bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Oncogenic Small Tumor Antigen of Merkel Cell Polyomavirus Is an Iron-Sulfur Cluster Protein That Enhances Viral DNA Replication
Authors: Tsang Sabrina H. , Wang Ranran , Nakamaru-Ogiso Eiko , Knight Simon A. B. , Buck Christopher B. , You Jianxin 
Published: November 2015

ABSTRACT
Merkel cell polyomavirus (MCPyV) plays an important role in Merkel cell carcinoma (MCC). MCPyV small T (sT) antigen has emerged as the key oncogenic driver in MCC carcinogenesis. It has also been shown to promote MCPyV LT-mediated replication by stabilizing LT. The importance of MCPyV sT led us to investigate sT functions and to identify potential ways to target this protein. We discovered that MCPyV sT purified from bacteria contains iron-sulfur (Fe/S) clusters. Electron paramagnetic resonance analysis showed that MCPyV sT coordinates a [2Fe-2S] and a [4Fe-4S] cluster. We also observed phenotypic conservation of Fe/S coordination in the sTs of other polyomaviruses. Since Fe/S clusters are critical cofactors in many nucleic acid processing enzymes involved in DNA unwinding and polymerization, our results suggested the hypothesis that MCPyV sT might be directly involved in viral replication. Indeed, we demonstrated that MCPyV sT enhances LT-mediated replication in a manner that is independent of its previously reported ability to stabilize LT. MCPyV sT translocates to nuclear foci containing actively replicating viral DNA, supporting a direct role for sT in promoting viral replication. Mutations of Fe/S cluster-coordinating cysteines in MCPyV sT abolish its ability to stimulate viral replication. Moreover, treatment with cidofovir, a potent antiviral agent, robustly inhibits the sT-mediated enhancement of MCPyV replication but has little effect on the basal viral replication driven by LT alone. This finding further indicates that MCPyV sT plays a direct role in stimulating viral DNA replication and introduces cidofovir as a possible drug for controlling MCPyV infection.

IMPORTANCE
MCPyV is associated with a highly aggressive form of skin cancer in humans. Epidemiological surveys for MCPyV seropositivity and sequencing analyses of healthy human skin suggest that MCPyV may represent a common component of the human skin microbial flora. However, much of the biology of the virus and its oncogenic ability remain to be investigated. In this report, we identify MCPyV sT as a novel Fe/S cluster protein and show that conserved cysteine clusters are important for sT's ability to enhance viral replication. Moreover, we show that sT sensitizes MCPyV replication to cidofovir inhibition. The discovery of Fe/S clusters in MCPyV sT opens new avenues to the study of the structure and functionality of this protein. Moreover, this study supports the notion that sT is a potential drug target for dampening MCPyV infection.
H1N1 Swine Influenza Viruses Differ from Avian Precursors by a Higher pH Optimum of Membrane Fusion
Authors: Baumann Jan , Kouassi Nancy Mounogou , Foni Emanuela , Klenk Hans-Dieter , Matrosovich Mikhail 
Published: November 2015

ABSTRACT

The H1N1 Eurasian avian-like swine (EAsw) influenza viruses originated from an avian H1N1 virus. To characterize potential changes in the membrane fusion activity of the hemagglutinin (HA) during avian-to-swine adaptation of the virus, we studied EAsw viruses isolated in the first years of their circulation in pigs and closely related contemporary H1N1 viruses of wild aquatic birds. Compared to the avian viruses, the swine viruses were less sensitive to neutralization by lysosomotropic agent NH
4
Cl in MDCK cells, had a higher pH optimum of hemolytic activity, and were less stable at acidic pH. Eight amino acid substitutions in the HA were found to separate the EAsw viruses from their putative avian precursor; four substitutions—T49
2
S, N72
2
D, R75
2
K, and S113
2
F—were located in the structural regions of the HA2 subunit known to play a role in acid-induced conformational transition of the HA. We also studied low-pH-induced syncytium formation by cell-expressed HA proteins and found that the HAs of the 1918, 1957, 1968, and 2009 pandemic viruses required a lower pH for fusion induction than did the HA of a representative EAsw virus. Our data show that transmission of an avian H1N1 virus to pigs was accompanied by changes in conformational stability and fusion promotion activity of the HA. We conclude that distinctive host-determined fusion characteristics of the HA may represent a barrier for avian-to-swine and swine-to-human transmission of influenza viruses.

