Intersectin associates with synapsin and regulates its nanoscale localization and function.

Neurotransmission is mediated by the exocytic release of neurotransmitters from readily releasable synaptic vesicles (SVs) at the active zone. To sustain neurotransmission during periods of elevated activity, release-ready vesicles need to be replenished from the reserve pool of SVs. The SV-associated synapsins are crucial for maintaining this reserve pool and regulate the mobilization of reserve pool SVs. How replenishment of release-ready SVs from the reserve pool is regulated and which other factors cooperate with synapsins in this process is unknown. Here we identify the endocytic multidomain scaffold protein intersectin as an important regulator of SV replenishment at hippocampal synapses. We found that intersectin directly associates with synapsin I through its Src-homology 3 A domain, and this association is regulated by an intramolecular switch within intersectin 1. Deletion of intersectin 1/2 in mice alters the presynaptic nanoscale distribution of synapsin I and causes defects in sustained neurotransmission due to defective SV replenishment. These phenotypes were rescued by wild-type intersectin 1 but not by a locked mutant of intersectin 1. Our data reveal intersectin as an autoinhibited scaffold that serves as a molecular linker between the synapsin-dependent reserve pool and the presynaptic endocytosis machinery

Constraining parameter space in type-II two-Higgs doublet model in light of a 126 GeV Higgs boson

We explore the implications of a 126 GeV Higgs boson indicated by the recent LHC results for two-Higgs doublet model (2HDM). Identifying the 126 GeV Higgs boson as either the lighter or heavier of CP even neutral Higgs bosons in 2HDM, we examine how the masses of Higgs fields and mixing parameters can be constrained by the theoretical conditions and experimental constraints. The theoretical conditions taken into account are the vacuum stability, perturbativity and unitarity required to be satisfied up to a cut-off scale. We also show how bounds on the masses of Higgs bosons and mixing parameters depend on the cut-off scale. In addition, we investigate whether the allowed regions of parameter space can accommodate particularly the enhanced di-photon signals, ZZ* and WW* decay modes of the Higgs boson, and examine the prediction of the signal strength of Z{\gamma} decay mode for the allowed regions of the parameter space.Comment: To be published in JHEP, 20 pages, 11 figures, Figures and results are updated for the recent LHC result

Two Distinct Coagulase-Dependent Barriers Protect Staphylococcus aureus from Neutrophils in a Three Dimensional in vitro Infection Model

Staphylococcus aureus is a pyogenic abscess-forming facultative pathogenic microorganism expressing a large set of virulence-associated factors. Among these, secreted proteins with binding capacity to plasma proteins (e.g. fibrinogen binding proteins Eap and Emp) and prothrombin activators such as Coagulase (Coa) and vWbp are involved in abscess formation. By using a three-dimensional collagen gel (3D-CoG) supplemented with fibrinogen (Fib) we studied the growth behavior of S. aureus strain Newman and a set of mutants as well as their interaction with mouse neutrophils by real-time confocal microscopy. In 3D-CoG/Fib, S. aureus forms microcolonies which are surrounded by an inner pseudocapsule and an extended outer dense microcolony-associated meshwork (MAM) containing fibrin. Coa is involved in formation of the pseudocapsule whereas MAM formation depends on vWbp. Moreover, agr-dependent dispersal of late stage microcolonies could be observed. Furthermore, we demonstrate that the pseudocapsule and the MAM act as mechanical barriers against neutrophils attracted to the microcolony. The thrombin inhibitor argatroban is able to prevent formation of both pseudocapsule and MAM and supports access of neutrophils to staphylococci. Taken together, this model can simulate specific stages of S. aureus abscess formation by temporal dissection of bacterial growth and recruitment of immune cells. It can complement established animal infection models in the development of new treatment options

Fluid shear stress modulation of hepatocyte like cell function

Freshly isolated human adult hepatocytes are considered to be the gold standard tool for in vitro studies. However, primary hepatocyte scarcity, cell cycle arrest and the rapid loss of cell phenotype limit their widespread deployment. Human embryonic stem cells and induced pluripotent stem cells provide renewable sources of hepatocyte-like cells (HLCs). Despite the use of various differentiation methodologies, HLCs like primary human hepatocytes exhibit unstable phenotype in culture. It has been shown that the functional capacity can be improved by adding back elements of human physiology, such as cell co-culture or through the use of natural and/or synthetic surfaces. In this study, the effect of fluid shear stress on HLC performance was investigated. We studied two important liver functions, cytochrome P450 drug metabolism and serum protein secretion, in static cultures and those exposed to fluid shear stress. Our study demonstrates that fluid shear stress improved Cyp1A2 activity by approximately fivefold. This was paralleled by an approximate ninefold increase in sensitivity to a drug, primarily metabolised by Cyp2D6. In addition to metabolic capacity, fluid shear stress also improved hepatocyte phenotype with an approximate fourfold reduction in the secretion of a foetal marker, alpha-fetoprotein. We believe these studies highlight the importance of introducing physiologic cues in cell-based models to improve somatic cell phenotype

