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1.
Nature ; 614(7949): 659-663, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36623548

RESUMEN

Transmission spectroscopy1-3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species-in particular the primary carbon-bearing molecules6,7. Here we report a broad-wavelength 0.5-5.5 µm atmospheric transmission spectrum of WASP-39b8, a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec's PRISM mode9 as part of the JWST Transiting Exoplanet Community Early Release Science Team Program10-12. We robustly detect several chemical species at high significance, including Na (19σ), H2O (33σ), CO2 (28σ) and CO (7σ). The non-detection of CH4, combined with a strong CO2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO2 (2.7σ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.

2.
J Biol Chem ; : 107579, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39025455

RESUMEN

NEIL1 is a DNA glycosylase that recognizes and initiates base excision repair of oxidized bases. The ubiquitous ssDNA binding scaffolding protein, replication protein A (RPA), modulates NEIL1 activity in a manner that depends on DNA structure. Interaction between NEIL1 and RPA has been reported, but the molecular basis of this interaction has yet to be investigated. Using a combination of NMR spectroscopy and isothermal titration calorimetry (ITC), we show that NEIL1 interacts with RPA through two contact points. An interaction with the RPA32C protein recruitment domain was mapped to a motif in the common interaction domain (CID) of NEIL1 and a dissociation constant (Kd) of 200 nM was measured. A substantially weaker secondary interaction with the tandem RPA70AB ssDNA binding domains was also mapped to the CID. Together these two contact points reveal NEIL1 has a high overall affinity (Kd ∼ 20 nM) for RPA. A homology model of the complex of RPA32C with the NEIL1 RPA binding motif in the CID was generated and used to design a set of mutations in NEIL1 to disrupt the interaction, which was confirmed by ITC. The mutant NEIL1 remains catalytically active against a thymine glycol lesion in duplex DNA in vitro. Testing the functional effect of disrupting the NEIL1-RPA interaction in vivo using a Fluorescence Multiplex-Host Cell Reactivation (FM-HCR) reporter assay revealed an unexpected role for NEIL1 in nucleotide excision repair. These findings are discussed in the context of the role of NEIL1 in replication-associated repair.

3.
J Autoimmun ; 147: 103263, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38851089

RESUMEN

RATIONALE: In inflammatory diseases such as rheumatoid arthritis (RA), steroid metabolism is a central component mediating the actions of immuno-modulatory glucocorticoids and sex steroids. However, the regulation and function of cellular steroid metabolism within key leukocyte populations such as macrophages remain poorly defined. In this study, the inflammatory regulation of global steroid metabolism was assessed in RA macrophages. METHODS: Bulk RNA-seq data from RA synovial macrophages was used to assess transcripts encoding key enzymes in steroid metabolism and signalling. Changes in metabolism were assessed in synovial fluids, correlated to measures of disease activity and functionally validated in primary macrophage cultures. RESULTS: RNA-seq revealed a unique pattern of differentially expressed genes, including changes in genes encoding the enzymes 11ß-HSD1, SRD5A1, AKR1C2 and AKR1C3. These correlated with disease activity, favouring increased glucocorticoid and androgen levels. Synovial fluid 11ß-HSD1 activity correlated with local inflammatory mediators (TNFα, IL-6, IL-17), whilst 11ß-HSD1, SRD5A1 and AKR1C3 activity correlated with systemic measures of disease and patient pain (ESR, DAS28 ESR, global disease activity). Changes in enzyme activity were evident in inflammatory activated macrophages in vitro and revealed a novel androgen activating role for 11ß-HSD1. Together, increased glucocorticoids and androgens were able to suppress inflammation in macrophages and fibroblast-like-synoviocytes. CONCLUSIONS: This study underscores the significant increase in androgen and glucocorticoid activation within inflammatory polarized macrophages of the synovium, contributing to local suppression of inflammation. The diminished profile of inactive steroid precursors in postmenopausal women may contribute to disturbances in this process, leading to increased disease incidence and severity.


Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1 , Artritis Reumatoide , Inflamación , Macrófagos , Humanos , Artritis Reumatoide/metabolismo , Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Macrófagos/metabolismo , Macrófagos/inmunología , Inflamación/metabolismo , Inflamación/inmunología , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , Miembro C3 de la Familia 1 de las Aldo-Ceto Reductasas/metabolismo , Líquido Sinovial/metabolismo , Líquido Sinovial/inmunología , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Masculino , Femenino , Membrana Sinovial/metabolismo , Membrana Sinovial/patología , Membrana Sinovial/inmunología , Células Cultivadas , Glucocorticoides/metabolismo , Esteroides/metabolismo , Regulación de la Expresión Génica , Hidroxiesteroide Deshidrogenasas
4.
BMC Cancer ; 24(1): 174, 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38317104