IMPORTANCE
Continuing cases of human infections with zoonotic influenza viruses highlight the necessity to understand which viral properties contribute to interspecies transmission. Efficient binding of the HA to cellular receptors in a new host species is known to be essential for the transmission. Less is known about required adaptive changes in the membrane fusion activity of the HA. Here we show that adaptation of an avian influenza virus to pigs in Europe in 1980s was accompanied by mutations in the HA, which decreased its conformational stability and increased pH optimum of membrane fusion activity. This finding represents the first formal evidence of alteration of the HA fusion activity/stability during interspecies transmission of influenza viruses under natural settings.
3C Protease of Enterovirus D68 Inhibits Cellular Defense Mediated by Interferon Regulatory Factor 7
Authors: Xiang Zichun , Liu Lulu , Lei Xiaobo , Zhou Zhuo , He Bin , Wang Jianwei 
Published: November 2015

ABSTRACT

Human enterovirus 68 (EV-D68) is a member of the EV-D species, which belongs to the EV genus of the
Picornaviridae
family. Over the past several years, clusters of EV-D68 infections have occurred worldwide. A recent outbreak in the United States is the largest one associated with severe respiratory illness and neurological complication. Although clinical symptoms are recognized, the virus remains poorly understood. Here we report that EV-D68 inhibits innate antiviral immunity by downregulation of interferon regulatory factor 7 (IRF7), an immune factor with a pivotal role in viral pathogenesis. This process depends on 3C
pro
, an EV-D68-encoded protease, to mediate IRF7 cleavage. When expressed in host cells, 3C
pro
targets Q167 and Q189 within the constitutive activation domain, resulting in cleavage of IRF7. Accordingly, wild-type IRF7 is fully active. However, IRF7 cleavage abrogated its capacity to activate type I interferon expression and limit replication of EV-D68. Notably, IRF7 cleavage strictly requires the protease activity of 3C
pro
. Together, these results suggest that a dynamic interplay between 3C
pro
and IRF7 may determine the outcome of EV-D68 infection.

IMPORTANCE
EV-D68 is a globally emerging pathogen, but the molecular basis of EV-D68 pathogenesis is unclear. Here we report that EV-D68 inhibits innate immune responses by targeting an immune factor, IRF7. This involves the 3C protease encoded by EV-D68, which mediates the cleavage of IRF7. These observations suggest that the 3C
pro
-IRF7 interaction may represent an interface that dictates EV-D68 infection.
The Interferon Type I/III Response to Respiratory Syncytial Virus Infection in Airway Epithelial Cells Can Be Attenuated or Amplified by Antiviral Treatment
Authors: McCutcheon K. M. , Jordan R. , Mawhorter M. E. , Noton S. L. , Powers J. G. , Fearns R. , Cihlar T. , Perron M. 
Published: November 2015

ABSTRACT

Human respiratory syncytial virus (RSV) is a single-stranded RNA virus that causes acute, and occasionally fatal, lower respiratory illness in young infants, the elderly, and immunocompromised patients. Therapeutic interventions able to cut short viral replication and quickly return the airways to normal function are needed. An understanding of antiviral activities and their effects on host defense mechanisms is important for the design of safe and effective therapy. We targeted functionally and temporally distinct steps within the viral life cycle using small-molecule RSV inhibitors and studied their antiviral activities and their effects on innate interferon responses of airway epithelial cells
in vitro
. Antivirals acting upstream of RSV polymerase activity (i.e., compounds targeting the fusion protein or the nucleoprotein) reduced viral load immediately postinfection and partially attenuated interferon responses. In contrast, antivirals directed to the RSV polymerase demonstrated activity throughout the viral replication cycle and specifically modulated the RIG-I/mitochondrial antiviral signaling protein (MAVS)/TBK1/IRF3/interferon-stimulated gene (ISG) axis, causing either an upregulation or a downregulation of interferon responses, depending on the mechanism of polymerase inhibition. Notably, polymerase inhibition leading to the accumulation of abortive RNA products correlated with the amplification of interferon-stimulated genes to up to 10 times above normal infection levels. Understanding how antiviral activities and their modulation of innate immunity may affect recovery from RSV infection will help guide the development of safe and effective therapies.

