bluuebunny/crossref_metadata_2025_split huggingface dataset:
An overview of OA research in two urban APLAR populations
Authors: LEUNG Ying Y. , THUMBOO Julian 
Published: April 2011

AbstractOsteoarthritis (OA), the most prevalent type of arthritis in the elderly, is also among the first five leading causes of disability in developed countries. With the ‘Westernized’ living environment and lifestyle among Southeast Asian urbanized cities, where obesity is on the rise and the populations are ageing, the incidence of OA is expected to rise in the next decades. There is need to summarize research work within these places. This article summarizes some of the research aspects of OA in Southeast Asian cities. These data may form a useful basis for future planning of medical resource and needs.
Update in surgery for osteoarthritis of the knee
Authors: CHOONG Peter F. M. , DOWSEY Michelle M. 
Published: April 2011

AbstractOsteoarthritis is a leading cause of disability with incidence and prevalence rising in most nations. Management to address the degenerative joint is stratified according to degree of severity of involvement and always begins with non‐surgical modalities before progressing through a range of surgeries, including arthroscopy, osteotomy, unicompartmental and total knee replacement. Predictability of results depends on the type of procedure with total joint replacement giving the most sustainable relief from symptoms, improvement of function and longevity of construct. Obesity is a health priority in developed countries where it is overrepresented in patients presenting for joint replacement. Complications, poor patient satisfaction and joint function can be directly attributable to obesity. Efforts to address obesity should be considered as part of the approach to managing osteoarthritis.
RNA Splicing in a New Rhabdovirus from
Culex
Mosquitoes
Authors: Kuwata Ryusei , Isawa Haruhiko , Hoshino Keita , Tsuda Yoshio , Yanase Tohru , Sasaki Toshinori , Kobayashi Mutsuo , Sawabe Kyoko 
Published: April 2011

ABSTRACT

Among members of the order
Mononegavirales
, RNA splicing events have been found only in the family
Bornaviridae
. Here, we report that a new rhabdovirus isolated from the mosquito
Culex tritaeniorhynchus
replicates in the nuclei of infected cells and requires RNA splicing for viral mRNA maturation. The virus, designated
Culex tritaeniorhynchus
rhabdovirus (CTRV), shares a similar genome organization with other rhabdoviruses, except for the presence of a putative intron in the coding region for the L protein. Molecular phylogenetic studies indicated that CTRV belongs to the family
Rhabdoviridae
, but it is yet to be assigned a genus. Electron microscopic analysis revealed that the CTRV virion is extremely elongated, unlike virions of rhabdoviruses, which are generally bullet shaped. Northern hybridization confirmed that a large transcript (approximately 6,500 nucleotides [nt]) from the CTRV L gene was present in the infected cells. Strand-specific reverse transcription-PCR (RT-PCR) analyses identified the intron-exon boundaries and the 76-nt intron sequence, which contains the typical motif for eukaryotic spliceosomal intron-splice donor/acceptor sites (GU-AG), a predicted branch point, and a polypyrimidine tract.
In situ
hybridization exhibited that viral RNAs are primarily localized in the nucleus of infected cells, indicating that CTRV replicates in the nucleus and is allowed to utilize the host's nuclear splicing machinery. This is the first report of RNA splicing among the members of the family
Rhabdoviridae
.
Blocking eIF4E-eIF4G Interaction as a Strategy To Impair Coronavirus Replication
Authors: Cencic Regina , Desforges Marc , Hall David R. , Kozakov Dima , Du Yuhong , Min Jaeki , Dingledine Raymond , Fu Haian , Vajda Sandor , Talbot Pierre J. , Pelletier Jerry 
Published: April 2011