RESUMEN

BACKGROUND: High levels of physical activity are associated with reduced risk of the blood cancer multiple myeloma (MM). MM is preceded by the asymptomatic stages of monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM) which are clinically managed by watchful waiting. A case study (N = 1) of a former elite athlete aged 44 years previously indicated that a multi-modal exercise programme reversed SMM disease activity. To build from this prior case study, the present pilot study firstly examined if short-term exercise training was feasible and safe for a group of MGUS and SMM patients, and secondly investigated the effects on MGUS/SMM disease activity. METHODS: In this single-arm pilot study, N = 20 participants diagnosed with MGUS or SMM were allocated to receive a 16-week progressive exercise programme. Primary outcome measures were feasibility and safety. Secondary outcomes were pre- to post-exercise training changes to blood biomarkers of MGUS and SMM disease activity- monoclonal (M)-protein and free light chains (FLC)- plus cardiorespiratory and functional fitness, body composition, quality of life, blood immunophenotype, and blood biomarkers of inflammation. RESULTS: Fifteen (3 MGUS and 12 SMM) participants completed the exercise programme. Adherence was 91 ± 11%. Compliance was 75 ± 25% overall, with a notable decline in compliance at intensities > 70% V̇O2PEAK. There were no serious adverse events. There were no changes to M-protein (0.0 ± 1.0 g/L, P =.903), involved FLC (+ 1.8 ± 16.8 mg/L, P =.839), or FLC difference (+ 0.2 ± 15.6 mg/L, P =.946) from pre- to post-exercise training. There were pre- to post-exercise training improvements to diastolic blood pressure (- 3 ± 5 mmHg, P =.033), sit-to-stand test performance (+ 5 ± 5 repetitions, P =.002), and energy/fatigue scores (+ 10 ± 15%, P =.026). Other secondary outcomes were unchanged. CONCLUSIONS: A 16-week progressive exercise programme was feasible and safe, but did not reverse MGUS/SMM disease activity, contrasting a prior case study showing that five years of exercise training reversed SMM in a 44-year-old former athlete. Longer exercise interventions should be explored in a group of MGUS/SMM patients, with measurements of disease biomarkers, along with rates of disease progression (i.e., MGUS/SMM to MM). REGISTRATION: https://www.isrctn.com/ISRCTN65527208 (14/05/2018).


Asunto(s)
Gammopatía Monoclonal de Relevancia Indeterminada , Mieloma Múltiple , Paraproteinemias , Mieloma Múltiple Quiescente , Humanos , Adulto , Gammopatía Monoclonal de Relevancia Indeterminada/terapia , Gammopatía Monoclonal de Relevancia Indeterminada/diagnóstico , Mieloma Múltiple/diagnóstico , Proyectos Piloto , Calidad de Vida , Progresión de la Enfermedad , Biomarcadores , Ejercicio Físico
5.
Hum Brain Mapp ; 44(17): 5729-5748, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37787573

RESUMEN

Despite the known benefits of data-driven approaches, the lack of approaches for identifying functional neuroimaging patterns that capture both individual variations and inter-subject correspondence limits the clinical utility of rsfMRI and its application to single-subject analyses. Here, using rsfMRI data from over 100k individuals across private and public datasets, we identify replicable multi-spatial-scale canonical intrinsic connectivity network (ICN) templates via the use of multi-model-order independent component analysis (ICA). We also study the feasibility of estimating subject-specific ICNs via spatially constrained ICA. The results show that the subject-level ICN estimations vary as a function of the ICN itself, the data length, and the spatial resolution. In general, large-scale ICNs require less data to achieve specific levels of (within- and between-subject) spatial similarity with their templates. Importantly, increasing data length can reduce an ICN's subject-level specificity, suggesting longer scans may not always be desirable. We also find a positive linear relationship between data length and spatial smoothness (possibly due to averaging over intrinsic dynamics), suggesting studies examining optimized data length should consider spatial smoothness. Finally, consistency in spatial similarity between ICNs estimated using the full data and subsets across different data lengths suggests lower within-subject spatial similarity in shorter data is not wholly defined by lower reliability in ICN estimates, but may be an indication of meaningful brain dynamics which average out as data length increases.


Asunto(s)
Mapeo Encefálico , Imagen por Resonancia Magnética , Humanos , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Reproducibilidad de los Resultados , Red Nerviosa/diagnóstico por imagen , Encéfalo/diagnóstico por imagen
6.
Ultrasound Obstet Gynecol ; 61(3): 377-385, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35866888

