75 research outputs found

    Non-steroidal anti-inflammatory drugs (NSAIDs) in cancer pain:A database analysis to determine recruitment feasibility for a clinical trial

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    BACKGROUND: Insufficient evidence exists to support or refute use of NSAIDs for managing cancer pain. Palliative physicians support a placebo-controlled trial of NSAIDs as strong opioid adjuncts for cancer-induced bone pain as the most pragmatic design to benefit clinical practice. AIM: We aimed to determine patient numbers receiving palliative radiotherapy for cancer-induced bone pain, estimate the suitability of NSAID prescription and determine survival, guiding future trial feasibility. DESIGN: A retrospective observational database analysis was undertaken using 5 years of routinely collected regional radiotherapy and healthcare data, filtered to achieve a cohort with cancer-induced bone pain. Demographics and survival were linked to available serology and co-morbidity data. SETTING/PARTICIPANTS: Data was sourced from the regional Leeds Cancer Centre, a tertiary care setting. Patients who underwent palliative single fraction 8 gray (Gy) radiotherapy treatment for cancer-induced bone pain were included, totalling 2411 over 5 years. RESULTS: A mean of 478 patients received palliative radiotherapy for cancer-induced bone pain annually. Median age (IQR) was 70 (62–77); negatively skewed (−0.69). 65.3% died within 1 year of radiotherapy; 48.0% within 6 months. Age was not associated with survival on univariable analysis (HR 0.999 (95% CI 0.996–1.003)). Serology from 1063 patients (44.2%) were available; eGFR was ⩾60 mL/min/1.73 m(2) in 83.0%. From available data (1352 pts; 51.6% of sample), 20.2% had a coded co-morbidity contra-indicating NSAIDs. Combining serology and co-morbidities, 68.5% could be considered for NSAID prescription. CONCLUSIONS: Patient numbers at a regional radiotherapy centre support the feasibility of trial recruitment. Available serology and co-morbidity data suggest two-thirds may be suitable for NSAID prescription

    Integrin-Mediated Host Cell Invasion by Type 1–Piliated Uropathogenic Escherichia coli

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    Uropathogenic Escherichia coli (UPEC), the primary causative agent of urinary tract infections, typically express filamentous adhesive organelles called type 1 pili that mediate both bacterial attachment to and invasion of bladder urothelial cells. Several host proteins have previously been identified as receptors for type 1 pili, but none have been conclusively shown to promote UPEC entry into host bladder cells. Using overlay assays with FimH, the purified type 1 pilus adhesin, and mass spectroscopy, we have identified β1 and α3 integrins as key host receptors for UPEC. FimH recognizes N-linked oligosaccharides on these receptors, which are expressed throughout the urothelium. In a bladder cell culture system, β1 and α3 integrin receptors co-localize with invading type 1–piliated bacteria and F-actin. FimH-mediated bacterial invasion of host bladder cells is inhibited by β1 and α3 integrin–specific antibodies and by disruption of the β1 integrin gene in the GD25 fibroblast cell line. Phosphorylation site mutations within the cytoplasmic tail of β1 integrin that alter integrin signaling also variably affect UPEC entry into host cells, by either attenuating or boosting invasion frequencies. Furthermore, focal adhesion and Src family kinases, which propagate integrin-linked signaling and downstream cytoskeletal rearrangements, are shown to be required for FimH-dependent bacterial invasion of target host cells. Cumulatively, these results indicate that β1 and α3 integrins are functionally important receptors for type 1 pili–expressing bacteria within the urinary tract and possibly at other sites within the host

    Developing lithium chemistry of 1,2-dihydropyridines : from kinetic intermediates to isolable characterized compounds

