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1.
Am J Ind Med ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849975

RESUMO

BACKGROUND: Unpaid overtime-describing a situation where extra hours are worked but not paid for-is a common feature of the labor market that, together with other forms of wage theft, costs workers billions of dollars annually. In this study, we examine the association between unpaid overtime and mental health in the Canadian working population. We also assess the relative strength of that association by comparing it against those of other broadly recognized work stressors. METHODS: Data were drawn from a survey administered to a heterogeneous sample of workers in Canada (n = 3691). Generalized linear models quantified associations between unpaid overtime, stress, and burnout, distinguishing between moderate (1-5) and excessive (6 or more) hours of unpaid overtime. RESULTS: Unpaid overtime was associated with higher levels of stress and burnout. Relative to those working no unpaid overtime, men working excessive unpaid overtime were 85% more likely to report stress (prevalence ratios [PR]: 1.85, 95% confidence interval [CI]: 1.26-2.72) and 84% more likely to report burnout (PR: 1.84, 95% CI: 1.34-2.54), while women working excessive unpaid overtime were 90% more likely to report stress (PR: 1.90, 95% CI: 1.32-2.75) and 52% more likely to report burnout (PR: 1.52; 95% CI: 1.12-2.06). The association of excessive unpaid overtime with mental health was comparable in magnitude to that of shift work and low job control. CONCLUSIONS: Unpaid overtime may present a significant challenge to the mental health of working people, highlighting the potential role of wage theft as a neglected occupational health hazard.

2.
Mol Cell ; 83(24): 4445-4460.e7, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37995689

RESUMO

The metazoan-specific Integrator complex catalyzes 3' end processing of small nuclear RNAs (snRNAs) and premature termination that attenuates the transcription of many protein-coding genes. Integrator has RNA endonuclease and protein phosphatase activities, but it remains unclear if both are required for complex function. Here, we show IntS6 (Integrator subunit 6) over-expression blocks Integrator function at a subset of Drosophila protein-coding genes, although having no effect on snRNAs or attenuation of other loci. Over-expressed IntS6 titrates protein phosphatase 2A (PP2A) subunits, thereby only affecting gene loci where phosphatase activity is necessary for Integrator function. IntS6 functions analogous to a PP2A regulatory B subunit as over-expression of canonical B subunits, which do not bind Integrator, is also sufficient to inhibit Integrator activity. These results show that the phosphatase module is critical at only a subset of Integrator-regulated genes and point to PP2A recruitment as a tunable step that modulates transcription termination efficiency.


Assuntos
Proteínas de Drosophila , Terminação da Transcrição Genética , Animais , RNA , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , RNA Nuclear Pequeno/genética , Fatores de Transcrição/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster
3.
BMC Med Res Methodol ; 20(1): 231, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32928140

RESUMO

BACKGROUND: Emergency Departments (EDs) are a first point-of-contact for many youth with mental health and suicidality concerns and can serve as an effective recruitment source for randomized controlled trials (RCTs) of mental health interventions. However, recruitment in acute care settings is impeded by several challenges. This pilot RCT of a youth suicide prevention intervention recruited adolescents aged 12 to 17 years presenting to a pediatric hospital ED with suicide related behaviors. METHODS: Recruitment barriers were identified during the initial study recruitment period and included: the time of day of ED presentations, challenges inherent to study presentation, engagement and participation during an acute presentation, challenges approaching and enrolling acutely suicidal patients and families, ED environmental factors, and youth and parental concerns regarding the study. We calculated the average recruitment productivity for published trials of adolescent suicide prevention strategies which included the ED as a recruitment site in order to compare our recruitment productivity. RESULTS: In response to identified barriers, an enhanced ED-centered recruitment strategy was developed to address low recruitment rate, specifically (i) engaging a wider network of ED and outpatient psychiatry staff (ii) dissemination of study pamphlets across multiple areas of the ED and relevant outpatient clinics. Following implementation of the enhanced recruitment strategy, the pre-post recruitment productivity, a ratio of patients screened to patients randomized, was computed. A total of 120 patients were approached for participation, 89 (74.2%) were screened and 45 (37.5%) were consented for the study from March 2018 to April 2019. The screening to randomization ratio for the study period prior to the introduction of the enhanced recruitment strategies was 3:1, which decreased to 1.8:1 following the implementation of enhanced recruitment strategies. The ratio for the total recruitment period was 2.1:1. This was lower than the average ratio of 3.2:1 for published trials. CONCLUSIONS: EDs are feasible sites for participant recruitment in RCTs examining new interventions for acute mental health problems, including suicidality. Engaging multi-disciplinary ED staff to support recruitment for such studies, proactively addressing anticipated concerns, and creating a robust recruitment pathway that includes approach at outpatient appointments can optimize recruitment. TRIAL REGISTRATION: ClinicalTrials.gov : NCT03488602 , retrospectively registered April 4, 2018.


Assuntos
Ideação Suicida , Prevenção do Suicídio , Adolescente , Criança , Serviço Hospitalar de Emergência , Hospitais Pediátricos , Humanos , Projetos Piloto
4.
FASEB J ; 34(6): 7404-7426, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32307754

RESUMO

Fragile X syndrome (FXS) is the leading known inherited intellectual disability and the most common genetic cause of autism. The full mutation results in transcriptional silencing of the Fmr1 gene and loss of fragile X mental retardation protein (FMRP) expression. Defects in neuroenergetic capacity are known to cause a variety of neurodevelopmental disorders. Thus, we explored the integrity of forebrain mitochondria in Fmr1 knockout mice during the peak of synaptogenesis. We found inefficient thermogenic respiration due to futile proton leak in Fmr1 KO mitochondria caused by coenzyme Q (CoQ) deficiency and an open cyclosporine-sensitive channel. Repletion of mitochondrial CoQ within the Fmr1 KO forebrain closed the channel, blocked the pathological proton leak, restored rates of protein synthesis during synaptogenesis, and normalized the key phenotypic features later in life. The findings demonstrate that FMRP deficiency results in inefficient oxidative phosphorylation during the neurodevelopment and suggest that dysfunctional mitochondria may contribute to the FXS phenotype.


