bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inwardly rectifying K+ channels are major contributors to flow‐induced vasodilatation in resistance arteries
Authors: Ahn Sang Joon , Fancher Ibra S. , Bian Jing‐Tan , Zhang Chong Xu , Schwab Sarah , Gaffin Robert , Phillips Shane A. , Levitan Irena 
Published: November 2016

Key points
Endothelial inwardly rectifying K+ (Kir2.1) channels regulate flow‐induced vasodilatation via nitric oxide (NO) in mouse mesenteric resistance arteries.
Deficiency of Kir2.1 channels results in elevated blood pressure and increased vascular resistance.
Flow‐induced vasodilatation in human resistance arteries is also regulated by inwardly rectifying K+ channels.
This study presents the first direct evidence that Kir channels play a critical role in physiological endothelial responses to flow.
AbstractInwardly rectifying K+ (Kir) channels are known to be sensitive to flow, but their role in flow‐induced endothelial responses is not known. The goal of this study is to establish the role of Kir channels in flow‐induced vasodilatation and to provide first insights into the mechanisms responsible for Kir signalling in this process. First, we establish that primary endothelial cells isolated from murine mesenteric arteries express functional Kir2.1 channels sensitive to shear stress. Then, using the Kir2.1+/− heterozygous mouse model, we establish that downregulation of Kir2.1 results in significant decrease in shear‐activated Kir currents and inhibition of endothelium‐dependent flow‐induced vasodilatation (FIV) assayed in pressurized mesenteric arteries pre‐constricted with endothelin‐1. Deficiency in Kir2.1 also results in the loss of flow‐induced phosphorylation of eNOS and Akt, as well as inhibition of NO generation. All the effects are fully rescued by endothelial cell (EC)‐specific overexpression of Kir2.1. A component of FIV that is Kir independent is abrogated by blocking Ca2+‐sensitive K+ channels. Kir2.1 has no effect on endothelium‐independent and K+‐induced vasodilatation in denuded arteries. Kir2.1+/− mice also show increased mean blood pressure measured by carotid artery cannulation and increased microvascular resistance measured using a tail‐cuff. Importantly, blocking Kir channels also inhibits flow‐induced vasodilatation in human subcutaneous adipose microvessels. Endothelial Kir channels contribute to FIV of mouse mesenteric arteries via an NO‐dependent mechanism, whereas Ca2+‐sensitive K+ channels mediate FIV via an NO‐independent pathway. Kir2 channels also regulate vascular resistance and blood pressure. Finally, Kir channels also contribute to FIV in human subcutaneous microvessels.
The formation of peak rings in large impact craters
Authors: Morgan Joanna V. , Gulick Sean P. S. , Bralower Timothy , Chenot Elise , Christeson Gail , Claeys Philippe , Cockell Charles , Collins Gareth S. , Coolen Marco J. L. , Ferrière Ludovic , Gebhardt Catalina , Goto Kazuhisa , Jones Heather , Kring David A. , Le Ber Erwan , Lofi Johanna , Long Xiao , Lowery Christopher , Mellett Claire , Ocampo-Torres Rubén , Osinski Gordon R. , Perez-Cruz Ligia , Pickersgill Annemarie , Poelchau Michael , Rae Auriol , Rasmussen Cornelia , Rebolledo-Vieyra Mario , Riller Ulrich , Sato Honami , Schmitt Douglas R. , Smit Jan , Tikoo Sonia , Tomioka Naotaka , Urrutia-Fucugauchi Jaime , Whalen Michael , Wittmann Axel , Yamaguchi Kosei E. , Zylberman William 
Published: November 2016

