bluuebunny/crossref_metadata_2025_split huggingface dataset:
The
cis
-Acting Family of Repeats Can Inhibit as well as Stimulate Establishment of an
oriP
Replicon
Authors: Leight Elizabeth R. , Sugden Bill 
Published: July 2002

ABSTRACT

Previously we have shown that the establishment of an
oriP
replicon is dependent on its epigenetic modification, which occurs in only 1 to 10% of proliferating cells (E. R. Leight and B. Sugden, Mol. Cell. Biol. 21:4149–4161, 2001). To gain insights into the
cis
-acting requirements for the establishment of
oriP
replicons, we monitored the replication of
oriP
plasmid derivatives for several weeks following their introduction into cells. In EBNA-1-positive 143B and H1299 cells, plasmids containing only the region of dyad symmetry (DS) of
oriP
replicated but were lost more rapidly from cells than were
oriP
plasmids, demonstrating that the family of repeats (FR) of
oriP
acts in
cis
to stimulate replication in these cells. Unexpectedly, we found that the DS plasmid was established efficiently in 293/EBNA-1 cells, being lost at a rate of only 8% per cell generation over 24 days posttransfection. However, plasmids containing the FR in addition to the DS of
oriP
replicated but were lost at a rate of approximately 30% per cell generation in 293/EBNA-1 cells, indicating that the FR inhibits
oriP
's establishment in this cell line. FR's enhancement of transcription of a promoter in
cis
and FR's ability to inhibit replication fork movement do not account solely for
oriP
's inefficient establishment. In addition, DNA looping between FR and DS neither stimulates nor inhibits replication. Deletion of 11 EBNA-1 binding sites in the FR or replacement of the FR with DS sequences, however, does overcome the inhibitory activity of the FR, thereby allowing efficient establishment of the
oriP
derivative in 293/EBNA-1 cells.
The Retroviruses Human Immunodeficiency Virus Type 1 and Moloney Murine Leukemia Virus Adopt Radically Different Strategies To Regulate Promoter-Proximal Polyadenylation
Authors: Furger Andre , Monks Joan , Proudfoot Nick J. 
Published: July 2002

ABSTRACT
Maximal gene expression in retroviruses requires that polyadenylation in the 5′ long terminal repeat (LTR) is suppressed. In human immunodeficiency virus type 1 (HIV-1) the promoter-proximal poly(A) site is blocked by interaction of U1 snRNP with the closely positioned major splice donor site (MSD) 200 nucleotides downstream. Here we investigated whether the same mechanism applies to down-regulate 5′ LTR polyadenylation in Moloney murine leukemia virus (MoMLV). Although the same molecular architecture is present in both viruses, the MoMLV poly(A) signal in the 5′ LTR is active whether or not the MSD is mutated. This surprising difference between the two retroviruses is not due to their actual poly(A) signals or MSD sequences, since exchange of either element between the two viral sequences does not alter their ability to regulate 5′ LTR poly(A) site use. Instead we demonstrate that sequence between the cap and AAUAAA is required for MSD-dependent poly(A) regulation in HIV-1, indicating a key role for this part of the LTR in poly(A) site suppression. We also show that the MoMLV poly(A) signal is an intrinsically weak RNA-processing signal. This suggests that in the absence of a poly(A) site suppression mechanism, MoMLV is forced to use a weak poly(A) signal.
Rapid CD4+T-Cell Loss Induced by Human Immunodeficiency Virus Type 1NCin Uninfected and Previously Infected Chimpanzees
Authors: Novembre Francis J. , de Rosayro Juliette , Nidtha Soumya , O'Neil Shawn P. , Gibson Terri R. , Evans-Strickfaden Tammy , Hart Clyde E. , McClure Harold M. 
Published: July 2002

