Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 259
Filtrar
1.
Nat Commun ; 15(1): 2003, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443359

RESUMO

Airborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We performed size-fractionated aerosol sampling (Andersen cascade impactor) and evaluated viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols <10µm and <5µm, respectively, for up to 9 days after symptom onset. Aerosol culturability is significantly associated with lower neutralizing antibody titers, and suppression of transcriptomic pathways related to innate immunity and the humoral response. A nasopharyngeal Ct <17 rules-in ~40% of aerosol culture-positives and identifies those who are probably highly infectious. A parsimonious three transcript blood-based biosignature is highly predictive of infectious aerosol generation (PPV > 95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols <5µm at ~6 days after symptom onset). These data, which comprehensively confirm variant-specific culturable SARS-CoV-2 in aerosol, inform the targeting of transmission-related interventions and public health containment strategies emphasizing improved ventilation.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Cinética , Aerossóis e Gotículas Respiratórios
2.
Photochem Photobiol Sci ; 22(5): 1093-1127, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37129840

RESUMO

Variations in stratospheric ozone and changes in the aquatic environment by climate change and human activity are modifying the exposure of aquatic ecosystems to UV radiation. These shifts in exposure have consequences for the distributions of species, biogeochemical cycles, and services provided by aquatic ecosystems. This Quadrennial Assessment presents the latest knowledge on the multi-faceted interactions between the effects of UV irradiation and climate change, and other anthropogenic activities, and how these conditions are changing aquatic ecosystems. Climate change results in variations in the depth of mixing, the thickness of ice cover, the duration of ice-free conditions and inputs of dissolved organic matter, all of which can either increase or decrease exposure to UV radiation. Anthropogenic activities release oil, UV filters in sunscreens, and microplastics into the aquatic environment that are then modified by UV radiation, frequently amplifying adverse effects on aquatic organisms and their environments. The impacts of these changes in combination with factors such as warming and ocean acidification are considered for aquatic micro-organisms, macroalgae, plants, and animals (floating, swimming, and attached). Minimising the disruptive consequences of these effects on critical services provided by the world's rivers, lakes and oceans (freshwater supply, recreation, transport, and food security) will not only require continued adherence to the Montreal Protocol but also a wider inclusion of solar UV radiation and its effects in studies and/or models of aquatic ecosystems under conditions of the future global climate.


Assuntos
Perda de Ozônio , Ozônio , Animais , Humanos , Ozônio Estratosférico , Raios Ultravioleta , Mudança Climática , Ecossistema , Concentração de Íons de Hidrogênio , Plásticos , Água do Mar
3.
Science ; 379(6634): 815-820, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36821693

RESUMO

Pyrocumulonimbus (pyroCb) are wildfire-generated convective clouds that can inject smoke directly into the stratosphere. PyroCb have been tracked for years, yet their apparent rarity and episodic nature lead to highly uncertain climate impacts. In situ measurements of pyroCb smoke reveal its distinctive and exceptionally stable aerosol properties and define the long-term influence of pyroCb activity on the stratospheric aerosol budget. Analysis of 13 years of airborne observations shows that pyroCb are responsible for 10 to 25% of the black carbon and organic aerosols in the "present-day" lower stratosphere, with similar impacts in both the North and South Hemispheres. These results suggest that, should pyroCb increase in frequency and/or magnitude in future climates, they could generate dominant trends in stratospheric aerosol.

