IMPORTANCE: Indwelling pleural catheter and talc pleurodesis are established treatments for malignant pleural effusions among patients with poor prognosis. OBJECTIVE: To determine whether indwelling ...pleural catheters are more effective than talc pleurodesis in reducing total hospitalization days in the remaining lifespan of patients with malignant pleural effusion. DESIGN, SETTING, AND PARTICIPANTS: This open-label, randomized clinical trial included participants recruited from 9 centers in Australia, New Zealand, Singapore, and Hong Kong between July 2012 and October 2014; they were followed up for 12 months (study end date: October 16, 2015). Patients (n = 146) with symptomatic malignant pleural effusion who had not undergone indwelling pleural catheter or pleurodesis treatment were included. INTERVENTIONS: Participants were randomized (1:1) to indwelling pleural catheter (n = 74) or talc pleurodesis (n = 72), minimized by malignancy (mesothelioma vs others) and trapped lung (vs not), and stratified by region (Australia vs Asia). MAIN OUTCOMES AND MEASURES: The primary end point was the total number of days spent in hospital from procedure to death or to 12 months. Secondary outcomes included further pleural interventions, patient-reported breathlessness, quality-of-life measures, and adverse events. RESULTS: Among the 146 patients who were randomized (median age, 70.5 years; 56.2% male), 2 withdrew before receiving the randomized intervention and were excluded. The indwelling pleural catheter group spent significantly fewer days in hospital than the pleurodesis group (median, 10.0 interquartile range IQR, 3-17 vs 12.0 IQR, 7-21 days; P = .03; Hodges-Lehmann estimate of difference, 2.92 days; 95% CI, 0.43-5.84). The reduction was mainly in effusion-related hospitalization days (median, 1.0 IQR, 1-3 day with the indwelling pleural catheter vs 4.0 (IQR, 3-6) days with pleurodesis; P < .001; Hodges-Lehmann estimate, 2.06 days; 95% CI, 1.53-2.58). Fewer patients randomized to indwelling pleural catheter required further ipsilateral invasive pleural drainages (4.1% vs 22.5%; difference, 18.4%; 95% CI, 7.7%-29.2%). There were no significant differences in improvements in breathlessness or quality of life offered by indwelling pleural catheter or talc pleurodesis. Adverse events were seen in 22 patients in the indwelling pleural catheter group (30 events) and 13 patients in the pleurodesis group (18 events). CONCLUSIONS AND RELEVANCE: Among patients with malignant pleural effusion, treatment with an indwelling pleural catheter vs talc pleurodesis resulted in fewer hospitalization days from treatment to death, but the magnitude of the difference is of uncertain clinical importance. These findings may help inform patient choice of management for pleural effusion. TRIAL REGISTRATION: anzctr.org.au Identifier: ACTRN12611000567921
ATP phosphoribosyltransferase catalyses the first step of histidine biosynthesis and is controlled via a complex allosteric mechanism where the regulatory protein HisZ enhances catalysis by the ...catalytic protein HisG
while mediating allosteric inhibition by histidine. Activation by HisZ was proposed to position HisG
Arg56 to stabilise departure of the pyrophosphate leaving group. Here we report active-site mutants of HisG
with impaired reaction chemistry which can be allosterically restored by HisZ despite the HisZ:HisG
interface lying ~20 Å away from the active site. MD simulations indicate HisZ binding constrains the dynamics of HisG
to favour a preorganised active site where both Arg56 and Arg32 are poised to stabilise leaving-group departure in WT-HisG
. In the Arg56Ala-HisG
mutant, HisZ modulates Arg32 dynamics so that it can partially compensate for the absence of Arg56. These results illustrate how remote protein-protein interactions translate into catalytic resilience by restoring damaged electrostatic preorganisation at the active site.