ABSTRACTTo investigate the pathogenicity of a virus originating in a chimpanzee with AIDS (C499), two chimpanzees were inoculated with a plasma-derived isolate termed human immunodeficiency virus type 1NC(HIV-1NC). A previously uninfected chimpanzee, C534, experienced rapid peripheral CD4+T-cell loss to fewer than 26 cells/μl by 14 weeks after infection. CD4+T-cell depletion was associated with high plasma HIV-1 loads but a low virus burden in the peripheral lymph node. The second chimpanzee, C459, infected 13 years previously with HIV-1LAV, experienced a more protracted course of peripheral CD4+T-cell loss after HIV-1NCinoculation, resulting in fewer than 200 cells/μl by 96 weeks postinoculation. The quantities of viral RNA in the plasma and peripheral lymph node from C459 were below the lower limits of detection prior to inoculation with HIV-1NCbut were significantly and persistently increased after superinfection, with HIV-1NCrepresenting the predominant viral genotype. These results show that viruses derived from C499 are more pathogenic for chimpanzees than any other HIV-1 isolates described to date.
Muscle-Specific Overexpression of the Adenovirus Primary Receptor CAR Overcomes Low Efficiency of Gene Transfer to Mature Skeletal Muscle
Authors: Nalbantoglu J. , Larochelle N. , Wolf E. , Karpati G. , Lochmuller H. , Holland P. C. 
Published: July 2002

ABSTRACT

Significant levels of adenovirus (Ad)-mediated gene transfer occur only in immature muscle or in regenerating muscle, indicating that a developmentally regulated event plays a major role in limiting transgene expression in mature skeletal muscle. We have previously shown that in developing mouse muscle, expression of the primary Ad receptor CAR is severely downregulated during muscle maturation. To evaluate how global expression of CAR throughout muscle affects Ad vector (AdV)-mediated gene transfer into mature skeletal muscle, we produced transgenic mice that express the CAR cDNA under the control of the muscle-specific creatine kinase promoter. Five-month-old transgenic mice were compared to their nontransgenic littermates for their susceptibility to AdV transduction. In CAR transgenics that had been injected in the tibialis anterior muscle with AdVCMVlacZ, increased gene transfer was demonstrated by the increase in the number of transduced muscle fibers (433 ± 121 in transgenic mice versus 8 ± 4 in nontransgenic littermates) as well as the 25-fold increase in overall β-galactosidase activity. Even when the reporter gene was driven by a more efficient promoter (the cytomegalovirus enhancer–chicken β-actin gene promoter), differential transducibility was still evident (893 ± 149 versus 153 ± 30 fibers;
P
< 0.001). Furthermore, a fivefold decrease in the titer of injected AdV still resulted in significant transduction of muscle (253 ± 130 versus 14 ± 4 fibers). The dramatic enhancement in AdV-mediated gene transfer to mature skeletal muscle that is observed in the CAR transgenics indicates that prior modulation of the level of CAR expression can overcome the poor AdV transducibility of mature skeletal muscle and significant transduction can be obtained at low titers of AdV.
SLAM (CD150)-Independent Measles Virus Entry as Revealed by Recombinant Virus Expressing Green Fluorescent Protein
Authors: Hashimoto Koji , Ono Nobuyuki , Tatsuo Hironobu , Minagawa Hiroko , Takeda Makoto , Takeuchi Kaoru , Yanagi Yusuke 
Published: July 2002

ABSTRACTWild-type measles virus (MV) strains use human signaling lymphocyte activation molecule (SLAM) as a cellular receptor, while vaccine strains such as the Edmonston strain can use both SLAM and CD46 as receptors. Although the expression of SLAM is restricted to cells of the immune system (lymphocytes, dendritic cells, and monocytes), histopathological studies with humans and experimentally infected monkeys have shown that MV also infects SLAM-negative cells, including epithelial, endothelial, and neuronal cells. In an attempt to explain these findings, we produced the enhanced green fluorescent protein (EGFP)-expressing recombinant MV (IC323-EGFP) based on the wild-type IC-B strain. IC323-EGFP showed almost the same growth kinetics as the parental recombinant MV and produced large syncytia exhibiting green autofluorescence in SLAM-positive cells. Interestingly, all SLAM-negative cell lines examined also showed green autofluorescence after infection with IC323-EGFP, although the virus hardly spread from the originally infected individual cells and thus did not induce syncytia. When the number of EGFP-expressing cells after infection was taken as an indicator, the infectivities of IC323-EGFP for SLAM-negative cells were 2 to 3 logs lower than those for SLAM-positive cells. Anti-MV hemagglutinin antibody or fusion block peptide, but not anti-CD46 antibody, blocked IC323-EGFP infection of SLAM-negative cells. This infection occurred under conditions in which entry via endocytosis was inhibited. These results indicate that MV can infect a variety of cells, albeit with a low efficiency, by using an as yet unidentified receptor(s) other than SLAM or CD46, in part explaining the observed MV infection of SLAM-negative cells in vivo.
Intracellular Localization of the
Peanut Clump Virus
Replication Complex in Tobacco BY-2 Protoplasts Containing Green Fluorescent Protein-Labeled Endoplasmic Reticulum or Golgi Apparatus
Authors: Dunoyer Patrice , Ritzenthaler Christophe , Hemmer Odile , Michler Pierre , Fritsch Christiane 
Published: July 2002

