bluuebunny/crossref_metadata_2025 huggingface dataset:
Kaposi's Sarcoma-Associated Herpesvirus K8β Is Derived from a Spliced Intermediate of K8 Pre-mRNA and Antagonizes K8α (K-bZIP) To Induce p21 and p53 and Blocks K8α-CDK2 Interaction
Authors: Yamanegi Koji , Tang Shuang , Zheng Zhi-Ming
Published: October 2005

Kaposi's sarcoma-associated herpesvirus (KSHV) is a lymphotropic DNA tumor virus that induces Kaposi's sarcoma and AIDS-related primary effusion lymphoma. KSHV open reading frame 50 and K8 genes in early viral lytic infection express, respectively, a tricistronic and a bicistronic pre-mRNA, which undergo alternative splicing to create two major spliced mRNA isoforms, α and β, by inclusion (β) or exclusion (α) of an intron at nucleotides 75563 to 75645. This intron contains some suboptimal features, which cause the intron 5′ splice site (ss) to interact weakly with U1 snRNA and the 3′ ss to bind a U2 auxiliary factor, U2AF, with low affinity. Optimization of this intron in K8 (K8 intron 2) promoted the interaction of the 5′ ss with U1 and the 3′ ss with U2AF, resulting in a substantial increase in intron splicing. Splicing of K8 intron 2 has also been shown to be stimulated by the splicing of a downstream intron. This was confirmed by the insertion of a human β-globin intron into the K8β exon 3-exon 4 splice junction, which promoted splicing of K8β intron 2 and conversion of the K8β mRNA to the K8α mRNA that encodes a K-bZIP protein. Intron 2 contains a premature termination codon, yet the K8β mRNA is insensitive to nonsense-mediated mRNA decay, suggesting that the truncated K8β protein may have a biological function. Indeed, although the truncated K8β protein is missing only a C-terminal leucine zipper domain from the K-bZIP, its expression antagonizes the ability of the K-bZIP to induce p53 and p21 and blocks K-bZIP-CDK2 interaction through interfering K8α mRNA production.
Predicted Inactivation of Viruses of Relevance to Biodefense by Solar Radiation
Authors: Lytle C. David , Sagripanti Jose-Luis
Published: October 2005

UV radiation from the sun is the primary germicide in the environment. The goal of this study was to estimate inactivation of viruses by solar exposure. We reviewed published reports on 254-nm UV inactivation and tabulated the sensitivities of a wide variety of viruses, including those with double-stranded DNA, single-stranded DNA, double-stranded RNA, or single-stranded RNA genomes. We calculatedD37values (fluence producing on average one lethal hit per virion and reducing viable virus to 37%) from all available data. We defined “size-normalized sensitivity” (SnS) by multiplying UV254sensitivities (D37values) by the genome size, and SnS values were relatively constant for viruses with similar genetic composition. In addition, SnS values were similar for complete virions and their defective particles, even when the correspondingD37values were significantly different. We used SnS to estimate the UV254sensitivities of viruses for which the genome composition and size were known but no UV inactivation data were available, including smallpox virus, Ebola, Marburg, Crimean-Congo, Junin, and other hemorrhagic viruses, and Venezuelan equine encephalitis and other encephalitis viruses. We compiled available data on virus inactivation as a function of wavelength and calculated a composite action spectrum that allowed extrapolation from the 254-nm data to solar UV. We combined our estimates of virus sensitivity with solar measurements at different geographical locations to predict virus inactivation. Our predictions agreed with the available experimental data. This work should be a useful step to understanding and eventually predicting the survival of viruses after their release in the environment.
Noncytopathogenic Pestivirus Strains Generated by Nonhomologous RNA Recombination: Alterations in the NS4A/NS4B Coding Region
Authors: Gallei Andreas , Orlich Michaela , Thiel Heinz-Juergen , Becher Paul
Published: October 2005

Several studies have demonstrated that cytopathogenic (cp) pestivirus strains evolve from noncytopathogenic (noncp) viruses by nonhomologous RNA recombination. In addition, two recent reports showed the rapid emergence of noncp
Bovine viral diarrhea virus
(BVDV) after a few cell culture passages of cp BVDV strains by homologous recombination between identical duplicated viral sequences. To allow the identification of recombination sites from noncp BVDV strains that evolve from cp viruses, we constructed the cp BVDV strains CP442 and CP552. Both harbor duplicated viral sequences of different origin flanking the cellular insertion Nedd8*; the latter is a prerequisite for their cytopathogenicity. In contrast to the previous studies, isolation of noncp strains was possible only after extensive cell culture passages of CP442 and CP552. Sequence analysis of 15 isolated noncp BVDVs confirmed that all recombinant strains lack at least most of Nedd8*. Interestingly, only one strain resulted from homologous recombination while the other 14 strains were generated by nonhomologous recombination. Accordingly, our data suggest that the extent of sequence identity between participating sequences influences both frequency and mode (homologous versus nonhomologous) of RNA recombination in pestiviruses. Further analyses of the noncp recombinant strains revealed that a duplication of 14 codons in the BVDV nonstructural protein 4B (NS4B) gene does not interfere with efficient viral replication. Moreover, an insertion of viral sequences between the NS4A and NS4B genes was well tolerated. These findings thus led to the identification of two genomic loci which appear to be suited for the insertion of heterologous sequences into the genomes of pestiviruses and related viruses.
Effect of Macromolecular Crowding Agents on Human Immunodeficiency Virus Type 1 Capsid Protein Assembly In Vitro
Authors: del Álamo Marta , Rivas Germán , Mateu Mauricio G.
Published: October 2005

