasmids from the library. Immunofluorescence studies and immune electron microscopy demonstrated that in cells infected with wild-type PrV, both proteins accumulate at the nuclear membrane, whereas in the absence of UL34 the UL31 protein is dispersed throughout the nucleus. Like the UL34 protein, the UL31 gene product is a component of enveloped virus particles within the perinuclear space and absent from mature virions. Our findings suggest that physical interaction between these two virus proteins might be a prerequisite for primary envelopment of PrV at the inner nuclear membrane and that this envelope is removed by fusion with the outer nuclear membrane.
Potent Inhibition of Human Immunodeficiency Virus Type 1 Replication by Template Analog Reverse Transcriptase Inhibitors Derived by SELEX (Systematic Evolution of Ligands by Exponential Enrichment)
Authors: Joshi Pheroze , Prasad Vinayaka R.
Published: July 2002

RNA aptamers derived by SELEX (systematic evolution of ligands by exponential enrichment) and specific for human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) bind at the template-primer cleft with high affinity and inhibit its activity. In order to determine the potential of such template analog RT inhibitors (TRTIs) to inhibit HIV-1 replication, 10 aptamers were expressed with flanking, self-cleaving ribozymes to generate aptamer RNA transcripts with minimal flanking sequences. From these, six aptamers (70.8,13, 70.15, 80.55,65, 70.28, 70.28t34, and 1.1) were selected based on binding constants (K

d

) and the degree of inhibition of RT in vitro (50% inhibitory concentration [IC
50
]). These six aptamers were each stably expressed in 293T cells followed by transfection of a molecular clone of HIV
R3B
. Analysis of the virion particles revealed that the aptamers were encapsidated into the virions released and that the packaging of the viral genomic RNA or the cognate primer, tRNA3Lys, was apparently unaffected. Infectivity of virions produced from 293T cell lines expressing the aptamers, as measured by infecting LuSIV reporter cells, was reduced by 90 to 99.5% compared to virions released from cells not expressing any aptamers. PCR analysis of newly made viral DNA upon infection with virions containing any of the three aptamers with the strongest binding affinities (70.8,13, 70.15, and 80.55,65) showed that all three were able to form the minus-strand strong-stop DNA. However, virions with the aptamers 70.8 and 70.15 were defective for first-strand transfer, suggesting an early block in viral reverse transcription. Jurkat T cells expressing each of the three aptamers, when infected with HIV
R3B
, completely blocked the spread of HIV in culture. We found that the replication of nucleoside analog RT inhibitor-, nonnucleoside analog RT inhibitor-, and protease inhibitor-resistant viruses was strongly suppressed by the three aptamers. In addition, some of the HIV subtypes were severely inhibited (subtypes A, B, D, E, and F), while others were either moderately inhibited (subtypes C and O) or were naturally resistant to inhibition (chimeric A/D subtype). As virion-encapsidated TRTIs can predispose virions for inhibition immediately upon entry, they should prove to be efficacious agents in gene therapy approaches for AIDS.
CD4 Independence of Simian Immunodeficiency Virus Envs Is Associated with Macrophage Tropism, Neutralization Sensitivity, and Attenuated Pathogenicity
Authors: Puffer Bridget A. , Pöhlmann Stefan , Edinger Aimee L. , Carlin Dan , Sanchez Melissa D. , Reitter Julie , Watry Debbie D. , Fox Howard S. , Desrosiers Ronald C. , Doms Robert W.
Published: July 2002

To investigate the basis for envelope (Env) determinants influencing simian immunodeficiency virus (SIV) tropism, we studied a number of Envs that are closely related to that of SIVmac239, a pathogenic, T-tropic virus that is neutralization resistant. The Envs from macrophage-tropic (M-tropic) virus strains SIVmac316, 1A11, 17E-Fr, and 1100 facilitated infection of CCR5-positive, CD4-negative cells. In contrast, the SIVmac239 Env was strictly dependent upon the presence of CD4 for membrane fusion. We also found that the Envs from M-tropic virus strains, which are less pathogenic in vivo, were very sensitive to antibody-mediated neutralization. Antibodies to the V3-loop, as well as antibodies that block SIV gp120 binding to CCR5, efficiently neutralized CD4-independent, M-tropic Envs but not the 239 Env. However, triggering the 239 Env with soluble CD4, presumably resulting in exposure of the CCR5 binding site, made it as neutralization sensitive as the M-tropic Envs. In addition, mutations of N-linked glycosylation sites in the V1/V2 region, previously shown to enhance antigenicity and immunogenicity, made the 239 Env partially CD4 independent. These findings indicate that Env-based determinants of M tropism of these strains are generally associated with decreased dependence on CD4 for entry into cells. Furthermore, CD4 independence and M tropism are also associated with neutralization sensitivity and reduced pathogenicity, suggesting that the humoral immune response may exert strong selective pressure against CD4-independent M-tropic SIVmac strains. Finally, genetic modification of viral Envs to enhance CD4 independence may also result in improved humoral immune responses.
Promotion of Alpha/Beta Interferon Induction during In Vivo Viral Infection through Alpha/Beta Interferon Receptor/STAT1 System-Dependent and -Independent Pathways
Authors: Malmgaard Lene , Salazar-Mather Thais P. , Lewis Casey A. , Biron Christine A.
Published: July 2002

