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1.
Nat Rev Genet ; 25(7): 460-475, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38366034

RESUMO

Short tandem repeats (STRs) are highly polymorphic sequences throughout the human genome that are composed of repeated copies of a 1-6-bp motif. Over 1 million variable STR loci are known, some of which regulate gene expression and influence complex traits, such as height. Moreover, variants in at least 60 STR loci cause genetic disorders, including Huntington disease and fragile X syndrome. Accurately identifying and genotyping STR variants is challenging, in particular mapping short reads to repetitive regions and inferring expanded repeat lengths. Recent advances in sequencing technology and computational tools for STR genotyping from sequencing data promise to help overcome this challenge and solve genetically unresolved cases and the 'missing heritability' of polygenic traits. Here, we compare STR genotyping methods, analytical tools and their applications to understand the effect of STR variation on health and disease. We identify emergent opportunities to refine genotyping and quality-control approaches as well as to integrate STRs into variant-calling workflows and large cohort analyses.


Assuntos
Genoma Humano , Repetições de Microssatélites , Humanos , Repetições de Microssatélites/genética , Análise de Sequência de DNA/métodos , Técnicas de Genotipagem/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Genótipo
2.
Nature ; 610(7933): 775-782, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36261529

RESUMO

The ubiquitin E3 ligase substrate adapter cereblon (CRBN) is a target of thalidomide and lenalidomide1, therapeutic agents used in the treatment of haematopoietic malignancies2-4 and as ligands for targeted protein degradation5-7. These agents are proposed to mimic a naturally occurring degron; however, the structural motif recognized by the thalidomide-binding domain of CRBN remains unknown. Here we report that C-terminal cyclic imides, post-translational modifications that arise from intramolecular cyclization of glutamine or asparagine residues, are physiological degrons on substrates for CRBN. Dipeptides bearing the C-terminal cyclic imide degron substitute for thalidomide when embedded within bifunctional chemical degraders. Addition of the degron to the C terminus of proteins induces CRBN-dependent ubiquitination and degradation in vitro and in cells. C-terminal cyclic imides form adventitiously on physiologically relevant timescales throughout the human proteome to afford a degron that is endogenously recognized and removed by CRBN. The discovery of the C-terminal cyclic imide degron defines a regulatory process that may affect the physiological function and therapeutic engagement of CRBN.


Assuntos
Imidas , Proteólise , Complexos Ubiquitina-Proteína Ligase , Humanos , Asparagina/química , Dipeptídeos/farmacologia , Glutamina/química , Imidas/química , Imidas/metabolismo , Lenalidomida/farmacologia , Ligantes , Peptídeo Hidrolases/metabolismo , Proteólise/efeitos dos fármacos , Proteoma/metabolismo , Talidomida/farmacologia , Ubiquitinação/efeitos dos fármacos , Motivos de Aminoácidos , Ciclização
3.
Nucleic Acids Res ; 51(11): 5714-5742, 2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37125644

RESUMO

The bacterial RecF, RecO, and RecR proteins are an epistasis group involved in loading RecA protein into post-replication gaps. However, the targeting mechanism that brings these proteins to appropriate gaps is unclear. Here, we propose that targeting may involve a direct interaction between RecF and DnaN. In vivo, RecF is commonly found at the replication fork. Over-expression of RecF, but not RecO or a RecF ATPase mutant, is extremely toxic to cells. We provide evidence that the molecular basis of the toxicity lies in replisome destabilization. RecF over-expression leads to loss of genomic replisomes, increased recombination associated with post-replication gaps, increased plasmid loss, and SOS induction. Using three different methods, we document direct interactions of RecF with the DnaN ß-clamp and DnaG primase that may underlie the replisome effects. In a single-molecule rolling-circle replication system in vitro, physiological levels of RecF protein trigger post-replication gap formation. We suggest that the RecF interactions, particularly with DnaN, reflect a functional link between post-replication gap creation and gap processing by RecA. RecF's varied interactions may begin to explain how the RecFOR system is targeted to rare lesion-containing post-replication gaps, avoiding the potentially deleterious RecA loading onto thousands of other gaps created during replication.