IMPORTANCE
RSV circulates seasonally, causing acute lower respiratory disease. Therapeutic interventions with efficacy throughout the viral replication cycle, rapid viral clearance, and prevention of potentially harmful inflammatory responses are desirable. Compounds targeting the RSV polymerase inhibited virus replication late in the viral life cycle and, depending on the functional domain targeted, either attenuated or amplified RIG-I and downstream interferon pathways in infected cells. These data will help guide the development of safe and effective therapies by providing new molecular evidence that the mechanism of inhibition by an antiviral compound can directly impact innate antiviral immune responses in the airway epithelium.
An Adenovirus DNA Replication Factor, but Not Incoming Genome Complexes, Targets PML Nuclear Bodies
Authors: Komatsu Tetsuro , Nagata Kyosuke , Wodrich Harald 
Published: November 2015

ABSTRACT
Promyelocytic leukemia protein nuclear bodies (PML-NBs) are subnuclear domains implicated in cellular antiviral responses. Despite the antiviral activity, several nuclear replicating DNA viruses use the domains as deposition sites for the incoming viral genomes and/or as sites for viral DNA replication, suggesting that PML-NBs are functionally relevant during early viral infection to establish productive replication. Although PML-NBs and their components have also been implicated in the adenoviral life cycle, it remains unclear whether incoming adenoviral genome complexes target PML-NBs. Here we show using immunofluorescence and live-cell imaging analyses that incoming adenovirus genome complexes neither localize at nor recruit components of PML-NBs during early phases of infection. We further show that the viral DNA binding protein (DBP), an early expressed viral gene and essential DNA replication factor, independently targets PML-NBs. We show that DBP oligomerization is required to selectively recruit the PML-NB components Sp100 and USP7. Depletion experiments suggest that the absence of one PML-NB component might not affect the recruitment of other components toward DBP oligomers. Thus, our findings suggest a model in which an adenoviral DNA replication factor, but not incoming viral genome complexes, targets and modulates PML-NBs to support a conducive state for viral DNA replication and argue against a generalized concept that PML-NBs target incoming viral genomes.

IMPORTANCE
The immediate fate upon nuclear delivery of genomes of incoming DNA viruses is largely unclear. Early reports suggested that incoming genomes of herpesviruses are targeted and repressed by PML-NBs immediately upon nuclear import. Genome localization and/or viral DNA replication has also been observed at PML-NBs for other DNA viruses. Thus, it was suggested that PML-NBs may immediately sense and target nuclear viral genomes and hence serve as sites for deposition of incoming viral genomes and/or subsequent viral DNA replication. Here we performed a detailed analyses of the spatiotemporal distribution of incoming adenoviral genome complexes and found, in contrast to the expectation, that an adenoviral DNA replication factor, but not incoming genomes, targets PML-NBs. Thus, our findings may explain why adenoviral genomes could be observed at PML-NBs in earlier reports but argue against a generalized role for PML-NBs in targeting invading viral genomes.
Mutated but Not Deleted Ovine PrP
C
N-Terminal Polybasic Region Strongly Interferes with Prion Propagation in Transgenic Mice
Authors: Khalifé Manal , Reine Fabienne , Paquet-Fifield Sophie , Castille Johan , Herzog Laetitia , Vilotte Marthe , Moudjou Mohammed , Moazami-Goudarzi Katayoun , Makhzami Samira , Passet Bruno , Andréoletti Olivier , Vilette Didier , Laude Hubert , Béringue Vincent , Vilotte Jean-Luc 
Published: November 2015