Viruses and viral components can be potent inducers of alpha/beta interferons (IFN-α/β). In culture, IFN-α/β prime for their own expression, in response to viruses, through interferon regulatory factor 7 (IRF-7) induction. The studies presented here evaluated the requirements for functional IFN receptors and the IFN signaling molecule STAT1 in IFN-α/β induction during infections of mice with lymphocytic choriomeningitis virus (LCMV). At 24 h after infection, levels of induced IFN-α/β in serum were reduced 90 to 95% in IFN-α/β receptor-deficient (IFN-α/βR−/−) and STAT1−/−mice compared to those in wild-type mice. However, at 48 h, these mice showed elevated expression in the serum whereas IFN-α/β levels were still reduced >75% in IFN-α/βγR−/−mice even though the viral burden was heavy. Levels of IFN-β, IFN-α4, and non-IFN-α4 subtype mRNA expression correlated with IFN-α/β bioactivity, and all IFN-α/β subtypes were coincidentally detectable. IRF-7 mRNA was induced under conditions of IFN-α/β production, including late production in IFN-α/βR−/−mice. These data demonstrate that the presence of the virus alone is not sufficient to induce IFN-α/β during LCMV infection in vivo. Instead, autocrine amplification through the IFN-α/βR is necessary for optimal induction. In the absence of a functional IFN-α/βR, however, alternative mechanisms, independent of STAT1 but requiring a functional IFN-γR, take over.
A Comparative Study of BOP as a Coupling Agent Using Simultaneous Multiple Peptide Synthesis
Authors: Ježek Jan , Houghten Richard A.
Published: July 2002

A parallel simultaneous synthesis of multiple peptides was carried out in which the coupling agents BOP and DIPCI were compared. For peptides lacking Asn, no differences in average yield or RP HPLC purity were found. For peptides having Asn in their sequences, however, the yield and purity were significantly lower for BOP when compared to DIPCI. The addition of HOBt to BOP mediated couplings did not lead to improved results. In fact, BOP condensations without HOBt gave, on average, slightly purer peptides. Comparing the results for peptides prepared with BOP dissolved in DMF, NMP, or NMP + 20% DMSO, NMP afforded the best and DMF the worst results, but the differences were not significant. Peptides prepared using BOP, combined with in situ neutralization, were obtained both in higher yield and purity when compared with classical neutralization. In all BOP mediated couplings, peptides with Asn were obtained in lower yield and purity than peptides without Asn. FAB MS and amino acid analysis revealed that the side products are peptides with deleted Asn.
Synthetic Peptides from the Region 30-54 of the Interleukin-2 Receptor β-Chain (IL-2Rβ)Affect IL-2 Binding to Human T-Cells
Authors: Drakopoulou Eugenia , Sotiropoulou Georgia , Tsilivakos Vassilis , Georgoulias Vassilis , Cordopatis Paul
Published: July 2002

The interleukin-2 receptor β-chain (IL-2Rβ) is responsible for the IL-2 internalization and signal transduction. To identify domains from the IL-2Rβ extracellular region which are involved in ligand receptor interactions, eight peptides of 8 to 25 amino acids corresponding to IL-2Rβ sequence 30-54 were synthesized. Their biological effect was tested with [125I]IL-2 equilibrium binding to PHA-blasts. Preincubation of [125I]IL-2 with peptides IL-2Rβ (35-54) and (30-42) affects IL-2 binding to both high and intermediate affinity receptors by revealing a greater number of active sites with lower affinity.
Gas-Agitated Liquid-Liquid Extraction in a Spray Column
Authors: Sovilj Milan , Kneževic Goran
Published: July 2002

