1,267 research outputs found
Vangl2-Regulated Polarisation of Second Heart Field-Derived Cells Is Required for Outflow Tract Lengthening during Cardiac Development.
Planar cell polarity (PCP) is the mechanism by which cells orient themselves in the plane of an epithelium or during directed cell migration, and is regulated by a highly conserved signalling pathway. Mutations in the PCP gene Vangl2, as well as in other key components of the pathway, cause a spectrum of cardiac outflow tract defects. However, it is unclear why cells within the mesodermal heart tissue require PCP signalling. Using a new conditionally floxed allele we show that Vangl2 is required solely within the second heart field (SHF) to direct normal outflow tract lengthening, a process that is required for septation and normal alignment of the aorta and pulmonary trunk with the ventricular chambers. Analysis of a range of markers of polarised epithelial tissues showed that in the normal heart, undifferentiated SHF cells move from the dorsal pericardial wall into the distal outflow tract where they acquire an epithelial phenotype, before moving proximally where they differentiate into cardiomyocytes. Thus there is a transition zone in the distal outflow tract where SHF cells become more polarised, turn off progenitor markers and start to differentiate to cardiomyocytes. Membrane-bound Vangl2 marks the proximal extent of this transition zone and in the absence of Vangl2, the SHF-derived cells are abnormally polarised and disorganised. The consequent thickening, rather than lengthening, of the outflow wall leads to a shortened outflow tract. Premature down regulation of the SHF-progenitor marker Isl1 in the mutants, and accompanied premature differentiation to cardiomyocytes, suggests that the organisation of the cells within the transition zone is important for maintaining the undifferentiated phenotype. Thus, Vangl2-regulated polarisation and subsequent acquisition of an epithelial phenotype is essential to lengthen the tubular outflow vessel, a process that is essential for on-going cardiac morphogenesis
Preliminary analysis of immune activation in early onset type 2 diabetes
Introduction. First Nations and other Aboriginal children are disproportionately affected by cardiometabolic diseases, including type 2 diabetes (T2D). In T2D, the disruption of insulin signalling can be driven by pro-inflammatory immunity. Pro-inflammatory responses can be fueled by toll-like receptors (TLR) on immune cells such as peripheral blood mononuclear cells (PBMC, a white blood cell population). TLR4 can bind to lipids from bacteria and food sources activating PBMC to produce cytokines tumour necrosis factor (TNF)-α and interleukin (IL)-1β. These cytokines can interfere with insulin signalling. Here, we seek to understand how TLR4 activation may be involved in early onset T2D. We hypothesized that immune cells from youth with T2D (n=8) would be more reactive upon TLR4 stimulation relative to cells from age and body mass index (BMI)-matched controls without T2D (n=8). Methods. Serum samples were assayed for adipokines (adiponectin and leptin), as well as cytokines. Freshly isolated PBMC were examined for immune reactivity upon culture with TLR4 ligands bacterial lipopolysaccharide (LPS, 2 and 0.2 ng/ml) and the fatty acid palmitate (200 µM). Culture supernatants were evaluated for the amount of TNF-α and IL-1β produced by PBMC. Results. Youth with T2D displayed lower median serum adiponectin levels compared to controls (395 vs. 904 ng/ml, p<0.05). PBMC isolated from youth with and without T2D produced similar levels of TNF-α and IL-1β after exposure to the higher LPS concentration. However, at the low LPS dose the T2D cohort exhibited enhanced IL-1β synthesis relative to the control cohort. Additionally, exposure to palmitate resulted in greater IL-1β synthesis in PBMCs isolated from youth with T2D versus controls (p<0.05). These differences in cytokine production corresponded to greater monocyte activation in the T2D cohort. Conclusion. These preliminary results suggest that cellular immune responses are exaggerated in T2D, particularly with respect to IL-1β activity. These studies aim to improve the understanding of the biology behind early onset T2D and its vascular complications that burden First Nations people
Neuroinflammation and structural injury of the fetal ovine brain following intra-amniotic Candida albicans exposure.
