RESUMEN
Non-genetic variations derived from expression noise at transcript or protein levels can result in cell-to-cell heterogeneity within an isogenic population. Although cells have developed strategies to reduce noise in some cellular functions, this heterogeneity can also facilitate varying levels of regulation and provide evolutionary benefits in specific environments. Despite several general characteristics of cellular noise having been revealed, the detailed molecular pathways underlying noise regulation remain elusive. Here, we established a dual-fluorescent reporter system in Saccharomyces cerevisiae and performed experimental evolution to search for mutations that increase expression noise. By analyzing evolved cells using bulk segregant analysis coupled with whole-genome sequencing, we identified the histone deacetylase Hos2 as a negative noise regulator. A hos2 mutant down-regulated multiple ribosomal protein genes and exhibited partially compromised protein translation, indicating that Hos2 may regulate protein expression noise by modulating the translation machinery. Treating cells with translation inhibitors or introducing mutations into several Hos2-regulated ribosomal protein genes-RPS9A, RPS28B and RPL42A-enhanced protein expression noise. Our study provides an effective strategy for identifying noise regulators and also sheds light on how cells regulate non-genetic variation through protein translation.
Asunto(s)
Regulación Fúngica de la Expresión Génica , Histona Desacetilasas , Biosíntesis de Proteínas , Proteínas Ribosómicas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Histona Desacetilasas/metabolismo , Histona Desacetilasas/genética , Mutación , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMEN
The fidelity of splice site selection is critical for proper gene expression. In particular, proper recognition of 3'-splice site (3'SS) sequences by the spliceosome is challenging considering the low complexity of the 3'SS consensus sequence YAG. Here, we show that absence of the Prp18p splicing factor results in genome-wide activation of alternative 3'SS in S. cerevisiae, including highly unusual non-YAG sequences. Usage of these non-canonical 3'SS in the absence of Prp18p is enhanced by upstream poly(U) tracts and by their potential to interact with the first intronic nucleoside, allowing them to dock in the spliceosome active site instead of the normal 3'SS. The role of Prp18p in 3'SS fidelity is facilitated by interactions with Slu7p and Prp8p, but cannot be fulfilled by Slu7p, identifying a unique role for Prp18p in 3'SS fidelity. This fidelity function is synergized by the downstream proofreading activity of the Prp22p helicase, but is independent from another late splicing helicase, Prp43p. Our results show that spliceosomes exhibit remarkably relaxed 3'SS sequence usage in the absence of Prp18p and identify a network of spliceosomal interactions centered on Prp18p which are required to promote the fidelity of the recognition of consensus 3'SS sequences.
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Sitios de Empalme de ARN , Saccharomyces cerevisiae , Empalme Alternativo , Empalme del ARN , Factores de Empalme de ARN/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Empalmosomas/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMEN
BACKGROUND: Nuisance and false alarms distract clinicians from urgent alerts, raising patient safety risks. LOCAL PROBLEM: High alarm rates in a pediatric progressive care unit resulted in experiencing 180-250 alarms per day or 1 alarm every 3 to 4 minutes per clinician. METHODS: Through Plan-Do-Study-Act cycles, environmental, policy, and technology changes were implemented to decrease the average alarms/day/bed and percentage of time in alarm. INTERVENTIONS: Alarm settings tailored to patient needs using features embedded within the patient monitoring system were implemented and monitored with the assistance of alarm champions. RESULTS: The average number of alarms/day/bed decreased from 177.69 to 96.94 over the course of 10 years, a 45.45% reduction. The percentage of time in alarm decreased from 7.52% to 2.83%, a 62.37% reduction. CONCLUSIONS: Arming clinicians with technology to analyze real-time clinical data made alarms meaningful and actionable, decreasing false alarms without compromising patient safety.
