bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of the FAST Workstation as an Objective Evaluator of Hand-Tied Surgical Knots
Authors: Schneider Andrew M. , Pedowitz Robert A. , Evans Douglas A. 
Published: October 2018

Introduction
Hand-tying surgical knots is an important skill that is applicable across all surgical disciplines. Knot quality is traditionally assessed in the operating room by visual inspection, which is inherently subjective. With the increasing prevalence of simulation training, surgical trainees having access to objective feedback of their knot-tying skills are paramount for skill evaluation. Our study aimed to validate a mechanical suture loop security tester as an objective evaluation method of hand-tied surgical knot quality.

Methods
Seventy-three subjects were recruited and categorized based on surgical expertise into one of the following three groups: medical students, surgical residents, and attending surgeons. They hand-tied five surgical knots consecutively using 0 Vicryl sutures. The knots were tested using the suture loop security workstation with 10 lbs of linear force for 10 seconds. Success of the suture loop was set at less than 3 mm of loop expansion. This protocol was based on previous research showing that 3 mm of loop expansion would represent clinical failure of the knot in vivo.

Results
The students, residents, and attending surgeons tied a median of two, three, and four successful knots, respectively. Post hoc pairwise comparisons revealed that residents tied more successful knots than students (p < 0.001), and attending physicians tied more successful knots than students (p < 0.001). However, there was no statistically significant difference in the number of successes between residents and attending physicians (p = 0.24).

Conclusions
Using the mechanical loop security workstation demonstrates construct validity as a reliable objective evaluation tool of hand-tied surgical knots.
Cooperation of partially-transformed clones: an invisible force behind the early stages of carcinogenesis
Authors: Esposito Alessandro 
Published: October 2018

AbstractMost tumours exhibit significant heterogeneity and are best described as communities of cellular populations competing for resources. Growing experimental evidence also suggests, however, that cooperation between cancer clones is important as well for the maintenance of tumour heterogeneity and tumour progression. However, a role for cell communication during the earliest steps in oncogenesis is not well characterised despite its vital importance in normal tissue and clinically manifest tumours. By modelling the interaction between the mutational process and cell-to-cell communication in three-dimensional tissue architecture, we show that non-cell-autonomous mechanisms of carcinogenesis could support and accelerate pre-cancerous clonal expansion through the cooperation of different, non- or partially- transformed mutants. We predict the existence of a ‘cell-autonomous time-horizon’, a time before which cooperation between cell-to-cell communication and DNA mutations might be one of the most fundamental forces shaping the early stages of oncogenesis. The understanding of this process could shed new light on the mechanisms leading to clinically manifest cancers.
FGFR4 phosphorylates MST1 to confer breast cancer cells resistance to MST1/2-dependent apoptosis
Authors: Turunen S. Pauliina , von Nandelstadh Pernilla , Öhman Tiina , Gucciardo Erika , Martins Beatriz , Rantanen Ville , Li Huini , Höpfner Katrin , Varjosalo Markku , Lehti Kaisa 
Published: October 2018

AbstractCancer cells balance with the equilibrium of cell death and growth to expand and metastasize. The activity of mammalian sterile20-like kinases MST1/2 has been linked to apoptosis and tumor suppression via YAP/Hippo pathway dependent and independent mechanisms. With a kinase substrate screen we identified here MST1 and MST2 among the top substrates for fibroblast growth factor receptor 4 (FGFR4). In COS-1 cells, MST1 was phosphorylated at Y433 residue in an FGFR4 kinase activity-dependent manner, as assessed by mass spectrometry. Blockade of this phosphorylation by Y433F mutation induced MST1 activation, as reflected by increased autophosphorylation at T183 in FGFR4 overexpressing MDA-MB-231 cells. Importantly, the specific short-term inhibition or knockdown of FGFR4 also led to MST1/2 activation in conjunction with induction of MST1/2-dependent apoptosis in an endogenous model of HER2+breast cancer cells. Moreover, FGFR4 knockdown increased the level of active nuclear MST1 coincidentally with cell polarization and membrane-association of YAP in three-dimensional breast cancer cell spheres. Consistently, FGFR4 overexpression correlated with reduced Hippo pathway-mediated, nuclear translocation-inhibiting YAP phosphorylation, and abysmal HER2+breast carcinoma patient outcome in TCGA cohort. Our results reveal a novel mechanism for FGFR4 oncogenic activity via suppression of the stress-associated MST1/2-dependent apoptosis machinery in the tumor cells with prominent HER/ERBB signaling driven proliferation.
Length asymmetry and heterozygosity strongly influences the evolution of poly-A microsatellites at meiotic recombination hotspots
Authors: Heissl Angelika , Betancourt Andrea J. , Hermann Philipp , Povysil Gundula , Arbeithuber Barbara , Futschik Andreas , Ebner Thomas , Tiemann-Boege Irene 
Published: October 2018