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    Generally considered kinetic intermediates in addition reactions of alkyllithiums to pyridine, 1-lithio-2-alkyl-1,2-dihydropyridines have been rarely isolated or characterized. This study develops their "isolated" chemistry. By a unique stoichiometric (that is 1:1, alkyllithium:pyridine ratios) synthetic approach using tridentate donors we show it is possible to stabilize and hence crystallize monomeric complexes where alkyl is tert-butyl. Theoretical calculations probing the donor-free parent tert-butyl species reveal 12 energetically similar stereoisomers in two distinct cyclotrimeric (LiN)3 conformations. NMR studies (including DOSY spectra) and thermal volatility analysis compare new sec-butyl and iso-butyl isomers showing the former is a hexane soluble efficient hydrolithiation agent converting benzophenone to lithium diphenylmethoxide. Emphasizing the criticalness of stoichiometry, reaction of nBuLi/Me6TREN with two equivalents of pyridine results in non-alkylated 1-lithio-1,4-dihydropyridine·Me6TREN and 2-n-butylpyridine, implying mechanistically the kinetic 1,2-n-butyl intermediate hydrolithiates the second pyridine

    Comparing large lecture mechanics curricula using the Force Concept Inventory: A five thousand student study

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    The performance of over 5000 students in introductory calculus-based mechanics courses at the Georgia Institute of Technology was assessed using the Force Concept Inventory (FCI). Results from two different curricula were compared: a traditional mechanics curriculum and the Matter & Interactions (M&I) curriculum. Post-instruction FCI averages were significantly higher for the traditional curriculum than for the M&I curriculum; the differences between curricula persist after accounting for factors such as pre-instruction FCI scores, grade point averages, and SAT scores. FCI performance on categories of items organized by concepts was also compared; traditional averages were significantly higher in each concept. We examined differences in student preparation between the curricula and found that the relative fraction of homework and lecture topics devoted to FCI force and motion concepts correlated with the observed performance differences. Limitations of concept inventories as instruments for evaluating curricular reforms are discussed.Comment: 21 pages, 4 figures, submitted to Am. J. Phys. arXiv admin note: substantial text overlap with arXiv:1112.559

    Experience of an NIHR Clinical Lectureship (medical/dental) and the determining factors for a clinical academic career post lectureship:a mixed-method evaluation

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    Objectives: The objective of this study is to investigate early-to-late postdoctoral clinical academic progression and the experiences of NIHR Clinical Lectureship (CL) fellows, considering enablers and barriers to success, and identifying the factors associated with immediate progression to a clinical academic role following completion of the award. Setting: Datasets of CL awardees across the UK. Participants: For semistructured interviews, n=40 CL awardees that had finished their award within the previous 5 years. For quantitative analysis, n=1226 completed or currently active CL awardees. Outcome measures: The responses from the semistructured interviews to the defined questions on experiences during the award, postaward progression, and enablers and barriers to academic progression. Other primary outcome measures were quantitative data on first destinations postaward, demographic data, and whether an awardee had previously held an NIHR Academic Clinical Fellowship (ACF) or was a recipient of the Academy of Medical Sciences (AMS) Starter Grant. Results: CL awardees identified numerous benefits to the award, with the majority achieving their aims. Most awardees progressed to a clinical academic role; however, some returned to a clinical only position, citing concerns around the time pressure associated with balancing clinical and academic responsibilities, and the competition to attain further postdoctoral awards. The region of the award partnership, year of award end and success in applying for an AMS Starter Grant were associated with progression to a clinical academic role. Gender, holding an ACF and having a craft or non-craft specialty had no independent statistical association with clinical academic progression. Conclusions: The CL is a valued element of the Integrated Academic Pathway. By addressing issues around later postdoctoral progression opportunities, responding to challenges experienced by CLs, and by understanding the factors identified in this study associated with clinical academic progression, it should be possible to increase the proportion of CLs that become fully independent clinical academic research leaders. Participants: 1226 NIHR CLs active or completed on the award between 2006 and 2020

    Three oxidative addition routes of alkali metal aluminyls to dihydroaluminates and reactivity with CO2

