bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of Human Immunodeficiency Virus Type 1 gp120 from Herpes Simplex Virus Type 1-Derived Amplicons Results in Potent, Specific, and Durable Cellular and Humoral Immune Responses
Authors: Hocknell Peter K. , Wiley Rebecca D. , Wang Xiuqing , Evans Thomas G. , Bowers William J. , Hanke Tomas , Federoff Howard J. , Dewhurst Stephen
Published: July 2002

Herpes simplex virus type 1 (HSV-1) infects a wide range of cells, including dendritic cells. Consequently, HSV-1 vectors may be capable of eliciting strong immune responses to vectored antigens. To test this hypothesis, an HSV-1 amplicon plasmid encoding human immunodeficiency virus type 1 gp120 was constructed, and murine immune responses to helper virus-free amplicon preparations derived from this construct were evaluated. Initial studies revealed that a single intramuscular (i.m.) injection of 106infectious units (i.u.) of HSV:gp120 amplicon particles (HSV:gp120) elicited Env-specific cellular and humoral immune responses. A potent, CD8+-T-cell-mediated response to an H-2Dd-restricted peptide from gp120 (RGPGRAFVTI) was measured by a gamma interferon ELISPOT and was confirmed by standard cytotoxic-T-lymphocyte assays. Immunoglobulin G enzyme-linked immunosorbent assay analysis showed the induction of a strong, Env-specific antibody response. An i.m. or an intradermal administration of HSV:gp120 at the tail base elicited a more potent cellular immune response than did an intraperitoneal (i.p.) inoculation, although an i.p. introduction generated a stronger humoral response. The immune response to HSV:gp120 was durable, with robust cellular and humoral responses persisting at 171 days after a single 106-i.u. inoculation. The immune response to HSV:gp120 was also found to be dose dependent: as few as 104i.u. elicited a strong T-cell response. Finally, HSV:gp120 elicited significant Env-specific cellular immune responses even in animals that had been previously infected with wild-type HSV-1. Taken together, these data strongly support the use of helper-free HSV-1 amplicon particles as vaccine delivery vectors.
Respiratory Syncytial Virus Infection of Human Airway Epithelial Cells Is Polarized, Specific to Ciliated Cells, and without Obvious Cytopathology
Authors: Zhang Liqun , Peeples Mark E. , Boucher Richard C. , Collins Peter L. , Pickles Raymond J.
Published: July 2002

Gene therapy for cystic fibrosis (CF) lung disease requires efficient gene transfer to airway epithelial cells after intralumenal delivery. Most gene transfer vectors so far tested have not provided the efficiency required. Although human respiratory syncytial virus (RSV), a common respiratory virus, is known to infect the respiratory epithelium, the mechanism of infection and the epithelial cell type targeted by RSV have not been determined. We have utilized human primary airway epithelial cell cultures that generate a well-differentiated pseudostratified mucociliary epithelium to investigate whether RSV infects airway epithelium via the lumenal (apical) surface. A recombinant RSV expressing green fluorescent protein (rgRSV) infected epithelial cell cultures with high gene transfer efficiency when applied to the apical surface but not after basolateral inoculation. Analyses of the cell types infected by RSV revealed that lumenal columnar cells, specifically ciliated epithelial cells, were targeted by RSV and that cultures became susceptible to infection as they differentiated into a ciliated phenotype. In addition to infection of ciliated cells via the apical membrane, RSV was shed exclusively from the apical surface and spread to neighboring ciliated cells by the motion of the cilial beat. Gross histological examination of cultures infected with RSV revealed no evidence of obvious cytopathology, suggesting that RSV infection in the absence of an immune response can be tolerated for >3 months. Therefore, rgRSV efficiently transduced the airway epithelium via the lumenal surface and specifically targeted ciliated airway epithelial cells. Since rgRSV appears to breach the lumenal barriers encountered by other gene transfer vectors in the airway, this virus may be a good candidate for the development of a gene transfer vector for CF lung disease.
A Single Mutation in the E2 Glycoprotein Important for Neurovirulence Influences Binding of Sindbis Virus to Neuroblastoma Cells
Authors: Lee Peiyu , Knight Ronald , Smit Jolanda M. , Wilschut Jan , Griffin Diane E.
Published: July 2002

The amino acid at position 55 of the E2 glycoprotein (E255) of Sindbis virus (SV) is a critical determinant of SV neurovirulence in mice. Recombinant virus strain TE (E255= histidine) differs only at this position from virus strain 633 (E255= glutamine), yet TE is considerably more neurovirulent than 633. TE replicates better than 633 in a neuroblastoma cell line (N18), but similarly in BHK cells. Immunofluorescence staining showed that most N18 cells were infected by TE at a multiplicity of infection (MOI) of 50 to 500 and by 633 only at an MOI of 5,000, while both viruses infected essentially 100% of BHK cells at an MOI of 5. When exposed to pH 5, TE and 633 viruses fused to similar extents with liposomes derived from BHK or N18 cell lipids, but fusion with N18-derived liposomes was less extensive (15 to 20%) than fusion with BHK-derived liposomes (∼50%). Binding of TE and 633 to N18, but not BHK, cells was dependent on the medium used for virus binding. Differences between TE and 633 binding to N18 cells were evident in Dulbecco's modified Eagle medium (DMEM), but not in RPMI. In DMEM, the binding efficiency of 633 decreased significantly as the pH was raised from 6.5 to 8.0, while that of TE did not change. The same pattern was observed with RPMI when the ionic strength of RPMI was increased to that of DMEM. TE bound better to heparin-Sepharose than 633, but this difference was not pH dependent. Growth of N18 and BHK cells in sodium chlorate to eliminate all sulfation decreased virus-cell binding, suggesting the involvement of sulfated molecules on the cell surface. Taken together, the presence of glutamine at E255impairs SV binding to neural cells under conditions characteristic of interstitial fluid. We conclude that mutation to histidine participates in or stabilizes the interaction between the virus and the surface of neural cells, contributing to greater neurovirulence.
Cytokines as Adjuvants for the Induction of Anti-Human Immunodeficiency Virus Peptide Immunoglobulin G (IgG) and IgA Antibodies in Serum and Mucosal Secretions after Nasal Immunization
Authors: Bradney Curtis P. , Sempowski Gregory D. , Liao Hua-Xin , Haynes Barton F. , Staats Herman F.
Published: July 2002