Drilling into Chicxulub's formationThe Chicxulub impact crater, known for its link to the demise of the dinosaurs, also provides an opportunity to study rocks from a large impact structure. Large impact craters have “peak rings” that define a complex crater morphology. Morganet al.looked at rocks from a drilling expedition through the peak rings of the Chicxulub impact crater (see the Perspective by Barton). The drill cores have features consistent with a model that postulates that a single over-heightened central peak collapsed into the multiple-peak-ring structure. The validity of this model has implications for far-ranging subjects, from how giant impacts alter the climate on Earth to the morphology of crater-dominated planetary surfaces.Science, this issue p.878; see also p.836
Detection of Clostridium difficile in Feces of Asymptomatic Patients Admitted to the Hospital
Authors: Terveer Elisabeth M. , Crobach Monique J. T. , Sanders Ingrid M. J. G. , Vos Margreet C. , Verduin Cees M. , Kuijper Ed J. 
Published: November 2016

ABSTRACT

Recent evidence shows that patients asymptomatically colonized with
Clostridium difficile
may contribute to the transmission of
C. difficile
in health care facilities. Additionally, these patients may have a higher risk of developing
C. difficile
infection. The aim of this study was to compare a commercially available PCR directed to both toxin A and B (
artus
C. difficile
QS-RGQ kit CE; Qiagen), an enzyme-linked fluorescent assay to glutamate dehydrogenase (GDH ELFA) (Vidas, bioMérieux), and an in-house-developed PCR to
tcdB
, with (toxigenic) culture of
C. difficile
as the gold standard to detect asymptomatic colonization. Test performances were evaluated in a collection of 765 stool samples obtained from asymptomatic patients at admission to the hospital. The
C. difficile
prevalence in this collection was 5.1%, and 3.1% contained toxigenic
C. difficile
. Compared to
C. difficile
culture, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the
C. difficile
GDH ELFA were 87.2%, 91.2%, 34.7%, and 99.3%, respectively. Compared with results of toxigenic culture, the sensitivity, specificity, PPV, and NPV of the commercially available PCR and the in-house PCR were 95.8%, 93.4%, 31.9%, 99.9%, and 87.5%, 98.8%, 70%, and 99.6%, respectively. We conclude that in a low-prevalence setting of asymptomatically colonized patients, both GDH ELFA and a nucleic acid amplification test can be applied as a first screening test, as they both display a high NPV. However, the low PPV of the tests hinders the use of these assays as stand-alone tests.
Progress in Quantitative Viral Load Testing: Variability and Impact of the WHO Quantitative International Standards
Authors: Hayden R. T. , Sun Y. , Tang L. , Procop G. W. , Hillyard D. R. , Pinsky B. A. , Young S. A. , Caliendo A. M. 
Published: November 2016

ABSTRACT

It has been hoped that the recent availability of WHO quantitative standards would improve interlaboratory agreement for viral load testing; however, insufficient data are available to evaluate whether this has been the case. Results from 554 laboratories participating in proficiency testing surveys for quantitative PCR assays of cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), adenovirus (ADV), and human herpesvirus 6 (HHV6) were evaluated to determine overall result variability and then were stratified by assay manufacturer. The impact of calibration to international units/ml (CMV and EBV) on variability was also determined. Viral loads showed a high degree of interlaboratory variability for all tested viruses, with interquartile ranges as high as 1.46 log
10
copies/ml and the overall range for a given sample up to 5.66 log
10
copies/ml. Some improvement in result variability was seen when international units were adopted. This was particularly the case for EBV viral load results. Variability in viral load results remains a challenge across all viruses tested here; introduction of international quantitative standards may help reduce variability and does so more or less markedly for certain viruses.
Coat Protein Regulation by CK2, CPIP, HSP70, and CHIP Is Required for Potato Virus A Replication and Coat Protein Accumulation
Authors: Lõhmus Andres , Hafrén Anders , Mäkinen Kristiina 
Published: November 2016