ABSTRACTCoronaviruses are a family of enveloped single-stranded positive-sense RNA viruses causing respiratory, enteric, and neurologic diseases in mammals and fowl. Human coronaviruses are recognized to cause up to a third of common colds and are suspected to be involved in enteric and neurologic diseases. Coronavirus replication involves the generation of nested subgenomic mRNAs (sgmRNAs) with a common capped 5′ leader sequence. The translation of most of the sgmRNAs is thought to be cap dependent and displays a requirement for eukaryotic initiation factor 4F (eIF4F), a heterotrimeric complex needed for the recruitment of 40S ribosomes. We recently reported on an ultrahigh-throughput screen to discover compounds that inhibit eIF4F activity by blocking the interaction of two of its subunits (R. Cencic et al., Proc. Natl. Acad. Sci. U. S. A.108:1046–1051, 2011). Herein we describe a molecule from this screen that prevents the interaction between eIF4E (the cap-binding protein) and eIF4G (a large scaffolding protein), inhibiting cap-dependent translation. This inhibitor significantly decreased human coronavirus 229E (HCoV-229E) replication, reducing the percentage of infected cells and intra- and extracellular infectious virus titers. Our results support the strategy of targeting the eIF4F complex to block coronavirus infection.
Capturing the Herpes Simplex Virus Core Fusion Complex (gB-gH/gL) in an Acidic Environment
Authors: Cairns Tina M. , Whitbeck J. Charles , Lou Huan , Heldwein Ekaterina E. , Chowdary Tirumala K. , Eisenberg Roselyn J. , Cohen Gary H. 
Published: April 2011

ABSTRACT
Herpes simplex virus (HSV) entry requires the core fusion machinery of gH/gL and gB as well as gD and a gD receptor. When gD binds receptor, it undergoes conformational changes that presumably activate gH/gL, which then activates gB to carry out fusion. gB is a class III viral fusion protein, while gH/gL does not resemble any known viral fusion protein. One hallmark of fusion proteins is their ability to bind lipid membranes. We previously used a liposome coflotation assay to show that truncated soluble gB, but not gH/gL or gD, can associate with liposomes at neutral pH. Here, we show that gH/gL cofloats with liposomes but only when it is incubated with gB at pH 5. When gB mutants with single amino acid changes in the fusion loops (known to inhibit the binding of soluble gB to liposomes) were mixed with gH/gL and liposomes at pH 5, gH/gL failed to cofloat with liposomes. These data suggest that gH/gL does not directly associate with liposomes but instead binds to gB, which then binds to liposomes via its fusion loops. Using monoclonal antibodies, we found that many gH and gL epitopes were altered by low pH, whereas the effect on gB epitopes was more limited. Our liposome data support the concept that low pH triggers conformational changes to both proteins that allow gH/gL to physically interact with gB.
Small Molecules Targeting Hepatitis C Virus-Encoded NS5A Cause Subcellular Redistribution of Their Target: Insights into Compound Modes of Action
Authors: Targett-Adams Paul , Graham Emily J. S. , Middleton Jenny , Palmer Amy , Shaw Stephen M. , Lavender Helen , Brain Philip , Tran Thien Duc , Jones Lyn H. , Wakenhut Florian , Stammen Blanda , Pryde David , Pickford Chris , Westby Mike 
Published: April 2011

ABSTRACTThe current standard of care for hepatitis C virus (HCV)-infected patients consists of lengthy treatment with interferon and ribavirin. To increase the effectiveness of HCV therapy, future regimens will incorporate multiple direct-acting antiviral (DAA) drugs. Recently, the HCV-encoded NS5A protein has emerged as a promising DAA target. Compounds targeting NS5A exhibit remarkable potencyin vitroand demonstrate early clinical promise, suggesting that NS5A inhibitors could feature in future DAA combination therapies. Since the mechanisms through which these molecules operate are unknown, we have used NS5A inhibitors as tools to investigate their modes of action. Analysis of replicon-containing cells revealed dramatic phenotypic alterations in NS5A localization following treatment with NS5A inhibitors; NS5A was redistributed from the endoplasmic reticulum to lipid droplets. The NS5A relocalization did not occur in cells treated with other classes of HCV inhibitors, and NS5A-targeting molecules did not cause similar alterations in the localization of other HCV-encoded proteins. Time course analysis of the redistribution of NS5A revealed that the transfer of protein to lipid droplets was concomitant with the onset of inhibition, as judged by the kinetic profiles for these compounds. Furthermore, analysis of the kinetic profile of inhibition for a panel of test molecules permitted the separation of compounds into different kinetic classes based on their modes of action. Results from this approach suggested that NS5A inhibitors perturbed the function of new replication complexes, rather than acting on preformed complexes. Taken together, our data reveal novel biological consequences of NS5A inhibition, which may help enable the development of future assay platforms for the identification of new and/or different NS5A inhibitors.
Replication-Coupled and Host Factor-Mediated Encapsidation of the Influenza Virus Genome by Viral Nucleoprotein
Authors: Kawaguchi Atsushi , Momose Fumitaka , Nagata Kyosuke 
Published: April 2011