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    Three distinct routes are reported to the soluble, dihydridoaluminate compounds, AM[Al(NONDipp)(H)2] (AM = Li, Na, K, Rb, Cs; [NONDipp]2– = [O(SiMe2NDipp)2]2–; Dipp = 2,6-iPr2C6H3) starting from the alkali metal aluminyls, AM[Al(NONDipp)]. Direct H2 hydrogenation of the heavier analogues (AM = Rb, Cs) produced the first examples of structurally characterized rubidium and caesium dihydridoaluminates, although harsh conditions were required for complete conversion. Using 1,4-cyclohexadiene (1,4-CHD) as an alternative hydrogen source in transfer hydrogenation reactions provided a lower energy pathway to the full series of products for AM = Li – Cs. A further moderation in conditions was noted for the thermal decomposition of the (silyl)(hydrido)aluminates, AM[Al(NONDipp)(H)(SiH2Ph)]. Probing the reaction of Cs[Al(NONDipp)] with 1,4-CHD provided access to a novel inverse sandwich complex, [{Cs(Et2O)}2{Al(NONDipp)(H)}2(C6H6)], containing the 1,4-dialuminated [C6H6]2– dianion and representing the first time that an intermediate in the commonly utilized oxidation process of 1,4-CHD to benzene has been trapped. The synthetic utility of the newly installed Al–H bonds has been demonstrated by their ability to reduce CO2 under mild conditions to form the bis-formate AM[Al(NONDipp)(O2CH)2] compounds, which exhibit a diverse series of eyecatching bimetallacyclic structures

    Analysis of multidrug resistance in the predominant Streptococcus pneumoniae serotypes in Canada:the SAVE study, 2011-15

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    Objectives: This study assessed MDR invasive isolates of Streptococcus pneumoniae, in relation to serotype evolution in Canada between 2011 and 2015 as part of the annual SAVE study. Methods: As part of a collaboration between the Canadian Antimicrobial Resistance Alliance and Public Health Agency of Canada-National Microbiology Laboratory, 6207 invasive isolates of S. pneumoniae were evaluated. All isolates were serotyped and had antimicrobial susceptibility testing performed, in accordance with CLSI guidelines (M07-A10, 2015). Complete susceptibility profiles were available for 6001 isolates. MDR was defined as resistance to three or more classes of antimicrobial agents (with penicillin MIC ≥2 mg/L defined as resistant). Results: The overall rate of MDR S. pneumoniae was 6.2% (372/6001) in SAVE, decreasing significantly from 8.5% in 2011 to 5.6% in 2015 (P = 0.0041). MDR was observed in 32 serotypes, with serotypes 15A and 19A predominating (26.6% and 41.7% of the MDR isolates, respectively). The overall proportion of serotypes 19A, 7F and 33A decreased significantly (P 5%) for 24F and 33F. Conclusions: In 2015, 56.3% of invasive MDR S. pneumoniae were serotypes included in the PCV-13 vaccine. PCV-13 includes the most commonly identified serotype, 19A; however, other increasingly important MDR serotypes, such as 15A, 24F and 33F, are notably not in the currently used vaccines

    Use of Zebrafish to Probe the Divergent Virulence Potentials and Toxin Requirements of Extraintestinal Pathogenic Escherichia coli

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    Extraintestinal pathogenic E. coli (ExPEC) cause an array of diseases, including sepsis, neonatal meningitis, and urinary tract infections. Many putative virulence factors that might modulate ExPEC pathogenesis have been identified through sequencing efforts, epidemiology, and gene expression profiling, but few of these genes have been assigned clearly defined functional roles during infection. Using zebrafish embryos as surrogate hosts, we have developed a model system with the ability to resolve diverse virulence phenotypes and niche-specific restrictions among closely related ExPEC isolates during either localized or systemic infections. In side-by-side comparisons of prototypic ExPEC isolates, we observed an unexpectedly high degree of phenotypic diversity that is not readily apparent using more traditional animal hosts. In particular, the capacity of different ExPEC isolates to persist and multiply within the zebrafish host and cause disease was shown to be variably dependent upon two secreted toxins, α-hemolysin and cytotoxic necrotizing factor. Both of these toxins appear to function primarily in the neutralization of phagocytes, which are recruited in high numbers to sites of infection where they act as an essential host defense against ExPEC as well as less virulent E. coli strains. These results establish zebrafish as a valuable tool for the elucidation and functional analysis of both ExPEC virulence factors and host defense mechanisms
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