Asunto(s)
Alarmas Clínicas , Seguridad del Paciente , Mejoramiento de la Calidad , Humanos , Alarmas Clínicas/normas , Seguridad del Paciente/normas , Monitoreo Fisiológico/métodos , Monitoreo Fisiológico/instrumentación , Hospitales Pediátricos , Pediatría/normas , Pediatría/métodosRESUMEN
The expression of bromodomain-containing proteins that regulate chromatin structure and accessibility must be tightly controlled to ensure the appropriate regulation of gene expression. In the yeast S. cerevisiae, Bromodomain Factor 2 (BDF2) expression is extensively regulated post-transcriptionally during stress by RNase III-mediated decay (RMD), which is triggered by cleavage of the BDF2 mRNA in the nucleus by the RNase III homolog Rnt1p. Previous studies have shown that RMD-mediated down-regulation of BDF2 is hyperactivated in osmotic stress conditions, yet the mechanisms driving the enhanced nuclear cleavage of BDF2 RNA under these conditions remain unknown. Here, we show that RMD hyperactivation can be detected in multiple stress conditions that inhibit mRNA export, and that Rnt1p remains primarily localized in the nucleus during salt stress. We show that globally inhibiting mRNA nuclear export by anchoring away mRNA biogenesis or export factors out of the nucleus can recapitulate RMD hyperactivation in the absence of stress. RMD hyperactivation requires Rnt1p nuclear localization but does not depend on the BDF2 gene endogenous promoter, and its efficiency is affected by the structure of the stem-loop cleaved by Rnt1p. Because multiple stress conditions have been shown to mediate global inhibition of mRNA export, our results suggest that the hyperactivation of RMD is primarily the result of the increased nuclear retention of the BDF2 mRNA during stress.
Asunto(s)
Núcleo Celular/metabolismo , Transporte de ARN , ARN Mensajero/metabolismo , Ribonucleasa III/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Estrés Salino , Factores de Transcripción/metabolismo , Transporte Activo de Núcleo Celular , Núcleo Celular/genética , ARN Mensajero/genética , Ribonucleasa III/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Factores de Transcripción/genéticaRESUMEN
3'-end poly(A)+ sequencing is an efficient and economical method for global measurement of mRNA levels and alternative poly(A) site usage. A common method involves oligo(dT)19V reverse-transcription (RT)-based library preparation and high-throughput sequencing with a custom primer ending in (dT)19. While the majority of library products have the first sequenced nucleotide reflect the bona fide poly(A) site (pA), a substantial fraction of sequencing reads arise from various mis-priming events. These can result in incorrect pA site calls anywhere from several nucleotides downstream to several kilobases upstream from the bona fide pA site. While these mis-priming events can be mitigated by increasing annealing stringency (e.g. increasing temperature from 37⯰C to 42⯰C), they still persist at an appreciable level (â¼10%) and computational methods must be used to prevent artifactual calls. Here we present a bioinformatics workflow for precise mapping of poly(A)+ 3' ends and handling of artifacts due to oligo(dT) mis-priming and sample polymorphisms. We test pA site calling with three different read mapping programs (STAR, BWA, and BBMap), and show that the way in which each handles terminal mismatches and soft clipping has a substantial impact on identifying correct pA sites, with BWA requiring the least post-processing to correct artifacts. We demonstrate the use of this pipeline for mapping pA sites in the model eukaryote S. cerevisiae, and further apply this technology to non-polyadenylated transcripts by employing in vitro polyadenylation prior to library prep (IVP-seq). As proof of principle, we show that a fraction of tRNAs harbor CCU 3' tails instead of the canonical CCA tail, and globally identify 3' ends of splicing intermediates arising from inefficiently spliced transcripts.
Asunto(s)
Anotación de Secuencia Molecular/métodos , RNA-Seq/métodos , Regiones no Traducidas 3'/genética , Biología Computacional/métodos , Nucleótidos/genética , Poli A/genética , Poliadenilación/genética , Empalme del ARN , ARN de Hongos/genética , Saccharomyces cerevisiae/genéticaRESUMEN
Li-Fraumeni Syndrome (LFS) is a hereditary disorder that confers an approximately 90% lifetime risk of cancer and requires comprehensive lifetime cancer screening. We explored healthcare roles for managing LFS-related cancer risks and treatments that were assumed by parents, adolescents, and adult children. Semi-structured interviews were conducted with 23 families. Family groupings were comprised of 2-5 members, with the younger generation in each family ranging in age from 7 to 40 years. Using grounded theory methods, we conducted open and focused coding of interview transcript content. Family members described how the role of health leader was implemented in their family, as well as factors such as maturation of a child or death of a member that determined who assumed particular roles and how these roles shifted over time. They often expressed collective responsibility for helping relatives understand LFS and implement appropriate cancer risk management. Members demonstrated their health role by attending others' medical appointments for support or information gathering. The health leader role was intergenerational and provided the family necessary support in navigating complicated healthcare decisions. Our findings provide insight into healthcare providers regarding how LFS patients and their relatives develop unique medical decision-making and caring roles influenced by the hereditary nature of LFS, and how these roles change over time. Providers who are attuned to family role dynamics may be better able to meet relatives' psychosocial and medical needs by understanding how living with LFS influences the family system's functioning and facilitating members' support for each other.