The hydrodynamic characteristics of the air water toluene three-phase system in a spray extraction column at 20 °C were examined. The average and local hold-up data of the dispersed phase were determined in dependence on the flow rates of the continuous, dispersed and gaseous phases. The average gas phase hold-up was also measured and analyzed. A comparison was made of the hydrodynamic characteristics of the two-phase (water - toluene) and three-phase (air - water - toluene) systems.
X-Ray Photoelectron Spectroscopic Studies of Palladium Dispersed on Carbon Surfaces Modified by Ion Beams and Plasmatic Oxidation
Authors: Bastl Zdeněk
Published: July 2002

The effects of ion bombardment and r.f. plasma oxidation of graphite surfaces on subsequent growth and electronic properties of vacuum deposited palladium clusters have been investigated by methods of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy with X-ray excitation (XAES). Due to the significantly increased density of surface defects on which the nucleation process occurs the bulk value of the Pd 3d core level binding energy is achieved at higher surface coverage by palladium on bombarded surfaces than on ordered graphite. Angle resolved photoelectron spectra of oxidized graphite surfaces reveal significant embedding of oxygen in graphite surface layers. The C 1s and O 1s photoelectron spectra are consistent with presence of two major oxygen species involving C-O and C=O type linkages which are not homogeneously distributed within the graphite surface layers. Two effects were observed on oxidized surfaces: an increase of palladium dispersion and interaction of the metal clusters with surface oxygen groups. Using the simple interpretation of the modified Auger parameter the relaxation and chemical shift contributions to the measured Pd core level shifts are estimated. In the region of low surface coverage by palladium the effect of palladium-oxygen interaction on Pd core level binding energy exceeds the effects of increased dispersity.
Effect of Li, Na, K and Cs on Vacuum Decomposition of Tetraammineplatinum(II) in Zeolites. Catalytic Activity in CO + NO Reaction
Authors: Nováková Jana , Brabec Libor , Kubelková Ludmila
Published: July 2002

[Pt(NH3)4]2+ ions were exchanged for alkali (Li, Na, K and Cs) in -X and -Y zeolites and decomposed in vacuum. TPR after this decomposition showed that autoreduction accompanying this process reduced roughly 2/3 of all Pt2+ to Pt0. The extent of the autoreduction rose with the ammonia pressure over the zeolite. The decomposition rate increased with increasing electropositivity of the alkali ion and this effect completely overlapped that of the zeolite structure. The CO + NO reaction rate also increased from Li to Cs, but -X zeolites were substantially more active than the -Y ones. Oxygen layer on the resulting Pt catalyst affected positively the reaction rate. The dispersion of Pt particles was relatively low, when compared to that obtained by decomposition of the Pt tetraammine complex in oxygen followed by hydrogen reduction. However, the reaction rate was higher.
Synthesis of trans β-Lactams of Estrane Series
Authors: Siddiqui Abdul U. , Satyanarayana Yelluru , Siddiqui Abdul H.
Published: July 2002

17,17-Ethylenedioxy-1,3,5(10)-estratrien-3β-ol (I) was converted into ethyl ester II by reaction with ethyl chloroacetate in the presence of potassium. The ethyl ester II on reaction with hydrazine gave hydrazide III, which on condensation with aromatic aldehydes gave Schiff bases IVa-IVd. The reaction of Schiff bases IVa-IVd with chloroacetyl chloride in the presence of triethylamine afforded β-lactams Va-Vd.
Synthesis of Fragments of the Vasoactive Intestinal Peptide (VIP) and Analysis of Their Residual Biological Activities
Authors: Zoulíková Ivana , Svoboda Ivan , Velek Jiří , Kašička Václav , Slaninová Jiřina , Barth Tomislav , Hrbas Pavel
Published: July 2002

