Nucleoside analogs have proven effective for the inhibition of viral polymerases and are the foundation of many antiviral therapies. In this work, the antiretroviral potential of 6-azauracil analogs ...was assessed using activity-based protein profiling techniques and functional assays. Probes based on the 6-azauracil scaffold were examined and found to bind to HCV polymerase and HIV-1 reverse transcriptase through covalent modification of residues near the active site. The modified sites on the HIV-1 RT were examined using a mass spectrometry approach, and it was discovered that the azauracil moieties modified the enzyme in proximity to its active site. However, these scaffolds gave little or no inhibition of enzyme activity. Instead, a bifunctional inhibitor was prepared using click chemistry to link the 6-azauracil moiety to azidothymidine (AzT) and the corresponding triphosphate (AzTTP). These bifunctional inhibitors were found to have potent inhibitory function through a mode of action that includes both alkylation and chain termination. An in vitro assay demonstrated that the bifunctional inhibitor was 23-fold more effective in inhibiting HIV-1 RT activity than the parent AzTTP. The bifunctional inhibitor was also tested in HIV-1 permissive T cells where it decreased Gag expression similarly to the front-line drug Efavirenz with no evidence of cytotoxicity. This new bifunctional scaffold represents an interesting tool for inhibiting HIV-1 by covalently anchoring a chain-terminating nucleoside analog in the active site of the reverse transcriptase, preventing its removal and abolishing enzymatic activity, and represents a novel mode of action for inhibiting polymerases including reverse transcriptases.
The end-Ordovician was an enigmatic interval in the Phanerozoic, known for massive glaciation potentially at elevated CO2 levels, biogeochemical cycle disruptions recorded as large isotope anomalies ...and a devastating extinction event. Ice-sheet volumes claimed to be twice those of the Last Glacial Maximum paradoxically coincided with oceans as warm as today. Here we argue that some of these remarkable claims arise from undersampling of incomplete geological sections that led to apparent temporal correlations within the relatively coarse resolution capability of Palaeozoic biochronostratigraphy. We examine exceptionally complete sedimentary records from two, low and high, palaeolatitude settings. Their correlation framework reveals a Cenozoic-style scenario including three main glacial cycles and higher-order phenomena. This necessitates revision of mechanisms for the end-Ordovician events, as the first extinction is tied to an early phase of melting, not to initial cooling, and the largest δ(13)C excursion occurs during final deglaciation, not at the glacial apex.
Ubiquitination was recently identified as a central process in the pathogenesis and development of numerous inflammatory diseases, such as obesity, atherosclerosis, and asthma. Treatment with ...proteasomal inhibitors led to severe side effects because ubiquitination is heavily involved in a plethora of cellular functions. Thus, new players regulating ubiquitination processes must be identified to improve therapies for inflammatory diseases. In addition to their role in adaptive immunity, endosomal MHC class II (MHCII) molecules were shown to modulate innate immune responses by fine tuning the TLR4 signaling pathway. However, the role of MHCII ubiquitination by membrane associated ring-CH-type finger 1 (MARCH1) E3 ubiquitin ligase in this process remains to be assessed. In this article, we demonstrate that MARCH1 is a key inhibitor of innate inflammation in response to bacterial endotoxins. The higher mortality of March1
mice challenged with a lethal dose of LPS was associated with significantly stronger systemic production of proinflammatory cytokines and splenic NK cell activation; however, we did not find evidence that MARCH1 modulates LPS or IL-10 signaling pathways. Instead, the mechanism by which MARCH1 protects against endotoxic shock rests on its capacity to promote the transition of monocytes from Ly6C
to Ly6C
Moreover, in competitive bone marrow chimeras, March1
monocytes and polymorphonuclear neutrophils outcompeted wild-type cells with regard to bone marrow egress and homing to peripheral organs. We conclude that MARCH1 exerts MHCII-independent effects that regulate the innate arm of immunity. Thus, MARCH1 might represent a potential new target for emerging therapies based on ubiquitination reactions in inflammatory diseases.
Context
Although the spatiotemporal dynamics of spruce budworm outbreaks have been intensively studied, forecasting outbreaks remains challenging. During outbreaks, budworm-linked warblers ...(Tennessee, Cape May, and bay-breasted warbler) show a strong positive response to increases in spruce budworm, but little is known about the relative timing of these responses.
Objectives
We hypothesized that these warblers could be used as sentinels of future defoliation of budworm host trees. We examined the timing and magnitude of the relationships between defoliation by spruce budworm and changes in the probability of presence of warblers to determine whether they responded to budworm infestation before local defoliation being observed by standard detection methods.