AbstractMeiotic recombination has strong, but poorly understood, effects on short tandem repeat (STR) instability. Here, we screened thousands of single recombinant products to characterize the transmission and evolution of polymorphic poly-A repeats at a human recombination hotspot. We show that length asymmetry between heterozygous poly-As plays a key role in the recombination outcome and their transmission. A difference of 10 As (9A/19A) elevates the frequency of non-crossovers, complex recombination products, and long conversion tracts. Moreover, asymmetry also influences STR transmission: the shorter allele is transmitted more frequently (deletion bias) at the asymmetric STR (9A/19A), while the longer allele is favored (insertion bias) at the site with a small STR length difference (6A/7A). Finally, potentially due to this opposing insertion/deletion driven evolution, we find that poly-As are enriched at human recombination hotspots predominantly with short poly-As, possibly influencing open chromatin regions that in turn can activate hotspots.
Multiple modes of PRC2 inhibition elicit global chromatin alterations in H3K27M pediatric glioma
Authors: Stafford James M. , Lee Chul-Hwan , Voigt Philipp , Descostes Nicolas , Saldaña-Meyer Ricardo , Yu Jia-Ray , Leroy Gary , Oksuz Ozgur , Chapman Jessica R. , Suarez Fernando , Modrek Aram S. , Bayin N. Sumru , Placantonakis Dimitris G. , Karajannis Matthias A. , Snuder Matija , Ueberheide Beatrix , Reinberg Danny 
Published: October 2018

ABSTRACTA methionine substitution at lysine 27 on histone H3 variants (H3K27M) characterizes ~80% of diffuse intrinsic pontine gliomas (DIPG) and inhibits PRC2 in a dominant negative fashion. Yet, the mechanisms for this inhibition and abnormal epigenomic landscape have not been resolved. Using quantitative proteomics, we discovered that robust PRC2 inhibition requires levels of H3K27M greatly exceeding those of PRC2, seen in DIPG. While PRC2 inhibition requires interaction with H3K27M, we found this interaction on chromatin is transient with PRC2 largely being released from H3K27M. Unexpectedly, inhibition persisted even after PRC2 dissociated from H3K27M-chromatin suggesting a lasting impact on PRC2. Furthermore, allosterically activated PRC2 is particularly sensitive to K27M leading to a failure to spread H3K27me3 at distinct foci. In turn, levels of Polycomb antagonists such as H3K36me2 are elevated suggesting a more global, downstream effect on the epigenome. Together, these findings reveal the conditions required for H3K27M-mediated PRC2 inhibition and reconcile seemingly paradoxical effects of H3K27M on PRC2 recruitment and activity.
CSNAP, the smallest CSN subunit, modulates proteostasis through cullin-RING ubiquitin ligases
Authors: Füzesi-Levi Maria G. , Enchev Radoslav Ivanov , Ben-Nissan Gili , Levin Yishai , Kupervaser Meital , Friedlander Gilgi , Salame Tomer Meir , Nevo Reinat , Peter Matthias , Sharon Michal 
Published: October 2018

AbstractThe cullin-RING ubiquitin E3 ligase (CRL) family consists of ~250 complexes that catalyze ubiquitylation of proteins to achieve cellular regulation. All CRLs are inhibited by the COP9 signalosome complex (CSN) through both enzymatic (deneddylation) and non-enzymatic (steric) mechanisms. The relative contribution of these two mechanisms is unclear. Here, we decouple the mechanisms using CSNAP, the recently discovered ninth subunit of the CSN. We find that CSNAP reduces the affinity of CSN toward CRL complexes. Removing CSNAP does not affect deneddylation, but leads to global effects on the CRL, causing altered reproductive capacity, suppressed DNA damage response, decreased viability, and delayed cell cycle progression. Thus, although CSNAP is only 2% of the CSN mass, it plays a critical role in the steric regulation of CRLs by the CSN.
Dorsal Hippocampus Not Always Necessary in a Radial Arm Maze Delayed Win-shift Task
Authors: Layfield Dylan , Sidell Nathan , Abdullahi Afnan , Newman Ehren L. 
Published: October 2018