Assuntos
Proteínas de Ligação a DNA , Proteínas de Escherichia coli , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Reparo do DNA , Replicação do DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo
4.
Ann Neurol ; 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37638552

RESUMO

OBJECTIVE: This study was undertaken to test the hypothesis that early vigabatrin treatment in tuberous sclerosis complex (TSC) infants improves neurocognitive outcome at 24 months of age. METHODS: A phase IIb multicenter randomized double-blind placebo-controlled trial was conducted of vigabatrin at first epileptiform electroencephalogram (EEG) versus vigabatrin at seizure onset in infants with TSC. Primary outcome was Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) cognitive assessment score at 24 months. Secondary outcomes were prevalence of drug-resistant epilepsy, additional developmental outcomes, and safety of vigabatrin. RESULTS: Of 84 infants enrolled, 12 were screen failures, 4 went straight to open label vigabatrin, and 12 were not randomized (normal EEG throughout). Fifty-six were randomized to early vigabatrin (n = 29) or placebo (n = 27). Nineteen of 27 in the placebo arm transitioned to open label vigabatrin, with a median delay of 44 days after randomization. Bayley-III cognitive composite scores at 24 months were similar for participants randomized to vigabatrin or placebo. Additionally, no significant differences were found between groups in overall epilepsy incidence and drug-resistant epilepsy at 24 months, time to first seizure after randomization, and secondary developmental outcomes. Incidence of infantile spasms was lower and time to spasms after randomization was later in the vigabatrin group. Adverse events were similar across groups. INTERPRETATION: Preventative treatment with vigabatrin based on EEG epileptiform activity prior to seizure onset does not improve neurocognitive outcome at 24 months in TSC children, nor does it delay onset or lower the incidence of focal seizures and drug-resistant epilepsy at 24 months. Preventative vigabatrin was associated with later time to onset and lower incidence of infantile spasms. ANN NEUROL 2023.

5.
J Nutr ; 154(5): 1676-1685, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38582388

RESUMO

BACKGROUND: Matrix effects are a known problem with immunoassays measuring serum 25-hydroxyvitamin D [25(OH)D]. OBJECTIVES: To determine if the inverse association between serum 25(OH)D and serum cholesterol concentrations is a function of assay method: Diasorin Liaison 25(OH) Vitamin D Total Assay (Liaison Total Assay), an immunoassay, compared with liquid chromatography tandem mass spectrometry (LC-MS/MS). METHODS: Canadian Health Measures Survey data and biobank serum (White males aged 20-79 y, n = 392) were evaluated for bias in serum 25(OH)D using Bland-Altman plots. Differences in serum 25(OH)D (Liaison Total Assay - LC-MS/MS) were compared among non-HDL-cholesterol <4.2 (n = 295) compared with ≥4.2 (n = 97) mmol/L and total cholesterol groups <5.2 (n = 256) compared with ≥5.2 (n = 136) mmol/L, and associations tested between 25(OH)D and non-HDL-cholesterol or total cholesterol concentrations, using regression. RESULTS: Serum 25(OH)D measured using Liaison Total Assay ranged from 10.7 to 137.0 nmol/L and 14.4 to 137.9 nmol/L by LC-MS/MS. Liaison Total Assay - LC-MS/MS showed a negative bias of 5.5 (95% limits of agreement -23.8, 12.7) nmol/L. Differences in 25(OH)D were -4.0 ± 9.0 (±SD) nmol/L if non-HDL-cholesterol was <4.2 mmol/L and -10.2 ± 8.7 nmol/L if ≥4.2 mmol/L (P < 0.0001). Differences in 25(OH)D, if total cholesterol was <5.2 mmol/L, were -3.4 ± 8.6 nmol/L and -9.6 ± 9.3 nmol/L if ≥5.2 mmol/L (P < 0.0001). Serum non-HDL-cholesterol (beta -3.17, P = 0.0014) and total cholesterol (beta -2.77, P = 0.0046) were inversely associated with Liaison Total Assay 25(OH)D (adjusted for age, fasting, and body mass index), but not with LC-MS/MS measured 25(OH)D. Interference by these lipoproteins was not eliminated by standardization of the Liaison Total Assay. Similar associations were observed with triglycerides as for the lipoproteins. CONCLUSIONS: Total cholesterol inversely associates with 25(OH)D, which is likely due to elevated non-HDL-cholesterol lipoprotein or triglyceride interference with the Liaison Total Assay. This is important as elevated cholesterol is common, and an underestimation of vitamin D status could be an unnecessary cause for concern.


Assuntos
Colesterol , Espectrometria de Massas em Tandem , Vitamina D , Humanos , Masculino , Pessoa de Meia-Idade , Vitamina D/sangue , Vitamina D/análogos & derivados , Adulto , Canadá , Idoso , Colesterol/sangue , Adulto Jovem , Cromatografia Líquida , Imunoensaio , Inquéritos Epidemiológicos , Bancos de Espécimes Biológicos , Estado Nutricional , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia
6.
J Nutr ; 154(5): 1665-1675, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38527736