ABSTRACT

The influenza virus RNA-dependent RNA polymerase is capable of initiating replication but mainly catalyzes abortive RNA synthesis in the absence of viral and host regulatory factors. Previously, we reported that IREF-1/minichromosome maintenance (MCM) complex stimulates a
de novo
initiated replication reaction by stabilizing an initiated replication complex through scaffolding between the viral polymerase and nascent cRNA to which MCM binds. In addition, several lines of genetic and biochemical evidence suggest that viral nucleoprotein (NP) is involved in successful replication. Here, using cell-free systems, we have shown the precise stimulatory mechanism of virus genome replication by NP. Stepwise cell-free replication reactions revealed that exogenously added NP free of RNA activates the viral polymerase during promoter escape while it is incapable of encapsidating the nascent cRNA. However, we found that a previously identified cellular protein, RAF-2p48/NPI-5/UAP56, facilitates replication reaction-coupled encapsidation as an NP molecular chaperone. These findings demonstrate that replication of the virus genome is followed by its encapsidation by NP in collaboration with its chaperone.
Genetic Evidence for Rift Valley Fever Outbreaks in Madagascar Resulting from Virus Introductions from the East African Mainland rather than Enzootic Maintenance
Authors: Carroll Serena A. , Reynes Jean-Marc , Khristova Marina L. , Andriamandimby Soa Fy , Rollin Pierre E. , Nichol Stuart T. 
Published: April 2011

ABSTRACT
Rift Valley fever virus (RVFV), a mosquito-borne phlebovirus, has been detected in Madagascar since 1979, with occasional outbreaks. In 2008 to 2009, a large RVFV outbreak was detected in Malagasy livestock and humans during two successive rainy seasons. To determine whether cases were due to enzootic maintenance of the virus within Madagascar or to importation from the East African mainland, nine RVFV whole genomic sequences were generated for viruses from the 1991 and 2008 Malagasy outbreaks. Bayesian coalescent analyses of available whole S, M, and L segment sequences were used to estimate the time to the most recent common ancestor for the RVFVs. The 1979 Madagascar isolate shared a common ancestor with strains on the mainland around 1972. The 1991 Madagascar isolates were in a clade distinct from that of the 1979 isolate and shared a common ancestor around 1987. Finally, the 2008 Madagascar viruses were embedded within a large clade of RVFVs from the 2006–2007 outbreak in East Africa and shared a common ancestor around 2003 to 2004. These results suggest that the most recent Madagascar outbreak was caused by a virus likely arriving in the country some time between 2003 and 2008 and that this outbreak may be an extension of the 2006–2007 East African outbreak. Clustering of the Malagasy sequences into subclades indicates that the viruses have continued to evolve during their short-term circulation within the country. These data are consistent with the notion that RVFV outbreaks in Madagascar result not from emergence from enzootic cycles within the country but from recurrent virus introductions from the East African mainland.
Pleiotropic Action of AP-1 in v-Src-Transformed Cells
Authors: Wang Lizhen , Rodrigues Natalie A. , Wu Ying , Maslikowski Bart M. , Singh Nishi , Lacroix Samantha , Bédard Pierre-André 
Published: April 2011

ABSTRACT
The activation of AP-1 is a hallmark of cell transformation by tyrosine kinases. In this study, we characterize the role of AP-1 proteins in the transformation of chicken embryo fibroblasts (CEF) by v-Src. In normal CEF, the expression of a dominant negative mutant of c-Jun (TAM67) induced senescence. In contrast, three distinct phenotypes were observed when TAM67 was expressed in v-Src-transformed CEF. While senescent cells were also present, the inhibition of AP-1 caused apoptosis in a fraction of the v-Src-transformed cells. In addition, cells containing lipid-rich vesicles accumulated, suggesting that a subpopulation of the v-Src-transformed cells underwent differentiation in response to the inhibition of AP-1. JunD and Fra-2 were the main components of this factor, while c-Jun accounted for a minor fraction of AP-1 in v-Src-transformed CEF. The downregulation of c-Jun expression by short hairpin RNA (shRNA) induced senescence in normal and v-Src-transformed cells. In contrast, a high incidence of apoptosis was caused by the downregulation of JunD, suggesting that it is required for the survival of v-Src-transformed CEF. Levels of the p53 tumor suppressor were elevated under conditions of JunD inhibition. Repression of p53 by shRNA enhanced the survival and anchorage-independent proliferation of v-Src-transformed CEF with JunD/AP-1 inhibition. The inhibition of Fra-2 had no visible phenotype in normal CEF but caused the appearance of lipid-rich vesicles in v-Src-transformed CEF. Therefore, AP-1 facilitated transformation by acting as a survival factor, by inhibiting premature entry into senescence, and by blocking the differentiation of v-Src-transformed CEF.
Rhinovirus-Induced Barrier Dysfunction in Polarized Airway Epithelial Cells Is Mediated by NADPH Oxidase 1
Authors: Comstock Adam T. , Ganesan Shyamala , Chattoraj Asamanja , Faris Andrea N. , Margolis Benjamin L. , Hershenson Marc B. , Sajjan Umadevi S. 
Published: April 2011