The vasoactive intestinal (poly)peptide (VIP) is a linear peptide containing 28 amino acid residues, whose primary structure indicates a low metabolic stability. The following VIP fragments, as potential metabolites, and their analogues were prepared by synthesis on a solid: [His(Dnp)1]VIP(1-10), VIP(11-14), [D-Arg12]VIP(11-14), [Lys(Pac)15,21,Arg20]VIP(15-22), and VIP(23-28). After purification, the peptides were characterized by amino acid analysis, mass spectrometry, RP HPLC, and capillary zone electrophoresis. In some tests, detailed examination of the biological activity of the substances in vivo and in vitro gave evidence of a low, residual activity of some fragments, viz. a depressoric activity in vivo for [His(Dnp)1]VIP(1-10) and a stimulating activity for the release of α-amylase in vitro and in vivo for [Lys(Pac)15,21,Arg20]VIP(15-22) and VIP(23-28).
Synthesis of Monomeric 2-[(2-Methyl-2-propenoyl)oxy]ethyl Esters of Prostaglandins
Authors: Paleček Jaroslav , Veselý Ivan
Published: July 2002

This paper describes a new synthesis of monomeric 2-/(2-methyl-2-propenoyl)oxy/ethyl esters of prostaglandins (IIa-IId). The monomeric esters were prepared by reaction of an alkali metal or triethylammonium salt of a prostaglandin of the F2a or A2 series (Ia-Id) with 2-iodoethyl (IIIa) or 2-bromoethyl-2-methyl-2-propenoate (IIIb) in good to high yields. These monomers have been used for preparing reversible anchoring of prostaglandins on a modified three-dimensional biocompatible hydrogels prepared by copolymerization with 2-hydroxyethyl 2-methyl-2-propenoate. The application of functionalized polymers could be used in drug forms with controlled liberation of biologically active PG derivatives.
Divergent Pathways of Reaction Between Cyclohexanone Enamines and α,β-Unsaturated Acid Chlorides
Authors: Butkus Eugenius , Bielinyte-Williams Birute
Published: July 2002

The reaction of cyclohexanone enamines with α,β-unsaturated acid chlorides and 2- and 3-chloropropanoyl chlorides under various conditions has been investigated. a,ae-Annulation of enamines Ia-Ie occurs on treatment with chlorides IIa-IId or 3-chloropropanoyl chloride to give bicyclo[3.3.1]nonane-2,9-dione derivatives III. The formation of isomeric bicyclononanediones IIIe and IIIh and chromanones VIIIa and VIIIb in the reaction of enamines derived from substituted cyclohexanones suggests that the cyclization might proceed also by another pathway than via [3,3] sigmatropic rearrangement. Based on the reaction course and product distribution in these reactions, a parallel reaction pathway involving a C-acylation-Michael addition has been suggested.
Electrophilic Substitution Reactions of [1]Benzothieno[3,2-b]furan
Authors: Svoboda Jiří , Pihera Pavel , Sedmera Petr , Paleček Jaroslav
Published: July 2002

In chlorination, bromination, iodination, nitration, sulfonation, formylation, and trifluoroacetylation of [1]benzothieno[3,2-b]furan (1) the substituent enters the 2-position. The said halogenations go by the addition-elimination mechanism. When the substitution is continued, the second substituent enters the 6-position of heterocycle 1. The 1H and 13C NMR spectra have been completely assigned. Substituent effects on NMR parameters are discussed.
Synthesis of Some "Abbreviated" NAD+ Analogues
Authors: Hocková Dana , Holý Antonín
Published: July 2002

Four new "abbreviated" NAD+ analogues with hydroxymethyl or carboxyl function as a substituent of an aliphatic chain linking the adenine and nicotinamide moieties were prepared using the Zincke reaction as the key step. As intermediates several new acyclic nucleoside analogues containing hydroxy, carboxyl, azido and amino group were prepared.
1-(3,5-O-Alkylidene-2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracils
Authors: Hřebabecký Hubert , Buděšínský Miloš , Masojídková Milena , Havlas Zdeněk , Holý Antonín
Published: July 2002