RESUMO

BACKGROUND: In Canada, nutrition policy, as outlined in the Nutrition for Healthy Term Infants recommendations, includes a daily vitamin D supplement of 10 µg (400 IU) for breastfed infants and young children to support adequate vitamin D status. OBJECTIVES: This study aimed to report on adherence to vitamin D supplementation recommendations for breastfed infants (≤12 months); and for children breastfed >12 mo. METHODS: Canadian Community Health Survey (paired-cycles 2015/2016 and 2017/2018) maternal experiences data for infants born 2012-2018 who received any breastmilk formed the sample (n = 7079). Whether the infant was given a vitamin D supplement (yes/no) and the frequency (daily/almost every day, 1-2/wk, or <1/wk) were surveyed. Weighted data (95% CI) were summarized according to breastfeeding history (exclusive to 6 mo and continuing; partial to 6 mo and continuing; and stopped ≤6 mo). Correlates of supplement adherence were explored using logistic regression. RESULTS: Overall, 87.1% (95% CI: 85.9%, 88.3%) of participants reported giving their infant (≤12 mo) a vitamin D supplement, and of these, 83.3% (95% CI: 81.9%, 84.7%) did so daily/almost every day, 12.4% (95% CI: 11.1%, 13.7%) did so 1-2/wk, and 4.3% (95% CI: 3.6%, 5.0%) did so <1/wk. Lower adjusted odds of adherence were observed among participants reporting: stopped breastfeeding ≤6 mo, lower education or income, recent immigration, and overweight prepregnancy body mass index; higher odds of adherence were observed in the western provinces. Regarding mothers of children >12 mo and breastfed (n = 2312), 58.0% (95% CI: 54.9%, 61.1%) gave a vitamin D supplement daily/almost every day. CONCLUSIONS: Adherence to providing a vitamin D supplement to breastfed infants is high in Canada. Nonetheless, we estimate that ∼27% of mothers are nonadherent to daily/almost every day administration of a vitamin D supplement and that adherence declines in children breastfed >12 mo. Further promotion to support uptake of the current guidance may be necessary, particularly for parents of recent immigration or lower socioeconomic status.


Assuntos
Aleitamento Materno , Suplementos Nutricionais , Vitamina D , Humanos , Lactente , Vitamina D/administração & dosagem , Canadá , Feminino , Masculino , Adulto , Recém-Nascido , Inquéritos Epidemiológicos , Pré-Escolar , Deficiência de Vitamina D/prevenção & controle
7.
BMC Med Res Methodol ; 24(1): 103, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38698315

RESUMO

BACKGROUND: Use of participatory research methods is increasing in research trials. Once partnerships are established with end-users, there is less guidance about processes research teams can use to successfully incorporate end-user feedback. The current study describes the use of a brief reflections process to systematically examine and evaluate the impact of end-user feedback on study conduct. METHODS: The Comparative Effectiveness of Trauma-Focused and Non-Trauma- Focused Treatment Strategies for PTSD among those with Co-Occurring SUD (COMPASS) study was a randomized controlled trial to determine the effectiveness of trauma-focused psychotherapy versus non-trauma-focused psychotherapy for Veterans with co-occurring posttraumatic stress disorder and substance use disorder who were entering substance use treatment within the Department of Veterans Affairs. We developed and paired a process of "brief reflections" with our end-user engagement methods as part of a supplemental evaluation of the COMPASS study engagement plan. Brief reflections were 30-minute semi-structured discussions with the COMPASS Team following meetings with three study engagement panels about feedback received regarding study issues. To evaluate the impact of panel feedback, 16 reflections were audio-recorded, transcribed, rapidly analyzed, and integrated with other study data sources. RESULTS: Brief reflections revealed that the engagement panels made recommended changes in eight areas: enhancing recruitment; study assessment completion; creating uniformity across Study Coordinators; building Study Coordinator connection to Veteran participants; mismatch between study procedures and clinical practice; therapist skill with patients with active substance use; therapist burnout; and dissemination of study findings. Some recommendations positively impact study conduct while others had mixed impact. Reflections were iterative and led to emergent processes that included revisiting previously discussed topics, cross-pollination of ideas across panels, and sparking solutions amongst the Team when the panels did not make any recommendations or recommendations were not feasible. CONCLUSIONS: When paired with end-user engagement methods, brief reflections can facilitate systematic examination of end-user input, particularly when the engagement strategy is robust. Reflections offer a forum of accountability for researchers to give careful thought to end-user recommendations and make timely improvements to the study conduct. Reflections can also facilitate evaluation of these recommendations and reveal end-user-driven strategies that can effectively improve study conduct. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04581434) on October 9, 2020; https://clinicaltrials.gov/ct2/show/study/NCT04581434?term=NCT04581434&draw=2&rank=1 .