Allele-specific chemical genetics enables selective inhibition within families of highly-conserved proteins. The four BET (bromodomain & extra-terminal domain) proteins - BRD2, BRD3, BRD4 and BRDT ...bind acetylated chromatin
their bromodomains and regulate processes such as cell proliferation and inflammation. BET bromodomains are of particular interest, as they are attractive therapeutic targets but existing inhibitors are pan-selective. We previously established a bump-&-hole system for the BET bromodomains, pairing a leucine/alanine mutation with an ethyl-derived analogue of an established benzodiazepine scaffold. Here we optimize upon this system with the introduction of a more conservative and less disruptive leucine/valine mutation. Extensive structure-activity-relationships of diverse benzodiazepine analogues guided the development of potent, mutant-selective inhibitors with desirable physiochemical properties. The active enantiomer of our best compound - 9-ME-1 - shows ∼200 nM potency, >100-fold selectivity for the L/V mutant over wild-type and excellent DMPK properties. Through a variety of
and cellular assays we validate the capabilities of our optimized system, and then utilize it to compare the relative importance of the first and second bromodomains to chromatin binding. These experiments confirm the primacy of the first bromodomain in all BET proteins, but also significant variation in the importance of the second bromodomain. We also show that, despite having a minor role in chromatin recognition, BRD4 BD2 is still essential for gene expression, likely through the recruitment of non-histone proteins. The disclosed inhibitor:mutant pair provides a powerful tool for future cellular and
target validation studies.
A surveillance study was undertaken to examine the population dynamics and antimicrobial resistance of Mannheimia haemolytica isolated from feedlot cattle. A total of 416 isolates were collected from ...the nasopharynx either upon entry or exit from two feedlots in southern Alberta, Canada. Isolates were serotyped, characterized by pulsed-field gel electrophoresis and tested for susceptibility to ten antimicrobial agents via disk diffusion. Resistant isolates were screened by PCR for select antimicrobial-resistance gene determinants. Isolates were highly diverse, with 335 unique pulsed-field profiles identified among 147 strongly related clusters (similarity ≥85%). Clonal spread of isolates throughout the feedlots was limited and no clear association was found between genetic relatedness of M. haemolytica and sampling event (entry or exit). Pulsed-field profiles sharing a common serotype and resistance phenotype tended to cluster together. The majority of isolates were identified as serotype 2 (74.5%) although both serotype 1 (11.9%) and 6 (12.7%) were detected. Only 9.54% of isolates exhibited antimicrobial resistance. Resistance to oxytetracycline was most prevalent (n=16), followed by ampicillin (n=10), and amoxicillin/clavulanic acid (n=7). Multi-drug resistance was observed in five isolates. The tetH gene was detected in all but two oxytetracycline resistant isolates. Other detectable resistance determinates included ermX and blaROB-1. In the two feedlots examined, M. haemolytica exhibited considerable genetic diversity and limited resistance to common veterinary antibiotics. Garnering further information on the linkage between genotype and phenotype should contribute toward a better understanding of the pathogenesis and dissemination of M. haemolytica in feedlots.
Summary Objective To identify differentially expressed microRNAs (miRNAs) in human osteoarthritic (OA) cartilage and bone tissue and to determine their relevance to chondrocyte function. Methods ...Cartilage and bone was obtained from OA patients who underwent total knee joint replacement surgery or from post-mortem patients with no previous history of OA. MiRNA expression was quantified by real-time PCR (RT-PCR). Functional pathway analysis of miRNA was performed using Ingenuity Pathway® Analysis. Primary chondrocytes were isolated by collagenase digestion and transfected with miRNA mimics and miRNA inhibitors using cationic lipid. Tumour Necrosis Factor-alpha (TNF-α) and Matrix metalloprotease 13 (MMP13) protein levels were measured by Enzyme-Linked ImmunoSorbent Assay (ELISA). Results In total we identified 17 miRNA that showed greater than 4-fold differential expression between OA and normal cartilage, and 30 miRNA that showed greater than 4-fold differential expression in OA bone. Functional pathway analysis of the predicted gene targets for miR-9, miR-98, which were upregulated in both OA bone and cartilage tissue, and miR-146, which was downregulated in OA cartilage, suggested that these miRNA mediate inflammatory functions and pathways. Over-expression of miR-9, miR-98 or miR-146 in isolated human chondrocytes reduced interleukin-1beta (IL-1β) induced TNF-α production. Furthermore, inhibition and over-expression of miR-9 modulated MMP13 secretion. Conclusions We have identified a number of differentially expressed miRNAs in late-stage human OA cartilage and bone. Functional analysis of miR-9, miR-98 and miR-146 in primary chondrocytes suggests a role in mediating the IL-1β induced production of TNF-α. MiR-9, upregulated in OA tissue, was found to inhibit secretion of the collagen type II-targeting metalloproteinase MMP13 in isolated human chondrocytes.
