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TEMPUS is a new detector system being developed for photon science. It is based on the Timepix4 chip and, thus, it can be operated in two distinct modes: a photon-counting mode, which allows for conventional full-frame readout at rates up to 40â kfps; and an event-driven time-stamping mode, which allows excellent time resolution in the nanosecond regime in measurements with moderate X-ray flux. In this paper, the initial prototype, a single-chip device, is introduced, and the readout system described. Moreover, and in order to evaluate its capabilities, some tests were performed at PETRAâ III and ESRF for which results are also presented.
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AIMS/HYPOTHESIS: The inflammatory milieu characteristic of insulitis affects translation fidelity and generates defective ribosomal products (DRiPs) that participate in autoimmune beta cell destruction in type 1 diabetes. Here, we studied the role of early innate cytokines (IFNα) and late immune adaptive events (IFNÉ£) in insulin DRiP-derived peptide presentation to diabetogenic CD8+ T cells. METHODS: Single-cell transcriptomics of human pancreatic islets was used to study the composition of the (immuno)proteasome. Specific inhibition of the immunoproteasome catalytic subunits was achieved using siRNA, and antigenic peptide presentation at the cell surface of the human beta cell line EndoC-ßH1 was monitored using peptide-specific CD8 T cells. RESULTS: We found that IFNγ induces the expression of the PSMB10 transcript encoding the ß2i catalytic subunit of the immunoproteasome in endocrine beta cells, revealing a critical role in insulin DRiP-derived peptide presentation to T cells. Moreover, we showed that PSMB10 is upregulated in a beta cell subset that is preferentially destroyed in the pancreases of individuals with type 1 diabetes. CONCLUSIONS/INTERPRETATION: Our data highlight the role of the degradation machinery in beta cell immunogenicity and emphasise the need for evaluation of targeted immunoproteasome inhibitors to limit beta cell destruction in type 1 diabetes. DATA AVAILABILITY: The single-cell RNA-seq dataset is available from the Gene Expression Omnibus (GEO) using the accession number GSE218316 ( https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE218316 ).
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Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Islotes Pancreáticos , Humanos , Insulina/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Autoinmunidad , Islotes Pancreáticos/metabolismo , Interferón-alfa/farmacología , Células Secretoras de Insulina/metabolismo , Interferón gamma/farmacología , Interferón gamma/metabolismoRESUMEN
Introduction: Active hydrothermal vents of volcanic origin provide a remarkable manifestation of life on Earth under extreme conditions, which may have consequences for our understanding of habitability on other terrestrial bodies as well. Methods: Here, we performed for the first time Illumina sequencing of bacterial and archaeal communities on sub-seafloor samples collected from the Santorini-Kolumbo volcanic field. A total of 19 (3-m long) gravity corers were collected and processed for microbial community analysis. Results: From a total of 6,46,671 produced V4 sequences for all samples, a total of 10,496 different Operational Taxonomic Units (OTUs) were identified that were assigned to 40 bacterial and 9 archaeal phyla and 14 candidate divisions. On average, the most abundant phyla in all samples were Chloroflexi (Chloroflexota) (24.62%), followed by Proteobacteria (Pseudomonadota) (11.29%), Firmicutes (Bacillota) (10.73%), Crenarchaeota (Thermoproteota) (8.55%), and Acidobacteria (Acidobacteriota) (8.07%). At the genus level, a total of 286 known genera and candidate genera were mostly dominated by members of Bacillus, Thermoflexus, Desulfatiglans, Pseudoalteromonas, and Pseudomonas. Discussion: In most of the stations, the Chao1 values at the deeper layers were comparable to the surface sediment samples denoting the high diversity in the subsurface of these ecosystems. Heatmap analysis based on the 100 most abundant OTUs, grouped the sampling stations according to their geographical location, placing together the two hottest stations (up to 99°C). This result indicates that this specific area within the active Kolumbo crater create a distinct niche, where microorganisms with adaptation strategies to withstand heat stresses can thrive, such as the endospore-forming Firmicutes.
