Quantum mechanics/molecular mechanics modeling of drug metabolism:Mexiletine N-hydroxylation by cytochrome P450 1A2

The mechanism of cytochrome P450­(CYP)-catalyzed hydroxylation of primary amines is currently unclear and is relevant to drug metabolism; previous small model calculations have suggested two possible mechanisms: direct N-oxidation and H-abstraction/rebound. We have modeled the N-hydroxylation of (<i>R</i>)-mexiletine in CYP1A2 with hybrid quantum mechanics/molecular mechanics (QM/MM) methods, providing a more detailed and realistic model. Multiple reaction barriers have been calculated at the QM­(B3LYP-D)/MM­(CHARMM27) level for the direct N-oxidation and H-abstraction/rebound mechanisms. Our calculated barriers indicate that the direct N-oxidation mechanism is preferred and proceeds via the doublet spin state of Compound I. Molecular dynamics simulations indicate that the presence of an ordered water molecule in the active site assists in the binding of mexiletine in the active site, but this is not a prerequisite for reaction via either mechanism. Several active site residues play a role in the binding of mexiletine in the active site, including Thr124 and Phe226. This work reveals key details of the N-hydroxylation of mexiletine and further demonstrates that mechanistic studies using QM/MM methods are useful for understanding drug metabolism

The impact of health literacy and life style risk factors on health-related quality of life of Australian patients

BACKGROUND: Limited evidence exists regarding the relationship between health literacy and health-related quality of life (HRQoL) in Australian patients from primary care. The objective of this study was to investigate the impact of health literacy on HRQoL in a large sample of patients without known vascular disease or diabetes and to examine whether the difference in HRQoL between low and high health literacy groups was clinically significant. METHODS: This was a cross-sectional study of baseline data from a cluster randomised trial. The study included 739 patients from 30 general practices across four Australian states conducted in 2012 and 2013 using the standard Short Form Health Survey (SF-12) version 2. SF-12 physical component score (PCS-12) and mental component score (MCS-12) are derived using the standard US algorithm. Health literacy was measured using the Health Literacy Management Scale (HeLMS). Multilevel regression analysis (patients at level 1 and general practices at level 2) was applied to relate PCS-12 and MCS-12 to patient reported life style risk behaviours including health literacy and demographic factors. RESULTS: Low health literacy patients were more likely to be smokers (12 % vs 6 %, P&thinsp;=&thinsp;0.005), do insufficient physical activity (63 % vs 47 %, P&thinsp;&lt;&thinsp;0.001), be overweight (68 % vs 52 %, P&thinsp;&lt;&thinsp;0.001), and have lower physical health and lower mental health with large clinically significant effect sizes of 0.56 (B (regression coefficient)&thinsp;= -5.4, P&thinsp;&lt;&thinsp;0.001) and 0.78(B&thinsp;=&thinsp;-6.4, P&thinsp;&lt;&thinsp;0.001) respectively after adjustment for confounding factors. Patients with insufficient physical activity were likely to have a lower physical health score (effect size&thinsp;=&thinsp;0.42, B&thinsp;= -3.1, P&thinsp;&lt;&thinsp;0.001) and lower mental health (effect size&thinsp;=&thinsp;0.37, B&thinsp;= -2.6, P&thinsp;&lt;&thinsp;0.001). Being overweight tended to be related to a lower PCS-12 (effect size&thinsp;=&thinsp;0.41, B&thinsp;=&thinsp;-1.8, P&thinsp;&lt;&thinsp;0.05). Less well-educated, unemployed and smoking patients with low health literacy reported worse physical health. Health literacy accounted for 45 and 70 % of the total between patient variance explained in PCS-12 and MCS-12 respectively. CONCLUSIONS: Addressing health literacy related barriers to preventive care may help reduce some of the disparities in HRQoL. Recognising and tailoring health related communication to those with low health literacy may improve health outcomes including HRQoL in general practice