El síndrome de Li-Fraumeni (LFS) es un trastorno hereditario que concede aproximadamente un 90 % de riesgo durante toda la vida de contraer cáncer y exige exámenes completos para la detección del cáncer de por vida. Analizamos los roles sanitarios a la hora de manejar los riesgos y los tratamientos de cáncer relacionados con el LFS que asumieron los padres, los adolescentes y los hijos adultos. Se realizaron entrevistas semiestructuradas con 23 familias. Los agrupamientos familiares estaban compuestos por entre 2 y 5 familiares, donde la edad de la generación más joven de cada familia oscilaba entre 7 y 40 años. Utilizando los métodos de la teoría fundamentada, realizamos una codificación abierta y centrada del contenido de la transcripción de la entrevista. Los miembros de la familia describieron cómo se implementó el rol de jefe de la salud en su familia, así como factores como la maduración de un niño o la muerte de un miembro que determinaron quiénes asumieron roles particulares y cómo estos roles cambiaron con el tiempo. Con frecuencia ellos expresaron la responsabilidad colectiva de ayudar a los familiares a comprender el LFS y a implementar el manejo adecuado del riesgo de contraer cáncer. Los familiares demostraron sus roles sanitarios asistiendo a citas médicas de los demás para recibir apoyo u obtener información. El rol de jefe sanitario fue intergeneracional y proporcionó a la familia el apoyo necesario para manejarse ante decisiones complicadas sobre la asistencia sanitaria. Nuestros resultados brindan información para los prestadores de servicios médicos con respecto a cómo los pacientes de LFS y sus familiares desarrollan roles únicos para la toma de decisiones médicas y el cuidado influenciados por la índole hereditaria del LFS, y cómo estos roles cambian con el tiempo. Es posible que los prestadores que estén acostumbrados a la dinámica de roles familiares sean más capaces de satisfacer las necesidades psicosociales y médicas de los familiares si comprenden cómo vivir con LFS influye en el funcionamiento del sistema familiar y si facilitan el apoyo mutuo de los familiares.
Asunto(s)
Salud de la Familia , Familia , Liderazgo , Síndrome de Li-Fraumeni , Rol , Adolescente , Adulto , Femenino , Humanos , Masculino , Adulto Joven , Familia/psicología , Composición Familiar , Teoría Fundamentada , Conductas Relacionadas con la Salud , Síndrome de Li-Fraumeni/psicología , Investigación CualitativaRESUMEN
To date, 12 protein lysine methyltransferases that modify translational elongation factors and ribosomal proteins (Efm1-7 and Rkm 1-5) have been identified in the yeast Saccharomyces cerevisiae. Of these 12, five (Efm1 and Efm4-7) appear to be specific to elongation factor 1A (EF1A), the protein responsible for bringing aminoacyl-tRNAs to the ribosome. In S. cerevisiae, the functional implications of lysine methylation in translation are mostly unknown. In this work, we assessed the physiological impact of disrupting EF1A methylation in a strain where four of the most conserved methylated lysine sites are mutated to arginine residues and in strains lacking either four or five of the Efm lysine methyltransferases specific to EF1A. We found that loss of EF1A methylation was not lethal but resulted in reduced growth rates, particularly under caffeine and rapamycin stress conditions, suggesting EF1A interacts with the TORC1 pathway, as well as altered sensitivities to ribosomal inhibitors. We also detected reduced cellular levels of the EF1A protein, which surprisingly was not reflected in its stability in vivo. We present evidence that these Efm methyltransferases appear to be largely devoted to the modification of EF1A, finding no evidence of the methylation of other substrates in the yeast cell. This work starts to illuminate why one protein can need five different methyltransferases for its functions and highlights the resilience of yeast to alterations in their posttranslational modifications.