BackgroundIntra-amniotic Candida albicans (C. Albicans) infection is associated with preterm birth and high morbidity and mortality rates. Survivors are prone to adverse neurodevelopmental outcomes. The mechanisms leading to these adverse neonatal brain outcomes remain largely unknown. To better understand the mechanisms underlying C. albicans-induced fetal brain injury, we studied immunological responses and structural changes of the fetal brain in a well-established translational ovine model of intra-amniotic C. albicans infection. In addition, we tested whether these potential adverse outcomes of the fetal brain were improved in utero by antifungal treatment with fluconazole.MethodsPregnant ewes received an intra-amniotic injection of 10(7) colony-forming units C. albicans or saline (controls) at 3 or 5 days before preterm delivery at 0.8 of gestation (term ~ 150 days). Fetal intra-amniotic/intra-peritoneal injections of fluconazole or saline (controls) were administered 2 days after C. albicans exposure. Post mortem analyses for fungal burden, peripheral immune activation, neuroinflammation, and white matter/neuronal injury were performed to determine the effects of intra-amniotic C. albicans and fluconazole treatment.ResultsIntra-amniotic exposure to C. albicans caused a severe systemic inflammatory response, illustrated by a robust increase of plasma interleukin-6 concentrations. Cerebrospinal fluid cultures were positive for C. albicans in the majority of the 3-day C. albicans-exposed animals whereas no positive cultures were present in the 5-day C. albicans-exposed and fluconazole-treated animals. Although C. albicans was not detected in the brain parenchyma, a neuroinflammatory response in the hippocampus and white matter was seen which was characterized by increased microglial and astrocyte activation. These neuroinflammatory changes were accompanied by structural white matter injury. Intra-amniotic fluconazole reduced fetal mortality but did not attenuate neuroinflammation and white matter injury.ConclusionsIntra-amniotic C. albicans exposure provoked acute systemic and neuroinflammatory responses with concomitant white matter injury. Fluconazole treatment prevented systemic inflammation without attenuating cerebral inflammation and injury
Medication administration errors for older people in long-term residential care
Background
Older people in long-term residential care are at increased risk of medication errors. The purpose of this study was to evaluate a computerised barcode medication management system designed to improve drug administrations in residential and nursing homes, including comparison of error rates and staff awareness in both settings.
Methods
All medication administrations were recorded prospectively for 345 older residents in thirteen care homes during a 3-month period using the computerised system. Staff were surveyed to identify their awareness of administration errors prior to system introduction. Overall, 188,249 attempts to administer medication were analysed to determine the prevalence of potential medication administration errors (MAEs). Error classifications included attempts to administer medication at the wrong time, to the wrong person or discontinued medication. Analysis compared data at residential and nursing home level and care and nursing staff groups.
Results
Typically each resident was exposed to 206 medication administration episodes every month and received nine different drugs. Administration episodes were more numerous (p < 0.01) in nursing homes (226.7 per resident) than in residential homes (198.7). Prior to technology introduction, only 12% of staff administering drugs reported they were aware of administration errors being averted in their care home. Following technology introduction, 2,289 potential MAEs were recorded over three months. The most common MAE was attempting to give medication at the wrong time. On average each resident was exposed to 6.6 potential errors. In total, 90% of residents were exposed to at least one MAE with over half (52%) exposed to serious errors such as attempts to give medication to the wrong resident. MAEs rates were significantly lower (p < 0.01) in residential homes than nursing homes. The level of non-compliance with system alerts was low in both settings (0.075% of administrations) demonstrating virtually complete error avoidance.
Conclusion
Potentially inappropriate administration of medication is a serious problem in long-term residential care. A computerised barcode system can accurately and automatically detect inappropriate attempts to administer drugs to residents. This tool can reliably be used by care staff as well as nurses to improve quality of care and patient safety
Antecedents and consequences of effectuation and causation in the international new venture creation process
The selection of the entry mode in an international market is of key importance for the venture. A process-based perspective on entry mode selection can add to the International Business and International Entrepreneurship literature. Framing the international market entry as an entrepreneurial process, this paper analyzes the antecedents and consequences of causation and effectuation in the entry mode selection. For the analysis, regression-based techniques were used on a sample of 65 gazelles. The results indicate that experienced entrepreneurs tend to apply effectuation rather than causation, while uncertainty does not have a systematic influence. Entrepreneurs using causation-based international new venture creation processes tend to engage in export-type entry modes, while effectuation-based international new venture creation processes do not predetermine the entry mod
The Enteropathogenic E. coli (EPEC) Tir Effector Inhibits NF-κB Activity by Targeting TNFα Receptor-Associated Factors
Enteropathogenic Escherichia coli (EPEC) disease depends on the transfer of effector proteins into epithelia lining the human small intestine. EPEC E2348/69 has at least 20 effector genes of which six are located with the effector-delivery system genes on the Locus of Enterocyte Effacement (LEE) Pathogenicity Island. Our previous work implied that non-LEE-encoded (Nle) effectors possess functions that inhibit epithelial anti-microbial and inflammation-inducing responses by blocking NF-κB transcription factor activity. Indeed, screens by us and others have identified novel inhibitory mechanisms for NleC and NleH, with key co-operative functions for NleB1 and NleE1. Here, we demonstrate that the LEE-encoded Translocated-intimin receptor (Tir) effector has a potent and specific ability to inhibit NF-κB activation. Indeed, biochemical, imaging and immunoprecipitation studies reveal a novel inhibitory mechanism whereby Tir interaction with cytoplasm-located TNFα receptor-associated factor (TRAF) adaptor proteins induces their proteasomal-independent degradation. Infection studies support this Tir-TRAF relationship but reveal that Tir, like NleC and NleH, has a non-essential contribution in EPEC's NF-κB inhibitory capacity linked to Tir's activity being suppressed by undefined EPEC factors. Infections in a disease-relevant intestinal model confirm key NF-κB inhibitory roles for the NleB1/NleE1 effectors, with other studies providing insights on host targets. The work not only reveals a second Intimin-independent property for Tir and a novel EPEC effector-mediated NF-κB inhibitory mechanism but also lends itself to speculations on the evolution of EPEC's capacity to inhibit NF-κB function
A fixed carbohydrate: protein ratio <= 1.8 on an energy basis consumed in the context of an energy-restricted diet and reduction of body weight: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006.