Assuntos
Transtornos de Estresse Pós-Traumáticos , Transtornos Relacionados ao Uso de Substâncias , Veteranos , Humanos , Transtornos de Estresse Pós-Traumáticos/terapia , Transtornos de Estresse Pós-Traumáticos/psicologia , Transtornos Relacionados ao Uso de Substâncias/terapia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Veteranos/psicologia , Veteranos/estatística & dados numéricos , United States Department of Veterans Affairs/estatística & dados numéricos , Psicoterapia/métodos , Estados Unidos , Participação do Paciente/métodos , Participação do Paciente/estatística & dados numéricos , Participação do Paciente/psicologia , Projetos de Pesquisa
8.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34417298

RESUMO

Plant pathogens are responsible for the annual yield loss of crops worldwide and pose a significant threat to global food security. A necessary prelude to many plant disease epidemics is the short-range dispersal of spores, which may generate several disease foci within a field. New information is needed on the mechanisms of plant pathogen spread within and among susceptible plants. Here, we show that self-propelled jumping dew droplets, working synergistically with low wind flow, can propel spores of a fungal plant pathogen (wheat leaf rust) beyond the quiescent boundary layer and disperse them onto neighboring leaves downwind. An array of horizontal water-sensitive papers was used to mimic healthy wheat leaves and showed that up to 25 spores/h may be deposited on a single leaf downwind of the infected leaf during a single dew cycle. These findings reveal that a single dew cycle can disperse copious numbers of fungal spores to other wheat plants, even in the absence of rain splash or strong gusts of wind.


Assuntos
Fungos/fisiologia , Interações Hospedeiro-Patógeno , Doenças das Plantas/microbiologia , Chuva , Esporos Fúngicos/fisiologia , Triticum/microbiologia , Vento , Folhas de Planta/microbiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-38687427

RESUMO

In 2023, the White House included the implementation and improvement of assisted outpatient treatment in a list of under-researched strategies to support recovery and long-term treatment engagement for people with serious mental illness. Assisted outpatient treatment is a community-based, court-ordered, mental health treatment program for a subset of individuals with serious mental illness who have a history of difficulty adhering to treatment and staying well while living in the community. There is research supporting the use of assisted outpatient treatment for this specific population, however, the majority focuses on limited geographic regions, specific program organizations, and is outdated. Meanwhile, assisted outpatient treatment programs have increasingly been adopted by counties and states across the country. More research is needed to ensure that assisted outpatient treatment programs are being implemented in the most effective and equitable way possible. In this paper, the authors identify several key gaps in the current literature base relating to the effectiveness and implementation of assisted outpatient treatment.

10.
J Gen Intern Med ; 38(12): 2647-2654, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37037986

RESUMO

BACKGROUND: Successful implementation can increase the availability of evidence-based treatments but continued patient access can be threatened if there is not deliberate focus on sustainment. Real-world examples are needed to elucidate contributors to sustainability. OBJECTIVE: We examined sustainability of outcomes of a study which tested a 12-month external facilitation intervention. The study evaluated change in access to medications for opioid use disorder (MOUD) in Veterans Health Administration (VHA) facilities in the lowest quartile of MOUD prescribing. DESIGN: Convergent mixed-methods design. PARTICIPANTS: Thirty-nine providers and leaders from eight VHA facilities. APPROACH: Thirty-minute post-implementation telephone interviews explored whether barriers identified pre-implementation were successfully addressed, the presence of any new challenges, helpfulness of external facilitation, and plans for sustaining MOUD access. Interviews were analyzed using a rapid turn-around approach. VHA administrative data were used to characterize the facilities and assess their ratio of patients with an OUD diagnosis receiving MOUD (MOUD/OUD ratio) at the end of a 9-month sustainability period. KEY RESULTS: Commonly reported contributors to sustained MOUD access included national attention on the opioid epidemic, accountability created by study participation, culture shift in MOUD acceptability, leadership support, and plans to build on initial progress. Frequently reported barriers included staffing issues and lack of MOUD-devoted time; the need to overhaul existing policies, practices, and/or processes; and fear and anxiety about MOUD prescribing. All facilities either maintained MOUD/OUD ratio improvement (n = 2) or further improved (n = 6) at the end of sustainability. Facilities with the highest and lowest ratio at the end of sustainability used a team-based approach to MOUD delivery; however, organizational setting differences may have impacted overall MOUD access. CONCLUSIONS: Ensuring stable and consistent staff, and sufficient time dedicated to MOUD are critical to sustaining access to evidence-based treatment in low-adopting facilities. This study highlights the importance of investing in local, system-level changes to improve and sustain access to effective treatments.