Safe and potent new adjuvants are needed for vaccines that are administered to mucosal surfaces. This study was performed to determine if interleukin-1α (IL-1α) combined with other proinflammatory cytokines provided mucosal adjuvant activity for induction of systemic and mucosal anti-human immunodeficiency virus (HIV) peptide antibody when intranasally administered with an HIV peptide immunogen. Nasal immunization of BALB/c mice with 10 μg of an HIVenvpeptide immunogen with IL-1α, IL-12, and IL-18 on days 0, 7, 14, and 28 induced peak serum anti-HIV peptide immunoglobulin G1 (IgG1) and IgA titers of 1:131,072 and 1:7,131, respectively (P= 0.05 versus no adjuvant). The use of cholera toxin (CT) as a mucosal adjuvant induced serum IgG1 and IgA titers of 1:32,768 and 1:776, respectively. The adjuvant combination of IL-1α, IL-12, and IL-18 induced anti-HIV peptide IgA titers of 1:1,176, 1:7,131, and 1:4,705 in saliva, fecal extracts and vaginal lavage, respectively. Titers induced by the use of CT as an adjuvant were 1:223, 1:1,176, and 1:675, respectively. These results indicate that the proinflammatory cytokines IL-1α, IL-12, and IL-18 can replace CT as a mucosal adjuvant for antibody induction and are important candidates for use as mucosal adjuvants with HIV and other vaccines.
The Magnitude and Specificity of Influenza A Virus-Specific Cytotoxic T-Lymphocyte Responses in Humans Is Related to HLA-A and -B Phenotype
Authors: Boon A. C. M. , de Mutsert G. , Graus Y. M. F. , Fouchier R. A. M. , Sintnicolaas K. , Osterhaus A. D. M. E. , Rimmelzwaan G. F.
Published: July 2002

The repertoire of human cytotoxic T-lymphocytes (CTL) in response to influenza A viruses has been shown to be directed towards multiple epitopes, with a dominant response to the HLA-A2-restricted M158–66epitope. These studies, however, were performed with peripheral blood mononuclear cells (PBMC) of individuals selected randomly with respect to HLA phenotype or selected for the expression of one HLA allele without considering an influence of other HLA molecules. In addition, little information is available on the influence of HLA makeup on the overall CTL response against influenza viruses. Here, the influenza A virus-specific CTL response was investigated in groups of HLA-A and -B identical individuals. Between groups the individuals shared two or three of the four HLA-A and -B alleles. After in vitro stimulation of PBMC with influenza virus, the highest CTL activity was found in HLA-A2+donors. A similar pattern was observed for the precursor frequency of virus-specific CTL (CTLp) ex vivo, with a higher CTLp frequency in HLA-A2-positive donors than in HLA-A2-negative donors, which were unable to recognize the immunodominant M158–66epitope. In addition, CTL activity and frequency of CTLp for the individual influenza virus epitopes were determined. The frequency of CTLp specific for the HLA-B8-restricted epitope NP380–388was threefold lower in HLA-B27-positive donors than in HLA-B27-negative donors. In addition, the frequency of CTLp specific for the HLA-A1-restricted epitope NP44–52was threefold higher in HLA-A1-, -A2-, -B8-, and -B35-positive donors than in other donors, which was confirmed by measuring the CTL activity in vitro. These findings indicate that the epitope specificity of the CTL response is related to the phenotype of the other HLA molecules. Furthermore, the magnitude of the influenza virus-specific CTL response seems dependent on the HLA-A and -B phenotypes.
Distribution of Chemokine ReceptorCCR2andCCR5Genotypes and Their Relative Contribution to Human Immunodeficiency Virus Type 1 (HIV-1) Seroconversion, Early HIV-1 RNA Concentration in Plasma, and Later Disease Progression
Authors: Tang Jianming , Shelton Brent , Makhatadze Nina J. , Zhang Yuting , Schaen Margaret , Louie Leslie G. , Goedert James J. , Seaberg Eric C. , Margolick Joseph B. , Mellors John , Kaslow Richard A.
Published: July 2002

At the CC (β) chemokine receptor 2 (CCR2) andCCR5loci, combinations of common single-nucleotide polymorphisms (SNPs) and a 32-bp deletion (Δ32) form nine stable haplotypes (designated A through G*2). The distribution of theseCCR2-CCR5haplotypes was examined among 703 participants in the Multicenter AIDS Cohort Study (MACS), the District of Columbia Gay (DCG) Study, and the San Francisco Men’s Health Study (SFMHS). Highly exposed and persistently seronegative (HEPS;n= 90) Caucasian men from MACS more frequently carried heterozygous G*2 (Δ32) genotypes (especially A/G*2) and less frequently carried the homozygous E/E genotype compared with 469 Caucasian seroconverters (SCs) from the same cohort (P= 0.004 to 0.042). Among 341 MACS Caucasian SCs with 6- to 12-month human immunodeficiency virus type 1 (HIV-1) seroconversion intervals and no potent antiretroviral therapy, mean plasma HIV-1 RNA level during the initial 42 months after seroconversion was higher in carriers of the E/E genotype and lower in those with the 64I-bearing haplotype F*2 or the Δ32-bearing haplotype G*2 (and especially genotypes A/G*2 and F*2/G*2). A multivariable model containing these CCR markers showed significant composite effects on HIV-1 RNA at each of four postconversion intervals (P= 0.0004 to 0.050). In other models using time to AIDS as the endpoint, the same markers showed more modest contributions (P= 0.08 to 0.24) to differential outcome during 11.5 years of follow-up. Broadly consistent findings in the larger MACS Caucasian SCs and the smaller groups of MACS African-American SCs and the DCG and SFMHS Caucasian SCs indicate that specificCCR2-CCR5haplotypes or genotypes mediate initial acquisition of HIV-1 infection, early host-virus equilibration, and subsequent pathogenesis.
Strong CD8 T-Cell Responses following Coimmunization with Plasmids Expressing the Dominant pp89 and Subdominant M84 Antigens of Murine Cytomegalovirus Correlate with Long-Term Protection against Subsequent Viral Challenge
Authors: Ye Ming , Morello Christopher S. , Spector Deborah H.
Published: July 2002