AbstractSpatial working memory is important for foraging and navigating the environment. However, its neural underpinnings remain poorly understood. The hippocampus, known for its spatial coding and involvement in spatial memory, is widely understood to be necessary for spatial working memory when retention intervals increase beyond seconds into minutes. Here, we describe new evidence that the dorsal hippocampus is not always necessary for spatial working memory for retention intervals of 8 minutes. Rats were trained to perform a delayed spatial win shift radial arm maze task (DSWS) with an 8-minute delay between study and test phases. We then tested whether bilateral inactivation of the dorsal hippocampus between the study and test phases impaired behavioral performance at test. Inactivation was achieved through a bilateral infusion of lidocaine. Performance following lidocaine was compared to control trials, in which, sterile phosphate buffered saline (PBS) was infused. Test performance did not differ between the lidocaine and PBS conditions, remaining high in each. To explore the possibility that this insensitivity to inactivation was a result of overtraining, a second cohort of animals received substantially less training prior to the infusions. In this second cohort, lidocaine infusions did significantly impair task performance. These data indicate that successful performance of a spatial win-shift task on the 8-arm maze need not always be hippocampally dependent.
Probing the flavin transfer mechanism in alkanesulfonate monooxygenase system
Authors: Dayal PV , Ellis HR 
Published: October 2018

AbstractBacteria acquire sulfur through the sulfur assimilation pathway, but under sulfur limiting conditions bacteria must acquire sulfur from alternative sources. The alkanesulfonate monooxygenase enzymes are expressed under sulfur-limiting conditions, and catalyze the desulfonation of wide-range of alkanesulfonate substrates. The SsuE enzyme is an NADPH-dependent FMN reductase that provides reduced flavin to the SsuD monooxygenase. The mechanism for the transfer of reduced flavin in flavin dependent two-component systems occurs either by free-diffusion or channeling. Previous studies have shown the presence of protein-protein interactions between SsuE and SsuD, but the identification of putative interaction sights have not been investigated. Current studies utilized HDX-MS to identify protective sites on SsuE and SsuD. A conserved α-helix on SsuD showed a decrease in percent deuteration when SsuE was included in the reaction. This suggests the role of α-helix in promoting protein-protein interactions. Specific SsuD variants were generated in order to investigate the role of these residues in protein-protein interactions and catalysis. Variant containing substitutions at the charged residues showed a six-fold decrease in the activity, while a deletion variant of SsuD lacking the α-helix showed no activity when compared to wild-type SsuD. In addition, there was no protein-protein interactions identified between SsuE and his-tagged SsuD variants in pull-down assays, which correlated with an increase in theKdvalue. The α-helix is located right next to a dynamic loop region, positioned at the entrance of the active site. The putative interaction site and dynamic loop region located so close to the active site of SsuD suggests the importance of this region in the SsuD catalysis. Stopped-flow studies were performed to analyze the lag-phase which signifies the stabilization and transfer of reduced flavin from SsuE to SsuD. The SsuD variants showed a decrease in lag-phase, which could be because of a downturn in flavin transfer. A competitive assay was devised to evaluate the mechanism of flavin transfer in the alkanesulfonate monooxygenase system. A variant of SsuE was generated which interacted with SsuD, but was not able to reduce FMN. Assays that included varying concentrations of Y118A SsuE and wild-type SsuE in the coupled assays showed a decrease in the desulfonation activity of SsuD. The decrease in activity could be by virtue of Y118A SsuE competing with the wild-type SsuE for the putative docking site on SsuD. These studies define the importance of protein-protein interactions for the efficient transfer of reduced flavin from SsuE to SsuD leading to the desulfonation of alkanesulfonates.
Phosphorylation of the α2 glycine receptor induces an extracellular conformational change and slows the rise and decay rates of glycinergic synaptic currents
Authors: Islam Sharifun , Chen Xiumin , Estrada-Mondragon Argel , Lynch Joseph. W. 
Published: October 2018