Assuntos
Buprenorfina , Transtornos Relacionados ao Uso de Opioides , Humanos , Ansiedade , Transtornos de Ansiedade , Medo , Liderança , Transtornos Relacionados ao Uso de Opioides/epidemiologia , Transtornos Relacionados ao Uso de Opioides/terapia
11.
J Nutr ; 153(5): 1534-1543, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36918146

RESUMO

BACKGROUND: In Canada, population iron status estimates are dated (2009-2011) and did not consider the presence of inflammation. OBJECTIVES: This study aimed to update iron status estimates in Canada using serum ferrin (SF) and evaluate different correction methods for inflammation based on c-reactive protein (CRP). METHODS: Data from the Canadian Health Measures Survey cycles 3-6 (2012-2019) formed a multiyear, cross-sectional, nationally representative sample (3-79 y) (n = 21,453). WHO cutoffs for SF and hemoglobin were used to estimate iron deficiency (ID), iron deficiency anemia (IDA), anemia, and elevated iron stores. ID was first estimated without considering inflammation. Correction approaches evaluated were excluding individuals with CRP >5 mg/L, using modified SF cutoffs, and regression correction. RESULTS: Total population uncorrected prevalence estimates were 7% (95% CI: 6.2, 7.9) ID, 6.1% (95% CI: 5.2, 7.0) anemia, and 2.0% (95% CI: 1.6, 2.4) IDA. The uncorrected prevalence of ID was the highest among females of reproductive age with 21.3% (95% CI: 17.6, 25.0) and 18.2% (95% CI: 15.4, 21.1) in 14-18 y and 19-50 y, respectively. Corrected ID estimates were higher than the uncorrected values, independent of the correction approach. Regression correction led to a moderate increase in the prevalence to 10.5% for the total population, whereas applying the higher modified SF cutoffs (70 µg/L for those older than 5 y) led to the largest increases in the prevalence, to 12.6%. Applying modified cutoffs led to implausibly high ID estimates among those with inflammation. Elevated iron stores were identified in 17.2% (95% CI: 16.2, 18.2) of the population, mostly in adult males. CONCLUSIONS: Correction methods for estimating population iron status need further research. Considering the fundamental drawbacks of each method, uncorrected and regression-corrected estimates provide a reasonable range for ID in the Canadian population. Important sex-based differences in iron status and a public health ID problem of moderate magnitude among females of reproductive age are evident in Canada.


Assuntos
Anemia Ferropriva , Anemia , Deficiências de Ferro , Adulto , Masculino , Feminino , Humanos , Ferro/metabolismo , Estudos Transversais , Ferritinas , Canadá/epidemiologia , Anemia Ferropriva/epidemiologia , Proteína C-Reativa/metabolismo , Inflamação/epidemiologia , Anemia/epidemiologia , Prevalência
12.
J Nutr ; 153(4): 1150-1161, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36848989

RESUMO

BACKGROUND: Vitamin D is recognized in bone health and the prevention of rickets and osteomalacia. OBJECTIVE: This study aimed to assess vitamin D status of people in Canada and to identify factors associated with vitamin D inadequacy and deficiency. METHODS: Serum 25-hydroxyvitamin D (25(OH)D) from the Canadian Health Measures Survey (cycles 3-6, n = 21,770, 3-79 y) were evaluated for geometric means and proportions <40 (inadequate) and <30 (risk of deficiency) nmol/L. Factors associated with inadequacy or deficiency were tested using logistic regression. RESULTS: Mean serum 25(OH)D was 57.9 (95% CI: 55.4, 60.5) nmol/L; the prevalence of inadequacy was 19.0% (95% CI: 15.7, 22.3) and risk of deficiency was 8.4% (95% CI: 6.5, 10.3). Prominent dietary factors associated with inadequacy in adults included: not consuming fish compared with ≥1/wk (adjusted ORadj: 1.60; 95% CI: 1.21, 2.11), none compared with ≥1/d for cow's milk (ORadj: 1.41; 95% CI: 1.02, 1.94) or margarine (ORadj: 1.42; 95% CI: 1.08, 1.88); or nonuser compared with user of vitamin D supplements (ORadj: 5.21; 95% CI: 3.88, 7.01). Notable demographic factors included: younger adults compared with 71 to 79 y (19-30 y ORadj: 2.33; 95% CI: 1.66, 3.29); BMI ≥30 compared with <25 kg/m2 (ORadj: 2.30; 95% CI: 1.79, 2.95); lower household income quartile 1 compared with 4 (ORadj: 1.46; 95% CI: 1.00, 2.15); and self-reported Black (ORadj: 8.06; 95% CI: 4.71, 13.81), East/Southeast Asian (ORadj: 3.83; 95% CI: 2.14, 6.85), Middle Eastern (ORadj: 4.57; 95% CI: 3.02, 6.92), and South Asian (ORadj: 4.63; 95% CI: 2.62, 8.19) race compared with White. Similar factors were observed in children and for deficiency. CONCLUSIONS: Most people in Canada have adequate vitamin D status; nonetheless, racialized groups have an elevated prevalence of inadequacy. Further research is required to evaluate if current strategies to improve vitamin D status, including increasing vitamin D in fortified foods and supplements, and dietary guidance to include a source of vitamin D every day help to reduce health inequality in Canada.