RESUMEN

OBJECTIVES: Fetal growth restriction (FGR) is often secondary to placental dysfunction and is suspected prenatally based on biometric or circulatory abnormalities detected on ultrasound. The aims of this study were to compare the screening performance of the Society for Maternal-Fetal Medicine (SMFM) biometric criteria (estimated fetal weight (EFW) or abdominal circumference (AC) < 10th centile) with that of the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG)-endorsed Delphi consensus criteria for late FGR for delivery of a small-for-gestational-age (SGA) infant at term, emergency Cesarean section (CS) for non-reassuring fetal status (NRFS), perinatal mortality and composite severe neonatal morbidity. METHODS: We classified retrospectively non-anomalous singleton infants as having late FGR (diagnosed ≥ 32 weeks) according to SMFM and ISUOG/Delphi criteria in a cohort of women who had been referred to the Mater Mother's Hospital, Brisbane, Australia and who delivered at term between January 2014 and December 2020. The study outcomes were delivery of a SGA infant (birth weight (BW) < 10th or < 3rd centile), emergency CS for NRFS, perinatal mortality (defined as stillbirth or neonatal death within 28 days of a live birth) and a composite of severe neonatal morbidity. We assessed the screening performance of various ultrasound variables by calculating the sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, false-positive and false-negative rates, positive likelihood ratio (LR+) and negative likelihood ratio. RESULTS: The SMFM and ISUOG/Delphi consensus criteria collectively classified 1030 cases as having late FGR. Of these, 400 cases were classified by both SMFM and ISUOG/Delphi criteria, whilst 548 cases were classified using only SMFM criteria and 82 cases were classified only by ISUOG/Delphi criteria. Prenatal detection of late FGR by SMFM and ISUOG/Delphi criteria was associated with increased odds of delivery of an infant with BW < 10th centile (SMFM: adjusted odds ratio (aOR), 133.0 (95% CI, 94.7-186.6); ISUOG/Delphi: aOR, 69.5 (95% CI, 49.1-98.2)) or BW < 3rd centile (SMFM: aOR, 348.7 (95% CI, 242.6-501.2); ISUOG/Delphi: aOR, 215.4 (95% CI, 148.4-312.7)). Compared with the SMFM criteria, the ISUOG/Delphi criteria were associated with lower odds (aOR, 0.5 (95% CI, 0.3-0.8)) of predicting a SGA infant with BW < 10th centile, but higher odds of predicting emergency CS for NRFS (aOR, 2.30 (95% CI, 1.14-4.66)) and composite neonatal morbidity (aOR, 1.22 (95% CI, 1.05-1.41)). Both SMFM and ISUOG/Delphi criteria were associated with high LR+, specificity, PPV and NPV for the prediction of infants with BW < 10th and BW < 3rd centile. However, both methods functioned much less efficiently for the prediction of composite severe neonatal morbidity or emergency CS for NRFS, with LR+ < 10. The SMFM biometric criteria alone, particularly AC < 3rd centile, had the highest LR+ values for the prediction of perinatal mortality. CONCLUSION: Both the SMFM and ISUOG/Delphi criteria had strong screening potential for the detection of infants with BW < 10th or < 3rd centile but not for adverse neonatal outcome. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Retardo del Crecimiento Fetal , Muerte Perinatal , Recién Nacido , Embarazo , Lactante , Femenino , Humanos , Retardo del Crecimiento Fetal/diagnóstico por imagen , Cesárea , Estudios Retrospectivos , Perinatología , Técnica Delphi , Placenta , Ultrasonografía Prenatal/métodos , Recién Nacido Pequeño para la Edad Gestacional , Peso al Nacer , Peso Fetal , Biometría , Edad Gestacional
7.
Neuroimage ; 251: 119013, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-35189361

RESUMEN

Resting-state functional magnetic resonance imaging is currently the mainstay of functional neuroimaging and has allowed researchers to identify intrinsic connectivity networks (aka functional networks) at different spatial scales. However, little is known about the temporal profiles of these networks and whether it is best to model them as continuous phenomena in both space and time or, rather, as a set of temporally discrete events. Both categories have been supported by series of studies with promising findings. However, a critical question is whether focusing only on time points presumed to contain isolated neural events and disregarding the rest of the data is missing important information, potentially leading to misleading conclusions. In this work, we argue that brain networks identified within the spontaneous blood oxygenation level-dependent (BOLD) signal are not limited to temporally sparse burst moments and that these event present time points (EPTs) contain valuable but incomplete information about the underlying functional patterns. We focus on the default mode and show evidence that is consistent with its continuous presence in the BOLD signal, including during the event absent time points (EATs), i.e., time points that exhibit minimum activity and are the least likely to contain an event. Moreover, our findings suggest that EPTs may not contain all the available information about their corresponding networks. We observe distinct default mode connectivity patterns obtained from all time points (AllTPs), EPTs, and EATs. We show evidence of robust relationships with schizophrenia symptoms that are both common and unique to each of the sets of time points (AllTPs, EPTs, EATs), likely related to transient patterns of connectivity. Together, these findings indicate the importance of leveraging the full temporal data in functional studies, including those using event-detection approaches.


Asunto(s)
Mapeo Encefálico , Imagen por Resonancia Magnética , Encéfalo/diagnóstico por imagen , Mapeo Encefálico/métodos , Neuroimagen Funcional , Humanos , Imagen por Resonancia Magnética/métodos , Red Nerviosa/diagnóstico por imagen
8.
Osteoporos Int ; 33(5): 1125-1136, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35034156