4.
BMJ Mil Health ; 169(6): 529-534, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-35078940

RESUMO

INTRODUCTION: At the start of the COVID-19 pandemic, individuals with pre-existing mental health difficulties were thought to be vulnerable to mental health deterioration due to the emerging threat and the actions taken to control infection rates. Yet, there remained a paucity of research investigating changes in veteran well-being, a population facing higher rates of mental health difficulties compared with the general public. This longitudinal study aimed to investigate the mental health and well-being of UK veterans with pre-existing mental health difficulties at two time points during the COVID-19 pandemic. METHODS: UK treatment-seeking veterans (N=121) completed an online survey administered towards the end of the first UK lockdown in June 2020 and 1 year later. Data were gathered on sociodemographic characteristics as well as psychometric measures of post-traumatic stress disorder (PTSD), common mental disorders (CMDs), anger difficulties and alcohol misuse. RESULTS: The proportion of veterans meeting criteria of PTSD, anger and alcohol misuse remained similar across the two time points, while significantly fewer veterans met criteria for CMDs 1 year later. A notable proportion of the sample reported challenges in attending mental and physical health appointments, which was positively associated with not working and negatively associated with more COVID-19-related stressors. CONCLUSIONS: These findings suggest that, to date, veterans with pre-existing mental health difficulties appear to demonstrate resilience as the COVID-19 pandemic progressed. However, as the pandemic continued, veterans faced significantly more COVID-19-related stressors, less social support, as well as difficulties attending health appointments.


Assuntos
Alcoolismo , COVID-19 , Veteranos , Humanos , Veteranos/psicologia , Saúde Mental , Pandemias , Estudos Longitudinais , Alcoolismo/psicologia , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Reino Unido/epidemiologia
5.
Microb Ecol ; 86(1): 282-296, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35608637

RESUMO

Heavily pigmented glacier ice algae Ancylonema nordenskiöldii and Ancylonema alaskanum (Zygnematophyceae, Streptophyta) reduce the bare ice albedo of the Greenland Ice Sheet, amplifying melt from the largest cryospheric contributor to eustatic sea-level rise. Little information is available about glacier ice algae interactions with other microbial communities within the surface ice environment, including fungi, which may be important for sustaining algal bloom development. To address this substantial knowledge gap and investigate the nature of algal-fungal interactions, an ex situ co-cultivation experiment with two species of fungi, recently isolated from the surface of the Greenland Ice Sheet (here proposed new species Penicillium anthracinoglaciei Perini, Frisvad and Zalar, Mycobank (MB 835602), and Articulospora sp.), and the mixed microbial community dominated by glacier ice algae was performed. The utilization of the dark pigment purpurogallin carboxylic acid-6-O-ß-D-glucopyranoside (C18H18O12) by the two fungi was also evaluated in a separate experiment. P. anthracinoglaciei was capable of utilizing and converting the pigment to purpurogallin carboxylic acid, possibly using the sugar moiety as a nutrient source. Furthermore, after 3 weeks of incubation in the presence of P. anthracinoglaciei, a significantly slower decline in the maximum quantum efficiency (Fv/Fm, inverse proxy of algal stress) in glacier ice algae, compared to other treatments, was evident, suggesting a positive relationship between these species. Articulospora sp. did uptake the glycosylated purpurogallin, but did not seem to be involved in its conversion to aglycone derivative. At the end of the incubation experiments and, in conjunction with increased algal mortality, we detected a substantially increasing presence of the zoosporic fungi Chytridiomycota suggesting an important role for them as decomposers or parasites of glacier ice algae.


Assuntos
Camada de Gelo , Estreptófitas , Camada de Gelo/microbiologia , Groenlândia , Benzocicloeptenos , Fungos
6.
JRSM Cardiovasc Dis ; 11: 20480040221096209, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35574238

RESUMO

Objective: Establish whether the reliable measurement of cardiac time intervals of the fetal ECG can be automated and to address whether this approach could be used to investigate large datasets. Design: Retrospective observational study. Setting: Teaching hospitals in London UK, Nottingham UK and New York USA. Participants: Singleton pregnancies with no known fetal abnormality. Methods: Archived fetal ECG's performed using the MonicaAN24 monitor. A single ECG (PQRST) complex was generated from 5000 signal-averaged beats and electrical cardiac time intervals measured in an automated way and manually. Main Outcome measure: Validation of a newly developed algorithm to measure the cardiac time intervals of the fetal ECG. Results: 188/236 (79.7%) subjects with fECGs of suitable signal:noise ratio were included for analysis comparing manual with automated measurement. PR interval was measured in 173/188 (92%), QRS complex in 170/188 (90%) and QT interval in 123/188 (65.4%). PR interval was 107.6 (12.07) ms [mean(SD)] manual vs 109.11 (14.7) ms algorithm. QRS duration was 54.72(6.35) ms manual vs 58.34(5.73) ms algorithm. QT-interval was 268.93 (21.59) ms manual vs 261.63 (36.16) ms algorithm. QTc was 407.5(32.71) ms manual vs 396.4 (54.78) ms algorithm. The QRS-duration increased with gestational age in both manual and algorithm measurements. Conclusion: Accurate measurement of fetal ECG cardiac time intervals can be automated with potential application to interpretation of larger datasets.