ABSTRACT

RNA-1 of
Peanut clump virus
(PCV) encodes the proteins P131 and P191, containing the signature motifs of replication proteins, and P15, which regulates viral RNA accumulation. In PCV-infected protoplasts both P131 and P191 were immunodetected in the perinuclear region. Laser scanning confocal microscopy (LSCM) showed that P131 and P191 colocalized with neosynthesized 5-bromouridine 5′-triphosphate-labeled RNA and double-stranded RNA, demonstrating that they belong to the replication complex. On the contrary, the P15 fused to the enhanced green fluorescent protein (EGFP) never colocalized with the two proteins. In endoplasmic reticulum (ER)-GFP transgenic BY-2 protoplasts, the distribution of the green fluorescent-labeled ER was strongly modified by PCV infection. LSCM showed that both P131 and P191 colocalized with ER green fluorescent bodies accumulating around the nucleus during infection. The replication process was not inhibited by cerulenin and brefeldin A, suggesting that PCV replication does not depend on de novo-synthesized membrane and does not require transport through the Golgi apparatus. Electron microscopy of ultrathin sections of infected protoplasts showed aggregates of broken ER but also visualized vesicles, some of which resembled modified peroxisomes. The results suggest that accumulation of PCV during infection is accompanied by specific association of PCV RNA-1-encoded proteins with membranes of the ER and other organelles. The concomitant extensive rearrangement of these membranous structures leads to the formation of intracellular compartments in which synthesis and accumulation of the viral RNA occur in defined areas.
Differential Activation of Influenza A Virus Endonuclease Activity Is Dependent on Multiple Sequence Differences between the Virion RNA and cRNA Promoters
Authors: Leahy Michael B. , Zecchin Giuseppe , Brownlee George G. 
Published: July 2002

ABSTRACT
Influenza virus endonuclease activity was studied in vitro with model virion RNA (vRNA) and cRNA molecules. We show that endonuclease activity can be partially rescued by transplanting vRNA-like promoter features into the model cRNA promoter. This study defines three distinctive features within the vRNA promoter—absent in the cRNA promoter—that are required for endonuclease cleavage.
Analysis of Hantavirus Genetic Diversity in Argentina: S Segment-Derived Phylogeny
Authors: Bohlman Marlene C. , Morzunov Sergey P. , Meissner John , Taylor Mary Beth , Ishibashi Kimiko , Rowe Joan , Levis Silvana , Enria Delia , St. Jeor Stephen C. 
Published: July 2002

ABSTRACTNucleotide sequences were determined for the complete S genome segments of the six distinct hantavirus genotypes from Argentina and for two cell culture-isolated Andes virus strains from Chile. Phylogenetic analysis indicates that, although divergent from each other, all Argentinian hantavirus genotypes group together and form a novel phylogenetic clade with the Andes virus. The previously characterized South American hantaviruses Laguna Negra virus and Rio Mamore virus make up another clade that originates from the same ancestral node as the Argentinian/Chilean viruses. Within the clade of Argentinian/Chilean viruses, three subclades can be defined, although the branching order is somewhat obscure. These are made of (i) “Lechiguanas-like” virus genotypes, (ii) Maciel virus and Pergamino virus genotypes, and (iii) strains of the Andes virus. Two hantavirus genotypes from Brazil, Araraquara and Castello dos Sonhos, were found to group with Maciel virus and Andes virus, respectively. The nucleocapsid protein amino acid sequence variability among the members of the Argentinian/Chilean clade does not exceed 5.8%. It is especially low (3.5%) among oryzomyine species-associated virus genotypes, suggesting recent divergence from the common ancestor. Interestingly, the Maciel and Pergamino viruses fit well with the rest of the clade although their hosts are akodontine rodents. Taken together, these data suggest that under conditions in which potential hosts display a high level of genetic diversity and are sympatric, host switching may play a prominent role in establishing hantavirus genetic diversity. However, cospeciation still remains the dominant factor in the evolution of hantaviruses.
Role of Lymphotoxin α in T-Cell Responses during an Acute Viral Infection
Authors: Suresh M. , Lanier Gibson , Large Mary Katherine , Whitmire Jason K. , Altman John D. , Ruddle Nancy H. , Ahmed Rafi 
Published: July 2002