ABSTRACT

Previously, we showed that rhinovirus (RV), which is responsible for the majority of common colds, disrupts airway epithelial barrier function, as evidenced by reduced transepithelial resistance (R
T
), dissociation of zona occludins 1 (ZO-1) from the tight junction complex, and bacterial transmigration across polarized cells. We also showed that RV replication is required for barrier function disruption. However, the underlying biochemical mechanisms are not known. In the present study, we found that a double-stranded RNA (dsRNA) mimetic, poly(I:C), induced tight junction breakdown and facilitated bacterial transmigration across polarized airway epithelial cells, similar to the case with RV. We also found that RV and poly(I:C) each stimulated Rac1 activation, reactive oxygen species (ROS) generation, and Rac1-dependent NADPH oxidase 1 (NOX1) activity. Inhibitors of Rac1 (NSC23766), NOX (diphenylene iodonium), and NOX1 (small interfering RNA [siRNA]) each blocked the disruptive effects of RV and poly(I:C) on R
T
, as well as the dissociation of ZO-1 and occludin from the tight junction complex. Finally, we found that Toll-like receptor 3 (TLR3) is not required for either poly(I:C)- or RV-induced reductions in R
T
. Based on these results, we concluded that Rac1-dependent NOX1 activity is required for RV- or poly(I:C)-induced ROS generation, which in turn disrupts the barrier function of polarized airway epithelia. Furthermore, these data suggest that dsRNA generated during RV replication is sufficient to disrupt barrier function.
Opposing Effects of CD70 Costimulation during Acute and Chronic Lymphocytic Choriomeningitis Virus Infection of Mice
Authors: Penaloza-MacMaster Pablo , Rasheed Ata Ur , Iyer Smita S. , Yagita Hideo , Blazar Bruce R. , Ahmed Rafi 
Published: April 2011

ABSTRACTT cell costimulation is important for T cell activation. The CD27/CD70 pathway contributes to effector and memory T cell development and is involved in T cell and B cell activation. CD27/CD70 is known for having opposing roles during different models of antigenic challenges. During primary T cell responses to influenza virus infection or during tumor challenges, CD27/CD70 costimulation has a positive role on T cell responses. However, during some chronic infections, constitutive triggering of this signaling pathway has a negative role on T cell responses. It is currently unclear what specific characteristic of an antigen determines the outcome of CD27/CD70 costimulation. We investigated the effect of a transient CD70 blockade during an acute or a chronic lymphocytic choriomeningitis virus (LCMV) infection in mice. Blockade of this pathway during acute LCMV infection (Armstrong strain) resulted in delayed T cell responses and decreased CD127 (interleukin-7 receptor α [IL-7Rα] chain) conversion. Upregulation of CD127 is an important event in T cell differentiation that heralds the passage of an effector T cell to a long-lived memory T cell. In contrast to the reduced CD8 T cell responses after CD70 blockade during acute infection, CD70 blockade during chronic LCMV infection resulted in increased CD8 T cell responses. Our data show the dual roles of this costimulatory pathway in acute versus persistent antigen challenge. Our findings suggest that antigen persistence may determine the effect of CD27/CD70 signaling on CD8 T cell responses. Tailored triggering or blockade of this costimulatory pathway may be important in vaccination regimens against acute or chronic pathogens.
Inhibition of Dengue Virus through Suppression of Host Pyrimidine Biosynthesis
Authors: Wang Qing-Yin , Bushell Simon , Qing Min , Xu Hao Ying , Bonavia Aurelio , Nunes Sandra , Zhou Jing , Poh Mee Kian , Florez de Sessions Paola , Niyomrattanakit Pornwaratt , Dong Hongping , Hoffmaster Keith , Goh Anne , Nilar Shahul , Schul Wouter , Jones Susan , Kramer Laura , Compton Teresa , Shi Pei-Yong 
Published: April 2011