AbstractThe α2 glycine receptor (GlyR) is a pentameric ligand-gated anion channel that plays a key role in cortical interneuron migration and in the differentiation of cortical progenitor cells into functional neurons. It also mediates tonic inhibitory chloride currents in adult forebrain neurons. Disruption of α2 GlyR gene expression or receptor function results in the aberrant functioning of neuronal circuits which contributes to the pathophysiology of schizophrenia, autism and epilepsy. This implicates the α2 GlyR as a possible therapeutic target for a range of neurological disorders. However, despite its therapeutic potential, little is known about the mechanisms by which α2 GlyRs are functionally modulated. To address this, we investigated whether the α2 GlyR is modulated by phosphorylation at a serine residue (S341) within the same PKA consensus sequence (R-E-S-R) that houses the α3 GlyR S346 residue that is known to be phosphorylated by PKA. Resolving this question might uncover a novel means of physiologically, pathologically or therapeutically modulating α2 GlyRs. We show using voltage-clamp fluorometry that forskolin-induced phosphorylation of S341 induces a conformational change in the glycine binding site. We also employed glycinergic artificial synapses to demonstrate that the S341E phospho-mimetic mutation slows the rise and decay rates of α2-mediated glycinergic inhibitory postsynaptic currents. These results suggest that PKA phosphorylation alters the structural and functional properties of the α2 GlyR. This information may help to identify new mechanisms by which α2 GlyRs may be pathologically modified or therapeutically targeted for the treatment of neurological disorders.
Different temporal windows for contextual fear memory destabilisation in the amygdala and hippocampus
Authors: Lee Jonathan L. C. , Amorim Felippe E. , Cassini Lindsey F. , Amaral Olavo B. 
Published: October 2018

AbstractReconsolidation is a process in which re-exposure to a reminder causes a previously acquired memory to undergo a process of destabilisation followed by subsequent restabilisation. Different molecular mechanisms have been postulated for destabilisation in the amygdala and hippocampus, including CB1 receptor activation, protein degradation and AMPA receptor exchange; however, most of the amygdala studies have used pre-re-exposure interventions, while those in the hippocampus have performed them after re-exposure. To test whether the temporal window for destabilisation is similar across both structures, we trained Lister Hooded rats in a contextual fear conditioning task, and 1 day later performed memory re-exposure followed by injection of either the NMDA antagonist MK-801 (0.1 mg/kg) or saline in order to block reconsolidation. In parallel, we also performed local injections of either the CB1 antagonist SR141716A or its vehicle in the hippocampus or in the amygdala, either immediately before or immediately after reactivation. Infusion of SR141716A in the hippocampus prevented the reconsolidation-blocking effect of MK-801 when performed after re-exposure, but not before it. In the amygdala, meanwhile, pre-reexposure infusions of SR141716A impaired reconsolidation blockade by MK-801, although the time-dependency of this effect was not as clear as in the hippocampus. Our results suggest the temporal windows for CB1-receptor-mediated memory destabilisation during reconsolidation vary between brain structures. Whether this reflects different time windows for engagement of these structures or different roles played by CB1 receptors in destabilisation across structures remains an open question for future studies.
Hfq-assisted RsmA regulation is central to Pseudomonas aeruginosa biofilm polysaccharide PEL expression
Authors: Irie Yasuhiko , Murina Victoriia , Hauryliuk Vasili , Shingler Victoria 
Published: October 2018

ABSTRACTExpression of biofilm-associated genes is controlled by multiple regulatory elements, allowing bacteria to appropriately switch between sessile and motile lifestyles. In Pseudomonas aeruginosa, the post-transcriptional regulator RsmA has been implicated in the control of various genes including those related to biofilms, but much of the evidence for these links is limited to transcriptomic and phenotypic studies. RsmA binds to target mRNAs to modulate translation by affecting ribosomal access and/or mRNA stability. Here we trace a global regulatory role of RsmA to the inhibition of Vfr – a transcription factor that controls a transcriptional regulator FleQ. FleQ directly controls biofilm-associated genes that encode the PEL polysaccharide biosynthesis machinery. Furthermore, we show that RsmA cannot bind vfr mRNA alone, but requires the RNA chaperone protein Hfq. This is the first example where a RsmA protein family member is demonstrated to require another protein for RNA binding.
The human cytomegalovirus G-protein coupled receptor US28 promotes latency by attenuating c-fos
Authors: Krishna Benjamin A. , Humby Monica S. , Miller William E. , O’Connor Christine M. 
Published: October 2018