Previous studies on the self-assembly of capsid protein CA of human immunodeficiency virus type 1 (HIV-1) in vitro have provided important insights on the structure and assembly of the mature HIV-1 capsid. However, CA polymerization in vitro was previously observed to occur only at very high ionic strength. Here, we have analyzed the effects on CA assembly in vitro of adding unrelated, inert macromolecules (crowding agents), aimed at mimicking the crowded (very high macromolecular effective concentration) environment within the HIV-1 virion. Crowding agents induced fast and efficient polymerization of CA even at low (close to physiological) ionic strength. The hollow cylinders thus assembled were indistinguishable in shape and dimensions from those formed in dilute protein solutions at high ionic strength. However, two important differences were noted: (i) disassembly by dilution of the capsid-like particles was undetectable at very high ionic strength, but occurred rapidly at low ionic strength in the presence of a crowding agent, and (ii) a variant CA from a presumed infectious HIV-1 with mutations at the CA dimerization interface was unable to assemble at any ionic strength in the absence of a crowding agent; in contrast, this mutation allowed efficient assembly, even at low ionic strength, when a crowding agent was used. The use of a low ionic strength and inert macromolecules to mimic the crowded environment inside the HIV-1 virion may lead to a better in vitro evaluation of the effects of conditions, mutations or/and other molecules, including potential antiviral compounds, on HIV-1 capsid assembly, stability and disassembly.
O Mannosylation of α-Dystroglycan Is Essential for Lymphocytic Choriomeningitis Virus Receptor Function
Authors: Imperiali Mauro , Thoma Claudio , Pavoni Ernesto , Brancaccio Andrea , Callewaert Nico , Oxenius Annette
Published: October 2005

α-Dystroglycan (α-DG) was identified as a common receptor for lymphocytic choriomeningitis virus (LCMV) and several other arenaviruses including the human pathogenic Lassa fever virus. Initial work postulated that interactions between arenavirus glycoproteins and α-DG are based on protein-protein interactions. We found, however, that susceptibility toward LCMV infection differed in various cell lines despite them expressing comparable levels of DG, suggesting that posttranslational modifications of α-DG would be involved in viral receptor function. Here, we demonstrate that glycosylation of α-DG, and in particular, O mannosylation, which is a rare type of O-linked glycosylation in mammals, is essential for LCMV receptor function. Cells that are defective in components of the O-mannosylation pathway showed strikingly reduced LCMV infectibility. As defective O mannosylation is associated with severe clinical symptoms in mammals such as congenital muscular dystrophies, it is likely that LCMV and potentially other arenaviruses may have selected this conserved and crucial posttranslational modification as the primary target structure for cell entry and infection.
The Human DEK Proto-Oncogene Is a Senescence Inhibitor and an Upregulated Target of High-Risk Human Papillomavirus E7
Authors: Wise-Draper Trisha M. , Allen Hillary V. , Thobe Megan N. , Jones Elizabeth E. , Habash Kristen B. , Münger Karl , Wells Susanne I.
Published: October 2005

The human DEK proto-oncogene is a nucleic acid binding protein with suspected roles in human carcinogenesis, autoimmune disease, and viral infection. Intracellular DEK functions, however, are poorly understood. In papillomavirus-positive cervical cancer cells, downregulation of viral E6/E7 oncogene expression results in cellular senescence. We report here the specific repression of DEK message and protein levels in senescing human papillomavirus type 16- (HPV16-) and HPV18-positive cancer cell lines as well as in primary cells undergoing replicative senescence. Cervical cancer cell senescence was partially overcome by DEK overexpression, and DEK overexpression was sufficient for extending the life span of primary keratinocytes, supporting critical roles for this molecule as a senescence regulator. In order to determine whether DEK is a bona fide HPV oncogene target in primary cells, DEK expression was monitored in human keratinocytes transduced with HPV E6 and/or E7. The results identify high-risk HPV E7 as a positive DEK regulator, an activity that is not shared by low-risk HPV E7 protein. Experiments in mouse embryo fibroblasts recapitulated the observed E7-mediated DEK induction and demonstrated that both basal and E7-induced regulation of DEK expression are controlled by the retinoblastoma protein family. Taken together, our results suggest that DEK upregulation may be a common event in human carcinogenesis and may reflect its senescence inhibitory function.
Human β-Defensins Suppress Human Immunodeficiency Virus Infection: Potential Role in Mucosal Protection
Authors: Sun Lingling , Finnegan Catherine M. , Kish-Catalone Tina , Blumenthal Robert , Garzino-Demo Paolo , La Terra Maggiore Gian M. , Berrone Sid , Kleinman Carol , Wu Zhibin , Abdelwahab Sayed , Lu Wuyuan , Garzino-Demo Alfredo
Published: October 2005

β-Defensins are small (3 to 5 kDa in size) secreted antimicrobial and antiviral proteins that are components of innate immunity. β-Defensins are secreted by epithelial cells, and they are expressed at high levels in several mucosae, including the mouth, where the concentration of these proteins can reach 100 μg/ml. Because of these properties, we wondered whether they could be part of the defenses that lower oral transmission of human immunodeficiency virus (HIV) compared to other mucosal sites. Our data show that select β-defensins, especially human β-defensin 2 (hBD2) and hBD3, inhibit R5 and X4 HIV infection in a dose-dependent manner at doses that are compatible with or below those measured in the oral cavity. We observed that β-defensin treatment inhibited accumulation of early products of reverse transcription, as detected by PCR. We could not, however, detect any reproducible inhibition ofenv-mediated fusion, and we did not observe any modulation of HIV coreceptors following treatment with hBD1 and hBD2, in both resting and phytohemagglutinin-activated cells. Our data instead suggest that, besides a direct inactivation of HIV virions, hBD2 inhibits HIV replication in the intracellular environment. Therefore, we speculate that β-defensins mediate a novel antiretroviral mechanism that contributes to prevention of oral HIV transmission in the oral cavity. Immunohistochemical data on hBD2 expression in oral mucosal tissue shows that hBD2 is constitutively expressed, forming a barrier layer across the epithelium in healthy subjects, while in HIV-positive subjects levels of hBD2 expression are dramatically diminished. This may predispose HIV-positive subjects to increased incidence of oral complications associated with HIV infection.
Rational Attenuation of a Morbillivirus by Modulating the Activity of the RNA-Dependent RNA Polymerase
Authors: Brown David D. , Rima Bertus K. , Allen Ingrid V. , Baron Michael D. , Banyard Ashley C. , Barrett Thomas , Duprex W. Paul
Published: October 2005