ABSTRACTViral replication relies on the host to supply nucleosides. Host enzymes involved in nucleoside biosynthesis are potential targets for antiviral development. Ribavirin (a known antiviral drug) is such an inhibitor that suppresses guanine biosynthesis; depletion of the intracellular GTP pool was shown to be the major mechanism to inhibit flavivirus. Along similar lines, inhibitors of the pyrimidine biosynthesis pathway could be targeted for potential antiviral development. Here we report on a novel antiviral compound (NITD-982) that inhibits host dihydroorotate dehydrogenase (DHODH), an enzyme required for pyrimidine biosynthesis. The inhibitor was identified through screening 1.8 million compounds using a dengue virus (DENV) infection assay. The compound contains an isoxazole-pyrazole core structure, and it inhibited DENV with a 50% effective concentration (EC50) of 2.4 nM and a 50% cytotoxic concentration (CC50) of >5 μM. NITD-982 has a broad antiviral spectrum, inhibiting both flaviviruses and nonflaviviruses with nanomolar EC90s. We also show that (i) the compound inhibited the enzymatic activity of recombinant DHODH, (ii) an NITD-982 analogue directly bound to the DHODH protein, (iii) supplementing the culture medium with uridine reversed the compound-mediated antiviral activity, and (iv) DENV type 2 (DENV-2) variants resistant to brequinar (a known DHODH inhibitor) were cross resistant to NITD-982. Collectively, the results demonstrate that the compound inhibits DENV through depleting the intracellular pyrimidine pool. In contrast to thein vitropotency, the compound did not show any efficacy in the DENV-AG129 mouse model. The lack ofin vivoefficacy is likely due to the exogenous uptake of pyrimidine from the diet or to a high plasma protein-binding activity of the current compound.
Need for ethics support in healthcare institutions: views of Dutch board members and ethics support staff
Authors: Dauwerse Linda , Abma Tineke , Molewijk Bert , Widdershoven Guy 
Published: April 2011

ObjectiveThe purpose of this article is to investigate the need for ethics support in Dutch healthcare institutions in order to understand why ethics support is often not used in practice and which factors are relevant in this context.MethodsThis study had a mixed methods design integrating quantitative and qualitative research methods. Two survey questionnaires, two focus groups and 17 interviews were conducted among board members and ethics support staff in Dutch healthcare institutions.FindingsMost respondents see a need for ethics support. This need is related to the complexity of contemporary healthcare, the contribution of ethics support to the core business of the organisation and to the surplus value of paying structural attention to ethical issues. The need for ethics support is, however, not unconditional. Reasons for a lacking need include: aversion of innovations, negative associations with the notion of ethics support service, and organisational factors like resources and setting.ConclusionThere is a conditioned need for ethics support in Dutch healthcare institutions. The promotion of ethics support in healthcare can be fostered by focusing on formats which fit the needs of (practitioners in) healthcare institutions. The emphasis should be on creating a (culture of) dialogue about the complex situations which emerge daily in contemporary healthcare practice.
Tunnelling in Brasília porous clay
Authors: Ortigao J AR , Kochen R , Farias M M , Assis A P 
Published: April 2011

The Brasília underground transportation system comprises 6.5 km of shallow tunnel excavated in a soft red soil known as porous clay that overlies harder residual soils. The tunnel diameter is 9.6 m. Settlement observations indicated that surface settlements were two to three fold the initially predicted value, although no indication of excavation instability was observed. Settlements reached, at one section, 500 mm without failure. Another striking feature was settlement amplification between the top of the excavation and the surface by a factor that averaged 1.2 but reached up to 4. This occured because of the collapsible nature of the porous clay, which presented a considerable reduction of volume as the tunnel face advanced. This paper describes tunnel design, construction, and instrumentation; and summarizes geology and soil properties from in situ and laboratory tests. Field measurements of settlements and horizontal displacements are described and analysed. The main cause of the large settlements was collapse of the porous clay structure. Key words: tunnelling, porous clay, settlements, collapse.