We previously showed that intradermal immunization with plasmids expressing the murine cytomegalovirus (MCMV) protein IE1-pp89 or M84 protects against viral challenge and that coimmunization has a synergistic protective effect (C. S. Morello, L. D. Cranmer, and D. H. Spector, J. Virol. 74:3696-3708, 2000). Using an intracellular gamma interferon cytokine staining assay, we have now characterized the CD8
+
T-cell response after DNA immunization with pp89, M84, or pp89 plus M84. The pp89- and M84-specific CD8
+
T-cell responses peaked rapidly after three immunizations. DNA immunization and MCMV infection generated similar levels of pp89-specific CD8
+
T cells. In contrast, a significantly higher level of M84-specific CD8
+
T cells was elicited by DNA immunization than by MCMV infection. Fusion of ubiquitin to pp89 enhanced the CD8
+
T-cell response only under conditions where vaccination was suboptimal. Three immunizations with either pp89, M84, or pp89 plus M84 DNA also provided significant protection against MCMV infection for at least 6 months, with the best protection produced by coimmunization. A substantial percentage of antigen-specific CD8
+
T cells remained detectable, and they responded rapidly to the MCMV challenge. These results underscore the importance of considering antigens that do not appear to be highly immunogenic during infection as DNA vaccine candidates.
Epstein-Barr Virus BALF1 Is a BCL-2-Like Antagonist of the Herpesvirus Antiapoptotic BCL-2 Proteins
Authors: Bellows David S. , Howell Melanie , Pearson Colin , Hazlewood Sheila A. , Hardwick J. Marie
Published: July 2002

Cellular BCL-2 family proteins can inhibit or induce programmed cell death in part by counteracting the activity of other BCL-2 family members. All sequenced gammaherpesviruses encode a BCL-2 homologue that potently inhibits apoptosis and apparently escapes some of the regulatory mechanisms that govern the functions of their cellular counterparts. Examples of these protective proteins include BHRF1 of Epstein-Barr virus (EBV) and KSBcl-2 of Kaposi's sarcoma-associated herpesvirus, also known as human herpesvirus 8. The gamma-1 subgroup of these viruses, such as EBV, encodes a second BCL-2 homologue. We have now found that this second BCL-2 homologue encoded by EBV, BALF1, inhibits the antiapoptotic activity of EBV BHRF1 and of KSBcl-2 in several transfected cell lines. However, BALF1 failed to inhibit the cellular BCL-2 family member, BCL-x
L
. Thus, BALF1 acts as a negative regulator of the survival function of BHRF1, similar to the counterbalance observed between cellular BCL-2 family members. Unlike the cellular BCL-2 family antagonists, BALF1 lacked proapoptotic activity and could not be converted into a proapoptotic factor in a manner similar to cellular BCL-2 proteins by caspase cleavage or truncation of the N terminus. Coimmunoprecipitation experiments and immunofluorescence assays suggest that a minimal amount, if any, of the BHRF1 and BALF1 proteins colocalizes inside cells, suggesting that mechanisms other than direct interaction explain the suppressive function of BALF1.
Reovirus-Induced Alterations in Gene Expression Related to Cell Cycle Regulation
Authors: Poggioli George J. , DeBiasi Roberta L. , Bickel Ryan , Jotte Robert , Spalding Aaron , Johnson Gary L. , Tyler Kenneth L.
Published: July 2002

Mammalian reovirus infection results in perturbation of host cell cycle progression. Since reovirus infection is known to activate cellular transcription factors, we investigated alterations in cell cycle-related gene expression following HEK293 cell infection by using the Affymetrix U95A microarray. Serotype 3 reovirus infection results in differential expression of 10 genes classified as encoding proteins that function at the G
1
-to-S transition, 11 genes classified as encoding proteins that function at G
2
-to-M transition, and 4 genes classified as encoding proteins that function at the mitotic spindle checkpoint. Serotype 1 reovirus infection results in differential expression of four genes classified as encoding proteins that function at the G
1
-to-S transition and three genes classified as encoding proteins that function at G
2
-to-M transition but does not alter any genes classified as encoding proteins that function at the mitotic spindle checkpoint. We have previously shown that serotype 3, but not serotype 1, reovirus infection induces a G
2
-to-M transition arrest resulting from an inhibition of cdc2 kinase activity. Of the differentially expressed genes encoding proteins regulating the G
2
-to-M transition, chk1, wee1, and GADD45 are known to inhibit cdc2 kinase activity. A hypothetical model describing serotype 3 reovirus-induced inhibition of cdc2 kinase is presented, and reovirus-induced perturbations of the G
1
-to-S, G
2
-to-M, and mitotic spindle checkpoints are discussed.
Heterologous Exchanges of the Glycoprotein and the Matrix Protein in a
Novirhabdovirus
Authors: Biacchesi Stéphane , Béarzotti Monique , Bouguyon Edwige , Brémont Michel
Published: July 2002

Infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicemia virus (VHSV) are two salmonid rhabdoviruses replicating at low temperatures (14 to 20°C). Both viruses belong to the
Novirhabdovirus
genus, but they are only distantly related and do not cross antigenically. By using a recently developed reverse-genetic system based on IHNV (S. Biacchesi et al., J. Virol. 74:11247-11253, 2000), we investigated the ability to exchange IHNV glycoprotein G with that of VHSV. Thus, the IHNV genome was modified so that the VHSV G gene replaced the complete IHNV G gene. A recombinant virus expressing VHSV G instead of IHNV G, rIHNV-Gvhsv, was generated and was shown to replicate as well as the wild-type rIHNV in cell culture. This study was extended by exchanging IHNV G with that of a fish vesiculovirus able to replicate at high temperatures (up to 28°C), the spring viremia of carp virus (SVCV). rIHNV-Gsvcv was successfully recovered; however, its growth was restricted to 14 to 20°C. These results show the nonspecific sequence requirement for the insertion of heterologous glycoproteins into IHNV virions and also demonstrate that an IHNV protein other than the G protein is responsible for the low-temperature restriction on growth. To determine to what extent the matrix (M) protein interacts with G, a series of chimeric pIHNV constructs in which all or part of the M gene was replaced with the VHSV counterpart was engineered and used to recover the respective recombinant viruses. Despite the very low percentage (38%) of amino acid identity between the IHNV and VHSV matrix proteins, viable chimeric IHNVs, harboring either the matrix protein or both the glycoprotein and the matrix protein from VHSV, were recovered and propagated. Altogether, these data show the extreme flexibility of IHNV to accommodate heterologous structural proteins.
Novel Immediate-Early Protein IE19 of Human Cytomegalovirus Activates the Origin Recognition Complex I Promoter in a Cooperative Manner with IE72
Authors: Shirakata Masaki , Terauchi Masakazu , Ablikim Melike , Imadome Ken-Ichi , Hirai Kanji , Aso Takeshi , Yamanashi Yuji
Published: July 2002

The major immediate-early (MIE) gene of human cytomegalovirus (HCMV) expresses IE86, IE72, IE55, and IE18 mRNA by differential splicing. Reverse transcription-PCR with IE72-specific primers generated an 0.65-kb cDNA from HCMV-infected fibroblast RNA, which does not correspond to any known MIE cDNA. Nucleotide sequencing revealed that the 0.65-kb cDNA is from exons 1, 2, and 3 and part of exon 4, indicating that it is derived from a novel alternatively spliced mRNA of the MIE gene. The cDNA encodes a 172-amino-acid polypeptide, termed IE19, which corresponds to an IE72 variant with an internal deletion from Val
86
to Pro
404
and appears as a band at 38 kDa on a sodium dodecyl sulfate-polyacrylamide gel. IE19 mRNA was expressed at a low level in the immediate-early, early, and late period of viral infection. IE19 was localized in nuclei, and a transient-expression assay revealed that IE19 enhances IE72-dependent activation of the
HsOrc1
promoter, which is identified here as an IE72 target promoter. Another MIE protein, IE86, activated the same promoter but only weakly compared to IE72, and coexpression of IE19 did not alter the IE86-mediated transcriptional activation. In addition, IE19 did not enhance the IE72-dependent activation of the HCMV UL54 promoter. These results suggest that IE19 is a transcriptional coactivator that works with IE72.
Evidence of a Role for Nonmuscle Myosin II in Herpes Simplex Virus Type 1 Egress
Authors: van Leeuwen Hans , Elliott Gill , O'Hare Peter
Published: July 2002

After cell entry, herpes simplex virus (HSV) particles are transported through the host cell cytoplasm to nuclear pores. Following replication, newly synthesized virus particles are transported back to the cell periphery via a complex pathway including a cytoplasmic phase involving some form of unenveloped particle. These various transport processes are likely to make use of one or more components of the cellular cytoskeletal systems and associated motor proteins. Here we report that the HSV type 1 (HSV-1) major tegument protein, VP22, interacts with the actin-associated motor protein nonmuscle myosin IIA (NMIIA). HSV-1 infection resulted in reorganization of NMIIA, inducing retraction of NMIIA from the cell periphery and condensation into a spoke-like distribution around the nucleus along with a second effect of accumulation in a perinuclear cluster. VP22 did not appear to colocalize with the reorganized cagelike distribution of NMIIA. However, VP22 has been previously reported to localize in a perinuclear vesicular pattern, and significant overlap was observed between this pattern and the perinuclear clusters of NMIIA. Inhibition of the ATPase activity of NMIIA with the myosin-specific inhibitor butanedione monoxime impaired the formation of the perinuclear vesicular VP22 accumulations and also the release of virus into the extracellular medium while having much less effect on the yield of cell-associated virus. Virus infection frequently results in the induction of highly extended processes emanating from the infected cell, and we observed that VP22-containing particles line up along NMIIA-containing filaments which run through these protrusions.
A Natural Intergenotypic Recombinant of Hepatitis C Virus Identified in St. Petersburg
Authors: Kalinina Olga , Norder Helene , Mukomolov Sergey , Magnius Lars O.
Published: July 2002

Hepatitis C virus (HCV) evolution is thought to proceed by mutations within the six genotypes. Here, we report on a viable spontaneous HCV recombinant and we show that recombination may play a role in the evolution of this virus. Previously, 149 HCV strains from St. Petersburg had been subtyped by limited sequencing within the NS5B region. In the present study, the core regions of 41 of these strains were sequenced to investigate the concordance of HCV genotyping for these two genomic regions. Two phylogenetically related HCV strains were found to belong to different subtypes, 2k and 1b, according to sequence analysis of the 5′ untranslated region (5′UTR)-core and the NS5B regions, respectively. By sequencing of the E2-p7-NS2 region, the crossover point was mapped within the NS2 region, probably between positions 3175 and 3176 (according to the numbering system for strain pj6CF). Sequencing of the 5′UTR-core regions of four other HCV strains, phylogenetically related to the above-mentioned two strains (based on analysis within the NS5B region), revealed that these four strains were also recombinants. Since a nonrecombinant 2k strain was found in St. Petersburg, the recombination may have taken place there around a decade ago. Since the frequency of this recombinant is now high enough to allow the detection of the recombinant in a fraction of the city's population, it seems to be actively spreading there. The reported recombinant is tentatively designated RF1_2k/1b, in agreement with the nomenclature used for HIV recombinants. Recombination between HCV genotypes must now be considered in the classification, laboratory diagnosis, and treatment of HCV infection.
Determination of Acridine, Benz[c]acridine and Dibenz[a,h]acridine by Fast Scan Differential Pulse Voltammetry and Adsorptive Stripping Voltammetry
Authors: Barek Jiří , Matějka Jaroslav , Zima Jiří
Published: July 2002