Negative-strand RNA viruses encode a single RNA-dependent RNA polymerase (RdRp) which transcribes and replicates the genome. The open reading frame encoding the RdRp from a virulent wild-type strain of rinderpest virus (RPV) was inserted into an expression plasmid. Sequences encoding enhanced green fluorescent protein (EGFP) were inserted into a variable hinge of the RdRp. The resulting polymerase was autofluorescent, and its activity in the replication/transcription of a synthetic minigenome was reduced. We investigated the potential of using this approach to rationally attenuate a virus by inserting the DNA sequences encoding the modified RdRp into a full-length anti-genome plasmid from which a virulent virus (rRPVKO) can be rescued. A recombinant virus, rRPVKOL-RRegfpR, which grew at an indistinguishable rate and to an identical titer as rRPVKOin vitro, was rescued. Fluorescently tagged polymerase was visible in large cytoplasmic inclusions and beneath the cell membrane. Subcutaneous injection of 104TCID50of the rRPVKOparental recombinant virus into cattle leads to severe disease symptoms (leukopenia/diarrhea and pyrexia) and death by 9 days postinfection. Animals infected with rRPVKOL-RRegfpR exhibited transient leukopenia and mild pyrexia, and the only noticeable clinical signs were moderate reddening of one eye and a slight ocular-nasal discharge. Viruses that expressed the modified polymerase were isolated from peripheral blood lymphocytes and eye swabs. This demonstrates that a virulent morbillivirus can be attenuated in a single step solely by modulating RdRp activity and that there is not necessarily a correlation between virus growth in vitro and in vivo.
Long Untranslated Regions of the Measles Virus M and F Genes Control Virus Replication and Cytopathogenicity
Authors: Takeda Makoto , Ohno Shinji , Seki Fumio , Nakatsu Yuichiro , Tahara Maino , Yanagi Yusuke
Published: October 2005

Measles is still a major cause of mortality mainly in developing countries. The causative agent,
measles virus
(MeV), is an enveloped virus having a nonsegmented negative-sense RNA genome, and belongs to the genus
Morbillivirus
of the family
Paramyxoviridae
. One feature of the moribillivirus genomes is that the M and F genes have long untranslated regions (UTRs). The M and F mRNAs of MeV have 426-nucleotide-long 3′ and 583-nucleotide-long 5′ UTRs, respectively. Though these long UTRs occupy as much as ∼6.4% of the virus genome, their function remains unknown. To elucidate the role of the long UTRs in the context of virus infection, we used the reverse genetics based on the virulent strain of MeV, and generated a series of recombinant viruses having alterations or deletions in the long UTRs. Our results showed that these long UTRs per se were not essential for MeV replication, but that they regulated MeV replication and cytopathogenicity by modulating the productions of the M and F proteins. The long 3′ UTR of the M mRNA was shown to have the ability to increase the M protein production, promoting virus replication. On the other hand, the long 5′ UTR of the F mRNA was found to possess the capacity to decrease the F protein production, inhibiting virus replication and yet greatly reducing cytopathogenicity. We speculate that the reduction in cytopathogenicity may be advantageous for MeV fitness and survival in nature.
The Toll-Like Receptor 7 (TLR7) Agonist, Imiquimod, and the TLR9 Agonist, CpG ODN, Induce Antiviral Cytokines and Chemokines but Do Not Prevent Vaginal Transmission of Simian Immunodeficiency Virus When Applied Intravaginally to Rhesus Macaques
Authors: Wang Yichuan , Abel Kristina , Lantz Katherine , Krieg Arthur M. , McChesney Michael B. , Miller Christopher J.
Published: October 2005

The initial host response to viral infection occurs after Toll-like receptors (TLRs) on dendritic cells (DC) are stimulated by viral nucleic acids (double-stranded RNA, single-stranded RNA) and alpha interferon (IFN-α) and IFN-β are produced. We hypothesized that pharmacologic induction of innate antiviral responses in the cervicovaginal mucosa by topical application of TLR agonists prior to viral exposure could prevent or blunt vaginal transmission of simian immunodeficiency virus (SIV). To test this hypothesis, we treated rhesus monkeys intravaginally with either the TLR9 agonist, CpG oligodeoxynucleotides (ODN), or the TLR7 agonist, imiquimod. Both immune modifiers rapidly induced IFN-α and other antiviral effector molecules in the cervicovaginal mucosa of treated animals. However, both CpG ODN and imiquimod also induced proinflammatory cytokine expression in the cervicovaginal mucosa. In the vaginal mucosa of imiquimod-treated monkeys, we documented a massive mononuclear cell infiltrate consisting of activated CD4+T cells, DC, and beta-chemokine-secreting cells. After vaginal SIV inoculation, all TLR agonist-treated animals became infected and had plasma vRNA levels that were higher than those of control monkeys. We conclude that induction of mucosal innate immunity including an IFN-α response is not sufficient to prevent sexual transmission of human immunodeficiency virus.
Role of Notch Signal Transduction in Kaposi's Sarcoma-Associated Herpesvirus Gene Expression
Authors: Chang Heesoon , Dittmer Dirk P. , Chul Shin-Young , Hong Youngkwon , Jung Jae U.
Published: October 2005