RESUMEN

Macro- and microarchitectural, bone material property, dynamic histomorphometric, and bone turnover marker data were studied in normal bone mineral density (BMD) post-menopausal women with fragility fracture. Women with fracture had thinner iliac cortices and more homogeneous bone material properties in cortical bone than age/BMD-matched non-fracture women. Low cortical thickness and bone tissue heterogeneity in normal BMD women are associated with prevalent fragility fracture. INTRODUCTION: Bone mass (bone mineral density, (BMD)) of the spine and hip is today's best single measurement for evaluating future fragility fracture risk. However, the majority of fragility fractures occur in women with BMD T-score above the WHO osteoporotic BMD threshold of - 2.5, indicating that non-BMD endpoints may play a role in their fragility fractures. We hypothesize that in non-osteoporotic women, bone micoarchitecture, bone material properties, dynamic histomorphometric endpoints, and bone turnover markers are related to fragility fracture. METHODS: Two groups (N = 60 each) of post-menopausal women with total hip BMD T-score ranging from + 0.3 to -2.49 were recruited: fragility fracture and age/BMD-matched, non-fragility fracture women. Normal (T-score > - 0.99) and osteopenic (T-score ≤ - 1.0) BMD cohorts were designated within both the fracture and non-fracture groups. Transiliac biopsy specimens were obtained to evaluate dynamic histomorphometric and microarchitectural endpoints and bone material properties by static and dynamic nanoindentation testing. All variables for fracture and non-fracture women within each BMD cohort were compared by the Wilcoxon signed-rank test (P < 0.01). RESULTS: Compared to non-fracture/normal BMD women, fracture/normal BMD women display lower iliac cortical thickness (- 12%, P = 0.0041) and lower heterogeneity of hardness (- 27%, P = 0.0068), elastic modulus (- 35%, P = 0.0009), and storage modulus (- 23%, P = 0.0054) in the cortical bone tissue, and lower heterogeneity of hardness (- 13%, P = 0.0088) in the trabecular bone tissue. Osteopenic women had no abnormalities related to fracture status. CONCLUSION: Post-menopausal women with normal BMD and fragility fracture have low cortical thickness and heterogeneity of several bone material properties in cortical and trabecular mineralized bone tissue. These differences may explain a portion of the excess bone fragility in women with normal BMD and fragility fracture.


Asunto(s)
Fracturas Óseas , Fracturas Osteoporóticas , Densidad Ósea , Remodelación Ósea , Hueso Esponjoso/patología , Femenino , Humanos , Ilion , Fracturas Osteoporóticas/etiología , Fracturas Osteoporóticas/patología , Posmenopausia
9.
Hum Brain Mapp ; 42(6): 1930-1939, 2021 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-33547694

RESUMEN

BACKGROUND: While effective treatments for posttraumatic stress disorder (PTSD) exist, many individuals, including military personnel and veterans fail to respond to them. Equine-assisted therapy (EAT), a novel PTSD treatment, may complement existing PTSD interventions. This study employs longitudinal neuro-imaging, including structural magnetic resonance imaging (sMRI), resting state-fMRI (rs-fMRI), and diffusion tensor imaging (DTI), to determine mechanisms and predictors of EAT outcomes for PTSD. METHOD: Nineteen veterans with PTSD completed eight weekly group sessions of EAT undergoing multimodal MRI assessments before and after treatment. Clinical assessments were conducted at baseline, post-treatment and at 3-month follow-up. RESULTS: At post-treatment patients showed a significant increase in caudate functional connectivity (FC) and reduction in the gray matter density of the thalamus and the caudate. The increase of caudate FC was positively associated with clinical improvement seen immediately at post-treatment and at 3-month follow-up. In addition, higher baseline caudate FC was associated with greater PTSD symptom reduction post-treatment. CONCLUSIONS: This exploratory study is the first to demonstrate that EAT can affect functional and structural changes in the brains of patients with PTSD. The findings suggest that EAT may target reward circuitry responsiveness and produce a caudate pruning effect from pre- to post-treatment.


Asunto(s)
Núcleo Caudado , Terapía Asistida por Caballos , Imagen por Resonancia Magnética , Neuroimagen , Trastornos por Estrés Postraumático , Adulto , Núcleo Caudado/diagnóstico por imagen , Núcleo Caudado/patología , Núcleo Caudado/fisiopatología , Conectoma , Imagen de Difusión Tensora , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Imagen Multimodal , Recompensa , Trastornos por Estrés Postraumático/diagnóstico por imagen , Trastornos por Estrés Postraumático/patología , Trastornos por Estrés Postraumático/fisiopatología , Trastornos por Estrés Postraumático/rehabilitación , Resultado del Tratamiento
10.
Nature ; 526(7572): 268-72, 2015 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-26390151

RESUMEN

Cell size fundamentally affects all biosynthetic processes by determining the scale of organelles and influencing surface transport. Although extensive studies have identified many mutations affecting cell size, the molecular mechanisms underlying size control have remained elusive. In the budding yeast Saccharomyces cerevisiae, size control occurs in G1 phase before Start, the point of irreversible commitment to cell division. It was previously thought that activity of the G1 cyclin Cln3 increased with cell size to trigger Start by initiating the inhibition of the transcriptional inhibitor Whi5 (refs 6-8). Here we show that although Cln3 concentration does modulate the rate at which cells pass Start, its synthesis increases in proportion to cell size so that its total concentration is nearly constant during pre-Start G1. Rather than increasing Cln3 activity, we identify decreasing Whi5 activity--due to the dilution of Whi5 by cell growth--as a molecular mechanism through which cell size controls proliferation. Whi5 is synthesized in S/G2/M phases of the cell cycle in a largely size-independent manner. This results in smaller daughter cells being born with higher Whi5 concentrations that extend their pre-Start G1 phase. Thus, at its most fundamental level, size control in budding yeast results from the differential scaling of Cln3 and Whi5 synthesis rates with cell size. More generally, our work shows that differential size-dependency of protein synthesis can provide an elegant mechanism to coordinate cellular functions with growth.