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Starting around 2008, there was rapid expansion of oil and natural gas (ONG) production into more heavily populated areas within the Dallas-Fort Worth metroplex in the Barnett Shale region of Texas. This colocation raised concerns regarding the effect of ONG activities on chemical levels in the air. In the current study, we examined the potential impacts of ONG activity on the types and concentrations of chemicals in ambient air in the Barnett Shale. Volatile organic compound (VOC) concentrations from 6-12 years (2008-2019) of hourly ambient air monitoring data from 15 monitors (4 monitors had ≥ 10 years of data) were compared to several metrics of ONG activity (number of active wells, natural gas production, condensate production) within a 2-mile radius of each monitor. Monitoring sites were also classified into urban, suburban, and rural areas as a surrogate for nearby vehicular emission sources. Analyses of this huge dataset showed that both peak and mean chemical concentrations of lighter alkane hydrocarbons (e.g., ethane) were most impacted by the number of gas wells. Levels of heavier alkanes (e.g., pentane) were increased by condensate production and at monitors located in areas with greater urbanicity, and therefore higher vehicular emissions. The levels of unsaturated alkynes (e.g., ethylene) were entirely driven by urbanicity and were unaffected by nearby ONG activity. The same pattern was seen with the ratio of iso:n-pentane, which is contrary to the findings of others and suggests an area for future research. Aromatic hydrocarbons were impacted by multiple emissions sources and did not show the same patterns as non-aromatic VOCs. No VOC concentrations were at levels of concern for human health or odor based on comparison to Texas air monitoring comparison values. Overall, ONG activities impact air quality, but this must be evaluated in the context of other emission sources such as automobiles.
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Contaminantes Atmosféricos , Contaminación del Aire , Compuestos Orgánicos Volátiles , Humanos , Gas Natural , Texas , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Yacimiento de Petróleo y Gas , Emisiones de Vehículos/análisis , Compuestos Orgánicos Volátiles/análisis , Monitoreo del AmbienteRESUMEN
The DNA polymerase zeta (Polζ) plays a critical role in bypassing DNA damage. REV3L, the catalytic subunit of Polζ, is also essential in mouse embryonic development and cell proliferation for reasons that remain incompletely understood. In this study, we reveal that REV3L protein interacts with heterochromatin components including repressive histone marks and localizes in pericentromeric regions through direct interaction with HP1 dimer. We demonstrate that Polζ/REV3L ensures progression of replication forks through difficult-to-replicate pericentromeric heterochromatin, thereby preventing spontaneous chromosome break formation. We also find that Rev3l-deficient cells are compromised in the repair of heterochromatin-associated double-stranded breaks, eliciting deletions in late-replicating regions. Lack of REV3L leads to further consequences that may be ascribed to heterochromatin replication and repair-associated functions of Polζ, with a disruption of the temporal replication program at specific loci. This is correlated with changes in epigenetic landscape and transcriptional control of developmentally regulated genes. These results reveal a new function of Polζ in preventing chromosome instability during replication of heterochromatic regions.
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Replicación del ADN , Proteínas de Unión al ADN/genética , ADN Polimerasa Dirigida por ADN/genética , ADN/genética , Células Madre Embrionarias/metabolismo , Epigénesis Genética , Heterocromatina/metabolismo , Animales , Línea Celular , Línea Celular Transformada , Proliferación Celular , Homólogo de la Proteína Chromobox 5/genética , Homólogo de la Proteína Chromobox 5/metabolismo , Inestabilidad Cromosómica , ADN/metabolismo , Roturas del ADN de Doble Cadena , Proteínas de Unión al ADN/metabolismo , ADN Polimerasa Dirigida por ADN/metabolismo , Embrión de Mamíferos , Células Madre Embrionarias/citología , Fibroblastos/citología , Fibroblastos/metabolismo , Regulación del Desarrollo de la Expresión Génica , Células HeLa , Heterocromatina/química , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Células 3T3 NIH , Transducción de SeñalRESUMEN
In this paper the back-side-illuminated Percival 2-Megapixel (P2M) detector is presented, along with its characterization by means of optical and X-ray photons. For the first time, the response of the system to soft X-rays (250â eV to 1â keV) is presented. The main performance parameters of the first detector are measured, assessing the capabilities in terms of noise, dynamic range and single-photon discrimination capability. Present limitations and coming improvements are discussed.