Following an application from Marks and Spencer PLC, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of the United Kingdom, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to a CHO:P ratio <= 1.8 on an energy basis in the context of an energy-restricted diet and body weight. The Panel considers that the food/constituent that is the subject of the health claim is sufficiently characterised. The Panel also considers that reduction of body weight in the context of an energy-restricted diet is a beneficial physiological effect. The target population proposed by the applicant is 'adults between the ages of 18 and 70 years with excess body weight'. No conclusions could be drawn from two unpublished studies investigating the effect of ready-to-eat meals with a CHO: P ratio <= 1.8 on body weight. The remaining 14 human intervention studies investigated the effect of diets targeting a CHO: P ratio <= 1.8 as compared to diets targeting a CHO: P ratio >= 3.0 on overweight and obese adults in the context of energy restriction. Four out of seven studies lasting < 12 weeks reported an effect of a CHO: P ratio <= 1.8 on body weight in overweight/obese subjects, whereas no significant effect was observed in six out of the seven studies lasting 12 weeks or more. The Panel considers that these studies do not provide evidence for a sustained effect of the food/constituent on body weight. The Panel concludes that a cause and effect relationship has not been established between the consumption of a fixed CHO: P ratio <= 1.8 on an energy basis consumed in the context of an energy-restricted diet and reduction of body weight. (C) 2017 European Food Safety Authority
Functional analysis and expression profiling of HcrVf1 and HcrVf2 for development of scab resistant cisgenic and intragenic apples
Apple scab resistance genes, HcrVf1 and HcrVf2, were isolated including their native promoter, coding and terminator sequences. Two fragment lengths (short and long) of the native gene promoters and the strong apple rubisco gene promoter (PMdRbc) were used for both HcrVf genes to test their effect on expression and phenotype. The scab susceptible cultivar ‘Gala’ was used for plant transformations and after selection of transformants, they were micrografted onto apple seedling rootstocks for scab disease tests. Apple transformants were also tested for HcrVf expression by quantitative RT-PCR (qRT-PCR). For HcrVf1 the long native promoter gave significantly higher expression that the short one; in case of HcrVf2 the difference between the two was not significant. The apple rubisco gene promoter proved to give the highest expression of both HcrVf1 and HcrVf2. The top four expanding leaves were used initially for inoculation with monoconidial isolate EU-B05 which belongs to race 1 of V. inaequalis. Later six other V. inaequalis isolates were used to study the resistance spectra of the individual HcrVf genes. The scab disease assays showed that HcrVf1 did not give resistance against any of the isolates tested regardless of the expression level. The HcrVf2 gene appeared to be the only functional gene for resistance against Vf avirulent isolates of V. inaequalis. HcrVf2 did not provide any resistance to Vf virulent strains, even not in case of overexpression. In conclusion, transformants carrying the apple-derived HcrVf2 gene in a cisgenic as well as in an intragenic configuration were able to reach scab resistance levels comparable to the Vf resistant control cultivar obtained by classical breeding, cv. ‘Santana’
Patient-reported outcomes of femoral osteotomy and total hip arthroplasty for osteonecrosis of the femoral head: a prospective case series study
Three-Dimensional Graphene Nano-Networks with High Quality and Mass Production Capability via Precursor-Assisted Chemical Vapor Deposition
We report a novel approach to synthesize chemical vapor deposition-grown three-dimensional graphene nano-networks (3D-GNs) that can be mass produced with large-area coverage. Annealing of a PVA/iron precursor under a hydrogen environment, infiltrated into 3D-assembled-colloidal silicas reduces iron ions and generates few-layer graphene by precipitation of carbon on the iron surface. The 3D-GN can be grown on any electronic device-compatible substrate, such as Al2O3, Si, GaN, or Quartz. The conductivity and surface area of a 3D-GN are 52 S/cm and 1,025 m(2)/g, respectively, which are much better than the previously reported values. Furthermore, electrochemical double-layer capacitors based on the 3D-GN have superior supercapacitor performance with a specific capacitance of 245 F/g and 96.5% retention after 6,000 cycles due to the outstanding conductivity and large surface area. The excellent performance of the 3D-GN as an electrode for supercapacitors suggests the great potential of interconnected graphene networks in nano-electronic devices and energy-related materials.open15
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