ABSTRACT

Mammalian prions are proteinaceous infectious agents composed of misfolded assemblies of the host-encoded, cellular prion protein (PrP). Physiologically, the N-terminal polybasic region of residues 23 to 31 of PrP has been shown to be involved in its endocytic trafficking and interactions with glycosaminoglycans or putative ectodomains of membrane-associated proteins. Several recent reports also describe this PrP region as important for the toxicity of mutant prion proteins and the efficiency of prion propagation, both
in vitro
and
in vivo
. The question remains as to whether the latter observations made with mouse PrP and mouse prions would be relevant to other PrP species/prion strain combinations given the dramatic impact on prion susceptibility of minimal amino acid substitutions and structural variations in PrP. Here, we report that transgenic mouse lines expressing ovine PrP with a deletion of residues 23 to 26 (KKRP) or mutated in this N-terminal region (KQHPH instead of KKRPK) exhibited a variable, strain-dependent susceptibility to prion infection with regard to the proportion of affected mice and disease tempo relative to findings in their wild-type counterparts. Deletion has no major effect on 127S scrapie prion pathogenesis, whereas mutation increased by almost 3-fold the survival time of the mice. Deletion marginally affected the incubation time of scrapie LA19K and ovine bovine spongiform encephalopathy (BSE) prions, whereas mutation caused apparent resistance to disease.

IMPORTANCE
Recent reports suggested that the N-terminal polybasic region of the prion protein could be a therapeutic target to prevent prion propagation or toxic signaling associated with more common neurodegenerative diseases such as Alzheimer's disease. Mutating or deleting this region in ovine PrP completes the data previously obtained with the mouse protein by identifying the key amino acid residues involved.
Methods for estimating causal relationships of adverse events with dietary supplements
Authors: Ide Kazuki , Yamada Hiroshi , Kitagawa Mamoru , Kawasaki Yohei , Buno Yuma , Matsushita Kumi , Kaji Masayuki , Fujimoto Kazuko , Waki Masako , Nakashima Mitsuyoshi , Umegaki Keizo 
Published: November 2015

ObjectiveDietary supplement use has increased over past decades, resulting in reports of potentially serious adverse events. The aim of this study was to develop optimised methods to evaluate the causal relationships between adverse events and dietary supplements, and to test these methods using case reports.DesignCausal relationship assessment using prospectively collected data.Setting and participants4 dietary supplement experts, 4 pharmacists and 11 registered dietitians (5 men and 14 women) examined 200 case reports of suspected adverse events using the modified Naranjo scale and the modified Food and Drug Administration (FDA) algorithm.Primary outcome measuresThe distribution of evaluation results was analysed and inter-rater reliability was evaluated for the two modified methods employed using intraclass correlation coefficients (ICC) and Fleiss’ κ.ResultsUsing these two methods, most of the 200 case reports were categorised as ‘lack of information’ or ‘possible’ adverse events. Inter-rater reliability among entire assessors ratings for the two modified methods, based on ICC and Fleiss’ κ, were classified as more than substantial (modified Naranjo scale: ICC (95% CI) 0.873 (0.850 to 0.895); Fleiss’ κ (95% CI) 0.615 (0.615 to 0.615). Modified FDA algorithm: Fleiss’ κ (95% CI) 0.622 (0.622 to 0.622).ConclusionsThese methods may help to assess the causal relationships between adverse events and dietary supplements. By conducting additional studies of these methods in different populations, researchers can expand the possibilities for the application of our methods.
How common is isolated dysphasia among patients with stroke treated with intravenous thrombolysis, and what is their outcome? Results from the SITS-ISTR
Authors: Lundström Erik , Zini Andrea , Wahlgren Nils , Ahmed Niaz 
Published: November 2015