The behaviour of the title compounds in fast scan differential pulse voltammetry and adsorptive stripping voltammetry was studied and the optimum conditions were found for their determination by FS DPV over the concentration region of (2 - 100) .10-7 mol l-1 and by AdSV over the concentration regions of (2 - 10) .10-8 mol l-1 for acridine and dibenz[a,h]acridine and (2 - 100) .10-9 mol l-1 for benz[c]acridine. Practical applicability of the methods to the monitoring of the chemical efficiency of destruction of the carcinogens with potassium permanganate was tested.
Ion-Associates of N,N-Diethyllysergamide with Some Sulfophthaleins and Azo Dyes
Authors: Skaličan Zdeněk , Kobliha Zbyněk , Halámek Emil
Published: July 2002

Ion-associates of N,N-diethyllysergamide with the sulfophthaleins: Bromoxylenol Blue, Eriochrome Cyanine R, Xylenol Blue, and Cresol Red, and the azo dyes: Acid Black I and Orange-I were studied by extraction spectrophotometry. The extraction recoveries, distribution ratios, conditional extraction constants and limits of detection and determination were calculated.
A Mathematical Model of a Gauze Reactor for the Ammonia Oxidation
Authors: Fíla Vlastimil , Bernauer Bohumil
Published: July 2002

The behaviour of an industrial reactor for the oxidation of ammonia with Pt-Rh gauzes was simulated by means of a mathematical model accounting for the axial dispersion of the components, radiative heat transmission in the reactor, and the effect of temperature on the physico-chemical properties of the reacting mixture. The effect of the preheating temperature, the input mixture composition, pressure and reactor load on the temperature distribution in the catalyst bed and on the NO yield was examined. The calculated NO yields agree well with the values actually attained in industrial reactors. The effect of the reaction mixture composition and total pressure on the yield is also consistent with observed dependences.
Spatial Structures in an Uncatalyzed Bromate Oscillator and Periodic Precipitation in Gels
Authors: Adamčíková Ľubica , Holba Vladislav , Parkániová Viera
Published: July 2002

Stationary and moving structures in the uncatalyzed bromate-aniline-sulfuric acid oscillator and the formation of Liesegang rings in gelatin and silica gel were investigated. Structural analogies were found in the systems which are of a different nature. They exhibit properties typical of Turing type structures.
Solid-Phase Organic Synthesis: Creation of Carbon-Carbon Double Bonds Under Mild Conditions by Wittig-Type Reactions
Authors: Vágner Josef , Krchňák Viktor , Lebl Michal , Barany George
Published: July 2002

Phosphorane ylides and phosphonate anions react smoothly with resin-bound aldehydes and ketones to provide alkenes in good yields and purities (assessed after cleavage of acid-labile PAL anchor to support). The reactions of aldehydes give excellent stereoselectivities. Effective conditions have been developed for carrying out these transformations.
Antitumor Agents. 192. Antitubulin Effect and Cytotoxicity of C(7)-Oxygenated Allocolchicinoids
Authors: Guan Jian , Zhu Xiao-Kang , Brossi Arnold , Tachibana Yoko , Bastow Kenneth F. , Verdier-Pinard Pascal , Hamel Ernest , McPhail Andrew T. , Lee Kuo-Hsiung
Published: July 2002

Two allocolchicinoids 6 and 8, prepared from colchicine, together with allo compounds 9-11, made from 6 by reduction and regiodemethylation, were evaluated for antitubulin and antitumor activities. Structures of 6, 8, and 10 were confirmed by X-ray crystallographic analysis. Compounds 6, 8, and 9 have high tubulin binding affinity and display potent inhibitory activities against tubulin polymerization and solid human tumor cell lines. Particularly, drug-resistant KB cell lines, including KB-7d, KB-VCR, and KB-CPT, do not show marked resistance to these compounds.
Metallaborane Reaction Chemistry. Part 7. B-Frame Supported Bimetallics: Ligand-to-β-Metal Organometallic Interaction in Dimetallaboranes and an Interesting Ligand Displacement Cascade
Authors: Kim Young-hee , McKinnes Yvonne M. , Cooke Paul A. , Greatrex Robert , Kennedy John D. , Thornton-Pett Mark
Published: July 2002

Reaction of [PtCl2(PMe2Ph)2] with [(PMe2Ph)2PtB10H12] generates [(PMe2Ph)2-μ-η1(Pt)- η1-(Pt')-{PMe2(C6H4)}-closo-Pt2B10H9(PMe2Ph)] in which the phenyl group of a phosphine ligand on one platinum atom exhibits ortho-cyclometallation to the second metal atom, whereas reaction of PPh3 with [(PMe2Ph)2PtB9H9Ru(pcym)] generates [(PMe2Ph)2-μ-η6(Ru)- η1(Pt)-(C6H5PPh2)-closo-PtRuB9H9] in which the phenyl group of a phosphine ligand on the platinum atom exhibits tridentate η6 coordination to the second metal atom.
Reactivity Studies of [1]Benzothieno[3,2-b][1]benzofuran
Authors: Pihera Pavel , Svoboda Jiří
Published: July 2002