Asunto(s)
Lisina/metabolismo , Factor 1 de Elongación Peptídica/química , Factor 1 de Elongación Peptídica/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimología , Secuencias de Aminoácidos , Metilación , Metiltransferasas/genética , Metiltransferasas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genéticaRESUMEN
RNA polymerase II (Pol II) transcription termination by the Nrd1p-Nab3p-Sen1p (NNS) pathway is critical for the production of stable noncoding RNAs and the control of pervasive transcription in Saccharomyces cerevisiae To uncover determinants of NNS termination, we mapped the 3'-ends of NNS-terminated transcripts genome-wide. We found that nucleosomes and specific DNA-binding proteins, including the general regulatory factors (GRFs) Reb1p, Rap1p, and Abf1p, and Pol III transcription factors enhance the efficiency of NNS termination by physically blocking Pol II progression. The same DNA-bound factors that promote NNS termination were shown previously to define the 3'-ends of Okazaki fragments synthesized by Pol δ during DNA replication. Reduced binding of these factors results in defective NNS termination and Pol II readthrough. Furthermore, inactivating NNS enables Pol II elongation through these roadblocks, demonstrating that effective Pol II termination depends on a synergy between the NNS machinery and obstacles in chromatin. Consistent with this finding, loci exhibiting Pol II readthrough at GRF binding sites are depleted for upstream NNS signals. Overall, these results underscore how RNA termination signals influence the behavior of Pol II at chromatin obstacles, and establish that common genomic elements define boundaries for both DNA and RNA synthesis machineries.
Asunto(s)
Replicación del ADN , Genoma Fúngico , ARN no Traducido/genética , Elongación de la Transcripción Genética , Terminación de la Transcripción Genética , ADN/genética , ADN Helicasas/genética , ADN Helicasas/metabolismo , ADN Polimerasa II/genética , ADN Polimerasa II/metabolismo , ADN Polimerasa III/genética , ADN Polimerasa III/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , ARN Helicasas/genética , ARN Helicasas/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Complejo Shelterina , Proteínas de Unión a Telómeros/genética , Proteínas de Unión a Telómeros/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Rpl3, a highly conserved ribosomal protein, is methylated at histidine 243 by the Hpm1 methyltransferase in Saccharomyces cerevisiae. Histidine 243 lies close to the peptidyl transferase center in a functionally important region of Rpl3 designated as the basic thumb that coordinates the decoding, peptidyl transfer, and translocation steps of translation elongation. Hpm1 was recently implicated in ribosome biogenesis and translation. However, the biological role of methylation of its Rpl3 substrate has not been identified. Here we interrogate the role of Rpl3 methylation at H243 by investigating the functional impact of mutating this histidine residue to alanine (rpl3-H243A). Akin to Hpm1-deficient cells, rpl3-H243A cells accumulate 35S and 23S pre-rRNA precursors to a similar extent, confirming an important role for histidine methylation in pre-rRNA processing. In contrast, Hpm1-deficient cells but not rpl3-H243A mutants show perturbed levels of ribosomal subunits. We show that Hpm1 has multiple substrates in different subcellular fractions, suggesting that methylation of proteins other than Rpl3 may be important for controlling ribosomal subunit levels. Finally, translational fidelity assays demonstrate that like Hpm1-deficient cells, rpl3-H243A mutants have defects in translation elongation resulting in decreased translational accuracy. These data suggest that Rpl3 methylation at H243 is playing a significant role in translation elongation, likely via the basic thumb, but has little impact on ribosomal subunit levels. Hpm1 is therefore a multifunctional methyltransferase with independent roles in ribosome biogenesis and translation.
Asunto(s)
Metiltransferasas/fisiología , Extensión de la Cadena Peptídica de Translación , Proteínas Ribosómicas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiología , Saccharomyces cerevisiae/metabolismo , Histidina/metabolismo , Metilación , Procesamiento Proteico-Postraduccional , Saccharomyces cerevisiae/genética , Especificidad por SustratoRESUMEN
The low costs of array-synthesized oligonucleotide libraries are empowering rapid advances in quantitative and synthetic biology. However, high synthesis error rates, uneven representation, and lack of access to individual oligonucleotides limit the true potential of these libraries. We have developed a cost-effective method called Recombinase Directed Indexing (REDI), which involves integration of a complex library into yeast, site-specific recombination to index library DNA, and next-generation sequencing to identify desired clones. We used REDI to generate a library of ~3,300 DNA probes that exhibited > 96% purity and remarkable uniformity (> 95% of probes within twofold of the median abundance). Additionally, we created a collection of ~9,000 individually accessible CRISPR interference yeast strains for > 99% of genes required for either fermentative or respiratory growth, demonstrating the utility of REDI for rapid and cost-effective creation of strain collections from oligonucleotide pools. Our approach is adaptable to any complex DNA library, and fundamentally changes how these libraries can be parsed, maintained, propagated, and characterized.