Asunto(s)
Ciclo Celular , Aumento de la Célula , Proteínas Represoras/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/metabolismo , División Celular , Ciclinas/metabolismo , Fase G1 , Ploidias , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Factores de Tiempo
11.
Nature ; 519(7543): 331-3, 2015 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-25788096

RESUMEN

Gas clouds in present-day galaxies are inefficient at forming stars. Low star-formation efficiency is a critical parameter in galaxy evolution: it is why stars are still forming nearly 14 billion years after the Big Bang and why star clusters generally do not survive their births, instead dispersing to form galactic disks or bulges. Yet the existence of ancient massive bound star clusters (globular clusters) in the Milky Way suggests that efficiencies were higher when they formed ten billion years ago. A local dwarf galaxy, NGC 5253, has a young star cluster that provides an example of highly efficient star formation. Here we report the detection of the J = 3→2 rotational transition of CO at the location of the massive cluster. The gas cloud is hot, dense, quiescent and extremely dusty. Its gas-to-dust ratio is lower than the Galactic value, which we attribute to dust enrichment by the embedded star cluster. Its star-formation efficiency exceeds 50 per cent, tenfold that of clouds in the Milky Way. We suggest that high efficiency results from the force-feeding of star formation by a streamer of gas falling into the galaxy.

12.
Nature ; 520(7545): 78-81, 2015 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-25832405

RESUMEN

Transition-metal complexes have long attracted interest for fundamental chemical reactivity studies and possible use in solar energy conversion. Electronic excitation, ligand loss from the metal centre, or a combination of both, creates changes in charge and spin density at the metal site that need to be controlled to optimize complexes for photocatalytic hydrogen production and selective carbon-hydrogen bond activation. An understanding at the molecular level of how transition-metal complexes catalyse reactions, and in particular of the role of the short-lived and reactive intermediate states involved, will be critical for such optimization. However, suitable methods for detailed characterization of electronic excited states have been lacking. Here we show, with the use of X-ray laser-based femtosecond-resolution spectroscopy and advanced quantum chemical theory to probe the reaction dynamics of the benchmark transition-metal complex Fe(CO)5 in solution, that the photo-induced removal of CO generates the 16-electron Fe(CO)4 species, a homogeneous catalyst with an electron deficiency at the Fe centre, in a hitherto unreported excited singlet state that either converts to the triplet ground state or combines with a CO or solvent molecule to regenerate a penta-coordinated Fe species on a sub-picosecond timescale. This finding, which resolves the debate about the relative importance of different spin channels in the photochemistry of Fe(CO)5 (refs 4, 16 - 20), was made possible by the ability of femtosecond X-ray spectroscopy to probe frontier-orbital interactions with atom specificity. We expect the method to be broadly applicable in the chemical sciences, and to complement approaches that probe structural dynamics in ultrafast processes.

13.
Support Care Cancer ; 29(3): 1337-1345, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32642951

RESUMEN

BACKGROUND: Sydney Cancer Survivorship Centre (SCSC) clinic provides multidisciplinary care after primary adjuvant treatment, with ~ 40% of attendees continuing follow-up with SCSC. METHODS: SCSC survivors completed measures of symptoms, quality-of-life and lifestyle factors at initial visit (T1), first follow-up (T2) and 1 year (T3). Analyses used mixed effect models, adjusted for age, sex and tumour type. RESULTS: Data from 206 survivors (2013-2019) were included: 51% male; median age 63 years; tumour types colorectal 68%, breast 12%, upper gastrointestinal 12%, other 8%. Mean time from: T1 to T2, 3.6 months; T1 to T3, 11.8 months. Mean weight remained stable, but 45% (35/77) of overweight/obese survivors lost weight from T1 to T3. Moderately-intense aerobic exercise increased by 63 mins/week at T2, and 68 mins/week T3. Proportion meeting aerobic exercise guidelines increased from 20 to 41%. Resistance exercise increased by 26 mins/week at T2. Global quality-of-life was unchanged from T1 to T2, improving slightly by T3 (3.7-point increase), mainly in males. Mean distress scores were stable, but at T3 the proportion scoring 4+/10 had declined from 41 to 33%. At T3, improvements were seen in pain, fatigue and energy, but > 20% reported moderate-severe fatigue, pain or sleep disturbance. Proportion reporting 5+ moderate-severe symptoms declined from 35% at T1 to 26% at T3, remaining higher in women. CONCLUSIONS: Survivors attending SCSC increased exercise by 3 months, and sustained it at 1 year. Most overweight/obese survivors avoided further weight gain. Survivors had relatively good quality-of-life, with improvement in many symptoms and lifestyle factors at 1 year.


Asunto(s)
Supervivientes de Cáncer/psicología , Calidad de Vida/psicología , Supervivencia , Australia , Instituciones Oncológicas , Femenino , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Factores de Tiempo
14.
Proc Biol Sci ; 287(1930): 20200894, 2020 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-32635873

RESUMEN

Termites in the genus Macrotermes construct large-scale soil mounds above their nests. The classic explanation for how termites coordinate their labour to build the mound, based on a putative cement pheromone, has recently been called into question. Here, we present evidence for an alternate interpretation based on sensing humidity. The high humidity characteristic of the mound's internal environment extends a short distance into the low-humidity external world, in a 'bubble' that can be disrupted by external factors like wind. Termites transport more soil mass into on-mound reservoirs when shielded from water loss through evaporation, and into experimental arenas when relative humidity is held at a high value. These results suggest that the interface between internal and external conditions may serve as a template for mound expansion, with workers moving freely within a zone of high humidity and depositing soil at its edge. Such deposition of additional moist soil will increase local humidity, in a feedback loop allowing the 'interior' zone to progress further outward and lead to mound expansion.