ABSTRACT

We demonstrate here that both coat protein (CP) phosphorylation by protein kinase CK2 and a chaperone system formed by two heat shock proteins, CP-interacting protein (CPIP) and heat shock protein 70 (HSP70), are essential for potato virus A (PVA; genus
Potyvirus
) replication and that all these host proteins have the capacity to contribute to the level of PVA CP accumulation. An E3 ubiquitin ligase called carboxyl terminus Hsc70-interacting protein (CHIP), which may participate in the CPIP-HSP70-mediated CP degradation, is also needed for robust PVA gene expression. Residue Thr
243
within the CK2 consensus sequence of PVA CP was found to be essential for viral replication and to regulate CP protein stability. Substitution of Thr
243
either with a phosphorylation-mimicking Asp (CP
ADA
) or with a phosphorylation-deficient Ala (CP
AAA
) residue in CP expressed from viral RNA limited PVA gene expression to the level of nonreplicating PVA. We found that both the CP
AAA
mutant and CK2 silencing inhibited, whereas CP
ADA
mutant and overexpression of CK2 increased, PVA translation. From our previous studies, we know that phosphorylation reduces the RNA binding capacity of PVA CP and an excess of CP fully blocks viral RNA translation. Together, these findings suggest that binding by nonphosphorylated PVA CP represses viral RNA translation, involving further CP phosphorylation and CPIP-HSP70 chaperone activities as prerequisites for PVA replication. We propose that this mechanism contributes to shifting potyvirus RNA from translation to replication.

IMPORTANCE
Host protein kinase CK2, two host chaperones, CPIP and HSP70, and viral coat protein (CP) phosphorylation at Thr
243
are needed for potato virus A (PVA) replication. Our results show that nonphosphorylated CP blocks viral translation, likely via binding to viral RNA. We propose that this translational block is needed to allow time and space for the formation of potyviral replication complex around the 3′ end of viral RNA. Progression into replication involves CP regulation by both CK2 phosphorylation and chaperones CPIP and HSP70.
Hepatitis C Virus-Induced Rab32 Aggregation and Its Implications for Virion Assembly
Authors: Pham Tu M. , Tran Si C. , Lim Yun-Sook , Hwang Soon B. 
Published: November 2016

ABSTRACT
Hepatitis C virus (HCV) is highly dependent on cellular factors for viral propagation. Using high-throughput next-generation sequencing, we analyzed the host transcriptomic changes and identified 30 candidate genes which were upregulated in cell culture-grown HCV (HCVcc)-infected cells. Of these candidates, we selected Rab32 for further investigation. Rab32 is a small GTPase that regulates a variety of intracellular membrane-trafficking events in various cell types. In this study, we demonstrated that both mRNA and protein levels of Rab32 were increased in HCV-infected cells. Furthermore, we showed that HCV infection converted the predominantly expressed GTP-bound Rab32 to GDP-bound Rab32, contributing to the aggregation of Rab32 and thus making it less sensitive to cellular degradation machinery. In addition, GDP-bound Rab32 selectively interacted with HCV core protein and deposited core protein into the endoplasmic reticulum (ER)-associated Rab32-derived aggregated structures in the perinuclear region, which were likely to be viral assembly sites. Using RNA interference technology, we demonstrated that Rab32 was required for the assembly step but not for other stages of the HCV life cycle. Taken together, these data suggest that HCV may modulate Rab32 activity to facilitate virion assembly.

IMPORTANCE
Rab32, a member of the Ras superfamily of small GTPases, regulates various intracellular membrane-trafficking events in many cell types. In this study, we showed that HCV infection concomitantly increased Rab32 expression at the transcriptional level and altered the balance between GDP- and GTP-bound Rab32 toward production of Rab32-GDP. GDP-bound Rab32 selectively interacted with HCV core protein and enriched core in the ER-associated Rab32-derived aggregated structures that were probably necessary for viral assembly. Indeed, we showed that Rab32 was specifically required for the assembly of HCV. Collectively, our study identifies that Rab32 is a novel host factor essential for HCV particle assembly.
A Transformation-Defective Polyomavirus Middle T Antigen with a Novel Defect in PI3 Kinase Signaling
Authors: Denis Deborah , Rouleau Cecile , Schaffhausen Brian S. 
Published: November 2016