1-(2,3-O-Cyclohexylidene-4-C-hydroxymethyl-α-L-lyxofuranosyl)uracil (1) was converted in seven steps into 1-(2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil (8) and further into 1-(2-deoxy-4-C-hydroxymethyl-3,5-O-isopropylidene-α-L-threo-pentofuranosyl)uracil (9). Successive benzoylation, removal of the isopropylidene group, reaction with acetaldehyde diethyl acetal, and debenzoylation afforded (R)- and (S)-1-(2-deoxy-3,5-O-ethylidene-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil (10a and 10b, respectively). Reaction of 1-(2-deoxy-4-C-triphenylmethyloxymethyl-α-L-threo-pentofuranosyl)uracil (14) with dichloromethane under conditions of phase transfer, followed by detritylation, afforded 1-(2-deoxy-4-C-hydroxymethyl-3,5-O-methylidene-α-L-threo- pentofuranosyl)uracil (15). Compound 14 was obtained from the derivative 8 by partial silylation, tritylation and desilylation. The absolute configuration of the isomeric ethylidene derivatives 10a and 10b was determined by NMR spectroscopy and the population of the deoxypentofuranose ring conformers was derived from the vicinal coupling constants J(H,H). The obtained results were compared with energy calculations. Neither of the prepared nucleoside analogues was active in vitro against HIV-1 and HIV-2.
Reactions of 21-Acetoxy-16α,17α-epoxypregn-4-ene-3,20-dione with Nitrogen-Containing Nucleophilic Agents
Authors: Protiva Jiří , Nguyen Thi Thu Huong , Urban Jiří , Klinotová Eva
Published: July 2002

21-Acetoxy-16α,17α-epoxypregn-4-ene-3,20-dione (1) enters a reaction with acetonitrile catalyzed by perchloric acid, giving unusual products with the furostane skeleton. In contrast to analogous reactions, the reaction with sodium azide results in the azido derivative possessing the non-rearranged ring D. The 1H NMR, 13C NMR, and mass spectra are discussed.
Insertion of Hydrogen and/or Lithium Into Cesium Tungsten Bronze
Authors: Bludská Jana , Vondrák Jiří , Jakubec Ivo
Published: July 2002

Hydrogen and/or lithium insertion into hexagonal cesium tungsten bronze, Cs0.3WO3, was studied using voltammetric and a.c. admittance methods. The close values of stoichiometric coefficients for hydrogen and/or lithium in coinsertion bronzes as well as the close values of diffusion coefficients DH and DLi are ascribed to a lattice distortion caused by large cesium species which influence both equilibrium and the mobility of inserting species regardless of their different chemical nature.
Axial Dispersion in a Three-Phase Gas-Agitated Spray Extraction Column
Authors: Sovilj Milan
Published: July 2002

The continuous-phase axial dispersion coefficients of the three-phase gas-liquid-liquid system in a gas-agitated spray extraction column 10 cm i.d. at 20 °C were examined. The system used was water as continuous phase, toluene as dispersed phase, and air as gaseous phase. The rise in the gas phase superficial velocity increased the continuous-phase axial dispersion coefficient. A non-linear dependence between the continuous-phase axial dispersion coefficient and the continuous phase superficial velocity was observed. No correlation was found between the continuous-phase axial dispersion coefficient and dispersed phase superficial velocity. The increase in the gas phase hold-up corresponded to a slight increase in the continuous-phase axial dispersion coefficient. The increase in the dispersed phase hold-up generated a growth of the continuous-phase axial dispersion coefficient. A comparison was made of the continuous-phase axial dispersion coefficients of the three-phase (air-water-toluene) and two-phase (water-toluene) systems.
Synthesis of Acyclic Nucleotide Analogues Derived from N3-Substituted Isoguanine
Authors: Alexander Petr , Holý Antonín , Buděšínský Miloš , Masojídková Milena
Published: July 2002

Reaction of 9-benzyl-6-{[(dimethylamino)methylidene]amino}purin-2(3H)-one (7) with ethylene carbonate gave a mixture of 9-benzyl-2-(2-hydroxyethoxy)purin-6-amine (10) and 2-amino-9-benzyl-3-(2-hydroxyethyl)purin-2(3H)-one (11). This mixture reacted with diisopropyl (tosyloxymethyl)phosphonate in the presence of NaH followed by catalytic hydrogenation and bromotrimethylsilane treatment to afford isomeric 6-amino-3-[2-(phosphonomethoxy)ethyl]purin-2(3H)-one (3) and 2-[2-(phosphonomethoxy)ethoxy]purin- 6-amine (15). Similar treatment of compound7with tritylglycidol gave two isomeric 2-hydroxy-3-(trityloxy)propyl derivatives18,20which were subsequently condensed with diisopropyl (tosyloxymethyl)phosphonate to afford protected diester intermediates21and22; these compounds were transformed by hydrogenolysis and ester cleavage with bromotrimethylsilane to the isomeric 6-amino-3-[3-hydroxy-2-(phosphonomethoxy)propyl]- purin-2(3H)-one (2) and 2-[3-hydroxy-2-(phosphonomethoxy)propoxy]purin-6-amine (24). None of the free phosphonates2,3,15or24exhibited any antiviral or cytostatic activity.
Air-Tight Three-Electrode Design of Coaxial Electrochemical-EPR Cell for Redox Studies at Low Temperatures
Authors: Hartl František , Groenestein Ronald P. , Mahabiersing Taasje
Published: July 2002