ABSTRACTThe importance of lymphotoxin α (LTα) in lymphoid organogenesis is well established. Although LTα has been implicated in the pathogenesis of T-cell-mediated immunopathologies, the requirement for LTα in T-cell activation and effector function in vivo is not well understood. To determine the role of LTα in T-cell activation in vivo, we compared the generation of antigen-specific T-cell responses between wild type (+/+) and LTα-deficient (LTα−/−) mice during an acute infection with lymphocytic choriomeningitis virus (LCMV). Our studies showed that LCMV-infected LTα−/−mice had a profound impairment in the activation and expansion of virus-specific CD8 T cells in the spleen, as determined by cytotoxicity assays, intracellular staining for gamma interferon, and staining with major histocompatibility complex class I tetramers. Further, the nonlymphoid organs of LTα−/−mice also contained substantially lower number of LCMV-specific CD8 T cells than those of +/+ mice. Greatly reduced virus-specific CD8 T-cell responses in LTα−/−mice led to a defect in LCMV clearance from the tissues. In comparison to that in +/+ mice, the activation of LCMV-specific CD4 T cells was also significantly attenuated in LTα−/−mice. Adoptive transfer experiments were conducted to determine if abnormal lymphoid architecture in LTα−/−mice caused the impairment in the activation of LCMV-specific T-cell responses. Upon adoptive transfer into +/+ mice, the activation and expansion of LCMV-specific LTα−/−T cells were restored to levels comparable to those of +/+ T cells. In a reciprocal cell transfer experiment, activation of +/+ T cells was significantly reduced upon transfer into LTα−/−mice. These results showed that impairment in the activation of LCMV-specific T cells in LTα−/−mice may be due to abnormal lymphoid architecture and not to an intrinsic defect in LTα−/−T cells.
FTIR Study of Metal Zeolites. Determination of Co(II) Cation in Co-Beta Zeolite by Deuterated Acetonitrile Adsorption
Authors: Kuriyavar Satish , Bortnovsky Oleg , Tvarůžková Zdena , Sobalík Zdeněk 
Published: July 2002

FTIR spectra of deuterated acetonitrile (ACD) adsorbed on Co-Beta zeolite were investigated. By analysing the IR region of zeolite framework perturbation, the conditions for the prevailing presence of the Co-ACD complex with 1 : 1 stochiometry were established. Analysis of the C≡N region with overlapping bands OH···ACD (2 297 cm-1), and Lewis(Al)···ACD (2 325 cm-1), provided a value of molar absorption coefficient for a band of Co-ACD complex in Co-Beta at 2 310 cm-1 equal to 7.12 ± 0.3 cm μmol-1.
Construction of Interconnected Acidity Functions Based on ortho Substituted Anilines and N-Methylanilines as Indicators
Authors: Pytela Oldřich , Kulhánek Jiří , Jirásková Eva , Nevěčná Taťjana 
Published: July 2002

The log I values of 15 mainly ortho substituted derivatives of aniline and N-methylaniline have been measured spectrophotometrically in sulfuric, perchloric, and methanesulfonic acids. A new algorithm has been suggested for construction of acidity functions enabling simultaneous and independent construction of acidity functions in various media under the condition of equal values of pKa of the same indicators in the given media. The so-called interconnected acidity functions have been constructed with using this algorithm and the log I values measured in the above media, and the pKa values have been calculated. The resulting acidity functions and pKa values agree well with the corresponding literature data.
Investigation of factors which might indicate susceptibility to particulate air pollution
Authors: Prescott G J , Lee R J , Cohen G R , Elton R A , Lee A J , Fowkes F G R , Agius R M 
Published: July 2002