Asunto(s)
Humedad , Isópteros/fisiología , Animales , Conducta Animal , Feromonas , Suelo , Temperatura
15.
Connect Tissue Res ; 61(2): 216-228, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31899969

RESUMEN

Purpose: This report explores the overlooked potential of bioprinting to automate biomanufacturing of simple tissue structures, such as the uniform deposition of (mono)layers of progenitor cells on sheetlike decellularized extracellular matrices (dECM). In this scenario, dECM serves as a biodegradable celldelivery matrix to provide enhanced regenerative microenvironments for tissue repair. The Tissue-Engineered Muscle Repair (TEMR) technology-where muscle progenitor cells are seeded onto a porcine bladder acellular matrix (BAM), serves as a representative testbed for bioprinting applications. Previous work demonstrated that TEMR implantation improved functional outcomes following VML injury in biologically relevant rodent models.Materials and Methods: In the described bioprinting system, a cell-laden hydrogel bioink is used to deposit high cell densities (1.4 × 105-3.5 × 105 cells/cm2), onto both sides of the bladder acellular matrix as proof-of-concept.Results: These bioprinting methods achieve a reproducible and homogeneous distribution of cells, on both sides of the BAM scaffold, after just 24hrs, with cell viability as high as 98%. These preliminary results suggest bioprinting allows for improved dual-sided cell coverage compared to manual-seeding.Conclusions: Bioprinting can enable automated fabrication of TEMR constructs with high fidelity and scalability, while reducing biomanufacturing costs and timelines. Such bioprinting applications are underappreciated, yet critical, to expand the overall biomanufacturing paradigm for tissue engineered medical products. In addition, biofabrication of sheet-like implantable constructs, with cells deposited on both sides, is a process that is both scaffold and cell-type agnostic, and furthermore, is amenable to many geometries, and thus, additional tissue engineering applications beyond skeletal muscle.


Asunto(s)
Implantes Absorbibles , Bioimpresión , Músculo Esquelético , Impresión Tridimensional , Regeneración , Ingeniería de Tejidos , Andamios del Tejido/química , Humanos , Músculo Esquelético/lesiones , Músculo Esquelético/fisiología
16.
Ultrasound Obstet Gynecol ; 55(2): 157-169, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31479546