ABSTRACT

Middle T antigen (MT), the principal oncoprotein of murine polyomavirus, transforms by association with cellular proteins. Protein phosphatase 2A (PP2A), YAP, Src family tyrosine kinases, Shc, phosphatidylinositol 3-kinase (PI3K), and phospholipase C-γ1 (PLCγ1) have all been implicated in MT transformation. Mutant dl1015, with deletion of residues 338 to 347 in the C-terminal region, has been an enigma, because the basis for its transformation defect has not been apparent. This work probes the dl1015 region of MT. Because the region is proline rich, the hypothesis that it targets Src homology domain 3 (SH3) domains was tested, but mutation of the putative SH3 binding motif did not affect transformation. During this work, two point mutants, W348R and E349K, were identified as transformation defective. Extensive analysis of the E349K mutant is described here. Similar to wild-type MT, the E349K mutant associates with PP2A, YAP, tyrosine kinases, Shc, PI3 kinase, and PLCγ1. The E349K mutant was examined to determine the mechanism for its transformation defect. Assays of cell localization and membrane targeting showed no obvious difference in localization. Src association was normal as assayed by
in vitro
kinase and MT phosphopeptide mapping. Shc activation was confirmed by its tyrosine phosphorylation. Association of type 1 PI3K with MT was demonstrated by coimmunoprecipitation, showing both PI3K subunits and
in vitro
activity. Nonetheless, expression of the mutants failed to lead to the activation of two known downstream targets of PI3K, Akt and Rac-1. Strikingly, despite normal association of the E349K mutant with PI3K, cells expressing the mutant failed to elevate phosphatidylinositol (3,4,5)-trisphosphate (PIP3) in mutant-expressing cells. These results indicate a novel unsuspected aspect to PI3K control.

IMPORTANCE
The gene coding for middle T antigen (MT) is the murine polyomavirus oncogene most responsible for tumor formation. Its study has a history of uncovering novel aspects of mammalian cell regulation. The importance of PI3K activity and tyrosine phosphorylation are two examples of insights coming from MT. This study describes new mutants unable to transform like the wild type that point to novel regulation of PI3K signaling. Previous mutants were defective in PI3K because they failed to bind the enzyme and bring the activity to the membrane. These mutants recruit PI3K activity like the wild type, but fail to elevate the cellular level of PIP3, the product used to signal downstream of PI3K. As a result, they fail to activate either Akt or Rac1, explaining the transformation defect.
Identification of Human Anti-HIV gp160 Monoclonal Antibodies That Make Effective Immunotoxins
Authors: Pincus Seth H. , Song Kejing , Maresh Grace A. , Hamer Dean H. , Dimitrov Dimiter S. , Chen Weizao , Zhang Mei-Yun , Ghetie Victor F. , Chan-Hui Po-Ying , Robinson James E. , Vitetta Ellen S. 
Published: November 2016

ABSTRACTThe envelope (Env) glycoprotein of HIV is the only intact viral protein expressed on the surface of both virions and infected cells. Env is the target of neutralizing antibodies (Abs) and has been the subject of intense study in efforts to produce HIV vaccines. Therapeutic anti-Env Abs can also exert antiviral effects via Fc-mediated effector mechanisms or as cytotoxic immunoconjugates, such as immunotoxins (ITs). In the course of screening monoclonal antibodies (MAbs) for their ability to deliver cytotoxic agents to infected or Env-transfected cells, we noted disparities in their functional activities. Different MAbs showed diverse functions that did not correlate with each other. For example, MAbs against the external loop region of gp41 made the most effective ITs against infected cells but did not neutralize virus and bound only moderately to the same cells that they killed so effectively when they were used in ITs. There were also differences in IT-mediated killing among transfected and infected cell lines that were unrelated to the binding of the MAb to the target cells. Our studies of a well-characterized antigen demonstrate that MAbs against different epitopes have different functional activities and that the binding of one MAb can influence the interaction of other MAbs that bind elsewhere on the antigen. These results have implications for the use of MAbs and ITs to kill HIV-infected cells and eradicate persistent reservoirs of HIV infection.IMPORTANCEThere is increased interest in using antibodies to treat and cure HIV infection. Antibodies can neutralize free virus and kill cells already carrying the virus. The virus envelope (Env) is the only HIV protein expressed on the surfaces of virions and infected cells. In this study, we examined a panel of human anti-Env antibodies for their ability to deliver cell-killing toxins to HIV-infected cells and to perform other antiviral functions. The ability of an antibody to make an effective immunotoxin could not be predicted from its other functional characteristics, such as its neutralizing activity. Anti-HIV immunotoxins could be used to eliminate virus reservoirs that persist despite effective antiretroviral therapy.
Association of psychological variables and outcome in tendinopathy: a systematic review
Authors: Mallows Adrian , Debenham James , Walker Tom , Littlewood Chris 
Published: November 2016