Assuntos
Respiração Celular/fisiologia , Síndrome do Cromossomo X Frágil/metabolismo , Síndrome do Cromossomo X Frágil/patologia , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Termogênese/fisiologia , Animais , Transtorno Autístico/metabolismo , Transtorno Autístico/patologia , Modelos Animais de Doenças , Feminino , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Masculino , Camundongos , Camundongos Knockout , Neurogênese/fisiologia , Prótons
5.
Biochemistry ; 58(48): 4857-4868, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31742390

RESUMO

The number of self-cleaving ribozymes has increased sharply in recent years, giving rise to elaborations of the four known ribozyme catalytic strategies, α, ß, γ, and δ. One such extension is utilized by the twister ribozyme, which is hypothesized to conduct δ, or general acid catalysis, via N3 of the syn adenine +1 nucleobase indirectly via buffer catalysis at biological pH and directly at lower pH. Herein, we test the δ catalysis role of A1 via chemical rescue and the catalytic relevance of the syn orientation of the nucleobase by conformational analysis. Using inhibited twister ribozyme variants with A1(N3) deaza or A1 abasic modifications, we observe >100-fold chemical rescue effects in the presence of protonatable biological small molecules such as imidazole and histidine, similar to observed rescue values previously reported for C75U/C76Δ in the HDV ribozyme. Brønsted plots for the twister variants support a model in which small molecules rescue catalytic activity via a proton transfer mechanism, suggesting that A1 in the wild type is involved in proton transfer, most likely general acid catalysis. Additionally, through glycosidic conformational analysis in an appropriate background that accommodates the bromine atom, we observe that an 8BrA1-modified twister ribozyme is up to 10-fold faster than a nonmodified A1 ribozyme, supporting crystallographic data that show that A1 is syn when conducting proton transfer. Overall, this study provides functional evidence that the nucleotide immediately downstream of the cleavage site participates directly or indirectly in general acid-base catalysis in the twister ribozyme while occupying the syn conformation.


Assuntos
Glicosídeos/química , RNA Catalítico/química , Catálise , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares
6.
ACS Sens ; 2(11): 1737-1743, 2017 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-29058887

RESUMO

Palladium is a highly valuable metal in automobile, chemical, and pharmaceutical industries. The metal is generally quantified by atomic absorption spectrometry or inductively coupled plasma mass spectrometry. These techniques are tedious and require expensive instruments that are operated mostly off site. As cost-effective and user-friendly alternatives to these techniques, we previously reported two practical fluorometric or colorimetric methods to quantify palladium. Both methods rely on the use of NaBH4, which cannot be stored in solution for more than 10 days. Commercially available solutions of NaBH4 are partially or fully degraded to di- or triborohydride species and cannot be used for palladium(0)-catalyzed allylic C-O bond cleavage for quantification purposes. Here, we report a new method that replaces NaBH4 with NH2NH2 for the palladium-catalyzed deallylation of fluorogenic and colorimetric chemodosimeter resorufin allyl ether. This method is slower but as sensitive as the most recent method from our laboratory. The method is selective for palladium and depends on the presence of tri(2-furyl)phosphine as a palladium ligand and NH2NH2 as a palladium-reducing reagent.


Assuntos
Paládio/análise , Espectrometria de Fluorescência/métodos , Alcenos/química , Boroidretos/química , Catálise , Cor
7.
Nat Commun ; 7: 10691, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26891765

RESUMO

Catalysis-based signal amplification makes optical assays highly sensitive and widely useful in chemical and biochemical research. However, assays must be fine-tuned to avoid signal saturation, substrate depletion and nonlinear performance. Furthermore, once stopped, such assays cannot be restarted, limiting the dynamic range to two orders of magnitude with respect to analyte concentrations. In addition, abundant analytes are difficult to quantify under catalytic conditions due to rapid signal saturation. Herein, we report an approach in which a catalytic reaction competes with a concomitant inactivation of the catalyst or consumption of a reagent required for signal generation. As such, signal generation proceeds for a limited time, then autonomously and reversibly stalls. In two catalysis-based assays, we demonstrate restarting autonomously stalled reactions, enabling accurate measurement over five orders of magnitude, including analyte levels above substrate concentration. This indicates that the dynamic range of catalysis-based assays can be significantly broadened through competitive and reversible deactivation.

8.
Chem Soc Rev ; 44(14): 4769-91, 2015 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-25705016

RESUMO

Neither palladium nor platinum is an endogenous biological metal. Imaging palladium in biological samples, however, is becoming increasingly important because bioorthogonal organometallic chemistry involves palladium catalysis. In addition to being an imaging target, palladium has been used to fluorometrically image biomolecules. In these cases, palladium species are used as imaging-enabling reagents. This review article discusses these fluorometric methods. Platinum-based drugs are widely used as anticancer drugs, yet their mechanism of action remains largely unknown. We discuss fluorometric methods for imaging or quantifying platinum in cells or biofluids. These methods include the use of chemosensors to directly detect platinum, fluorescently tagging platinum-based drugs, and utilizing post-labeling to elucidate distribution and mode of action.


Assuntos
Microscopia de Fluorescência/métodos , Paládio , Platina , Animais , Escherichia coli , Células HeLa , Humanos , Paládio/análise , Paládio/química , Platina/análise , Platina/química , Peixe-Zebra
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