Asunto(s)
Análisis de Secuencia de ADN/métodos , Levaduras/genética , Sistemas CRISPR-Cas , Biología Computacional/métodos , ADN de Hongos/genética , Biblioteca de GenesRESUMEN
OBJECTIVES: To describe provider characteristics, knowledge acquisition, perceived relevance, and instruction quality of the Society of Critical Care Medicine's Pediatric Fundamentals of Critical Care Support course pilot implementation in Botswana. DESIGN: Observational, single center. SETTING: Academic, upper middle-income country. SUBJECTS: Healthcare providers in Botswana. INTERVENTIONS: A cohort of healthcare providers completed the standard 2-day Pediatric Fundamentals of Critical Care Support course and qualitative survey during the course. Cognitive knowledge was assessed prior to and immediately following training using standard Pediatric Fundamentals of Critical Care Support multiple choice questionnaires. Data analysis used Fisher exact, chi-square, paired t test, and Wilcoxon rank-sum where appropriate. MAIN RESULTS: There was a significant increase in overall multiple choice questionnaires scores after training (mean 67% vs 77%; p < 0.001). Early career providers had significantly lower mean baseline scores (56% vs 71%; p < 0.01), greater knowledge acquisition (17% vs 7%; p < 0.02), but no difference in posttraining scores (73% vs 78%; p = 0.13) compared with more senior providers. Recent pediatric resuscitation or emergency training did not significantly impact baseline scores, posttraining scores, or decrease knowledge acquisition. Eighty-eight percent of providers perceived the course was highly relevant to their clinical practice, but only 71% reported the course equipment was similar to their current workplace. CONCLUSIONS: Pediatric Fundamentals of Critical Care Support training significantly increased provider knowledge to care for hospitalized seriously ill or injured children in Botswana. Knowledge accrual is most significant among early career providers and is not limited by previous pediatric resuscitation or emergency training. Further contextualization of the course to use equipment relevant to providers work environment may increase the value of training.
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Personal de Salud/educación , Pediatría/educación , Evaluación de Programas y Proyectos de Salud , Botswana , Niño , Cuidados Críticos , Países en Desarrollo , Femenino , Humanos , Masculino , Investigación Cualitativa , Encuestas y CuestionariosRESUMEN
OBJECTIVES: To determine whether the Safer Dx Instrument, a structured tool for finding diagnostic errors in primary care, can be used to reliably detect diagnostic errors in patients admitted to a PICU. DESIGN AND SETTING: The Safer Dx Instrument consists of 11 questions to evaluate the diagnostic process and a final question to determine if diagnostic error occurred. We used the instrument to analyze four "high-risk" patient cohorts admitted to the PICU between June 2013 and December 2013. PATIENTS: High-risk cohorts were defined as cohort 1: patients who were autopsied; cohort 2: patients seen as outpatients within 2 weeks prior to PICU admission; cohort 3: patients transferred to PICU unexpectedly from an acute care floor after a rapid response and requiring vasoactive medications and/or endotracheal intubation due to decompensation within 24 hours; and cohort 4: patients transferred to PICU unexpectedly from an acute care floor after a rapid response without subsequent decompensation in 24 hours. INTERVENTIONS: Two clinicians used the instrument to independently review records in each cohort for diagnostic errors, defined as missed opportunities to make a correct or timely diagnosis. Errors were confirmed by senior expert clinicians. MEASUREMENTS AND MAIN RESULTS: Diagnostic errors were present in 26 of 214 high-risk patient records (12.1%; 95% CI, 8.2-17.5%) with the following frequency distribution: cohort 1: two of 16 (12.5%); cohort 2: one of 41 (2.4%); cohort 3: 13 of 44 (29.5%); and cohort 4: 10 of 113 (8.8%). Overall initial reviewer agreement was 93.6% (κ, 0.72). Infections and neurologic conditions were the most commonly missed diagnoses across all high-risk cohorts (16/26). CONCLUSIONS: The Safer Dx Instrument has high reliability and validity for diagnostic error detection when used in high-risk pediatric care settings. With further validation in additional clinical settings, it could be useful to enhance learning and feedback about diagnostic safety in children.