Assuntos
Disparidades nos Níveis de Saúde , Deficiência de Vitamina D , Humanos , Feminino , Animais , Bovinos , Canadá/epidemiologia , Vitamina D , Vitaminas , Suplementos Nutricionais , Prevalência
13.
J Phys Chem A ; 127(8): 1941-1959, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36802584

RESUMO

The automated kinetics workflow code, KinBot, was used to explore and characterize the regions of the C7H7 potential energy surface that are relevant to combustion environments and especially soot inception. We first explored the lowest-energy region, which includes the benzyl, fulvenallene + H, and cyclopentadienyl + acetylene entry points. We then expanded the model to include two higher-energy entry points, vinylpropargyl + acetylene and vinylacetylene + propargyl. The automated search was able to uncover the pathways from the literature. In addition, three important new routes were discovered: a lower-energy pathway connecting benzyl with vinylcyclopentadienyl, a decomposition mechanism from benzyl that results in side-chain hydrogen atom loss to produce fulvenallene + H, and shorter and lower energy routes to the dimethylene-cyclopentenyl intermediates. We systematically reduced the extended model to a chemically relevant domain composed of 63 wells, 10 bimolecular products, 87 barriers, and 1 barrierless channel and constructed a master equation using the CCSD(T)-F12a/cc-pVTZ//ωB97X-D/6-311++G(d,p) level of theory to provide rate coefficients for chemical modeling. Our calculated rate coefficients show excellent agreement with measured ones. We also simulated concentration profiles and calculated branching fractions from the important entry points to provide an interpretation of this important chemical landscape.

14.
J Phys Chem A ; 127(3): 565-588, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36607817

RESUMO

Automation of rate-coefficient calculations for gas-phase organic species became possible in recent years and has transformed how we explore these complicated systems computationally. Kinetics workflow tools bring rigor and speed and eliminate a large fraction of manual labor and related error sources. In this paper we give an overview of this quickly evolving field and illustrate, through five detailed examples, the capabilities of our own automated tool, KinBot. We bring examples from combustion and atmospheric chemistry of C-, H-, O-, and N-atom-containing species that are relevant to molecular weight growth and autoxidation processes. The examples shed light on the capabilities of automation and also highlight particular challenges associated with the various chemical systems that need to be addressed in future work.

15.
J Phys Chem A ; 127(13): 3000-3019, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-36897578

RESUMO

We used aerosol mass spectrometry coupled with tunable synchrotron photoionization to measure radical and closed-shell species associated with particle formation in premixed flames and during pyrolysis of butane, ethylene, and methane. We analyzed photoionization (PI) spectra for the C7H7 radical to identify the isomers present during particle formation. For the combustion and pyrolysis of all three fuels, the PI spectra can be fit reasonably well with contributions from four radical isomers: benzyl, tropyl, vinylcyclopentadienyl, and o-tolyl. Although there are significant experimental uncertainties in the isomeric speciation of C7H7, the results clearly demonstrate that the isomeric composition of C7H7 strongly depends on the combustion or pyrolysis conditions and the fuel or precursors. Fits to the PI spectra using reference curves for these isomers suggest that all of these isomers may contribute to m/z 91 in butane and methane flames, but only benzyl and vinylcyclopentadienyl contribute to the C7H7 isomer signal in the ethylene flame. Only tropyl and benzyl appear to play a role during pyrolytic particle formation from ethylene, and only tropyl, vinylcyclopentadienyl, and o-tolyl appear to participate during particle formation from butane pyrolysis. There also seems to be a contribution from an isomer with an ionization energy below 7.5 eV for the flames but not for the pyrolysis conditions. Kinetic models with updated and new reactions and rate coefficients for the C7H7 reaction network predict benzyl, tropyl, vinylcyclopentadienyl, and o-tolyl to be the primary C7H7 isomers and predict negligible contributions from other C7H7 isomers. These updated models provide better agreement with the measurements than the original versions of the models but, nonetheless, underpredict the relative concentrations of tropyl, vinylcyclopentadienyl, and o-tolyl in both flames and pyrolysis and overpredict benzyl in pyrolysis. Our results suggest that there are additional important formation pathways for the vinylcyclopentadienyl, tropyl, and o-tolyl radicals and/or loss pathways for the benzyl radical that are currently unaccounted for in the present models.