ObjectivesTo describe the frequency and outcome of isolated dysphasia among patients treated with intravenous thrombolysis (IVT).DesignPatients registered in the SITS International Stroke Thrombolysis Register (SITS-ISTR).ParticipantsPatients with stroke (N=58 293) treated with IVT between December 2002 and December 2012.SettingA multinational, prospective, observational monitoring register.Main outcome measuresIsolated dysphasia and modified Rankin Scale (mRS).MethodsWe identified patients presenting with isolated dysphasia by reviewing items within the baseline National Institutes of Health Stroke Scale (NIHSS). We performed descriptive statistics for baseline and demographic data, and reported patients’ characteristics, radiological data and changes in their NIHSS score within 7 days and mRS score at 3 months. We also reported corresponding data from the general SITS-ISTR cohort.ResultsWe found isolated dysphasia at baseline in 1.14% (663/58 293) of all patients treated with IVT patients. Patients with isolated dysphasia had a longer onset to treatment time, lower proportion of visible infarctions on admission imaging scan and atrial fibrillation, and were less often classified as having large vessels causing strokes, in comparison with the rest of the SITS-ISTR. Symptomatic intracerebral haemorrhage occurred in 2.3% of patients per SITS-MOST definition and fatal outcome in 5.5%. At 7 days, 50% of patients with isolated dysphasia recovered completely and at 3 months, 86.3% patients were functionally independent (mRS score 0–2), 71.7% had an excellent outcome (mRS score 0–1) and 45.5% had an mRS score of 0.ConclusionsA low proportion of patients with isolated dysphasia are treated with IVT. Half of these patients were fully recovered at 7 days.
Hypoglycaemia monitoring in a medical receiving ward
Authors: Ellis Ryan 
Published: November 2015

AbstractIt has been suggested that current care for diabetes inpatients remains inadequate and that greater attention is required for high quality management. In this project the aspect of hypoglycaemia was studied in a busy medical receiving ward at the Glasgow Royal Infirmary. A large proportion of inpatients have diabetes and episodes of hypoglycaemia experienced by this population can delay discharge and indeed be detrimental to health. Thus it is important from both an organisational and patient perspective to manage this population well. In this project BM machine data was analysed to identify patients who were hypoglycaemic. These patients were then tracked down to study the subsequent management and compared this against recommended guidance. Following this an intervention was made to promote identification, management, documentation, and prevention of hypoglycaemia. This was deliberately a simple intervention involving discussions with staff and provision of basic documented guidance next to every BM machine. In the first phase 17 patients were identified and in a second and third phase 16 patients each time were further identified. Patients in the study were both type 1 and type 2 diabetics. Initial results in phase I were compared to results in phase II and III respectively. This intervention produced significant improvements in management with correct monitoring of low BMs (i.e. upon identification of low BM repeat within 1 hour) improving from 47% to 100% (for Phase II and III). Also, recording of preventative measures of hypoglycaemia improved from 35% to 88% and 94% with an improvement from 24% to 69% and 75% in recording of treatment given if needed. In conclusion, the study successfully demonstrated that simple measures can significantly improve the quality care of inpatient diabetic patients in relation to hypoglycaemia management.
Micro-PIXE elemental mapping for ionome studies of crop plants
Authors: Vogel-Mikuš Katarina , Pongrac Paula , Pelicon Primož 
Published: November 2015

In order to maintain homeostasis and consequent optimal cell functioning and integrity and/or to avoid toxicity, proper allocation of elements at organ, tissue, cellular and subcellular level is needed. Studies of element localization are therefore crucial to reveal the mechanisms of element trafficking and also tolerance and toxicity. Moreover, studies of localization and speciation of trace elements in grains of staple crops are also of high applicative value, allowing one to determine major and trace element concentrations in different grain tissues without possible contamination. In the last decade, a remarkable progress has been made in the development and application of different 2D imaging techniques in complex biological systems, especially in the sense of improved lateral resolution and sensitivity. The superiority of micro-PIXE over other 2D imaging techniques lies in its wide elemental range (from sodium (Na) to uranium (U)), high elemental sensitivity below micron spatial resolution and fully quantitative element concentration analysis. The aim of this review is to summarize the latest development of micro-PIXE for imaging of the distribution of major and trace elements in crop plants with emphasis on sample preparation methodologies and post-imaging analysis. Case studies of element localization in the grains of major crop plants are also presented.