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Cuidados Críticos/normas , Errores Diagnósticos/estadística & datos numéricos , Unidades de Cuidado Intensivo Pediátrico/normas , Garantía de la Calidad de Atención de Salud/métodos , Adolescente , Niño , Preescolar , Cuidados Críticos/estadística & datos numéricos , Errores Diagnósticos/prevención & control , Registros Electrónicos de Salud , Femenino , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Pediátrico/estadística & datos numéricos , Masculino , Evaluación de Procesos y Resultados en Atención de Salud/métodos , Mejoramiento de la Calidad , Reproducibilidad de los Resultados , Medición de Riesgo , Sensibilidad y EspecificidadRESUMEN
Purpose This article offers constructive commentary on The Life Course Health and Development Model (LCHD) as an organizing framework for MCH research. Description The LCHD has recently been proposed as an organizing framework for MCH research. This model integrates biomedical, biopsychosocial, and life course frameworks, to explain how "individual health trajectories" develop over time. In this article, we propose that the LCHD can improve its relevance to MCH policy and practice by: (1) placing individual health trajectories within the context of family health trajectories, which unfold within communities and societies, over historical and generational time; and (2) placing greater weight on the social determinants that shape health development trajectories of individuals and families to produce greater or lesser health equity. Assessment We argue that emphasizing these nested, historically specific social contexts in life course models will enrich study design and data analysis for future developmental science research, will make the LCHD model more relevant in shaping MCH policy and interventions, and will guard against its application as a deterministic framework. Specific ways to measure these and examples of how they can be integrated into the LCHD model are articulated. Conclusion Research applying the LCHD should incorporate the specific family and socio-historical contexts in which development occurs to serve as a useful basis for policy and interventions. Future longitudinal studies of maternal and child health should include collection of time-dependent data related to family environment and other social determinants of health, and analyze the impact of historical events and trends on specific cohorts.
Asunto(s)
Familia , Promoción de la Salud/métodos , Modelos Biológicos , Salud Pública , Determinantes Sociales de la Salud , Femenino , Humanos , Modelos TeóricosRESUMEN
Bromodomain proteins are key regulators of gene expression. How the levels of these factors are regulated in specific environmental conditions is unknown. Previous work has established that expression of yeast Bromodomain factor 2 (BDF2) is limited by spliceosome-mediated decay (SMD). Here we show that BDF2 is subject to an additional layer of post-transcriptional control through RNase III-mediated decay (RMD). We found that the yeast RNase III Rnt1p cleaves a stem-loop structure within the BDF2 mRNA to down-regulate its expression. However, these two nuclear RNA degradation pathways play distinct roles in the regulation of BDF2 expression, as we show that the RMD and SMD pathways of the BDF2 mRNA are differentially activated or repressed in specific environmental conditions. RMD is hyper-activated by salt stress and repressed by hydroxyurea-induced DNA damage while SMD is inactivated by salt stress and predominates during DNA damage. Mutations of cis-acting signals that control SMD and RMD rescue numerous growth defects of cells lacking Bdf1p, and show that SMD plays an important role in the DNA damage response. These results demonstrate that specific environmental conditions modulate nuclear RNA degradation pathways to control BDF2 expression and Bdf2p-mediated gene regulation. Moreover, these results show that precise dosage of Bromodomain factors is essential for cell survival in specific environmental conditions, emphasizing their importance for controlling chromatin structure and gene expression in response to environmental stress.