ObjectiveFear, anxiety, depression, distress and catastrophisation are all factors known to affect pain and disability levels. To date, the association of such psychological factors has yet to be established in tendinopathy. Therefore, the purpose of this paper was to determine if psychological variables are associated with tendinopathy and whether any such variables may be associated with pain and disability outcomes in conservative management of tendinopathy.DesignA systematic review was undertaken and included studies were appraised for risk of bias using the Newcastle-Ottawa Scale. Owing to heterogeneity of studies, a qualitative synthesis was undertaken.Data sourcesAn electronic search of MEDLINE, CiNAHL, SPORTDiscus, PsycINFO, EMBASE and PsycARTICLES was undertaken from their inception to April 2016.Eligibility criteria for selecting studiesAny study design that incorporated psychological measures and clinical outcomes using participants with tendinopathy.ResultsTen articles describing nine studies and 1108 participants were included. Conflicting evidence exists regarding the association of anxiety, depression and lateral epicondylalgia (LE). Strong evidence suggests LE is not associated with kinesiophobia. Moderate evidence links catastrophisation and distress with LE. Moderate evidence suggests distress is not associated with rotator cuff tendinopathy, but kinesiophobia and catastrophisation are. Limited evidence suggests patellar tendinopathy is not associated with anxiety or depression and kinesiophobia may be linked with suboptimal outcomes in Achilles tendinopathy.Summary/conclusionsTendinopathy requires an individualised approach to management. Clinicians should consider using validated screening tools for the presence of psychological variables as a part of their holistic management.
Perceived barriers to accessing mental health services among black and minority ethnic (BME) communities: a qualitative study in Southeast England
Authors: Memon Anjum , Taylor Katie , Mohebati Lisa M , Sundin Josefin , Cooper Max , Scanlon Thomas , de Visser Richard 
Published: November 2016

ObjectiveIn most developed countries, substantial disparities exist in access to mental health services for black and minority ethnic (BME) populations. We sought to determine perceived barriers to accessing mental health services among people from these backgrounds to inform the development of effective and culturally acceptable services to improve equity in healthcare.Design and settingQualitative study in Southeast England.Participants26 adults from BME backgrounds (13 men, 13 women; aged >18 years) were recruited to 2 focus groups. Participants were identified through the registers of the Black and Minority Ethnic Community Partnership centre and by visits to local community gatherings and were invited to take part by community development workers. Thematic analysis was conducted to identify key themes about perceived barriers to accessing mental health services.ResultsParticipants identified 2 broad themes that influenced access to mental health services. First, personal and environmental factors included inability to recognise and accept mental health problems, positive impact of social networks, reluctance to discuss psychological distress and seek help among men, cultural identity, negative perception of and social stigma against mental health and financial factors. Second, factors affecting the relationship between service user and healthcare provider included the impact of long waiting times for initial assessment, language barriers, poor communication between service users and providers, inadequate recognition or response to mental health needs, imbalance of power and authority between service users and providers, cultural naivety, insensitivity and discrimination towards the needs of BME service users and lack of awareness of different services among service users and providers.ConclusionsPeople from BME backgrounds require considerable mental health literacy and practical support to raise awareness of mental health conditions and combat stigma. There is a need for improving information about services and access pathways. Healthcare providers need relevant training and support in developing effective communication strategies to deliver individually tailored and culturally sensitive care. Improved engagement with people from BME backgrounds in the development and delivery of culturally appropriate mental health services could facilitate better understanding of mental health conditions and improve access.