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Professional antigen-presenting cells (APCs), such as dendritic cells and macrophages, are known for their ability to present exogenous antigens to T cells. However, many other cell types, including endothelial cells, fibroblasts, and lymph node stromal cells, are also capable of presenting exogenous antigens to either CD8+ or CD4+ T cells via cross-presentation or major histocompatibility complex (MHC) class II-mediated presentation, respectively. Antigen presentation by these stromal nonprofessional APCs differentially affect T cell function, depending on the type of cells that present the antigen, as well as the local (inflammatory) micro-environment. It has been recently appreciated that nonprofessional APCs can, as such, orchestrate immunity against pathogens, tumor survival, or rejection, and aid in the progression of various auto-immune pathologies. Therefore, the interest for these nonprofessional APCs is growing as they might be an important target for enhancing various immunotherapies. In this review, the different nonprofessional APCs are discussed, as well as their functional consequences on the T cell response, with a focus on immuno-oncology.
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Presentación de Antígeno/inmunología , Células Presentadoras de Antígenos/inmunología , Células del Estroma/inmunología , Animales , Reactividad Cruzada/inmunología , Células Endoteliales/inmunología , Humanos , Linfocitos T/inmunologíaRESUMEN
The Adaptive Gain Integrating Pixel Detector (AGIPD) is an X-ray imager, custom designed for the European X-ray Free-Electron Laser (XFEL). It is a fast, low-noise integrating detector, with an adaptive gain amplifier per pixel. This has an equivalent noise of less than 1â keV when detecting single photons and, when switched into another gain state, a dynamic range of more than 104â photons of 12â keV. In burst mode the system is able to store 352 images while running at up to 6.5â MHz, which is compatible with the 4.5â MHz frame rate at the European XFEL. The AGIPD system was installed and commissioned in August 2017, and successfully used for the first experiments at the Single Particles, Clusters and Biomolecules (SPB) experimental station at the European XFEL since September 2017. This paper describes the principal components and performance parameters of the system.
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In 2015, the United States Environmental Protection Agency (US EPA) set the ozone National Ambient Air Quality Standards (NAAQS) at 0.070â¯parts per million (ppm), for an annual 4th highest daily 8-hour (h) maximum average concentration, averaged over three years, with compliance based on the monitor with the highest concentrations. Numerous epidemiological studies have evaluated associations between ozone and health effects, but how the ozone concentrations derived from those studies can be compared to the ozone NAAQS is not clear, because of the complexity of the standard. The purpose of the present work was to determine how ozone summary metrics used in key epidemiology studies compare to the metrics that comprise the ozone regulatory value. Evaluation of epidemiology studies used for quantitative risk assessment in the 2015 ozone NAAQS review demonstrated that the most commonly used summary metrics that differed from the NAAQS were: 1-h maximum or 24-h average concentrations; multiple-day averages from 2 to 30â¯days; and averaging of ozone concentrations across all monitors in an area and over different months of the year. Using different ozone summary metrics to calculate the ozone regulatory value in twelve US cities for 2000-2002 or 2013-2015 generated alternative ozone regulatory values that were often substantively different and that may or may not vary commensurate with the regulatory standard. Comparison of epidemiology study metrics to other countries' ozone standards or guideline levels produces similar challenges as described here for the NAAQS. In conclusion, many of the ozone concentration metrics used in epidemiology studies cannot be directly compared to the ozone NAAQS, and using simple conversion ratios adds substantial uncertainty to concentration estimates. These summary metrics must be reconciled to the regulatory value before any judgements are made as to the protectiveness of current and alternative standards based on epidemiology study results.
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Contaminantes Atmosféricos/análisis , Contaminación del Aire/estadística & datos numéricos , Monitoreo del Ambiente , Política Ambiental , Ozono/análisis , Contaminación del Aire/legislación & jurisprudencia , Medición de Riesgo , Estados Unidos , United States Environmental Protection AgencyRESUMEN
DNA polymerase ζ (pol ζ) is a specialized enzyme important for DNA damage tolerance, facilitating synthesis past lesions caused by radiation or chemical damage. Here we report that disruption of Rev3l (encoding the catalytic subunit of pol ζ) in mouse epidermis leads to a defect in proliferation that impairs cutaneous wound healing. A striking increase in epidermal skin pigmentation accompanied both wound healing and UV irradiation in these mice. This was a consequence of stress-induced migration of Rev3l-proficient melanocytes to the Rev3l-defective epidermis. This pigmentation corresponded with p53 activation in keratinocytes and was absent in p53-negative areas of the epidermis. Expression of the kit ligand (Kitl) gene, a p53-controlled mediator of keratinocyte to melanocyte signaling, was enhanced during wound healing or following UV irradiation. This study extends the function of pol ζ to the process of proliferation during wound healing. Rev3l-deficient epidermis may be a useful mouse model system for examining communication between damaged keratinocytes and melanocytes, including signaling relevant to human disease.