16.
BMC Pediatr ; 23(1): 397, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37580663

RESUMO

BACKGROUND: Vitamin D deficiency (VDD) is highly prevalent in the pediatric intensive care unit (ICU) and associated with worse clinical course. Trials in adult ICU demonstrate rapid restoration of vitamin D status using an enteral loading dose is safe and may improve outcomes. There have been no published trials of rapid normalization of VDD in the pediatric ICU. METHODS: We conducted a multicenter placebo-controlled phase II pilot feasibility randomized clinical trial from 2016 to 2017. We randomized 67 critically ill children with VDD from ICUs in Canada, Chile and Austria using a 2:1 randomization ratio to receive a loading dose of enteral cholecalciferol (10,000 IU/kg, maximum of 400,000 IU) or placebo. Participants, care givers, and outcomes assessors were blinded. The primary objective was to determine whether the loading dose normalized vitamin D status (25(OH)D > 75 nmol/L). Secondary objectives were to evaluate for adverse events and assess the feasibility of a phase III trial. RESULTS: Of 67 randomized participants, one was withdrawn and seven received more than one dose of cholecalciferol before the protocol was amended to a single loading dose, leaving 59 participants in the primary analyses (40 treatment, 19 placebo). Thirty-one/38 (81.6%) participants in the treatment arm achieved a plasma 25(OH)D concentration > 75 nmol/L versus 1/18 (5.6%) the placebo arm. The mean 25(OH)D concentration in the treatment arm was 125.9 nmol/L (SD 63.4). There was no evidence of vitamin D toxicity and no major drug or safety protocol violations. The accrual rate was 3.4 patients/month, supporting feasibility of a larger trial. A day 7 blood sample was collected for 84% of patients. A survey administered to 40 participating families showed that health-related quality of life (HRQL) was the most important outcome for families for the main trial (30, 75%). CONCLUSIONS: A single 10,000 IU/kg dose can rapidly and safely normalize plasma 25(OH)D concentrations in critically ill children with VDD, but with significant variability in 25(OH)D concentrations. We established that a phase III multicentre trial is feasible. Using an outcome collected after hospital discharge (HRQL) will require strategies to minimize loss-to-follow-up. CLINICALTRIALS: gov NCT02452762 Registered 25/05/2015.


Assuntos
Colecalciferol , Deficiência de Vitamina D , Adulto , Humanos , Criança , Colecalciferol/uso terapêutico , Estado Terminal/terapia , Qualidade de Vida , Estudos de Viabilidade , Método Duplo-Cego , Vitamina D , Vitaminas/uso terapêutico , Deficiência de Vitamina D/tratamento farmacológico , Deficiência de Vitamina D/complicações , Unidades de Terapia Intensiva Pediátrica , Suplementos Nutricionais
17.
Med Teach ; 45(10): 1155-1162, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37026472

RESUMO

PURPOSE: We evaluate the impacts of the Academic Scholars and Leaders (ASL) Program in achieving 3 key objectives: treatment of education as a scholarly pursuit, improved education leadership, and career advancement. MATERIALS AND METHODS: We report on the twenty-year experience of the ASL Program-a national, longitudinal faculty development program of the Association of Professors of Obstetrics and Gynecology (APGO) covering instruction, curriculum development/program evaluation, assessment/feedback, leadership/professional development, and educational scholarship. We conducted a cross-sectional, online survey of ASL participants who graduated in 1999-2017. We sought evidence of impact using Kirkpatrick's 4-level framework. Descriptive quantitative data were analyzed, and open-ended comments were organized using content analysis. RESULTS: 64% (260) of graduates responded. The vast majority (96%) felt the program was extremely worthwhile (Kirkpatrick level 1). Graduates cited learned skills they had applied to their work, most commonly curricular development (48%) and direct teaching (38%) (Kirkpatrick 2&3 A). Since participation, 82% of graduates have held institutional, education-focused leadership roles (Kirkpatrick 3B). Nineteen percent had published the ASL project as a manuscript and 46% additional education papers (Kirkpatrick 3B). CONCLUSIONS: The APGO ASL program has been associated with successful outcomes in treatment of education as a scholarly pursuit, education leadership, and career advancement. Going forward, APGO is considering ways to diversify the ASL community and to support educational research training.


Assuntos
Ginecologia , Obstetrícia , Humanos , Docentes de Medicina , Currículo , Estudos Transversais , Avaliação de Programas e Projetos de Saúde , Liderança , Desenvolvimento de Programas , Desenvolvimento de Pessoal
18.
J Bacteriol ; 204(6): e0003222, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35604222