RESUMEN

OBJECTIVE: To perform a meta-analysis and meta-regression of randomized controlled trials (RCTs) to evaluate the impact of low-dose aspirin (LDA) on perinatal outcome, independent of its effect on pre-eclampsia (PE), preterm birth and low birth weight. METHODS: An electronic search of EMBASE, PubMed, CENTRAL, PROSPERO and Google Scholar databases was performed to identify RCTs assessing the impact of LDA in pregnancy, published in English prior to May 2019, which reported perinatal outcomes of interest (placental abruption, delivery mode, low 5-min Apgar score, neonatal acidosis, neonatal intensive care unit admission, periventricular hemorrhage and perinatal death). Risk ratios (RR) and 95% CI were calculated and pooled for analysis. Analysis was stratified according to gestational age at commencement of treatment (≤ 16 weeks vs > 16 weeks) and subgroup analysis was performed to assess the impact of aspirin dose (< 100 mg vs ≥ 100 mg). Meta-regression was used to assess the impact of LDA on perinatal outcome, independent of the reduction in PE, preterm birth and low birth weight. RESULTS: Forty studies involving 34 807 participants were included. When LDA was commenced ≤ 16 weeks' gestation, it was associated with a significant reduction in the risk of perinatal death (RR, 0.47; 95% CI, 0.25-0.88; P = 0.02; number needed to treat, 92); however, this risk reduction was only seen when a daily dose of ≥ 100 mg was administered. If commenced > 16 weeks' gestation, LDA was associated with a significant reduction in 5-min Apgar score < 7 (RR, 0.75; 95% CI, 0.58-0.96; P = 0.02) and periventricular hemorrhage (RR, 0.68; 95% CI, 0.47-0.99; P = 0.04), but a trend towards an increase in the risk of placental abruption (RR, 1.20; 95% CI, 1.00-1.46; P = 0.06) was also noted. LDA was not associated with any significant increase in adverse events if commenced ≤ 16 weeks gestation. LDA had no effect on delivery mode, irrespective of the gestational age at which it was started. Meta-regression confirmed that the effect of LDA on perinatal death, when treatment was started ≤ 16 weeks' gestation, was independent of any reduction in the rate of PE and preterm birth. CONCLUSION: LDA improves some important perinatal outcomes, without increasing adverse events such as placental abruption or periventricular hemorrhage, and its utility, if commenced prior to 16 weeks' gestation, may be considered in a wider context beyond the prevention of PE or fetal growth restriction. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Impacto de la aspirina en dosis bajas en los resultados perinatales adversos: metaanálisis y metaregresión OBJETIVO: Realizar un metaanálisis y una metaregresión de ensayos controlados aleatorizados (ECA) para evaluar el impacto de la aspirina en dosis bajas (LDA, por sus siglas en inglés) en el resultado perinatal, independientemente de su efecto en la preeclampsia (PE), el parto pretérmino y el peso bajo al nacer. MÉTODOS: Se realizó una búsqueda electrónica en las bases de datos EMBASE, PubMed, CENTRAL, PROSPERO y Google Scholar para identificar ECA que hubieran evaluado el impacto de la LDA en el embarazo, publicados en inglés antes de mayo de 2019, que informaran sobre resultados perinatales de interés (desprendimiento de la placenta, modo de parto, baja puntuación de Apgar a los 5 minutos, acidosis neonatal, ingreso en la unidad de cuidados intensivos neonatales, hemorragia periventricular y muerte perinatal). Se calcularon los cocientes de riesgo (CR) y el IC del 95% y se combinaron para el análisis. El análisis se estratificó según la edad gestacional al comienzo del tratamiento (≤16 semanas vs. >16 semanas) y se realizaron análisis de subgrupos para evaluar el impacto de la dosis de aspirina (<100 mg vs ≥100 mg). Se utilizó la metarregresión para evaluar el impacto de LDA en el resultado perinatal, independientemente de la reducción de la PE, el parto pretérmino y el bajo peso al nacer. RESULTADOS: Se incluyeron 40 estudios con 34 807 participantes. Cuando se inició el tratamiento con LDA a ≤ 16 semanas de gestación, se asoció con una reducción significativa del riesgo de muerte perinatal (CR, 0,47; IC 95%, 0,25-0,88; P=0,02; número necesario a tratar, 92); sin embargo, esta reducción del riesgo sólo se observó cuando se administró una dosis diaria de ≥ 100 mg. Si se inició con una gestación de > 16 semanas, el tratamiento con LDA se asoció con una reducción significativa en la puntuación de Apgar a los 5 minutos < 7 (CR, 0,75; 95% CI, 0,58-0,96; P = 0,02) y la hemorragia periventricular (CR, 0,68; 95% CI, 0,47-0,99; P = 0,04), pero también se notó una tendencia al aumento en el riesgo de desprendimiento prematuro de la placenta (CR, 1,20; 95% CI, 1,00-1,46; P = 0.06). El tratamiento con LDA no se asoció con ningún aumento significativo de los eventos adversos si se inició a ≤ 16 semanas de gestación. El tratamiento con LDA no tuvo ningún efecto sobre el modo de parto, independientemente de la edad gestacional en la que se inició. La metaregresión confirmó que el efecto de la LDA en la muerte perinatal, cuando se inició el tratamiento a ≤ 16 semanas de gestación, fue independiente de cualquier reducción en la tasa de PE y de nacimientos prematuros. CONCLUSIÓN: El tratamiento con LDA mejora algunos resultados perinatales importantes, sin aumentar los eventos adversos como el desprendimiento de la placenta o la hemorragia periventricular, y su utilidad, si se inicia antes de las 16 semanas de gestación, puede considerarse en un contexto más amplio, más allá de la prevención de la PE o la restricción del crecimiento fetal. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Desprendimiento Prematuro de la Placenta/inducido químicamente , Aspirina/efectos adversos , Parto Obstétrico/estadística & datos numéricos , Enfermedades del Recién Nacido/inducido químicamente , Atención Prenatal/métodos , Puntaje de Apgar , Aspirina/administración & dosificación , Femenino , Retardo del Crecimiento Fetal/prevención & control , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Unidades de Cuidado Intensivo Neonatal/estadística & datos numéricos , Muerte Perinatal/etiología , Preeclampsia/prevención & control , Embarazo , Resultado del Embarazo , Nacimiento Prematuro/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto , Análisis de Regresión
17.
Colorectal Dis ; 22(12): 1924-1932, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32609919

RESUMEN

AIM: Colorectal cancer is predominantly a disease of the elderly and up to 30% of these patients will present as an emergency. We compared the outcomes of 'elderly' patients presenting to our unit with a colorectal cancer emergency over a 10-year period with those of a 'younger' cohort. METHODS: A single centre retrospective review of colorectal cancer emergencies between 1 April 2007 and 1 April 2017 was performed. Patients were separated into two cohorts: 'young' (< 75 years) and 'elderly' (≥ 75 years). Data collected included demographics, disease status, treatment and outcomes. RESULTS: A total of 341 patients (< 75 years: n = 154; ≥ 75 years: n = 187) presented as a colorectal cancer emergency. Significantly fewer 'elderly' patients underwent curative surgical procedures (72% vs 49%, P < 0.0001) or received adjuvant chemotherapy (56% vs 21%, P < 0.0001). 'Elderly' patients had significantly more postoperative cardio-respiratory complications (7% vs 36%, P < 0.0001), but despite this there was no significant difference in 30-day mortality (7% vs 12%) and survival rates at 1 year (75% vs 74%) or 3 years (56% vs 49%). Elderly patients treated with best supportive care had a median overall survival of just 62 (range 1-955) days. CONCLUSION: Patients ≥ 75 years presenting as a colorectal cancer emergency were significantly less likely to undergo emergency curative surgery or receive adjuvant chemotherapy than those < 75 years. However, the 30-day mortality, 1- and 3-year survival rates for patients undergoing curative surgery were comparable.