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In October 2015, the United States Environmental Protection Agency (EPA) lowered the level of the ozone National Ambient Air Quality Standard (NAAQS) from 0.075 ppm to 0.070 ppm (annual 4th highest daily maximum 8-h concentration, averaged over three years). The EPA estimated a 2025 annual national non-California net benefit of $1.5 to $4.5 billion (2011$, 7% discount rate) for a 0.070 ppm standard, and a -$1.0 to $14 billion net benefit for an alternative 0.065 ppm standard. The purpose of this work is to present a combined toxicological and economic assessment of the EPA's benefit-cost analysis of the 2015 ozone NAAQS. Assessing the quality of the epidemiology studies based on considerations of bias, confounding, chance, integration of evidence, and application of the studies for future population risk estimates, we derived several alternative benefits estimates. We also considered the strengths and weaknesses of the EPA's cost estimates (e.g., marginal abatement costs), as well as estimates completed by other authors, and provided our own alternative cost estimate. Based on our alternative benefits and cost calculations, we estimated an alternative net benefit of between -$0.3 and $1.8 billion for a 0.070 ppm standard (2011 $, 7% discount rate) and between -$23 and -$17 billion for a 0.065 ppm standard. This work demonstrates that alternative reasonable assumptions can generate very difference cost and benefits estimates that may impact how policy makers view the outcomes of a major rule.
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Contaminantes Atmosféricos/normas , Contaminantes Atmosféricos/toxicidad , Ozono/normas , Ozono/toxicidad , United States Environmental Protection Agency , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/economía , Contaminación del Aire/análisis , Análisis Costo-Beneficio , Estudios Epidemiológicos , Humanos , Ozono/análisis , Ozono/economía , Estados UnidosRESUMEN
An inhalation reference concentration (RfC) was developed for diethanolamine (DEA), based principally on evaluation of three animal studies (Gamer et al., 1993, 1996, 2008). The RfC (25 µg/m3) was based on statistically significantly increased relative liver weight in female rats in Gamer et al. (2008) as the critical effect. The lower confidence limit on the benchmark dose (BMDL10 of 5.5 mg/m3) was adjusted to a human equivalent concentration and to continuous exposure before dividing the final point of departure (2.3 mg/m3) by a total factor of 90 that considered standard key areas of uncertainty (intrahuman variability, potential interspecies toxicodynamic differences, database limitations). While laryngeal effects observed in Gamer et al. (2008) were also considered as candidate critical effects, evaluation of the adversity and human relevance of rat laryngeal squamous metaplasia and concomitant effects at the various exposure levels resulted in identifying a LOAEL for laryngeal squamous hyperplasia and chronic inflammation that was much higher than the liver weight LOAEL identified. The RfC of 25 µg/m3 is considered health protective for the general population and can be used to evaluate the potential health effects of long-term environmental exposure of the general public (i.e., long-term, ambient air dispersion modelling or monitoring data).