Electrophilic substitution and metallation reactions of the title compound 1 were studied. Bromination, acetylation, benzoylation, formylation, and nitration usually afforded nonseparable mixtures of 2- and 7-substituted derivatives as the main product. Disubstitution reactions preferably led to 2,7-disubstituted derivatives. [1]Benzothieno[3,2-b][1]benzofuran 10,10-dioxide (17) and [1]benzothieno[3,2-b][1]benzofuran 10-oxide (18) can be selectively obtained by oxidation of 1. Mononitration of 17 and 18 led selectively to corresponding 7-nitro derivatives 19 and 21, respectively. Only sulfoxides 19 and 20 were successfully reduced. Reduction of the 5-oxide moieties was successful only at the sulfoxide stage. Metallation of 1 with butyllithium preferably proceeds in positions 1 and 6; subsequent reaction with methyl iodide or carbon dioxide led to the corresponding dimethyl derivative 25 or esters 26 and 27, respectively. An unusual addition of butyllithium to the central double bond of 1 was also observed in a small extent producing 9b-butyl-4b,9b-dihydro[1]benzothieno[3,2-b][1]benzofuran-4b-ol (29). The structures of all products were elucidated by NMR.
Synthesis of Acyclic Adenine 8,N-Anhydronucleosides
Authors: Meszárosová Kateřina , Holý Antonín , Masojídková Milena
Published: July 2002

9-(4-Hydroxybutyl)adenine (10) was obtained by reaction of adenine with 4-[(2-tetrahydropyran-2-yl)oxy]butyl chloride (7) in the presence of DBU. 8-Bromo-9-(4-hydroxybutyl)adenine (13) was prepared by bromination of 10 or by alkylation of 8-bromoadenine (11) with 4-bromoethyl acetate followed by methanolysis. Tosylation of compound 13 afforded the 4-tosyloxy derivative 15 which gave on heating with methylamine or cyclopropylamine 6-methyl- (17a) or 6-cyclopropyl-7,8,9,10-tetrahydro-6H-[1,3]diazepino[1,2-e]purin-4-amine (17b), while the reaction with hydrazine afforded 7,8,9,10-tetrahydro-6H-[1,3]diazepino[1,2-e]purine-4,6-diamine (17d). Treatment of compound 13 with thionyl chloride gave 9-(4-chlorobutyl)-8-chloroadenine (18) as the main product which was transformed to 17b, 6-propyl-7,8,9,10-tetrahydro-6H-[1,3]diazepino[1,2-e]purin-4-amine (17c) or 7,8,9,10-tetrahydro-6H-[1,3]diazepino[1,2-e]purin-4-amine (17e) by reaction with cyclopropylamine, propylamine or ammonia, respectively. Compound 17e was quite stable both in acid and alkaline solutions, at room temperature or at 90 °C. Compound 13 was converted to 9-(4-hydroxybutyl)-8-methylaminoadenine (19) by reaction with methylamine. Compound 19 failed to undergo intramolecular cyclization to diazepine 17a on treatment with diphenyl carbonate, bis(4-nitrophenyl) carbonate or 1,1'-carbonyldiimidazole.
Interactions of 1-[(S)-3-Hydroxy-2-(phosphonomethoxy)propyl]cytosine (Cidofovir) Diphosphate with DNA Polymerases α, δ and ε*
Authors: Birkuš Gabriel , Votruba Ivan , Otmar Miroslav , Holý Antonín
Published: July 2002

The inhibitory and/or substrate activity of 1-[(S)-3-hydroxy-2-(phosphonomethoxy)propyl]cytosine [(S)-HPMPC, cidofovir, Vistide™] diphosphate towards eukaryotic DNA polymerases α, δ and ε* was examined. Cidofovir diphosphate is a weak competitive inhibitor of the above enzymes, approximately 3 to 7 times weaker than its adenine analogue (S)-HPMPApp. The enzymes also catalyze incorporation of (S)-HPMPC into DNA; after insertion of one (S)-HPMPC residue into DNA, another dNMP residue may incorporate. DNA polymerase δ and ε* can successively accommodate in the growing chain two (S)-HPMPC residues at the maximum, whereas pol α up to three residues.
Dipstick measurements of urine specific gravity are unreliable
Authors: Roessingh A S de Buys , Drukker A , Guignard J-P
Published: July 2002

AIM

To evaluate the reliability of dipstick measurements of urine specific gravity (U-SG).

METHODS

Fresh urine specimens were tested for urine pH and osmolality (U-pH, U-Osm) by a pH meter and an osmometer, and for U-SG by three different methods (refractometry, automatic readout of a dipstick (Clinitek-50), and (visual) change of colour of the dipstick).

RESULTS

The correlations between the visual U-SG dipstick measurements and U-SG determined by a refractometer and the comparison of Clinitek®-50 dipstick U-SG measurements with U-Osm were less than optimal, showing very wide scatter of values. Only the U-SG refractometer values and U-Osm had a good linear correlation. The tested dipstick was unreliable for the bedside determination of U-SG, even after correction for U-pH, as recommended by the manufacturer.

CONCLUSIONS

Among the bedside determinations, only refractometry gives reliable U-SG results. Dipstick U-SG measurements should be abandoned.
Propensity for osteoarthritis and lower limb joint pain in retired professional soccer players
Authors: Drawer S , Fuller C W
Published: July 2002

Objective—To quantify the prevalence of osteoarthritis and the severity of pain in the lower limb joints of players retired from English professional soccer.

Method—An anonymous self administered questionnaire was distributed to 500 former players registered with the English Professional Footballers' Association. The questionnaire was designed to gather information on personal details, physical activity loading patterns, history of lower limb joint injury, and current medical condition of the lower limb joints.