Kaposi's sarcoma-associated herpesvirus (KSHV) RTA transcription factor is recruited to its responsive elements through interaction with a Notch-mediated transcription factor, RBP-Jκ, indicating that RTA mimics cellular Notch signal transduction to activate viral lytic gene expression. To test whether cellular Notch signal transduction and RTA are functionally exchangeable for viral gene expression, human Notch intracellular (hNIC) domain that constitutively activates RBP-Jκ transcription factor activity was expressed in KSHV-infected primary effusion lymphoma BCBL1 cells (TRExBCBL1-hNIC) in a tetracycline-inducible manner. Gene expression profiling showed that like RTA, hNIC robustly induced expression of a number of viral genes, including viral interleukin 6 (vIL-6), K3, and K5. Unlike RTA, however, hNIC was not capable of evoking the full repertoire of lytic viral gene expression and thereby lytic replication. To further understand the role of Notch signal transduction in KSHV gene expression, vIL-6 growth factor and K5 immune modulator genes were selected for detailed analysis. Despite the presence of multiple RBP-Jκ binding sites, hNIC targeted the specific RBP-Jκ binding sites of vIL-6 and K5 promoter regions to regulate their gene expression. These results indicate that cellular Notch signal transduction not only is partially exchangeable with RTA in regard to activation of viral lytic gene expression but also provides a novel expression profile of KSHV growth and immune deregulatory genes that is likely different from that of RTA-independent standard latency program as well as RTA-dependent lytic reproduction program.
Novel Type of Hepatitis B Virus Mutation: Replacement Mutation Involving a Hepatocyte Nuclear Factor 1 Binding Site Tandem Repeat in Chronic Hepatitis B Virus Genotype E
Authors: Fujiwara Kei , Tanaka Yasuhito , Paulon Emma , Orito Etsuro , Sugiyama Masaya , Ito Kiyoaki , Ueda Ryuzo , Mizokami Masashi , Naoumov Nikolai V.
Published: October 2005

The genetic diversity of hepatitis B virus (HBV) strains has evolved through mutations such as point mutations, deletions or insertions, and recombination. We identified and characterized a novel type of mutation which is a complex of external insertion, deletion, and internal duplication in sequences from one of six patients with chronic hepatitis B virus genotype E (HBV/E). We provisionally named this mutation a “replacement mutation”; the core promoter upstream regulatory sequence/basic core promoter was replaced with a part of the S1 promoter covering the hepatocyte nuclear factor 1 (HNF1) binding site, followed by a tandem repeat of the HNF1 site. A longitudinal analysis of the HBV population over 6 years showed the clonal change from wild-type HBV/E to replacement-mutant type, resulting in a lower hepatitis B (HB) e antigen titer, a high HBV DNA level in serum, and progression of liver fibrosis. In an in vitro study using a replication model, the replacement-mutant HBV showed higher replication levels than the wild-type HBV/E replicon, probably mediated by altered transcription factor binding. Additionally, this HNF1 site replacement mutation was associated with excessive HB nucleocapsid protein expression in hepatocytes, in both in vivo and in vitro studies. This novel mutation may be specific to HBV genotype E, and its prevalence requires further investigation.
Intracellular Interference of Infectious Bursal Disease Virus
Authors: González Dolores , Rodríguez Jose Francisco , Abaitua Fernando
Published: October 2005

A search for dominant-negative mutant polypeptides hampering infectious bursal disease virus (IBDV) replication has been undertaken. We have found that expression of a mutant version of the VP3 structural polypeptide known as VP3/M3, partially lacking the domain responsible for the interaction with the virus-encoded RNA polymerase, efficiently interferes with the IBDV replication cycle. Transformed cells stably expressing VP3/M3 show a significant reduction (up to 96%) in their ability to support IBDV growth. Our findings provide a new tool for the characterization of the IBDV replication cycle and might facilitate the generation of genetically modified chicken lines with a reduced susceptibility to IBDV infection.
An N-Linked Glycoprotein with α(2,3)-Linked Sialic Acid Is a Receptor for BK Virus
Authors: Dugan Aisling S. , Eash Sylvia , Atwood Walter J.
Published: October 2005

BK virus (BKV) is a common human polyomavirus infecting >80% of the population worldwide. Infection with BKV is asymptomatic, but reactivation in renal transplant recipients can lead to polyomavirus-associated nephropathy. In this report, we show that enzymatic removal of α(2,3)-linked sialic acid from cells inhibited BKV infection. Reconstitution of asialo cells with α(2,3)-specific sialyltransferase restored susceptibility to infection. Inhibition of N-linked glycosylation with tunicamycin reduced infection, but inhibition of O-linked glycosylation did not. An O-linked-specific α(2,3)-sialyltransferase was unable to restore infection in asialo cells. Taken together, these data indicate that an N-linked glycoprotein containing α(2,3)-linked sialic acid is a critical component of the cellular receptor for BKV.
Murine Coronavirus with an Extended Host Range Uses Heparan Sulfate as an Entry Receptor
Authors: de Haan Cornelis A. M. , Li Zhen , te Lintelo Eddie , Bosch Berend Jan , Haijema Bert Jan , Rottier Peter J. M.
Published: October 2005

Only a relatively few mutations in its spike protein allow the murine coronavirus to switch from a murine-restricted tropism to an extended host range by being passaged in vitro. One such virus that we studied had acquired two putative heparan sulfate-binding sites while preserving another site in the furin-cleavage motif. The adaptation of the virus through the use of heparan sulfate as an attachment/entry receptor was demonstrated by increased heparin binding as well as by inhibition of infection through treatment of cells and the virus with heparinase and heparin, respectively.
Convergence Properties of the Normal Mode Optimization and Its Combination with Molecular Geometry Constraints
Authors: Bouř Petr
Published: October 2005