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Etanolaminas/administración & dosificación , Etanolaminas/química , Animales , Etanolaminas/efectos adversos , Femenino , Humanos , Hiperplasia/inducido químicamente , Inflamación/inducido químicamente , Inhalación/efectos de los fármacos , Enfermedades de la Laringe/inducido químicamente , Masculino , Metaplasia/inducido químicamente , RatasRESUMEN
BACKGROUND: Many studies have evaluated associations between asthma emergency department (ED) visits, hospital admissions (HAs), and ambient ozone (O3) across the US, but not in Texas. We investigated the relationship between O3 and asthma HAs, and the potential impacts of outdoor pollen, respiratory infection HAs, and the start of the school year in Texas. METHODS: We obtained daily time-series data on asthma HAs and ambient O3 concentrations for Dallas, Houston, and Austin, Texas for the years 2003-2011. Relative risks (RRs) and 95% confidence intervals (CIs) of asthma HAs per 10-ppb increase in 8-h maximum O3 concentrations were estimated from Poisson generalized additive models and adjusted for temporal trends, meteorological factors, pollen, respiratory infection HAs, day of the week, and public holidays. We conducted a number of sensitivity analyses to assess model specification. RESULTS: We observed weak associations between total asthma HAs and O3 at lags of 1 day (RR10 ppb = 1.012, 95% CI: 1.004-1.021), 2 days (RR10 ppb = 1.011, 95% CI: 1.002-1.019), and 0-3 days (RR10 ppb = 1.017, 95% CI: 1.005-1.030). The associations were primarily observed in children aged 5-14 years (e.g., for O3 at lag 0-3 days, RR10 ppb = 1.037, 95% CI: 1.011-1.064), and null in individuals 15 years or older. The effect estimates did not change significantly with adjustment for pollen and respiratory infections, but they attenuated considerably and lost statistical significance when August and September data were excluded. A significant interaction between time around the start of the school year and O3 at lag 2 day was observed, with the associations with pediatric asthma HAs stronger in August and September (RR10 ppb = 1.040, 95% CI: 1.012-1.069) than in the rest of the year (October-July) (RR10 ppb = 1.006, 95% CI: 0.986-1.026). CONCLUSIONS: We observed small but statistically significant positive associations between total and pediatric asthma HAs and short-term O3 exposure in Texas, especially in August and September. Further research is needed to determine how the start of school could modify the observed association between O3 and pediatric asthma HAs.
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This paper highlights the pervasive misconception concerning 1994 findings from Hatch et al. about ozone (O3) tissue dose in humans versus rats. That study exposed humans to 0.4 ppm and rats to 2 ppm 18O-labeled O3 and found comparable incorporation of 18O into bronchoalveolar lavage constituents. However, during O3 exposure humans were exercising, which increased their ventilation rate five-fold, while rats were at rest. This resulted in similar O3 tissue doses between the two species, and predominantly explained the comparable 18O incorporation at five-fold different concentrations. The five-times higher exercising human inhalation rate offset the five-times lower concentration, producing the same human dose expected at rest at 2 ppm (i.e. 0.4 ppm × 4686 L/2 hour ≈ 2 ppm × 998 L/2 hour). In 2013, Hatch et al. showed that resting humans and resting rats experienced fairly comparable 18O incorporation at the same O3 exposure concentration and activity state into BALF cells. Despite these findings, we show here that in the peer-reviewed literature a substantial proportion of researchers continue to perpetuate the misunderstanding that human lung tissue doses of O3 are simply 3-5 times greater than rat doses at the same O3 concentration, due to interspecies differences, and not considering activity state. It is important to correct this misconception to ensure an appropriate understanding of the implications of O3 studies by the scientific community and policy experts making regulatory decisions (e.g. the US Environmental Protection Agency's National Ambient Air Quality Standards for O3).
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Contaminantes Atmosféricos , Pulmón/metabolismo , Ozono/administración & dosificación , Animales , Humanos , Ratas , Especificidad de la EspecieRESUMEN
BACKGROUND: Short-term exposure to ozone has been associated with asthma hospital admissions (HA) and emergency department (ED) visits, but the shape of the concentration-response (C-R) curve is unclear. METHODS: We conducted a time series analysis of asthma HAs and ambient ozone concentrations in six metropolitan areas in Texas from 2001 to 2013. Using generalized linear regression models, we estimated the effect of daily 8-hour maximum ozone concentrations on asthma HAs for all ages combined, and for those aged 5-14, 15-64, and 65+years. We fit penalized regression splines to evaluate the shape of the C-R curves. RESULTS: Using a log-linear model, estimated risk per 10ppb increase in average daily 8-hour maximum ozone concentrations was highest for children (relative risk [RR]=1.047, 95% confidence interval [CI]: 1.025-1.069), lower for younger adults (RR=1.018, 95% CI: 1.005-1.032), and null for older adults (RR=1.002, 95% CI: 0.981-1.023). However, penalized spline models demonstrated significant nonlinear C-R relationships for all ages combined, children, and younger adults, indicating the existence of thresholds. We did not observe an increased risk of asthma HAs until average daily 8-hour maximum ozone concentrations exceeded approximately 40ppb. CONCLUSION: Ozone and asthma HAs are significantly associated with each other; susceptibility to ozone is age-dependent, with children at highest risk. C-R relationships between average daily 8-hour maximum ozone concentrations and asthma HAs are significantly curvilinear for all ages combined, children, and younger adults. These nonlinear relationships, as well as the lack of relationship between average daily 8-hour maximum and peak ozone concentrations, have important implications for assessing risks to human health in regulatory settings.