Results—Of 500 questionnaires distributed, 185 (37%) were returned. Nearly half of the respondents (79: 47%) retired because of injury; 42% (33) were acute injuries and 58% (46) chronic injuries. Most of the acute injuries that led to early retirement were of the knee (15: 46%), followed by the ankle (7: 21%) and lower back (5: 15%). Most of the chronic injuries that led to early retirement were also of the knee (17: 37%), followed by the lower back (10: 22%) and the hip (4: 9%). Of all respondents, 32% (59) had been medically diagnosed with osteoarthritis in at least one of the lower limb joints. More respondents had been diagnosed with osteoarthritis in the knee joints than either the ankle or the hip joints. Significantly (p<0.001) more respondents reported pain in one lower extremity joint during one or more daily activities than those who did not (joint pain: 137, 80%; no joint pain: 35, 20%).

Conclusion—The risk for professional soccer players of osteoarthritis in at least one of the lower extremity joints is very high and significantly greater than for the general population. The results support the suggestion that professional soccer players should be provided with health surveillance during their playing career.
Absence of endogenous interleukin 10 enhances early stress response during post-ischaemic injury in mice intestine
Authors: Zingarelli B , Yang Z , Hake P W , Denenberg A , Wong H R
Published: July 2002

BACKGROUND

Interleukin 10 (IL-10) exerts a wide spectrum of regulatory activities in immune and inflammatory responses.

AIMS

The aim of this study was to investigate the role of endogenous IL-10 on modulation of the early inflammatory response after splanchnic ischaemia and reperfusion.

METHODS

Intestinal damage was induced by clamping the superior mesenteric artery and the coeliac trunk for 45 minutes followed by reperfusion in IL-10 deficient mice (IL-10−/−) and wild-type controls.

RESULTS

IL-10−/−mice experienced a higher rate of mortality and more severe tissue injury compared with wild-type mice subjected to ischaemia and reperfusion. Splanchnic injury was characterised by massive epithelial haemorrhagic necrosis, upregulation of P-selectin and intercellular adhesion molecule 1, and neutrophil infiltration. The degree of oxidative and nitrosative damage was significantly higher in IL-10−/−mice than in wild-type littermates, as indicated by elevated malondialdehyde levels and formation of nitrotyrosine. Plasma levels of the proinflammatory cytokines tumour necrosis factor α and interleukin 6 were also greatly enhanced in comparison with wild-type mice. These events were preceded by increased immunostaining and activity of the stress regulated c-Jun NH2terminal kinase and activation of the transcription factor activator protein 1 in the cellular nuclei of damaged tissue.

CONCLUSIONS

These data demonstrate that endogenous IL-10 exerts an anti-inflammatory role during reperfusion injury, possibly by regulating early stress related genetic response, adhesion molecule expression, neutrophil recruitment, and subsequent cytokine and oxidant generation.
Inhibition of carbachol stimulated acid secretion by interleukin 1β in rabbit parietal cells requires protein kinase C
Authors: Beales I L P , Calam J
Published: July 2002

BACKGROUND

Interleukin 1β (IL-1β) is a potent inhibitor of gastric acid secretion. Regulatory actions at several levels have previously been demonstrated, including direct inhibition of parietal cell acid secretion. Although IL-1β may activate several intracellular signalling pathways, the mechanisms responsible for inhibition of carbachol stimulated acid secretion have not been determined.

AIMS

To investigate the roles of protein kinase C (PKC) and the sphingomyelinase signalling pathways in the regulation of acid secretion by IL-1β.

METHODS

Rabbit parietal cells were obtained by collagenase-EDTA digestion and centrifugal elutriation. Acid secretion stimulated by carbachol andA23187 (to mimic elevations in intracellular calcium) was assessed by14C aminopyrine uptake in response to IL-1β, PKC, and sphingomyelinase manipulation.

RESULTS

IL-1β inhibited carbachol and A23187 stimulated acid secretion in a dose dependent manner. The inhibitory actions were completely reversed by each of three different PKC inhibitors, staurosporine, H-7, and chelerythrine, as well as by PKC depletion with high dose phorbol ester pretreatment. IL-1β did not downregulate parietal cell muscarinic receptor. IL-1β significantly increased membrane PKC activity. Activation of the sphingomyelinase/ceramide pathway had no effect on basal or stimulated acid secretion. The inhibitory action of IL-1β was independent of protein kinase A and protein kinase G activity.

CONCLUSIONS

IL-1β directly inhibits parietal cell carbachol stimulated acid secretion. This action occurs distal to muscarinic receptor activation and elevations in intracellular calcium and requires PKC.
Interferon responsiveness in patients infected with hepatitis C virus 1b differs depending on viral subtype
Authors: Nakano I , Fukuda Y , Katano Y , Toyoda H , Hayashi K , Hayakawa T , Kumada T , Nakano S
Published: July 2002

BACKGROUND

Genotype 1b of hepatitis C virus (HCV) comprises mainly three subtypes, each named for its geographic prevalence (worldwide, W; Japan, J; and not in Japan, NJ).

AIM

To characterise the newly identified subtypes of genotype 1b and to review factors associated with response to interferon (IFN) for each subtype.

PATIENTS

Chronic hepatitis patients (80 men and 41 women; mean age 48.5 years, range 20.7–69.3) with HCV genotype 1b (W type, n=41; J type, n=38) or genotype 2a (n=42) were treated according to the same IFN protocol. Forty four patients (36.4%) negative for serum HCV RNA six months after cessation of treatment were considered complete responders.

METHODS

Factors associated with complete response were investigated.