Optimization in the normal mode coordinates has been established as a useful tool for modeling of vibrational spectra (J. Chem. Phys. 2002, 117, 4126). In this work the algorithm is extended with the aid of harmonic penalty functions to allow for multiple restraints of geometry parameters, such as bond lengths, bond and dihedral angles, and for simultaneous optimization of more molecules. Additionally, geometry optimization when atomic nuclei are maintained on the constant electrostatic potential surface was implemented and its applications for solvent models are discussed. Model systems include small molecules, water cluster, antiparallel β-sheet peptide containing intermolecular hydrogen bonds, periodic α-helix and a parallel β-sheet segments. The normal mode method provided better numerical stability than the conventional redundant internal coordinates, especially for weakly hydrogen-bonded systems, while the speed of the optimization was found similar as for the Cartesian coordinates.
Asymmetric Synthesis of (S)-2-Amino-3-(1-naphthyl)propanoic Acid via Chiral Nickel Complex. Crystal Structure, Circular Dichroism, 1H and 13C NMR Spectra of the Complex
Authors: Popkov Alexander , Císařová Ivana , Sopková Jana , Jirman Josef , Lyčka Antonín , Kochetkov Konstantin A.
Published: October 2005

The recently published environmentally friendly preparation of a glycine synthon 2 from regeneratable chiral auxiliary BPB ((S)-N-(2-benzoylphenyl)-N'-benzylprolinamide) was used for preparative asymmetric synthesis of the non-coded amino acid 3-(1-naphthyl)alanine (1). Full assignment of 1H and 13C NMR of both intermediate complex 3 and 1 and X-ray structure determination of complex 3 were made. Cotton effects observed in circular dichroism spectrum of complex 3 are consistent with published empirical rules.
Synthesis of 1,6-Anhydro-β-D-hexopyranoses Fused to the Piperidine Ring
Authors: Trtek Tomáš , Černý Miloslav , Buděšínský Miloš , Trnka Tomáš , Císařová Ivana
Published: October 2005

Two piperidine derivatives (6 and 17) containing fused 1,6-anhydro-β-D-hexopyranose moiety were prepared from 1,6-anhydro-β-D-glucopyranose (1). The first synthetic route led via the known 1,6:2,3-dianhydro-4-deoxy-4-(3-hydroxypropyl)-β-D-mannopyranose (2) obtained in four steps from 1. Its hydroxyl group was converted into amino group via tosylate and azide. The corresponding amino epoxide 5 readily rearranged into 3-amino-1,6-anhydro-3,4-dideoxy-3-N,4-C-(propane-1,3-diyl)-β-D-altropyranose (6). The second route used the known 1,6-anhydro-2,4-di-O-tosyl-β-D-ribo-hexopyranos-3-ulose (9) as an intermediate. Addition of allylmagnesium chloride to ketose 9 afforded 3-C-allyl-1,6-anhydro-2,4-di-O-tosyl-β-D-allopyranose (10). Hydroboration of its double bond followed by transformation of the resulting primary hydroxyl group into tosylamido group gave tritosyl derivative 15. Intramolecular replacement of the tosyloxy group in position 4 by tosylamido group gave tosylated piperidine derivative 16. Detosylation of 16 afforded the target 4-amino-1,6-anhydro-3,4-dideoxy-3-C,4-N-(propane-1,3-diyl)-β-D-gulopyranose (17).
Preparation of New Oxidized 18-α-Oleanane Derivatives
Authors: Kvasnica Miroslav , Tišlerová Iva , Šarek Jan , Sejbal Jan , Císařová Ivana
Published: October 2005

19β,28-Epoxy-4,5-seco-3,5-cyclo-18α-olean-3(5)-ene (2) is an appropriate compound for oxidations, which lead to new oxidized compounds with potential biological activities. Several oxidations were used such as epoxidation, allylic oxidation, oxidative cleavage of double bond and other ones. From the starting compound epoxides 3a, 3b and unsaturated ketone 4 were prepared. This ketone was further oxidized to diketone 6 and anhydride 7. The double bonds of all unsaturated compounds were cleaved with ruthenium tetroxide to afford new A-seco oleananes. The structure and stereochemistry of the compounds were derived from IR, MS, 1H and 13C NMR spectra (1D and 2D COSY, TOCSY, NOESY, HSQC, HMBC).
Simple Transformation of Thymine 1-[3-Hydroxy-2-(phosphonomethoxy)propyl] Derivatives to Their 1-[3-Fluoro-2-(phosphonomethoxy)propyl] Counterparts
Authors: Pomeisl Karel , Pohl Radek , Holý Antonín , Votruba Ivan
Published: October 2005

A novel method of transformation of HOCH2 group to FCH2 was successfully applied to the preparation of fluorine-containing pyrimidine acyclic nucleoside phosphonates (FPMP compounds) such as (S)- and (R)-1-[3-fluoro-2-(phosphonomethoxy)propyl]thymine (7a, 7b) (FPMPT). The key displacement of hydroxy group with fluorine in 1-{2-[(diisopropoxyphosphoryl)- methoxy]-3-hydroxypropyl}-4-methoxy-5-methylpyrimidin-2(1H)-one (5a, 5b) was performed using perfluorobutane-1-sulfonyl fluoride in the presence of DBU. Novel pyrimidine acyclic nucleoside phosphonates were investigated as inhibitors of thymidine phosphorylase.
Receptor-Based 3D QSAR Analysis of Serotonin 5-HT1D Receptor Agonists
Authors: Terzioglu Nalan , Höltje Hans-Dieter
Published: October 2005