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Proteínas Fúngicas/genética , ARN de Hongos/genética , Estrés Fisiológico/genética , Factores de Transcripción/genética , Levaduras/fisiología , Carbono/metabolismo , Supervivencia Celular/genética , Daño del ADN/efectos de los fármacos , Replicación del ADN/efectos de los fármacos , Exones , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica , Hidroxiurea/farmacología , Intrones , Mutación , Conformación de Ácido Nucleico , Estabilidad del ARN , ARN de Hongos/química , ARN de Hongos/metabolismo , ARN Mensajero/química , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ribonucleasa III/genética , Ribonucleasa III/metabolismo , Saccharomyces cerevisiae/fisiología , Tolerancia a la Sal/genética , Empalmosomas/metabolismo , Factores de Transcripción/metabolismo , Levaduras/efectos de los fármacosRESUMEN
IMPORTANCE: Diagnostic errors are common and harmful, but difficult to define and measure. Measurement of diagnostic errors often depends on retrospective medical record reviews, frequently resulting in reviewer disagreement. OBJECTIVES: We aimed to test the accuracy of an instrument to help detect presence or absence of diagnostic error through record reviews. DESIGN: We gathered questions from several previously used instruments for diagnostic error measurement, then developed and refined our instrument. We tested the accuracy of the instrument against a sample of patient records (n = 389), with and without previously identified diagnostic errors (n = 129 and n = 260, respectively). RESULTS: The final version of our instrument (titled Safer Dx Instrument) consisted of 11 questions assessing diagnostic processes in the patient-provider encounter and a main outcome question to determine diagnostic error. In comparison with the previous sample, the instrument yielded an overall accuracy of 84 %, sensitivity of 71 %, specificity of 90 %, negative predictive value of 86 %, and positive predictive value of 78 %. All 11 items correlated significantly with the instrument's error outcome question (all p values ≤ 0.01). Using factor analysis, the 11 questions clustered into two domains with high internal consistency (initial diagnostic assessment, and performance and interpretation of diagnostic tests) and a patient factor domain with low internal consistency (Cronbach's alpha coefficients 0.93, 0.92, and 0.38, respectively). CONCLUSIONS: The Safer Dx Instrument helps quantify the likelihood of diagnostic error in primary care visits, achieving a high degree of accuracy for measuring their presence or absence. This instrument could be useful to identify high-risk cases for further study and quality improvement.
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Errores Diagnósticos/estadística & datos numéricos , Atención Primaria de Salud/normas , Mejoramiento de la Calidad , Pruebas Diagnósticas de Rutina/normas , Humanos , Registros Médicos , Seguridad del Paciente/normas , Seguridad del Paciente/estadística & datos numéricos , Valor Predictivo de las Pruebas , Curva ROC , Estudios Retrospectivos , Sensibilidad y Especificidad , TexasRESUMEN
OBJECTIVE: Our study objectives were to explore moral distress among pediatric team clinicians within the context of resuscitation experiences, and determine whether there were any distinctively ethical perspectives on moral distress that could be conceptualized as challenges to professional integrity, rather than to previously described psychological responses of clinicians. DESIGN: Descriptive, exploratory qualitative study. SETTING: A large tertiary pediatric academic hospital in Houston, TX. SUBJECTS: Twenty-five PICU resuscitation team clinicians were interviewed from December 2012 to April 2013. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All clinicians reported experiencing moral distress during certain resuscitations. Twenty-one of 25 clinicians reflected and acknowledged that their sense of professional integrity had been challenged during those resuscitation events. Four main components of resuscitation experience that induced moral distress were identified: 1) experiences where there was lack of understanding of the big picture; 2) experiences where there was suboptimal team leadership; 3) experiences where there was variable meanings to the word "resuscitation"; and 4) experiences were there was uncertainty of role responsibility. CONCLUSIONS: The perception of moral distress exists among pediatric clinicians during resuscitations and could be conceptualized as challenges to professional integrity. This ethical framework offers an alternative approach to understanding and investigating the complex layers of moral distress.
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Actitud del Personal de Salud , Principios Morales , Grupo de Atención al Paciente/ética , Profesionalismo/ética , Resucitación/ética , Estrés Psicológico/etiología , Niño , Femenino , Hospitales Pediátricos , Humanos , Satisfacción en el Trabajo , Masculino , Pediatría , Investigación CualitativaRESUMEN
Methylation of various components of the translational machinery has been shown to globally affect protein synthesis. Little is currently known about the role of lysine methylation on elongation factors. Here we show that in Saccharomyces cerevisiae, the product of the EFM3/YJR129C gene is responsible for the trimethylation of lysine 509 on elongation factor 2. Deletion of EFM3 or of the previously described EFM2 increases sensitivity to antibiotics that target translation and decreases translational fidelity. Furthermore, the amino acid sequences of Efm3 and Efm2, as well as their respective methylation sites on EF2, are conserved in other eukaryotes. These results suggest the importance of lysine methylation modification of EF2 in fine tuning the translational apparatus.