OBJECTIVESTo determine whether previous symptoms or recognised risk factors of cardiovascular ill health, are associated with an increased likelihood of adverse health effects related to particulate air pollution.METHODSCardiovascular event rates were studied relative to urban concentrations of particulate air pollution and baseline risk factors. The Edinburgh artery study consisted of a cohort of 1592 subjects aged 55–74 and was followed up to the end of March 1998 for a median of 10 years resulting in about 5 million person-days of observation. Baseline measurements included plasma fibrinogen and blood and plasma viscosity. A nested case-control approach was used to investigate a possible interaction between effects of these selected baseline risk factors and particulate air pollution, on subsequent event rates.RESULTSDuring the follow up period there were 343 fatal and non-fatal myocardial infarctions or strokes. Trends in adverse cardiovascular outcomes related to pollution were identified among subjects belonging to the highest baseline quintile of plasma fibrinogen. Evidence for interactions between concentrations of particulate pollution and fibrinogen was not established at conventional levels of significance.CONCLUSIONSPeople with high concentrations of plasma fibrinogen might be more susceptible to adverse cardiovascular effects of particulate air pollution, but limitations of power mean that evidence relating to such an interaction is not conclusive. A range of cardiopulmonary risk factors warrant investigation in relation to possible susceptibility to air pollution.
Reactions from the medical and nursing professions to Nightingale’s “reform(s)” of nurse training in the late 19th century
Authors: Cook G C , Webb A J 
Published: July 2002

Abstract
In 1860, the Nightingale School of Nursing opened at St Thomas’s Hospital, London. Florence Nightingale’s overriding raison d’etre in the setting up of this foundation was a replacement of the old fashioned nurse (caricatured by Mrs Gamp—an “ignorant and immoral drunkard”) by the highly trained, and eminently respectable “lady-nurse”. While this change met with a great deal of approval from the lay public and the majority of the nursing profession, a minority of the latter together with the bulk of medical practitioners (including several leading physicians and surgeons of the day) wholeheartedly opposed this revolutionary move. It was felt, by them, that the medical profession was in danger of losing control over nursing with the resultant sacrifice of satisfactory patient care. Today, both medical student and nurse training is moving noticeably away from the bedside, an orientation which has added such an important dimension to British medical/nurse training over so many generations. Is this 19th century experience yet another example of history repeating itself in the medical sphere?
RANKIN–COHEN TYPE DIFFERENTIAL OPERATORS FOR SIEGEL MODULAR FORMS
Authors: EHOLZER WOLFGANG , IBUKIYAMA TOMOYOSHI 
Published: July 2002

Let ℍn be the Siegel upper half space and let F and G be automorphic forms on ℍn of weights k and l, respectively. We give explicit examples of differential operators D acting on functions on ℍn × ℍn such that the restriction of [Formula: see text] to Z = Z1 = Z2 is again an automorphic form of weight k + l + v on ℍn. Since the elliptic case, i.e. n = 1, has already been studied some time ago by R. Rankin and H. Cohen we call such differential operators Rankin–Cohen type operators. We also discuss a generalisation of Rankin–Cohen type operators to vector valued differential operators.
CASE STUDIES IN SURFACE GEOMETRY: ADSORBATE AND COADSORBATE STRUCTURES ON Ru(001), AND SOME IMPLICATIONS
Authors: MENZEL DIETRICH 
Published: July 2002

Using a CCD LEED system for the collection of IV data with minimal beam damage, and full dynamical as well as Tensor LEED calculations, the geometries of about 20 adsorbate and coadsorbate structures on Ru(001) have been determined over the past decade. With work by other groups, more than 30 accurate adsorbate structures are now available for this surface. The advantage of this concentrated effort directed at a single surface with equivalent methods is that comparisons of trends can be made on this basis, and that the correlation of different structures lends additional credibility to the separately determined structural parameters. This then justifies comparisons with results of first principles theoretical calculations and other conclusions. Here a short overview is given of the methods used and of the structures derived, and some methodological questions (reliability of "LEED only," and the importance of supporting evidence; reproducibility vs. accuracy; temperature effects and the influence of soft vibrations) are discussed. This data set is then used to briefly discuss some examples, including: • Influences of site selection and environment on the adsorbate structure; • Lateral interactions in coadsorbate structures; • Possible chemical contributions in rare gas adsorption; • Global and local relaxations of the Ru surface atoms and their interpretation. Comparison to theoretical results is made where possible.