A three-dimensional quantitative structure-activity relationship study (3D QSAR) has been successfully applied to explain the binding affinities for the serotonin 5-HT1Dreceptor of a triptan series. The paper describes the development of a receptor-based 3D QSAR model of some known agonists and recently developed triptans on the 5-HT1Dserotonergic receptor, showing a significant correlation between predicted and experimentally measured binding affinity (pIC50). The pIC50values of these agonists are in the range from 5.40 to 9.50. The ligand alignment obtained from dynamic simulations was taken as basis for a 3D QSAR analysis applying the GRID/GOLPE program. 3D QSAR analysis of the ligands resulted in a model of high quality (r2= 0.9895,q2LOO= 0.7854). This is an excellent result and proves both the validity of the proposed pharmacophore and the predictive quality of the 3D QSAR model for the triptan series of serotonin 5-HT1Dreceptor agonists.
The role of enterovirus in chronic fatigue syndrome
Authors: Chia J K S
Published: October 2005

Two and a half decades after coining of the term chronic fatigue syndrome (CFS), the diagnosis of this illness is still symptom based and the aetiology remains elusive. Enteroviruses are well known causes of acute respiratory and gastrointestinal infections, with tropism for the central nervous system, muscles, and heart. Initial reports of chronic enteroviral infections causing debilitating symptoms in patients with CFS were met with skeptism, and had been largely forgotten for the past decade. Observations from in vitro experiments and from animal models clearly established a state of chronic persistence through the formation of double stranded RNA, similar to findings reported in muscle biopsies of patients with CFS. Recent evidence not only confirmed the earlier studies, but also clarified the pathogenic role of viral RNA through antiviral treatment. This review summarises the available experimental and clinical evidence that supports the role of enterovirus in chronic fatigue syndrome.
Alveolar adenoma of the lung: a clinicopathological description of a case of this very unusual tumour
Authors: Halldorsson A , Dissanaike S , Kaye K S
Published: October 2005

Alveolar adenomas are extremely rare, and are probably benign lung tumours of unknown histogenesis. This report describes a case of alveolar adenoma in a 43 year old white man, who presented with pleuritic chest pain. A chestx ray and computerised tomography scan demonstrated a solitary left lower lobe lung nodule. Although a positron emission tomography scan seemed to document the benign nature of the lesion, a thoracoscopic wedge resection was performed to alleviate the symptoms and verify the diagnosis. Histologically, the lesion was well demarcated, dominated by large and small cysts with no normal lung parenchyma. The interstitial cellular component consisted of both epithelioid and vaguely spindle shaped cells. The cystic cell linings were mostly indistinct, although areas of cuboidal epithelial cells were seen. Multiple histochemical and immunohistochemical tests were performed. There were no histological signs of malignancy and the patient is doing well one and a half years postoperatively.
An unusual case of hyponatraemia in diabetic ketoacidosis: Table 1
Authors: Twomey P J , Cordle J , Pledger D R , Miao Y
Published: October 2005

This report outlines a case of diabetic ketoacidosis associated hyponatraemia in an 18 year old woman with type 1 diabetes who presented to the accident and emergency department and was quickly admitted to the intensive treatment unit. Causes of hyponatraemia include sodium depletion, pseudohyponatraemia, and extracellular hypertonicity. Hypertonicity secondary to hyperglycaemia is thought to be the major cause of hyponatraemia in diabetic ketoacidosis. Indirect and direct sodium measurements were performed until the glucose concentration stabilised. The large difference between the presenting sodium concentrations is consistent with pseudohyponatraemia. However, the causes of pseudohyponatraemia (large increases in total protein, triglyceride, and cholesterol concentrations) were excluded. Analytical error should always be considered when the laboratory results do not agree with the clinical picture. Sometimes, however, even after excluding all known effects, the cause may remain unexplained, as in this case.
Activation of the extracellular signal regulated kinase (ERK) pathway in human melanoma
Authors: Zhuang L , Lee C S , Scolyer R A , McCarthy S W , Palmer A A , Zhang X D , Thompson J F , Bron L P , Hersey P
Published: October 2005

Background:Several studies suggest that melanoma may be resistant to treatment because of resistance to apoptosis and that this may be the result of activation of the extracellular signal regulated kinase (ERK1/2) pathway.

Aims:To test this hypothesis by examining the expression of ERK1/2 and its activated form in histological sections of melanoma and its relation to known prognostic features of the disease.

Materials/Methods:Immunohistochemistry with antibodies to ERK1/2 and phosphorylated ERK (p-ERK) was performed on formalin fixed sections from 42 primary melanomas, 38 metastases, and 20 naevi. Fourteen of the primary melanomas were in the radial and 28 in the vertical growth phase.

Results:ERK1/2 was widely expressed (100%) in all the (pigmented) lesions studied. p-ERK1/2 expression was much lower in compound (32.4%) and dysplastic (54.5%) naevi than in primary melanoma (nodular 78.8%, superficial spreading 67%) and subcutaneous metastases (76.3%). p-ERK expression was much lower in lymph node metastases (48.5%), suggesting that the microenvironment may influence the activation of ERK. There was a (non-significant) trend for p-ERK expression to be higher in thick (>1.0 mm) versus thin (⩽1.0 mm) melanoma (p = 0.23). There was a trend for overall survival to be related to p-ERK expression in patients with melanoma over 1 mm in thickness.