Methods
We modelled this relationship using large-scale point count surveys of songbirds and maps of cumulative time-lagged defoliation over multiple spatial scales (2–30 km radius around sampling points) in Quebec, Canada.
Results
All three warbler species responded positively to defoliation at each spatial scale considered, but the timing of their response differed. Maximum probability of presence of Tennessee and Cape May warbler coincided with observations of local defoliation, or provided a one year warning, making them of little use to guide early interventions. In contrast, the probability of presence of bay-breasted warbler consistently increased 3–4 years before defoliation was detectable.
Conclusions
Early detection is a critical step in the management of spruce budworm outbreaks and rapid increases in the probability of presence of bay-breasted warbler could be used to identify future epicenters and target ground-based local sampling of spruce budworm.
Stable (H,O,N,C) and radiogenic isotope (Sr) data for cheese, milk, animal feed and soil from six artisanal cheese producers in Quebec, Canada, demonstrated the potential of isotope geochemistry in ...linking land/terroir to agricultural produce. The hydrogen and oxygen isotope compositions of the water, milk and cheese samples showed good general alignment with the Global Meteoric Water Line, with small off-sets in the milk and cheese samples related to cheese production. Carbon and nitrogen isotope data for the cheese and milk reflect the diet of the cattle and fertilization of the cattle grazing pastures. The strontium isotope compositions of the soils, milk and cheese are similar for a given farm/cheese producer, but vary widely between producers due to differences in geology. Combining the climate-sensitive δ18O and geology-sensitive 87Sr/86Sr proxies shows potential for discriminating between Quebec artisanal cheeses, commercial Canadian cheeses and European cheeses.
Appropriate training for community pharmacists may improve the quality of medication use. Few studies have reported the impact of such programs on medication management for patients with chronic ...kidney disease (CKD).
Multicenter, cluster-randomized, controlled trial.
Patients with CKD stage 3a, 3b, or 4 from 6 CKD clinics (Quebec, Canada) and their community pharmacies.
Each cluster (a pharmacy and its patients) was randomly assigned to either ProFiL, a training-and-communication network program, or the control group. ProFiL pharmacists completed a 90-minute interactive web-based training program on use of medications in CKD and received a clinical guide, patients’ clinical summaries, and facilitated access to the CKD clinic.
Drug-related problems (primary outcome), pharmacists’ knowledge and clinical skills, and patients’ clinical attributes (eg, blood pressure and glycated hemoglobin concentration).
Drug-related problems were evaluated the year before and after the recruitment of patients using a validated set of significant drug-related problems, the Pharmacotherapy Assessment in Chronic Renal Disease (PAIR) criteria. Pharmacists’ questionnaires were completed at baseline and after 1 year. Clinical attributes were documented at baseline and after 1 year using available information in medical charts.
207 community pharmacies, 494 pharmacists, and 442 patients with CKD participated. After 1 year, the mean number of drug-related problems per patient decreased from 2.16 to 1.60 and from 1.70 to 1.62 in the ProFiL and control groups, respectively. The difference in reduction of drug-related problems per patient between the ProFiL and control groups was −0.32 (95% CI, −0.63 to −0.01). Improvements in knowledge (difference, 4.5%; 95% CI, 1.6%-7.4%) and clinical competencies (difference, 7.4%; 95% CI, 3.5%-11.3%) were observed among ProFiL pharmacists. No significant differences in clinical attributes were observed across the groups.
High proportion of missing data on knowledge and clinical skills questionnaire (34.6%) and clinical attributes (11.1%).
Providing community pharmacists with essential clinical data, appropriate training, and support from hospital pharmacists with expertise in nephrology increases pharmacists’ knowledge and reduces drug-related problems in patients with CKD who are followed up in clinics incorporating a multidisciplinary health care team.
Aluminium is increasingly replacing steel in many structural applications, primarily for its lightness and corrosion resistance. Such replacement remains a challenge requiring careful design and ...sizing to compensate for the aluminium Young modulus, toward a comparable level of reliability or rigidity. To that end, for road transport or bridge applications, extrusions are typically used along with welded, bolted, riveted or adhesively assembled connections. Breaking free from this constraint by designing profiles that are assembled by mechanical clips, using the elasticity of aluminium, is therefore a sensible alternative from cost, performance, and assembly time viewpoints.
This study is based on finite element analysis and sizing of assembly forces, strength for typical load cases and geometrical optimization. This work is conducted on SolidWorks for design and ANSYS for simulations with many adjustments between these two software programs. An experimental study is also carried out on custom made extrusions subjected to assembly, static, and fatigue tests. The overall objective of this work is to propose a sizing and testing methodology for extruded aluminium profiles assembled by mechanical snap-fit.
