Phos-tag analysis of Rab10 phosphorylation by LRRK2:a powerful assay for assessing kinase function and inhibitors

Autosomal dominant mutations that activate the leucine-rich repeat kinase-2 (LRRK2) cause inherited Parkinson's disease. Recent work has revealed that LRRK2 directly phosphorylates a conserved Thr/Ser residue in the effector-binding switch-II motif of a number of Rab GTPase proteins, including Rab10. Here we describe a facile and robust method to assess phosphorylation of endogenous Rab10 in mouse embryonic fibroblasts (MEFs), lung and spleen derived B Cells, based on the ability of the Phos-tag reagent to retard the electrophoretic mobility of LRRK2 phosphorylated Rab10. We exploit this assay to show that phosphorylation of Rab10 is ablated in kinase inactive LRRK2[D2017A] knock-in MEFs and mouse lung, demonstrating that LRRK2 is the major Rab10 kinase in these cells/tissue. We also establish that the Phos-tag assay can be deployed to monitor the impact that activating LRRK2 pathogenic (G2019S and R1441G) knock-in mutations have on stimulating Rab10 phosphorylation. We show that upon addition of LRRK2 inhibitors, Rab10 is dephosphorylated within 1-2 min, markedly more rapidly than the Ser935 and Ser1292 biomarker sites that require 40-80 min. Furthermore, we find that phosphorylation of Rab10 is suppressed in LRRK2[S910A, S935A] knock-in MEFs indicating that phosphorylation of Ser910 and Ser935 and potentially 14-3-3 binding play a role in facilitating the phosphorylation of Rab10 by LRRK2 in vivo. The Rab Phos-tag assay has the potential to significantly aide with evaluating the effect that inhibitors, mutations and other factors have on the LRRK2 signalling pathway

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Integrated Micromachined Millimeter Wave Patch Antenna

We have proposed 3-D micromachined elevated patch antenna for G-band (140GHz to 220GHz) applications. ne antenna is consisted of coplanar waveguide (CPW) feed line, a feeding post, air-bridge, supporting posts, and elevated patch. The antenna topology effectively creates a low dielectric substrate and undesired substrate effects can be eliminated, since the antenna substrate is essentially air which the lowest possible dielectric constant. This will increase the radiation efficiency, gain, and the radiation bandwidth. The measurement result shows the bandwidth is about 7GHz, from 170GHz to 177GHz with nearly constant broadside radiation pattern. Also, this work has demonstrated the capability of fabricating a high performance antenna design in a MMICs compatible proces

Efficacy of entecavir with or without tenofovir disoproxil fumarate for nucleos(t)ide-nave patients with chronic hepatitis B

BACKGROUND & AIMS: Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are potent antiviral agents that might have additive or synergistic antiviral activity in treatment of patients with chronic hepatitis B (CHB). We compared the efficacy and safety of ETV monotherapy with those of a combination of ETV and TDF. METHODS: We performed a randomized, open-label, multicenter, superiority study of 379 nucleos(t)ide-nave patients with hepatitis B e antigen (HBeAg)-positive (n = 264) or HBeAg-negative (n = 115) CHB. Subjects were given ETV 0.5 mg (n = 182) or a combination of ETV 0.5 mg and TDF 300 mg (n = 197) for 100 weeks. RESULTS: At week 96, comparable proportions of patients in each study arm achieved the primary end point of a level of hepatitis B virus (HBV) DNA <50 IU/mL (83.2% vs 76.4%; P = .088). Among HBeAg-positive patients, a greater proportion given combination therapy achieved levels of HBV DNA <50 IU/mL than those given ETV alone (80.4% vs 69.8%; P = .046). However, this difference was observed only in patients with baseline levels of HBV DNA <108 IU/mL (79% vs 62%) and not in those with baseline levels of HBV DNA <108 IU/mL (83% in both arms). Rates of HBeAg loss and HBeAg seroconversion were comparable between groups, whereas the rate of alanine aminotransferase normalization was greater in the ETV monotherapy group. No HBV variants associated with ETV or TDF resistance were detected. Safety profiles were consistent with previous reports of ETV or TDF monotherapy. CONCLUSIONS: The antiviral efficacy of ETV monotherapy is comparable to that of ETV plus TDF in a mixed population of nucleos(t)ide-nave patients with CHB (70% HBeAg positive). The combination therapy could provide an incremental benefit to HBeAg-positive patients with baseline levels of HBV DNA ?108 IU/mL. Clinical trial information: ETV-110, the BE-LOW study; NCT00410072. © 2012 AGA Institute

Adefovir-resistant hepatitis B can be associated with viral rebound and hepatic decompensation

BACKGROUND/AIMS: The susceptibility of adefovir-resistant hepatitis B virus (HBV) mutants is only reduced by 3-10-fold in in vitro studies, suggesting that virologic breakthrough and clinical deterioration are unlikely. The aim of this study was to describe the clinical course of patients with adefovir-resistant HBV infection. METHODS: Testing for adefovir-resistant mutations was performed on patients who had a suboptimal response or virologic breakthrough on adefovir. Adefovir-resistant mutations were detected using a line probe assay and direct sequencing of the HBV P-gene. RESULTS: Eight male patients with pre-existing lamivudine resistance or breakthrough (mean age 47+/-13 years) were found to have adefovir-resistant mutations rtA181V/T or rtN236T. Baseline median ALT was 66IU/L (range, 27-1161) and median HBV DNA 7.9log(10) copies/ml (range, 6-8.3). At the time of adefovir resistance (mean of 20+/-9 months), HBV DNA increased to >/=5log(10) copies/ml in 7 patients. After detection of adefovir resistance, hepatic decompensation occurred in 2 patients, 1 of whom died. Salvage therapy with lamivudine, entecavir or tenofovir was given to 7 patients and a reduction in HBV DNA by >/=3log(10) was seen in 3 patients. CONCLUSIONS: In conclusion, adefovir resistance can be associated with significant viral rebound and hepatic decompensation which may be fatal