A cross-sectional survey of the prevalence of environmental tobacco smoke preventive care provision by child health services in Australia

Background: Despite the need for a reduction in levels of childhood exposure to environmental tobacco smoke (ETS) being a recognised public health goal, the delivery of ETS preventive care in child health service settings remains a largely unstudied area. The purpose of this study was to determine the prevalence of ETS preventive care in child health services; differences in the provision of care by type of service; the prevalence of strategies to support such care; and the association between care support strategies and care provision. Method: One-hundred and fifty-one (83%) child health service managers within New South Wales, Australia completed a questionnaire in 2002 regarding the: assessment of parental smoking and child ETS exposure; the provision of parental smoking cessation and ETS-exposure reduction advice; and strategies used to support the provision of such care. Child health services were categorised based on their size and case-mix, and a chi-square analysis was performed to compare the prevalence of ETS risk assessment and ETS prevention advice between service types. Logistic regression analysis was used to examine associations between the existence of care support strategies and the provision of ETS risk assessment and ETS exposure prevention advice. Results: A significant proportion of services reported that they did not assess parental smoking status (26%), and reported that they did not assess the ETS exposure (78%) of any child. Forty four percent of services reported that they did not provide smoking cessation advice and 20% reported they did not provide ETS exposure prevention advice. Community based child and family health services reported a greater prevalence of ETS preventive care compared to other hospital based units. Less than half of the services reported having strategies to support the provision of ETS preventive care. The existence of such support strategies was associated with greater odds of care provision. Conclusions: The existence of major gaps in recommended ETS preventive care provision suggests a need for additional initiatives to increase such care delivery. The low prevalence of strategies that support such care delivery suggests a potential avenue to achieve this outcome

The Spin Structure of the Nucleon

We present an overview of recent experimental and theoretical advances in our understanding of the spin structure of protons and neutrons.Comment: 84 pages, 29 figure

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Colorectal cancer health services research study protocol: the CCR-CARESS observational prospective cohort project

BACKGROUND: Colorectal cancers are one of the most common forms of malignancy worldwide. But two significant areas of research less studied deserve attention: health services use and development of patient stratification risk tools for these patients. METHODS:DESIGN: a prospective multicenter cohort study with a follow up period of up to 5 years after surgical intervention. Participant centers: 22 hospitals representing six autonomous communities of Spain. Participants/Study population: Patients diagnosed with colorectal cancer that have undergone surgical intervention and have consented to participate in the study between June 2010 and December 2012. Variables collected include pre-intervention background, sociodemographic parameters, hospital admission records, biological and clinical parameters, treatment information, and outcomes up to 5 years after surgical intervention. Patients completed the following questionnaires prior to surgery and in the follow up period: EuroQol-5D, EORTC QLQ-C30 (The European Organization for Research and Treatment of Cancer quality of life questionnaire) and QLQ-CR29 (module for colorectal cancer), the Duke Functional Social Support Questionnaire, the Hospital Anxiety and Depression Scale, and the Barthel Index. The main endpoints of the study are mortality, tumor recurrence, major complications, readmissions, and changes in health-related quality of life at 30 days and at 1, 2, 3 and 5 years after surgical intervention. STATISTICAL ANALYSIS: In relation to the different endpoints, predictive models will be used by means of multivariate logistic models, Cox or linear mixed-effects regression models. Simulation models for the prediction of discrete events in the long term will also be used, and an economic evaluation of different treatment strategies will be performed through the use of generalized linear models. DISCUSSION: The identification of potential risk factors for adverse events may help clinicians in the clinical decision making process. Also, the follow up by 5 years of this large cohort of patients may provide useful information to answer different health services research questions

Proliferating versus differentiating stem and cancer cells exhibit distinct midbody-release behaviour

The central portion of the midbody, a cytoplasmic bridge between nascent daughter cells at the end of cell division, has generally been thought to be retained by one of the daughter cells, but has, recently, also been shown to be released into the extracellular space. The significance of midbody-retention versus -release is unknown. Here we show, by quantitatively analysing midbody-fate in various cell lines under different growth conditions, that the extent of midbody-release is significantly greater in stem cells than cancer-derived cells. Induction of cell differentiation is accompanied by an increase in midbody-release. Knockdown of the endosomal sorting complex required for transport family members, Alix and tumour-suppressor gene 101, or of their interaction partner, centrosomal protein 55, impairs midbody-release, suggesting mechanistic similarities to abscission. Cells with such impaired midbody-release exhibit enhanced responsiveness to a differentiation stimulus. Taken together, midbody-release emerges as a characteristic feature of cells capable of differentiation