RESUMO

The opportunistic pathogen A. baumannii has a remarkable capacity to persist in the hospital environment and cause devastating human infections. This capacity can be attributed partly to the sensing and regulatory systems that enable this pathogen to modify its physiology based on environmental cues. One of the signals that A. baumannii senses and responds to is light through the sensing and regulatory roles of the BlsA photoreceptor protein in cells cultured at temperatures below 30°C. This report presents evidence that a light stimulon is operational at 37°C, a condition at which the BlsA production and activity are drastically impaired. Global transcriptional analysis showed that the 37°C light stimulon includes the differential expression of chromosomal genes encoding a wide range of functions that are known to be involved in the adaptation to different metabolic conditions, as well as virulence and persistence in the host and the medical environment. Unexpectedly, the 37°C light stimulon also includes the differential expression of conjugation functions encoded by pAB3 plasmid genes. Our work further demonstrates that the TetR1 and H-NS regulators encoded by this conjugative plasmid control the expression of H2O2 resistance and surface motility, respectively. Furthermore, our data showed that pAB3 has an overall negative effect on the expression of these phenotypes and plays no significant virulence role. Although the nature of the bacterial factors and the mechanisms by which the regulation is attained at 37°C remain unknown, taken together, our work expands the current knowledge about light sensing and gene regulation in A. baumannii. IMPORTANCE As a facultative pathogen, Acinetobacter baumannii persists in various environments by sensing different environmental cues, including light. This report provides evidence of light-dependent regulation at 37°C of the expression of genes coding for a wide range of functions, including those involved in the conjugation of the pAB3 plasmid. Although this plasmid affects the expression of virulence traits when tested under laboratory conditions, it does not have a significant impact when tested using ex vivo and in vivo experimental models. These findings provide a better understanding of the interplay between light regulation and plasmid persistence in the pathobiology of A. baumannii.


Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , Peróxido de Hidrogênio/metabolismo , Plasmídeos/genética , Temperatura , Virulência/genética
19.
J Am Chem Soc ; 144(1): 606-614, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34978798

RESUMO

The thalidomide analogue lenalidomide (Len) is a clinical therapeutic that alters the substrate engagement of cereblon (CRBN), a substrate receptor for the CRL4 E3 ubiquitin ligase. Here, we report the development of photolenalidomide (pLen), a Len probe with a photoaffinity label and enrichment handle, designed for target identification by chemical proteomics. pLen preserves the substrate degradation profile, phenotypic antiproliferative and immunomodulatory properties of Len, and enhances interactions with the thalidomide-binding domain of CRBN, as revealed by binding site mapping and molecular modeling. Using pLen, we captured the known targets IKZF1 and CRBN from multiple myeloma MM.1S cells and further identified a new target, eukaryotic translation initiation factor 3 subunit i (eIF3i), from HEK293T cells. eIF3i is directly labeled by pLen and forms a ternary complex with CRBN in the presence of Len across several epithelial cell lines but is itself not ubiquitylated or degraded. These data point to the existence of a broader array of targets induced by ligands to CRBN that may or may not be degraded, which can be identified by the highly translatable application of pLen to additional biological systems.


Assuntos
Lenalidomida
20.
J Gen Intern Med ; 37(14): 3594-3602, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-34981352

RESUMO

BACKGROUND: Identifying effective strategies to improve access to medication treatments for opioid use disorder (MOUD) is imperative. Within the Veterans Health Administration (VHA), provision of MOUD varies significantly, requiring development and testing of implementation strategies that target facilities with low provision of MOUD. OBJECTIVE: Determine the effectiveness of external facilitation in increasing the provision of MOUD among VHA facilities with low baseline provision of MOUD compared to matched controls. DESIGN: Pre-post, block randomized study designed to compare facility-level outcomes in a stratified sample of eligible facilities. Four blocks (two intervention facilities in each) were defined by median splits of both the ratio of patients with OUD receiving MOUD and number of patients with OUD not currently receiving MOUD (i.e., number of actionable patients). Intervention facilities participated in a 12-month implementation intervention. PARTICIPANTS: VHA facilities in the lowest quartile of MOUD provision (35 facilities), eight of which were randomly assigned to participate in the intervention (two per block) with twenty-seven serving as matched controls by block. INTERVENTION: External facilitation included assessment of local barriers/facilitators, formation of a local implementation team, a site visit for action planning and training/education, cross-facility quarterly calls, monthly coaching calls, and consultation. MAIN MEASURES: Pre- to post-change in the facility-level ratio of patients with an OUD diagnosis receiving MOUD compared to control facilities. KEY RESULTS: Intervention facilities significantly increased the ratio of patients with OUD receiving MOUD from an average of 18% at baseline to 30% 1 year later, with an absolute difference of 12% (95% confidence interval [CI]: 6.6%, 17.0%). The difference in differences between intervention and control facilities was 3.0% (95% CI: - 0.2%. 6.7%). The impact of the intervention varied by block, with smaller, less complex facilities more likely to outperform matched controls. CONCLUSIONS: Intensive external facilitation improved the adoption of MOUD in most low-performing facilities and may enhance adoption beyond other interventions less tailored to individual facility contexts.


Assuntos
Buprenorfina , Transtornos Relacionados ao Uso de Opioides , Humanos , Buprenorfina/uso terapêutico , Tratamento de Substituição de Opiáceos , Saúde dos Veteranos , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Transtornos Relacionados ao Uso de Opioides/diagnóstico
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