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Contaminantes Atmosféricos/análisis , Asma/epidemiología , Hospitalización/estadística & datos numéricos , Ozono/análisis , Adolescente , Adulto , Anciano , Contaminantes Atmosféricos/efectos adversos , Niño , Preescolar , Exposición a Riesgos Ambientales/efectos adversos , Exposición a Riesgos Ambientales/análisis , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ozono/efectos adversos , Medición de Riesgo , Texas/epidemiología , Adulto JovenRESUMEN
Routine dietary consumption of foods that contain aflatoxins is the second leading cause of environmental carcinogenesis worldwide. Aflatoxin-driven mutagenesis is initiated through metabolic activation of aflatoxin B1 (AFB1) to its epoxide form that reacts with N7 guanine in DNA. The resulting AFB1-N7-dG adduct undergoes either spontaneous depurination or imidazole-ring opening yielding formamidopyrimidine AFB1 (AFB1-Fapy-dG). Because this latter adduct is known to persist in human tissues and contributes to the high frequency G-to-T mutation signature associated with many hepatocellular carcinomas, we sought to establish the identity of the polymerase(s) involved in processing this lesion. Although our previous biochemical analyses demonstrated the ability of polymerase ζ (pol ζ) to incorporate an A opposite AFB1-Fapy-dG and extend from this mismatch, biological evidence supporting a unique role for this polymerase in cellular tolerance following aflatoxin exposure has not been established. Following challenge with AFB1, survival of mouse cells deficient in pol ζ (Rev3L-/-) was significantly reduced relative to Rev3L+/- cells or Rev3L-/- cells complemented through expression of the wild-type human REV3L. Furthermore, cell-cycle progression of Rev3L-/- mouse embryo fibroblasts was arrested in late S/G2 following AFB1 exposure. These Rev3L-/- cells showed an increase in replication-dependent formation of γ-H2AX foci, micronuclei, and chromosomal aberrations (chromatid breaks and radials) relative to Rev3L+/- cells. These data suggest that pol ζ is essential for processing AFB1-induced DNA adducts and that, in its absence, cells do not have an efficient backup polymerase or a repair/tolerance mechanism facilitating survival.
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Carcinoma Hepatocelular/genética , Proteínas de Unión al ADN/genética , ADN Polimerasa Dirigida por ADN/genética , Neoplasias Hepáticas/genética , Aflatoxina B1/análogos & derivados , Aflatoxina B1/genética , Aflatoxina B1/toxicidad , Aflatoxinas/toxicidad , Animales , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/patología , Supervivencia Celular/efectos de los fármacos , Aberraciones Cromosómicas/efectos de los fármacos , Citidina/análogos & derivados , Citidina/genética , Citidina/toxicidad , Aductos de ADN/efectos de los fármacos , Aductos de ADN/genética , Daño del ADN/efectos de los fármacos , Reparación del ADN/genética , ADN Polimerasa Dirigida por ADN/química , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/patología , Ratones , Mutagénesis/efectos de los fármacos , Mutagénesis/genética , MutaciónRESUMEN
OBJECTIVE: Burnout is a process of physical and emotional exhaustion that often results in clinical depression. Detailed descriptions and evaluations of specialized psychosomatic treatment are rare. This pilot study investigates the feasibility of inpatient and day hospital treatment of patients with burnout syndrome. Additionally, we present results of an initial, noncontrolled, pre-post-evaluation of changes in symptoms and individual work-related risk factors for burnout. METHODS: Sixty-four consecutive patients with burnout syndrome were assessed before and after specialized multimodal treatment using a clinical symptom checklist (ICD-10 Symptom Rating) and burnout-specific instruments (Maslach Burnout Inventory, Occupational Stress & Coping Inventory). RESULTS: Patients' average age was 45 (range 23 to 61), 70% were currently employed, 24% in managerial positions or self-employed, and 89% diagnosed with an affective disorder. The average length of time off work due to illness in the past year was 13 weeks. Treatment lasted five weeks on average. After treatment, depression (p < 0.001; effect size d = 0.79), emotional exhaustion (p = 0.001; d = 0.41), and the subjective significance of work (p = 0.001; d = 0.36) decreased, while emotional distancing (p < 0.001; d = 0.56), balance and mental stability (p < 0.001; d = 0.38) and life satisfaction (p < 0.001; d = 0.37) increased. Clinical significance was determined using the Reliable Change Index. CONCLUSIONS: The treatment program described here is well accepted by patients with severe burnout. It contributes to positive changes in symptoms and work-related risk factors. Controlled studies are necessary to establish treatment efficacy.