Asunto(s)
Metiltransferasas/fisiología , Factor 2 de Elongación Peptídica/metabolismo , Procesamiento Proteico-Postraduccional , Proteínas de Saccharomyces cerevisiae/fisiología , Saccharomyces cerevisiae/genética , Secuencia de Aminoácidos , Dominio Catalítico , Secuencia Conservada , Metilación , Metiltransferasas/química , Modelos Moleculares , Datos de Secuencia Molecular , Filogenia , Biosíntesis de Proteínas , Saccharomyces cerevisiae/enzimología , Proteínas de Saccharomyces cerevisiae/químicaRESUMEN
This chapter introduces the innovative field-based studies on disadvantaged men that are featured in this volume. Together, these studies of disadvantaged men from diverse racial and ethnic backgrounds and both urban and nonurban settings complement and extend recent discussions of emerging adulthood, which typically conceptualizes the transition to adulthood as a normative and linear process. The authors offer that the research presented here provides a more accurate rendering of the transition to adulthood for young disadvantaged men. For disadvantaged young men, the transition to adulthood is often complex and nonlinear, and features a diversity of pathways that are often overlooked in contemporary research on transitions to adulthood. The chapter ends with a call for research and theory that better reflects the precarious nature of pathways to adulthood for disadvantaged men in urban and nonurban settings. Researchers are encouraged to draw on findings from field-based studies to inform policies and practices directed at minimizing the marginalization of disadvantaged men from mainstream society.
Asunto(s)
Desarrollo del Adolescente/fisiología , Problemas Sociales/psicología , Poblaciones Vulnerables/psicología , Adolescente , Adulto , Humanos , Masculino , Teoría Social , Factores Socioeconómicos , Adulto JovenRESUMEN
Many children in economically disadvantaged communities assume adult roles in their families. Negotiating the responsibilities and expectations associated with becoming what some young men describe as "man of the house" has important implications for how adolescent boys move into adulthood. In this study, we share insights from field work and life-history interviews with low-income, young African American men and Salvadoran men in the Washington, DC/Baltimore region to illustrate how adultification may deliver contradictory expectations for adolescents. The findings also show how the accelerated responsibilities that accompany the experience of adultification create difficulties in the young men's transition into adulthood. These findings indicate that the age period of emerging adulthood may begin earlier for economically disadvantaged young men.
Asunto(s)
Desarrollo del Adolescente , Relaciones Familiares/etnología , Pobreza/etnología , Poblaciones Vulnerables/etnología , Adolescente , Adulto , Negro o Afroamericano/etnología , Baltimore/etnología , District of Columbia/etnología , El Salvador/etnología , Hispánicos o Latinos/etnología , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: Due to high rates of unintended pregnancies in Delaware, the state launched a public health initiative in 2014 to increase access to contraceptive services. OBJECTIVES: This study was designed to assess the practice-level barriers and facilitators to providing contraceptive care, particularly long-acting reversible contraceptives (LARCs), to adolescents in primary care settings. DESIGN: This qualitative study was part of a larger process evaluation of the Delaware Contraceptive Access Now (DelCAN) initiative. METHODS: In-depth, semi-structured qualitative interviews were conducted with 16 practice administrators at 13 adolescent-serving primary care sites across the state of Delaware. A process of open, axial, and selective coding was used to analyze the data. RESULTS: Despite the interest in LARC among their adolescent patients, administrators described numerous barriers to providing LARC for adolescents including confidentiality in patient visits and billing, preceptorship, and provider discomfort and assumptions about the need for contraception among adolescent patients. CONCLUSION: Findings from this study reveal substantial barriers to providing contraception to adolescents, even in primary care practices that were committed to comprehensive contraceptive access for their adolescent patients. This study supports the need for contraceptive care to be integrated into training of pediatricians at every stage of their education. Such training must go beyond education about contraceptive options and the clinical skills necessary for LARC insertion and removal, to include counseling skills based in a reproductive justice framework. Additional changes in policies and practices for adolescent patients would further increase access to contraceptive care.