The weak point of the original Allendoerfer electrochemical-EPR cell has been the reference electrode, placed outside the space-limited electrolysis cavity or not used at all in experiments at low temperatures. We present here an elegant solution to this problem, based on a modified air-tight design of an Allendoerfer cell equipped with a silver-wire pseudoreference electrode. The cell performance is demonstrated on one-electron electrochemical oxidation of heterocyclic 3,6-diphenyl-1,2-dithiine and one-electron reduction of 6-methyl-6-phenylfulvene and the pseudo-octahedral complex fac-[Re(benzyl)(CO)3(dmb)] (dmb = 4,4'-dimethyl-2,2'-bipyridine). In the latter case, the EPR spectrum of the radical anion [Re(benzyl)(CO)3(dmb)]•- points to predominant localization of the unpaired electron on the dmb ligand, in agreement with UV-VIS and IR spectroelectrochemical data.
Synthesis of 8-Amino- and N-Substituted 8-Aminoadenine Derivatives of Acyclic Nucleoside and Nucleotide Analogs
Authors: Janeba Zlatko , Holý Antonín , Masojídková Milena
Published: July 2002

8-Aminoadenine derivatives2were obtained from 8-bromoadenines1in one-pot reactionvia8-azidoadenines. Reaction of 8-bromoadenines1with methylamine or dimethylamine in ethanol afforded the correspondingN9-substituted 8-(methylamino)adenines3and 8-(dimethylamino)adenines4. Alkylation of 8-aminoadenine (2a) with diverse alkylation agents affordedN9-substituted 8-aminoadenine derivatives2, and alkylation of 8-(dimethylamino)adenine (4a) gave mixtures of the correspondingN9-substituted 8-(dimethylamino)adenines4and theirN3-substituted regioisomers5. 8,3'-N-Anhydro derivatives7were prepared by tosylation of (S)-8-bromo-9-{2-[(diisopropoxyphosphoryl)- methoxy]-3-hydroxypropyl}adenine (1c) followed by treatment with methanolic ammonia or methylamine solution.
Specificity and Non-Specificity in the Sensitized CO2-Laser-Induced Reaction of Tetrachloroethene
Authors: Earl Boyd L. , Titus Richard L.
Published: July 2002

Previous workers have investigated the reaction of tetrachloroethene using thermal initiation and CO2-laser initiation via sensitizing species. In both instances, the principal product was found to be hexachlorobenzene. One group reported evidence of laser specificity in this reaction, in that BCl3 acted as a sensitizer to produce hexachlorobenzene as the principal product, but SF6 and BBr3 did not. We have found that specificity is highly dependent on reaction conditions. We reproduced the previous results using similar experimental conditions, but under different conditions, we found that the specificity is lost, with all three sensitizers which we used (BCl3, SF6, and SiF4) sensitizing the reaction to produce mainly hexachlorobenzene. There were some differences among the sensitizers, as, for example, the fact that SF6 produced the most nearly pure hexachlorobenzene product.
Oxidation of Furost-20(22)-enes with 3-Chloroperoxybenzoic Acid and Osmium Tetroxide
Authors: Morzycki Jacek W. , Jastrzębska Izabella , Katryński Krzysztof S.
Published: July 2002

6β-Methoxy-3α,5-cyclo-5α-furost-20(22)-ene and its 17α-hydroxy derivative were oxidized with 3-chloroperoxybenzoic acid and OsO4. The former compound afforded hydroxylated products, whereas the latter underwent degradation to C21 or C19 steroids.
Novel Rearrangements of the 2-Chloroacrylonitrile Cycloadducts of Steroidal 14,16-Dien-17-yl Acetates
Authors: Bull James R. , Gordon Richard S. , Grundler Claudia
Published: July 2002