Conclusions:Expression of activated ERK1/2 in melanocytic lesions appears to be related to malignant potential so that activation of ERK1/2 may be important in melanoma progression. These results provide important histological support for the proposal that inhibition of this signalling pathway may be useful in treatment of melanoma.
Solitary ovarian splenosis
Authors: Vydianath B , Gurumurthy M , Crocker J
Published: October 2005

This report describes the case of an asymptomatic, solitary splenotic nodule in the right ovary, revealed incidentally at histopathological examination. In gynaecological patients, splenosis most often presents as multiple pelvic nodules mimicking endometriosis. Two cases of ovarian splenosis accompanying pelvic and serosal splenotic nodules have been reported previously. However, this is the first documented case of solitary intraovarian splenosis.
Evidence based criteria for the histopathological diagnosis of toxoplasmic lymphadenopathy
Authors: Eapen M , Mathew C F , Aravindan K P
Published: October 2005

Aims:To formulate evidence based histopathological criteria for the diagnosis of acquired toxoplasmic lymphadenitis, in an area of high tuberculosis prevalence.

Methods:Multiple histopathological parameters were assessed in a consecutive sample of biopsies from 68 patients presenting with lymphadenopathy with a duration of less than six months. Serum IgM enzyme linked immunosorbent assay was used as the standard reference test for the diagnosis of toxoplasmic lymphadenitis. The sensitivity, specificity, and likelihood ratios of various histological parameters were estimated.

Results:The presence of microgranulomas (p < 0.0001), paracortical widening (p  =  0.006), paracortical hyperplasia (p  =  0.02), monocytoid B cells in sinuses (p  =  0.007), lower than grade 2 macrogranuloma (p  =  0.002), and the absence of giant cells (p  =  0.05) were found to discriminate between IgM positive cases and IgM negative controls. Using a composite criterion—(1) presence of microgranulomas, (2) lower than grade 2 macrogranuloma, (3) absence of giant cells, and (4) follicular hyperplasia—toxoplasmic lymphadenitis can be diagnosed with a high degree of sensitivity (100%), specificity (96.6%), and positive likelihood ratio (29).

Conclusion:Toxoplasma lymphadenitis can be diagnosed with a high degree of confidence using the specific histopathological criteria identified here.
Grading melanocytic dysplasia in paraffin wax embedded tissue by the nucleic acid index
Authors: Berman D M , Wincovitch S , Garfield S , Romeo M J
Published: October 2005

Background:Although nucleic acid derangements are the hallmark of melanocytic dysplasia, the gold standard for its diagnosis remains the microscopic evaluation of haematoxylin and eosin stained slides. However, light microscopy is subjective and crucial genomic changes do not always show as changes in histology.

Aims:To introduce the nucleic acid index (NAI) as a means of analysing nucleic acid derangements in histological sections at the level of the individual cell and within the context of its microenvironment.

Methods:Confocal laser scanning microscopy was performed on melanocytic lesions stained with acridine orange (AO), a fluorescent stain for DNA and RNA. The NAI, calculated by measuring the fluorescence intensities of AO in nuclei relative to the surrounding cytoplasm, reflects the concentration of DNA relative to RNA.

Results:When applied to benign naevi, dysplastic naevi, and melanoma, a very strong significant association was seen between lower NAI and malignant potential (p < 0.0001). Strong inverse correlations were found between NAI and both mitotic index and Breslow thickness. Interestingly, the NAI for dysplastic naevi is between that of melanoma and most benign naevi, consistent with their intermediate biological behaviour and histological appearance.

Conclusion:By providing a quantitative measure for melanocytic neoplasia, the NAI may improve the diagnosis of melanocytic lesions and the selection of treatment.
Interobserver reproducibility of histological features in cutaneous malignant melanoma
Authors: Urso C , Rongioletti F , Innocenzi D , Saieva C , Batolo D , Chimenti S , Filotico R , Gianotti R , Lentini M , Tomasini C , Rebora A , Pippione M
Published: October 2005

Aims:To assess the interobserver reproducibility of certain histological features proposed for the diagnosis of melanoma.

Methods:In a series of melanomas, 13 histological parameters were analysed: dimension > 6 mm, asymmetry, poor circumscription, irregular confluent nests, single melanocytes predominating, absence of maturation, suprabasal melanocytes, asymmetrical melanin, melanin in deep cells, cytological atypia, mitoses, dermal lymphocytic infiltrate, and necrosis.

Results:The agreement (reproducibility) between the nine observers was excellent (κ > 0.75) for 10 of the 13 examined features (dimension > 6 mm, poor circumscription, irregular confluent nests, single melanocytes predominating, absence of maturation, suprabasal melanocytes, asymmetrical melanin, melanin in deep cells, mitoses, and necrosis). The agreement for asymmetry was very close to excellence (κ  =  0.74), and that for cytological atypia (κ  =  0.65) and dermal lymphocytic infiltrate (κ  =  0.47) was slightly lower, but in the fair to good agreement range. The κ values obtained by comparison with the majority diagnosis were generally high (⩾ 0.85); the mean value of κ was lower (0.70) for only one parameter (dermal lymphocytic infiltrate).

Conclusions:The parameters investigated showed an overall good reproducibility.
CD44s is useful in the differentiation of benign and malignant papillary lesions of the breast
Authors: Tse G M K , Tan P-H , Ma T K F , Gilks C B , Poon C S P , Law B K B
Published: October 2005

Background/Aims:CD44s, the standard form of CD44, has been shown to be downregulated during malignant transformation of breast cancers. It has also been reported recently to be a useful marker in differentiating between benign and malignant papillary lesions of the breast, with high expression in the former. CD44s expression in benign and malignant papillary lesions was evaluated.

Methods:CD44s expression was assessed by immunohistochemistry in 101 benign papillomas and 59 papillary carcinomas (seven invasive papillary carcinomas, 41 papillary ductal carcinomas in situ, and 11 ductal carcinomas involving papillomas).

Results:Patients’ age and tumour size were significantly different between the papilloma and papillary carcinoma groups (p < 0.0001). CD44s showed positive staining in 45 papillomas (45%) and five papillary carcinomas (8%), and the difference was significant (p < 0.0001). The myoepithelial cells, when present, were also positive for CD44s in both groups, with no observable differences. Using CD44s positive staining to differentiate between benign and malignant papillary lesions gives a sensitivity, specificity, and accuracy of 45%, 92%, and 62%, respectively.