RESULTS

Genotype 2a patients had lower viral loads (odds ratio 0.11 (95% confidence intervals (CI) 0.049–0.256)) and a better IFN response (odds ratio 0.25 (95% CI 0.117–0.552)) than genotype 1b patients whereas W type and J type patients had similar viral loads and responses to IFN. IFN response in W type patients was associated with female sex (odds ratio 0.23 (95% CI 0.055–0.983)) and low viral load (odds ratio 84.00 (95% CI 14.04–502.6)) whereas response in J type patients was related to transfusion history (odds ratio 7.20 (95% CI 1.443–35.91)), low viral load (odds ratio 117.0 (95% CI 17.82–768.3)), and genetic mutation in the interferon sensitivity determining region of the virus (odds ratio 0.08 (95% CI 0.013–0.553)). Multivariate analysis found low viral load (odds ratio 64.19 (95% CI 14.66–281.06)) to be the only significant independent factor associated with IFN response.

CONCLUSIONS

Factors associated with IFN responsiveness in HCV infection differ with viral subtype.
Teaching medical ethics to experienced staff: participants, teachers and method
Authors: Nilstun Tore , Cuttini Marina , Saracci Rodolfo
Published: July 2002

Almost all articles on education in medical ethics present proposals for or describe experiences of teaching students in different health professions. Since experienced staff also need such education, the purpose of this paper is to exemplify and discuss educational approaches that may be used after graduation. As an example we describe the experiences with a five-day European residential course on ethics for neonatal intensive care personnel. In this multidisciplinary course, using a case-based approach, the aim was to enhance the participants' understanding of ethical principles and their relevance to clinical and research activities. Our conclusion is that working with realistic cases encourages practising nurses and physicians to apply their previous knowledge and new concepts learnt in the course, thus helping them to bridge the gap between theory and practice.
Disease, illness, sickness, health, healing and wholeness: exploring some elusive concepts
Authors: Boyd Kenneth M
Published: July 2002

Concepts such as disease and health can be difficult to define precisely. Part of the reason for this is that they embody value judgments and are rooted in metaphor. The precise meaning of terms like health, healing and wholeness is likely to remain elusive, because the disconcerting openness of the outlook gained from experience alone resists the reduction of first-person judgments (including those of religion) to third-person explanations (including those of science).
Detection of specific antibodies to pigeon serum and bloom antigens by enzyme linked immunosorbent assay in pigeon breeder's disease
Authors: Rodrigo M J , Benavent M I , Cruz M J , Rosell M , Murio C , Pascual C , Morell F
Published: July 2002

BACKGROUND

Pigeon breeder's disease is an extrinsic allergic alveolitis in the lungs of sensitised people, caused by hypersensitivity reactions to inhaled pigeon antigens. Antigens from different sources of the animal are used for diagnostic purposes, with serum being the most widely used. Bloom is rarely used; very little is known of its antigenicity and diagnostic performance, particularly when used with the enzyme linked immunosorbent assay (ELISA) method, which is the most popular test as it permits measurement of the antibody response.

METHODS

To (a) standardise an ELISA for the measurement of specific IgG against pigeon serum and pigeon bloom extract; (b) to establish reference values for specific IgG in 73 non-exposed controls, (c) to show the presence of specific IgG against pigeon serum and bloom in serum samples of 17 patients with bird fancier's lung and 11 asymptomatic fanciers, and (d) to study the similarity of the two antigen sources by cross reactivity experiments.

RESULTS

Reference values of specific IgG were defined with the 97.5 percentile (367.9 U/ml for pigeon serum and 953.7 U/ml for pigeon bloom extract). Of symptomatic patients 100% had values higher than the cut off for both antigens. In asymptomatic fanciers values were higher than the cut off for pigeon serum in 45% and bloom extract in 54%. Cross reactivity experiments showed that the two antigens differed in antigenic content although some components may be common to both.

CONCLUSION

The ELISA methods used proved to be useful tools for evaluating specific IgG antibody responses against both antigens. The diagnostic performance of both ELISA methods performed with these antigen sources was similar, showing very high sensitivity but moderate specificity. Although some antigenic similarity was found between pigeon serum and bloom extract, cross reactivity studies showed that various antigens seemed to be specific to the bloom extract. However, the antigens responsible for pigeon breeder's disease seem to be present in both antigenic sources.
Validity of self reported occupational exposures to hand transmitted and whole body vibration
Authors: Palmer Keith T , Haward Barbara , Griffin Michael J , Bendall Holly , Coggon David
Published: July 2002

OBJECTIVES

To assess the accuracy with which workers report their exposure to occupational sources of hand transmitted (HTV) and whole body vibration (WBV).

METHODS

179 Workers from various jobs involving exposure to HTV or WBV completed a self administered questionnaire about sources of occupational exposure to vibration in the past week. They were then observed at work over 1 hour, after which they completed a second questionnaire concerning their exposures during this observation period. The feasibility of reported sources of exposure during the past week was examined by questioning managers and by inspection of tools and machines in the workplace. The accuracy of reported sources and durations of exposure in the 1 hour period were assessed relative to what had been observed.

RESULTS

The feasibility of exposure in the previous week was confirmed for 97% of subjects who reported exposure to HTV, and for 93% of subjects who reported exposure to WBV. The individual sources of exposure reported were generally plausible, but occupational use of cars was substantially overreported, possibly because of confusion with their use in travel to and from work. The accuracy of exposures reported during the observation period was generally high, but some sources of HTV were confused—for example, nailing and stapling guns reported as riveting hammers, and hammer drills not distinguished from other sorts of drill. Workers overestimated their duration of exposure to HTV by a median factor of 2.5 (interquartile range (IQR) 1.6–5.9), but estimated durations of exposure were more accurate when the exposure was relatively continuous rather than for intermittent short periods. Reported durations of exposure to WBV were generally accurate (median ratio of reported to observed time 1.1, IQR 1.0–1.2).

CONCLUSIONS

Sources of recent occupational exposure to vibration seem to be reported with reasonable accuracy, but durations of exposure to HTV are systematically overestimated, particularly when the exposure is intermittent and for short periods. This raises the possibility that dose-response relations may have been biased in some of the studies on which exposure standards might be based, and that the levels in currently proposed standards may be too high. Future studies should pay attention to this source of error during data collection.