Asunto(s)
Neoplasias Colorrectales , Urgencias Médicas , Anciano , Estudios de Cohortes , Neoplasias Colorrectales/terapia , Humanos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Periodo Posoperatorio , Estudios Retrospectivos
18.
Prehosp Emerg Care ; 24(5): 601-609, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31800338

RESUMEN

Objective: Identify determinants of emergency medical service (EMS) personnel's willingness to work during an influenza pandemic. Background: Little is known about the willingness of EMS personnel to work during a future influenza pandemic or the extent to which they are receiving pandemic training. Methods: EMS personnel were surveyed in July 2018 - Feb 2019 using a cross-sectional approach; the survey was available both electronically and on paper. Participants were provided a pandemic scenario and asked about their willingness to respond if requested or required; additional questions assessed their attitudes and beliefs and training received. Chi-square tests assessed differences in attitude/belief questions by willingness to work. Logistic regressions were used to identify significant predictors of response willingness when requested or required, controlling for gender and race. Results: 433 individuals completed the survey (response rate = 82.9%). A quarter (26.8%, n = 116) received no pandemic training; 14.3% (n = 62) participated in a pandemic exercise. Significantly more EMS personnel were willing to work when required versus when only requested (88.2% vs 76.9%, X2 = 164.1, p < .001). Predictors of willingness to work when requested included believing it is their responsibility to work, believing their coworkers were likely to work, receiving prophylaxis for themselves and their family members, and feeling safe working during a pandemic. Discussion: Many emergency medical services personnel report lacking training or disaster exercises related to influenza pandemics, and a fair percentage are unwilling to work during a future event. This may limit healthcare surge capacity and could contribute to increased morbidity and mortality. Findings from this study indicate that prehospital staff's attitudes and beliefs about pandemics influence their willingness to work. Pre-event training and planning should address these concerns.


Asunto(s)
Actitud del Personal de Salud , Servicios Médicos de Urgencia , Personal de Salud/educación , Gripe Humana , Pandemias , Adolescente , Adulto , Estudios Transversales , Femenino , Humanos , Gripe Humana/epidemiología , Masculino , Persona de Mediana Edad , Adulto Joven
19.
JAAPA ; 33(2): 1-7, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31990841

RESUMEN

Clinical practice includes contributions from physicians, pharmacists, NPs, and physician assistants. Drug safety considerations are of considerable importance. This article discusses drug-induced proarrhythmia, with a specific focus on torsades de pointes, a polymorphic ventricular tachycardia that typically occurs in self-limiting bursts that can lead to dizziness, palpitations, syncope, and seizures, but on rare occasions can progress to ventricular fibrillation and sudden cardiac death. A dedicated clinical pharmacology study conducted during a drug's clinical development program has assessed its propensity to induce torsades using prolongation of the QT interval as seen on the ECG as a biomarker.Identification of QT-interval prolongation does not necessarily prevent a drug from receiving marketing approval if its overall benefit-risk balance is favorable, but, if approved, a warning is placed in its prescribing information. This article explains why drugs can have a proarrhythmic propensity.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Asistentes Médicos , Rol del Médico , Torsades de Pointes/etiología , Torsades de Pointes/prevención & control , Muerte Súbita Cardíaca/etiología , Mareo/etiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/diagnóstico , Electrocardiografía , Femenino , Humanos , Masculino , Rol de la Enfermera , Seguridad , Convulsiones/etiología , Síncope/etiología , Torsades de Pointes/diagnóstico , Fibrilación Ventricular/etiología
20.
Am Heart J ; 215: 178-186, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31349109

RESUMEN

Cardiovascular outcome trials (CVOTs) have been employed in multiple therapeutic areas to explore whether a noncardiovascular drug increases the risk for cardiovascular events. These studies are now a central part of drug development programs for antihyperglycemic drugs. These programs are expected to demonstrate that new antihyperglycemic drugs for patients with Type 2 diabetes do not have unacceptable cardiovascular risk. The hazard ratio, which is usually provided as evidence that patients receiving the investigational treatment are not at statistically significantly greater cardiovascular risk than patients on the control treatment, can be difficult to interpret for various reasons. Therefore, an alternative approach known as the Restricted Mean Survival Time (RMST) or τ-year mean survival time is presented, and its ability to overcome interpretation challenges with the hazard ratio discussed. The RMST approach is applied to five completed CVOTs and is compared with the corresponding hazard ratios. Additionally, detailed considerations are given on how to design a non-inferiority CVOT using the RMST approach. The RMST methodology is shown to be a practical alternative to the hazard ratio methodology for designing a non-inferiority CVOT.


Asunto(s)
Enfermedades Cardiovasculares/mortalidad , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Desarrollo de Medicamentos , Hipoglucemiantes/uso terapéutico , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/etiología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/mortalidad , Salud Global , Humanos , Tasa de Supervivencia/tendencias
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