Cycloaddition of 3-methoxyestra-1,3,5(10),14,16-pentaen-17-yl acetate (1) with 2-chloroacrylonitrile furnishes 17β-acetoxy-16α-chloro-3-methoxy-14,17α-ethenoestra-1,3,5(10)-triene-16β-carbonitrile (2) as the major product, which undergoes alkali-mediated rearrangement to (161R)-3-methoxy-17-oxo-16β,15β,14-(ethane[1,1,2]triyl)-14β-estra-1,3,5(10)-triene-161-carbonitrile (7). A similar reaction course is followed by the related 16-methyl derivative 4, and it is shown that minor 15-chloro-15-cyano cycloadducts 3 and 6 undergo Grob fragmentation. Functional group manipulations and regioselective bond-scission processes are described, for conversion of rearrangement product 7 into 16β,15β,14-(ethane[1,1,2]triyl) and cyclobuta[14β,15β] analogues of estradiol.
Total serum IgE and outcome in infants with recurrent wheezing
Authors: Rusconi F , Patria M F , Cislaghi G U , Sideri S , Gagliardi L
Published: July 2002

OBJECTIVE

To investigate the relation between total serum IgE at 0.5–3 and 3–6 years, and the risk of allergic sensitisation and persistent wheezing up to 8 years of age.

METHODS

Prospective follow up study of 45 infants with highly recurrent wheezing, no allergic symptoms, and negative skin tests.

RESULTS

In the last follow up year, 15 children still suffered from wheezing. Five wheeze-free and four episodically wheezing children had become sensitised. No association was found between early (0.5–3 years) IgE z scores and the recurrence of wheezing during follow up, or atopic sensitisation. IgE z scores at 3–6 years were significantly higher in children with positive skin tests (p = 0.013), but were still not associated with recurrence of wheezing.

CONCLUSIONS

In subjects with frequent early wheezing and no signs of atopy, early total serum IgE measurements are not predictive of outcome.
Increased urinary leukotriene E4during febrile attacks in the hyperimmunoglobulinaemia D and periodic fever syndrome
Authors: Frenkel J , Willemsen M A A P , Weemaes C M R , Dorland L , Mayatepek E
Published: July 2002

BACKGROUND

The hyperimmunoglobulinaemia D and periodic fever syndrome is a hereditary periodic fever, caused by deficiency of the enzyme mevalonate kinase. It is unclear how this defect leads to recurrent fever episodes.

AIM

To assess the involvement of cysteinyl leukotrienes in the pathogenesis of fever attacks as reflected by urinary leukotriene E4(LTE4) excretion.

METHODS

Urinary LTE4was measured in seven patients while febrile and afebrile.

RESULTS

LTE4was raised during fever in all subjects (46–199 nmol/mol creatinine, mean 92; normal <40). Urinary LTE4was normal between attacks, as well as in normal children with fever as a result of miscellaneous causes.

CONCLUSION

Our results suggest that cysteinyl leukotrienes play a role in the pathophysiology of this disorder. As no effective treatment is yet available, leukotriene receptor antagonists might offer a new therapeutic approach for patients with the hyperimmunoglobulinaemia D and periodic fever syndrome.
Long term health impact of playing professional football in the United Kingdom
Authors: Turner Andy P , Barlow Julie H , Heathcote-Elliott Christian
Published: July 2002

Objective—To describe the long term impact of football on the health related quality of life (HRQL) of former professional footballers in the United Kingdom.

Method—A cross sectional survey gathered data from 284 former professional players. Respondents reported medical treatments, osteoarthritis (OA) diagnosis, other morbidity, disability status, and work related disability since their football career. The EuroQol (EQ-5D) and global health rating scales were selected to assess HRQL.

Results—Medical treatment for football related injuries was a common feature, as was OA, with the knee being the most commonly affected joint. Respondents with OA reported poorer HRQL compared with those without OA. As with medical treatments and problems on each of the five EQ-5D dimensions (pain, mobility, usual activities, anxiety/depression, self care), frequency of disability and work related disability were higher among respondents with OA than those without.

Conclusion—This exploratory study suggests that playing professional football can impact on the health of United Kingdom footballers in later life. The development of OA was associated with poorer outcomes on all aspects of HRQL.
A unique insight into the incidence of rugby injuries using referee replacement reports
Authors: Sharp J C M , Murray G D , Macleod D A D
Published: July 2002

Objectives—To obtain further information on the incidence of injuries and playing positions affected in club rugby in Scotland.

Methods—Routine reports of injury (permanent) and blood (temporary) replacements occurring in competitive club rugby matches by referees to the Scottish Rugby Union during seasons 1990–1991 to 1996–1997 were analysed.