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Agotamiento Profesional/terapia , Centros de Día , Trastorno Depresivo Mayor/terapia , Hospitales Psiquiátricos , Admisión del Paciente , Adulto , Agotamiento Profesional/diagnóstico , Agotamiento Profesional/psicología , Terapia Combinada , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/psicología , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Grupo de Atención al Paciente , Proyectos Piloto , Servicio de Psiquiatría en Hospital , Factores de RiesgoRESUMEN
DNA polymerase ι (Pol ι) is an attractive candidate for somatic hypermutation in antibody genes because of its low fidelity. To identify a role for Pol ι, we analyzed mutations in two strains of mice with deficiencies in the enzyme: 129 mice with negligible expression of truncated Pol ι, and knock-in mice that express full-length Pol ι that is catalytically inactive. Both strains had normal frequencies and spectra of mutations in the variable region, indicating that loss of Pol ι did not change overall mutagenesis. We next examined if Pol ι affected tandem mutations generated by another error-prone polymerase, Pol ζ. The frequency of contiguous mutations was analyzed using a novel computational model to determine if they occur during a single DNA transaction or during two independent events. Analyses of 2,000 mutations from both strains indicated that Pol ι-compromised mice lost the tandem signature, whereas C57BL/6 mice accumulated significant amounts of double mutations. The results support a model where Pol ι occasionally accesses the replication fork to generate a first mutation, and Pol ζ extends the mismatch with a second mutation.
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ADN Polimerasa Dirigida por ADN/fisiología , Genes de Inmunoglobulinas , Hipermutación Somática de Inmunoglobulina , Animales , Ratones , Ratones Endogámicos C57BL , Mutación , ADN Polimerasa iotaRESUMEN
DNA polymerase ζ (pol ζ) is exceptionally important for maintaining genome stability. Inactivation of the Rev3l gene encoding the polymerase catalytic subunit causes a high frequency of chromosomal breaks, followed by lethality in mouse embryos and in primary cells. Yet it is not known whether the DNA polymerase activity of pol ζ is specifically essential, as the large REV3L protein also serves as a multiprotein scaffold for translesion DNA synthesis via multiple conserved structural domains. We report that Rev3l cDNA rescues the genomic instability and DNA damage sensitivity of Rev3l-null immortalized mouse fibroblast cell lines. A cDNA harboring mutations of conserved catalytic aspartate residues in the polymerase domain of REV3L could not rescue these phenotypes. To investigate the role of REV3L DNA polymerase activity in vivo, a Rev3l knock-in mouse was constructed with this polymerase-inactivating alteration. No homozygous mutant mice were produced, with lethality occurring during embryogenesis. Primary fibroblasts from mutant embryos showed growth defects, elevated DNA double-strand breaks and cisplatin sensitivity similar to Rev3l-null fibroblasts. We tested whether the severe Rev3l-/- phenotypes could be rescued by deletion of DNA polymerase η, as has been reported with chicken DT40 cells. However, Rev3l-/- Polh-/- mice were inviable, and derived primary fibroblasts were as sensitive to DNA damage as Rev3l-/- Polh+/+ fibroblasts. Therefore, the functions of REV3L in maintaining cell viability, embryonic viability and genomic stability are directly dependent on its polymerase activity, and cannot be ameliorated by an additional deletion of pol η. These results validate and encourage the approach of targeting the DNA polymerase activity of pol ζ to sensitize tumors to DNA damaging agents.