Aims. We investigate the properties of a variability-selected complete sample of active galactic nuclei (AGN) in order to identify the mechanisms which cause large amplitude X-ray variability on ...timescales of years. Methods. A complete sample of 24 sources was constructed, from AGN which changed their soft X-ray luminosity by more than one order of magnitude over 5–20 years between ROSAT observations and the XMM-Newton slew survey. Follow-up observations were obtained with the Swift satellite. We analysed the spectra of these AGN at the Swift and XMM observation epochs, where six sources had continued to display extreme variability. Multiwavelength data are used to calculate black hole masses and the relative X-ray brightness αOX. Results. After removal of two probable spurious sources, we find that the sample has global properties which differ little from a non-varying control sample drawn from the wider XMM-slew/ROSAT/Veron sample of all secure AGN detections. A wide range of AGN types are represented in the varying sample. The black hole mass distributions for the varying and non-varying sample are not significantly different. This suggests that long timescale variability is not strongly affected by black hole mass. There is marginal evidence that the variable sources have a lower redshift (2σ) and X-ray luminosity (1.7σ). Apart from two radio-loud sources, the sample sources have normal optical-X-ray ratios (αOX) when at their peak but are X-ray weak during their lowest flux measurements. Conclusions. Drawing on our results and other studies, we are able to identify a variety of variability mechanisms at play: tidal disruption events, jet activity, changes in absorption, thermal emission from the inner accretion disc, and variable accretion disc reflection. Little evidence for strong absorption is seen in the majority of the sample and single-component absorption can be excluded as the mechanism for most sources.
Reported here are transverse single-spin asymmetries (AN) in the production of charged hadrons as a function of transverse momentum (pT) and Feynman-x (xF) in polarized p↑ + p, p↑ + Al, and p↑ + Au ...collisions at $\sqrt{^SNN}$ = 200 GeV. The measurements have been performed at forward and backward rapidity (1.4 < |η| < 2.4) over the range of 1.5 GeV /c < pT < 7.0 GeV /c and 0.04 < |xF| < 0.2. A nonzero asymmetry is observed for positively charged hadrons at forward rapidity (xF > 0) in p↑ + p collisions, whereas the p↑ + Al and p↑ + Au results show smaller asymmetries. This finding provides new opportunities to investigate the origin of transverse single-spin asymmetries and a tool to study nuclear effects in p + A collisions.
Many transplant centers use endoscopically directed brachytherapy to provide locoregional control in patients with otherwise incurable cholangiocarcinoma (CCA) who are awaiting liver transplantation ...(LT). The use of endoscopic retrograde cholangiopancreatography (ERCP)‐directed photodynamic therapy (PDT) as an alternative to brachytherapy for providing locoregional control in this patient population has not been studied. The aim of this study was to report on our initial experience using ERCP‐directed PDT to provide local control in patients with unresectable CCA who were awaiting LT. Patients with unresectable CCA who underwent protocol‐driven neoadjuvant chemoradiation and ERCP‐directed PDT with the intent of undergoing LT were reviewed. Four patients with confirmed or suspected CCA met the inclusion criteria for protocol LT. All four patients (100%) successfully underwent ERCP‐directed PDT. All patients had chemoradiation dose delays, and two patients had recurrent cholangitis despite PDT. None of these patients had progressive locoregional disease or distant metastasis following PDT. All four patients (100%) underwent LT. Intention‐to‐treat disease‐free survival was 75% at mean follow‐up of 28.1 months. In summary, ERCP‐directed PDT is a reasonably well tolerated and safe procedure that may have benefit by maintaining locoregional tumor control in patients with CCA who are awaiting LT.
Photodynamic therapy is a reasonably well tolerated and safe endoscopic ablation technique that may maintain locoregional tumor control in patients with cholangiocarcinoma who are awaiting liver transplantation.
Presented are the first measurements of the transverse single-spin asymmetries ($A_N$) for neutral pions and eta mesons in $\textit{p}$ + Au and $\textit{p}$ + Al collisions at $\sqrt{s_{NN}}$ = 200 ...GeV in the pseudorapidity range |$\textit{η}$| < 0.35 with the PHENIX detector at the Relativistic Heavy Ion Collider. The asymmetries are consistent with zero, similar to those for midrapidity neutral pions and eta mesons produced in $\textit{p}$ + $\textit{p}$ collisions. These measurements show no evidence of additional effects that could potentially arise from the more complex partonic environment present in proton-nucleus collisions.
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