Results—A total of 3513 injuries (87 per 100 scheduled matches) and 1000 blood replacements (34 per 100 scheduled matches) were reported. Forwards accounted for 60% of the injury and 72% of the blood replacements. Flankers and the front row were the most commonly replaced forwards while wing and centre three quarters were the most vulnerable playing positions among backs. The incidence of injury replacements increased as the match progressed up until the last 10 minutes when the trend was reversed. Blood replacements showed a different pattern with 60% occurring during the first half of the match.

Conclusion—The most important finding of the study was reliability of referees in documenting the vulnerability of certain playing positions, and the timing when injuries took place, thus assisting coaches and team selectors when choosing replacement players for competitive club and representative rugby matches. This study re-emphasises the need for continuing epidemiological research.
Organisation of safety measures in an Alpine World Junior Championship
Authors: Bergstrøm K A , Bergstrøm A , Ekeland A
Published: July 2002

Objectives—To study the implementation of skiing safety during the Alpine World Junior Championship of 1995.

Methods—A map of the area was made with descriptions of the slopes and all its facilities and the security measures along the course. The number of competitors who started and any injuries reported were recorded in a questionnaire.

Results—A total of 452 girls and 546 boys started in the different races. Only four injuries were recorded, all in girls. The overall injury rate was 4 per 1000 runs. An injury rate of 8.3 per 1000 runs was recorded in the downhill. One skier had a possibly severe injury (ISS = 14) in the downhill; the rest of the injuries were minor (ISS = 1). The mean ISS was 4.3 and the total ISS was 17.

Conclusions—A significantly higher injury rate was recorded for young female than young male racers. The injury rate was significantly higher in downhill than the other alpine disciplines in the Alpine World Junior Championship. The injury rate was not significantly different from that recorded one year previously for Olympic racers, and juniors therefore need the same safety measures as Olympic racers.
Results of a 10 week community based strength and balance training programme to reduce fall risk factors: a randomised controlled trial in 65–75 year old women with osteoporosis
Authors: Carter N D , Khan K M , Petit M A , Heinonen A , Waterman C , Donaldson M G , Janssen P A , Mallinson A , Riddell L , Kruse K , Prior J C , Flicker L , McKay H A
Published: July 2002

Objective—To test the efficacy of a community based 10 week exercise intervention to reduce fall risk factors in women with osteoporosis.

Methods—Static balance was measured by computerised dynamic posturography (Equitest), dynamic balance by timed figure of eight run, and knee extension strength by dynamometry. Subjects were randomised to exercise intervention (twice weekly Osteofit classes for 10 weeks) or control groups.

Results—The outcome in 79 participants (39 exercise, 40 control) who were available for measurement 10 weeks after baseline measurement is reported. After confounding factors had been controlled for, the exercise group did not make significant gains compared with their control counterparts, although there were consistent trends toward greater improvement in all three primary outcome measures. Relative to the change in control subjects, the exercise group improved by 2.3% in static balance, 1.9% in dynamic balance, and 13.9% in knee extension strength.

Conclusions—A 10 week community based physical activity intervention did not significantly reduce fall risk factors in women with osteoporosis. However, trends toward improvement in key independent risk factors for falling suggest that a study with greater power may show that these variables can be improved to a level that reaches statistical significance.
Expression of human α-defensin 5 (HD5) mRNA in nasal and bronchial epithelial cells
Authors: Frye M , Bargon J , Dauletbaev N , Weber A , Wagner T O F , Gropp R
Published: July 2002

Background/Aims—Human defensins are antibiotic peptides expressed in myeloid and epithelial cells. Human α-defensin 5 (HD5) has been detected in Paneth cell granules in the crypts of Lieberkühn and has recently been identified in the female reproductive tract. The aim of this study was to investigate the presence of HD5 mRNA in nasal and bronchial epithelial cells.

Methods/Results—Semiquantitative reverse transcription polymerase chain reaction (RT–PCR) analysis showed that HD5 mRNA was expressed infrequently and to varying degrees in bronchial and nasal epithelial cells. In situ hybridisation resulted in a positive signal in the epithelial layer of nasal polyps. HD5 mRNA was locally restricted to a specific area of epithelial cells and also occurred in submucosal glands.

Conclusions—HD5 mRNA expression in nasal and bronchial epithelial cells is rare and seemed to be locally induced. The results indicate that HD5 might play a role in innate defence in nasal and bronchial epithelia.