SARS-CoV-2 omicron (B.1.1.529)-related COVID-19 sequelae in vaccinated and unvaccinated patients with cancer: results from the OnCovid registry

Background COVID-19 sequelae can affect about 15% of patients with cancer who survive the acute phase of SARS-CoV-2 infection and can substantially impair their survival and continuity of oncological care. We aimed to investigate whether previous immunisation affects long-term sequelae in the context of evolving variants of concern of SARS-CoV-2. Methods OnCovid is an active registry that includes patients aged 18 years or older from 37 institutions across Belgium, France, Germany, Italy, Spain, and the UK with a laboratory-confirmed diagnosis of COVID-19 and a history of solid or haematological malignancy, either active or in remission, followed up from COVID-19 diagnosis until death. We evaluated the prevalence of COVID-19 sequelae in patients who survived COVID-19 and underwent a formal clinical reassessment, categorising infection according to the date of diagnosis as the omicron (B.1.1.529) phase from Dec 15, 2021, to Jan 31, 2022; the alpha (B.1.1.7)-delta (B.1.617.2) phase from Dec 1, 2020, to Dec 14, 2021; and the pre-vaccination phase from Feb 27 to Nov 30, 2020. The prevalence of overall COVID-19 sequelae was compared according to SARS-CoV-2 immunisation status and in relation to post-COVID-19 survival and resumption of systemic anticancer therapy. This study is registered with ClinicalTrials.gov, NCT04393974. Findings At the follow-up update on June 20, 2022, 1909 eligible patients, evaluated after a median of 39 days (IQR 24-68) from COVID-19 diagnosis, were included (964 [ 50 center dot 7%] of 1902 patients with sex data were female and 938 [49 center dot 3%] were male). Overall, 317 (16 center dot 6%; 95% CI 14 center dot 8-18 center dot 5) of 1909 patients had at least one sequela from COVID-19 at the first oncological reassessment. The prevalence of COVID-19 sequelae was highest in the prevaccination phase (191 [19 center dot 1%; 95% CI 16 center dot 4-22 center dot 0] of 1000 patients). The prevalence was similar in the alpha-delta phase (110 [16 center dot 8%; 13 center dot 8- 20 center dot 3] of 653 patients, p=0 center dot 24), but significantly lower in the omicron phase (16 [6 center dot 2%; 3 center dot 5-10 center dot 2] of 256 patients, p<0 center dot 0001). In the alpha- delta phase, 84 (18 center dot 3%; 95% CI 14 center dot 6-22 center dot 7) of 458 unvaccinated patients and three (9 center dot 4%; 1 center dot 9- 27 center dot 3) of 32 unvaccinated patients in the omicron phase had sequelae. Patients who received a booster and those who received two vaccine doses had a significantly lower prevalence of overall COVID-19 sequelae than unvaccinated or partially vaccinated patients (ten [7 center dot 4%; 95% CI 3 center dot 5-13 center dot 5] of 136 boosted patients, 18 [9 center dot 8%; 5 center dot 8-15 center dot 5] of 183 patients who had two vaccine doses vs 277 [ 18 center dot 5%; 16 center dot 5-20 center dot 9] of 1489 unvaccinated patients, p=0 center dot 0001), respiratory sequelae (six [4 center dot 4%; 1 center dot 6-9 center dot 6], 11 [6 center dot 0%; 3 center dot 0-10 center dot 7] vs 148 [9 center dot 9%; 8 center dot 4- 11 center dot 6], p= 0 center dot 030), and prolonged fatigue (three [2 center dot 2%; 0 center dot 1-6 center dot 4], ten [5 center dot 4%; 2 center dot 6-10 center dot 0] vs 115 [7 center dot 7%; 6 center dot 3-9 center dot 3], p=0 center dot 037)

Quantum Mechanics/Molecular Mechanics Modeling of Drug Metabolism: Mexiletine N-Hydroxylation by Cytochrome P450 1A2