The signalling output of many transmembrane receptors that mediate cell-cell communication is restricted by the endosomal sorting complex required for transport (ESCRT), but the impact of this ...machinery on Eph tyrosine kinase receptor function is unknown. We identified the ESCRT-associated adaptor protein HD-PTP as part of an EphB2 proximity-dependent biotin identification (BioID) interactome, and confirmed this association using co-immunoprecipitation. HD-PTP loss attenuates the ephrin-B2:EphB2 signalling-induced collapse of cultured cells and axonal growth cones, and results in aberrant guidance of chick spinal motor neuron axons in vivo. HD-PTP depletion abrogates ephrin-B2-induced EphB2 clustering, and EphB2 and Src family kinase activation. HD-PTP loss also accelerates ligand-induced EphB2 degradation, contrasting the effects of HD-PTP loss on the relay of signals from other cell surface receptors. Our results link Eph function to the ESCRT machinery and demonstrate a role for HD-PTP in the earliest steps of ephrin-B:EphB signalling, as well as in obstructing premature receptor depletion.
Background Explicit criteria for judging medication safety and use issues in patients with chronic kidney disease (CKD) are lacking. Study Design Quality improvement report. Setting & Participants ...Nephrologists (n = 4), primary care physicians (n = 2), hospital pharmacists with expertise in nephrology (n = 4), and community pharmacists (n = 2). The PAIR (Pharmacotherapy Assessment in Chronic Renal Disease) criteria were applied retrospectively to 90 patients with CKD in a randomized study. Quality Improvement Plan Development of an explicit set of criteria to enable rapid and systematic detection of drug-related problems (DRPs). Using a RAND method, experts judged the clinical significance of DRPs and the appropriateness of a community pharmacist intervention. The PAIR criteria include 50 DRPs grouped into 6 categories. Outcomes DRPs detected using the PAIR criteria compared with implicit clinical judgment by nephrology pharmacists. Measurements Prevalence of DRPs and reliability, validity, and responsiveness of the PAIR criteria. Results A mean of 2.5 DRPs/patient (95% CI, 2.0-3.1) was identified based on the PAIR criteria compared with 3.9 DRPs/patient (95% CI, 3.4-4.5) based on clinical judgment of nephrology pharmacists. Inter-rater reliability coefficients (κ) by PAIR category varied from 0.80-1.00, with an intraclass correlation coefficient (ICC) of 0.93 (95% CI, 0.89-0.95) for total DRPs per patient. Test-retest reliability coefficients by category varied from 0.74-1.00, with an ICC of 0.91 (95% CI, 0.82-0.96) for total DRPs per patient. During the study, the mean number of DRPs per patient did not change significantly when assessed using the PAIR criteria and clinical judgment. Limitation The prevalence of PAIR DRPs may be underestimated due to the retrospective nature of the validation. Conclusion The prevalence of DRPs requiring the intervention of community pharmacists is high in patients with CKD. The PAIR criteria are reliable, but their responsiveness remains to be shown.
Introduction:
Chronic kidney disease (CKD) patients are multimorbid elderly at high risk of drug‐related problems. A Web‐based training program was developed based on a list of significant ...drug‐related problems in CKD patients requiring a pharmaceutical intervention. The objectives were to evaluate the impact of the program on community pharmacists' knowledge and skills and their satisfaction with the training.
Methods:
Pharmacists were randomized to the training program or the control group. Training comprised a 60‐minute Web‐based interactive session supported by a clinical guide. Pharmacists completed a questionnaire on knowledge (10 multiple‐choice questions) and skills (2 clinical vignettes) at baseline and a second time within 1 month. Trained pharmacists completed a written satisfaction questionnaire. Semidirected telephone interviews were conducted with 8 trained pharmacists. Changes in knowledge and skills scores were compared between the groups.
Results:
Seventy pharmacists (training: 52; control: 18) were recruited; the majority were women with <15 years' experience. Compared with the control group, an adjusted incremental increase in the knowledge score (22%; 95% confidence interval CI: 16%–27%) and skills score (24%; 95% CI: 16%–33%) was observed in the training group. Most pharmacists (87%–100%) rated each aspect of the program “excellent'' or “very good.” Additional training and adding a discussion forum were suggested to complement the program.
Discussion:
Pharmacists like the Web‐based continuing education program. Over a short time span, the program improved their knowledge and skills. Its impact on their clinical practices and quality of medication use in CKD patients remains to be assessed.
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