Conclusions:CD44s may be useful as an adjunct in the evaluation of morphologically problematic cases of papillary lesion of the breast.
Pathology parameters and adjuvant tamoxifen response in a randomised premenopausal breast cancer trial
Authors: Jirström K , Rydén L , Anagnostaki L , Nordenskjöld B , Stål O , Thorstenson S , Chebil G , Jönsson P-E , Fernö M , Landberg G
Published: October 2005

Background:Subgroups of breast cancer that have an impaired response to endocrine treatment, despite hormone receptor positivity, are still poorly defined. Breast cancer can be subdivided according to standard pathological parameters including histological type, grade, and assessment of proliferation. These parameters are the net result of combinations of genetic alterations effecting tumour behaviour and could potentially reflect subtypes that respond differently to endocrine treatment.

Aims:To investigate the usefulness of these parameters as predictors of the response to tamoxifen in premenopausal women with breast cancer.

Materials/methods:Clinically established pathological parameters were assessed and related to the tamoxifen response in 500 available tumour specimens from 564 premenopausal patients with breast cancer randomised to either two years of tamoxifen or no treatment with 14 years of follow up. Proliferation was further evaluated by immunohistochemical Ki-67 expression.

Results:Oestrogen receptor positive ductal carcinomas responded as expected to tamoxifen, whereas the difference in recurrence free survival between control and tamoxifen treated patients was less apparent in the relatively few lobular carcinomas. For histological grade, there was no obvious difference in treatment response between the groups. The relation between proliferation and tamoxifen response seemed to be more complex, with a clear response in tumours with high and low proliferation, whereas tumours with intermediate proliferation defined by Ki-67 responded more poorly.

Conclusions:Clinically established pathology parameters seem to mirror the endocrine treatment response and could potentially be valuable in future treatment decisions for patients with breast cancer.
Role of mesangial fibrinogen deposition in the pathogenesis of crescentic Henoch-Schönlein nephritis in children
Authors: Shin J I , Park J M , Shin Y H , Lee J S , Jeong H J
Published: October 2005

Aims:To clarify the role of mesangial fibrinogen deposition in crescentic Henoch-Schönlein nephritis (HSN).

Methods:A retrospective analysis of 21 children with HSN treated with immunosuppressants. Serial renal biopsies were performed before and after treatment. They were divided into two groups according to the immunofluorescent course of fibrinogen deposition: group I (n = 9), no or decreased deposition; group II (n = 12), persistent or increased deposition.

Results:There were no differences between the two groups in renal manifestations or laboratory and histological findings at presentation. However, the activity index after immunosuppressive treatment was significantly decreased in group I (mean, 7.9 (SEM, 0.7)v2.9 (0.4); p = 0.008) and unchanged in group II (mean, 6.8 (SEM, 0.3)v6.0 (2.1)). The chronicity index was unchanged in group I, but increased in group II (mean, 0.8 (SEM, 0.3)v1.8 (0.3); p = 0.02). Univariate analysis revealed that the only factor significantly related to persistent or increased fibrinogen deposition was age more than 9 years (p = 0.03). Furthermore, the intensity of fibrinogen deposition at the second biopsy correlated positively with the age at onset (R2 = 0.306; p = 0.009) and changes in the percentage of crescents (post-treatment crescents (%) minus pretreatment crescents (%)) correlated positively with the intensity of fibrinogen deposition at the second biopsy (R2 = 0.193; p = 0.046).

Conclusions:This study indicates that fibrinogen deposition has an important role to play in renal injury of crescentic HSN and reflects persistent severe histological activity.
Mucinous metaplasia of the vulva in a case of lichen sclerosus. A case report
Authors: Rakha E , Mayne C , Brown L
Published: October 2005

Mucinous metaplasia of the genital area is a rare condition characterised by the emergence of mucin containing cells in stratified squamous epithelium. This report describes a unique case of benign mucinous metaplasia of the vulva associated with lichen sclerosus in a 60 year old woman. Histopathology revealed cervical type metaplasia with otherwise typical lichen sclerosus. This report discusses the pathogenesis and differential diagnosis of mucinous epithelium.
ELECTRICAL CONDUCTION IN SUBSTITUTED Li-FERRITES PREPARED BY MICROWAVE PROCESSING
Authors: MAISNAM MAMATA , PHANJOUBAM SUMITRA , SARMA H. N. K. , PRAKASH CHANDRA , DEVI L. RADHAPIYARI , THAKUR O. P.
Published: October 2005

Samples with representative formula Li 0.45 Ni 0.1 Mn 0.1 Fe 2.35 O 4 have been sintered by conventional sintering technique and microwave sintering technique. Both the samples showed single-phase with spinel structure. The lattice constant for the microwave sintered (MS) sample showed a lower value than the conventionally sintered (CS) sample. The density of the MS sample has been found to be higher than the CS sample. And MS sample showed a higher value of resistivity and activation energy compared to the CS sample. The possible mechanisms are discussed.
A QUANTITATIVE STUDY ON TUNNELING CONDUCTIVITY OF A FLOATING-GATE MOSFET IN TERMS OF THE OXIDE-LAYER WIDTH
Authors: GRADO-CAFFARO M. A. , GRADO-CAFFARO M.
Published: October 2005

We study quantitatively the variation of the electrical tunneling conductivity in an MOSFET with control gate and floating gate in terms of the oxide-layer width. This study is performed by defining a suitable parameter to evaluate the sensitivity of the above conductivity to the oxide-layer thickness. In addition, this sensitivity is expressed in terms of the electronic density of states.