The mechanism of cytochrome P450(CYP)-catalyzed hydroxylation of primary amines is currently unclear, and is relevant to drug metabolism. Previous small model calculations have suggested two possible mechanisms: direct N-oxidation and H-abstraction/rebound. We have modeled the N-hydroxylation of (R)-mexiletine in CYP1A2 with hybrid quantum mechanics/molecular mechanics (QM/MM) methods, providing a more detailed and realistic model. Multiple reaction barriers have been calculated at the QM(B3LYP- D)/MM(CHARMM27) level for the direct N-oxidation and H-abstraction/rebound mechanisms. Our calculated barriers indicate that the direct N-oxidation mechanism is preferred and proceeds via the doublet spin state of Compound I. Molecular dynam- ics simulations indicate that the presence of an ordered water molecule in the active site assists in the binding of mexiletine in the active site, but is not a prerequisite for reaction via either mechanism. Several active site residues play a role in the binding of mexiletine in the active site, including Thr124 and Phe226. This work reveals key details in the N-hydroxylation of mexiletine and further demonstrates that mechanistic studies using QM/MM methods are useful for understanding drug metabolism.status: publishe

Protocol for a scoping review of health equity frameworks and models applied in empirical studies of chronic disease prevention and control

Abstract Background Chronic diseases, such as cancers and cardiovascular diseases, present the greatest burden of morbidity and mortality worldwide. This burden disproportionately affects historically marginalized populations. Health equity is rapidly gaining increased attention in public health, health services, and implementation research, though many health inequities persist. Health equity frameworks and models (FM) have been called upon to guide equity-focused chronic disease and implementation research. However, there is no clear synthesis of the health equity FM used in chronic disease research or how these are applied in empirical studies. This scoping review seeks to fill this gap by identifying and characterizing health equity FM applied in empirical studies along the chronic disease prevention and control continuum, describing how these FM are used, and exploring potential applications to the field of implementation science. Methods We follow established guidance for conducting scoping reviews, which includes six stages: (1) identify the research question; (2) identify relevant studies; (3) select studies for inclusion; (4) data extraction; (5) collating, summarizing, and reporting the results; and (6) consultation. This protocol presents the iterative, collaborative approach taken to conceptualize this study and develop the search strategy. We describe the criteria for inclusion in this review, methods for conducting two phases of screening (title and abstract, full text), data extraction procedures, and quality assurance approaches taken throughout the project. Discussion The findings from this review will inform health-equity focused chronic disease prevention and control research. FM identified through this review will be added to an existing website summarizing dissemination and implementation science frameworks, and we will offer case examples and recommendations for utilizing a health equity FM in empirical studies. Our search strategy and review methodology may serve as an example for scholars seeking to conduct reviews of health equity FM in other health disciplines. Systematic review registration Open Science Framework Registration https://doi.org/10.17605/OSF.IO/SFVE

Amine-reactive OVA multimers for auto-vaccination against cytokines and other mediators: perspectives illustrated for GCP-2 in L. major infection.

Anticytokine auto-vaccination is a powerful tool for the study of cytokine functions in vivo but has remained rather esoteric as a result of numerous technical difficulties. We here describe a two-step procedure based on the use of OVA multimers purified by size exclusion chromatography after incubation with glutaraldehyde at pH 6. When such polymers are incubated with a target protein at pH 8.5 to deprotonate reactive amines, complexes are formed that confer immunogenicity to self-antigens. The chemokine GCP-2/CXCL6, the cytokines GM-CSF, IL-17F, IL-17E/IL-25, IL-27, and TGF-β1, and the MMP-9/gelatinase B are discussed as examples. mAb, derived from such immunized mice, have obvious advantages for in vivo studies of the target proteins. Using a mAb against GCP-2, obtained by the method described here, we provide the first demonstration of the major role played by this chemokine in rapid neutrophil mobilization after Leishmania major infection. Pre-activated OVA multimers reactive with amine residues thus provide an efficient carrier for auto-vaccination against 9-90 kDa autologous proteins