AbstractHuman cytomegalovirus (HCMV) is a ubiquitous pathogen that undergoes latency in cells of the hematopoietic compartment, though the mechanisms underlying establishment and maintenance of latency remain elusive. We previously reported that the HCMV-encoded G-protein coupled receptor (GPCR) homolog,US28is required for successful latent infection. We now show that US28 protein (pUS28) providedin transcomplements the US28Δ lytic phenotype in myeloid cells, suggesting that sustained US28 expression is necessary for long-term latency. Furthermore, expression of pUS28 at the time of infection represses transcription from the major immediate early promoter (MIEP) within 24 hours. However, this repression is only maintained in the presence of continual pUS28 expression providedin trans. Our data also reveal that pUS28-mediated signaling attenuates both expression and phosphorylation of cellular fos (c-fos), an AP-1 transcription factor subunit, to repress MIEP-driven transcription. AP-1 binds to the MIEP and promotes lytic replication, and in line with this, we find that US28Δ infection results in an increase in AP-1 binding to the MIEP, compared to wild type latent infection. Pharmacological inhibition of c-fos represses the MIEP during US28Δ infection to similar levels we observe during wild type latent infection. Together, our data reveal that US28 is required for both establishment and long-term maintenance of HCMV latency, which is modulated, at least in part, by repressing functional AP-1 binding to the MIEP.Significance StatementHuman cytomegalovirus (HCMV) is a wise-spread pathogen that remains with an individual for life in a quiescent/latent state, posing little threat to an otherwise healthy person. However, when an individual’s immune system is severely compromised, HCMV can reactivate to its active/lytic state, resulting in viral spread and disease that is often fatal. The biological mechanisms underlying HCMV latency and reactivation remain poorly understood. Herein we show that the viral-encoded G-protein coupled receptor (GPCR)US28aids in the establishment and the maintenance of viral latency. Furthermore, we find that US28 modulates host cell proteins to suppress viral processes associated with active/lytic replication, thereby promoting latent infection. This work provides mechanism by which HCMV modulates the host cell environment to its advantage.
Domain-specific and nonspecific outcomes of work-family interface
Authors: Bhalla Abha , Kang Lakhwinder Singh 
Published: October 2018

Purpose
The purpose of this paper is to examine the pattern of work-family interface outcomes by empirically testing work-family conflict and facilitation bidirectional dimensions simultaneously in relation to domains-specific (job and family) and domain nonspecific (life) satisfactions. In addition, the indirect effects of work-family interface dimensions on life satisfaction (LS), mediated through both domain-specific satisfactions are also examined to understand which domain satisfaction elicits major impact on LS.

Design/methodology/approach
Structural equation modeling analysis was conducted on questionnaire data obtained from 212 fulltime journalists working in top ten dailies of Punjab, India. Parallel multiple mediated regression was used to estimate specific indirect effects caused by each of the two parallel mediators (job satisfaction (JS) and family satisfaction (FS)).

Findings
Results illustrate that both dimensions of work-family conflict strongly decreased satisfaction of an originating domain than satisfaction of the receiving domain while both dimensions of work-family facilitation increased satisfaction of both the domains on equal basis. Results further reveal that the effect of work-family conflict and facilitation dimensions on LS is indirect rather than direct. On comparison of specific indirect effects results demonstrate that only originating domain satisfaction act as a mediator to work-family conflict and LS relationship, while both JS and FS act as mediators to work-family facilitation and LS relationship.

Practical implications
Media organizations can offer interventions like family friendly policies, overtime pay, more autonomy, work rewards and skill variety, so that employees’ workplace resource reservoir can be strongly built up to meet future work and family demands. In this way, positive intrusion from work-to-family takes place, which leads to more JS and FS and in turn increased overall LS.

Originality/value
The study removes inconsistency regarding pattern of work-family conflict and facilitation outcomes by testing a comprehensive model that integrates originating domain, receiving-domain and domain-nonspecific outcomes.