7.
Photochem Photobiol Sci ; 21(3): 275-301, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35191005

RESUMO

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth's surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1-67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.


Assuntos
Perda de Ozônio , Ozônio , Mudança Climática , Ecossistema , Humanos , Ozônio/química , Ozônio Estratosférico , Raios Ultravioleta
8.
BMJ Mil Health ; 168(1): 29-33, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33243764

RESUMO

INTRODUCTION: Data are emerging showing the adverse consequences on mental health of the general public due to the COVID-19 pandemic. Little is known about the needs of veterans with pre-existing mental health difficulties during the COVID-19 pandemic. METHODS: Data were collected through a cross-sectional online survey from a randomly selected sample (n=1092) of military veterans who have sought help for mental health difficulties from a veteran-specific UK-based charity. The response rate was 25.2% (n=275). Participants were asked to complete a range of standardised mental health outcomes (post-traumatic stress disorder (PTSD): Post-traumatic Stress Disorder Checklist, common mental health difficulties (CMDs): 12-Item General Health Questionnaire, difficulties with anger: 5-Item Dimensions of Anger Reactions-Revised and alcohol misuse: Alcohol Use Disorders Identification Test) and endorse a list of potential stressors related to changes to daily life resulting from COVID-19. Regression analyses were fitted to explore predictors of mental health severity. RESULTS: It was observed that symptoms of common mental disorder and PTSD (69.3% and 65.0%, respectively) were the most commonly reported to have been exacerbated by the pandemic. Lack of social support and reporting increasing numbers of stressors related to COVID-19 were consistently associated with increasing severity of a range of mental health difficulties. CONCLUSIONS: Our findings suggest veterans who had pre-existing mental health difficulties prior to the outbreak of COVID-19 may be at increased risk of experiencing CMDs as a result of the pandemic. Intervening to improve levels of social support and offering practical guidance to better manage any additional stressors relating to the pandemic may provide strategies to help reduce the burden of mental health symptoms.


Assuntos
Alcoolismo , COVID-19 , Veteranos , Estudos Transversais , Humanos , Saúde Mental , Pandemias , Distanciamento Físico , SARS-CoV-2
9.
BJOG ; 129(3): 378, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34651410
10.
Materials (Basel) ; 14(21)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34772258

RESUMO

Additive Friction Stir-Deposition (AFS-D) is a transformative, metallic additive manufacturing (AM) process capable of producing near-net shape components with a wide variety of material systems. The solid-state nature of the process permits many of these materials to be successfully deposited without the deleterious phase and thermally activated defects commonly observed in other metallic AM technologies. This work is the first to investigate the as-deposited microstructure and mechanical performance of a free-standing AA5083 deposition. An initial process parameterization was conducted to down-select optimal parameters for a large deposition to examine build direction properties. Microscopy revealed that constitutive particles were dispersed evenly throughout the matrix when compared to the rolled feedstock. Electron backscatter diffraction revealed a significant grain refinement from the inherent dynamic recrystallization from the AFS-D process. Tensile experiments determined a drop in yield strength, but an improvement in tensile strength in the longitudinal direction. However, a substantial reduction in tensile strength was observed in the build direction of the structure. Subsequent fractographic analysis revealed that the recommended lubrication applied to the feedstock rods, necessary for successful depositions via AFS-D, was ineffectively dispersed into the structure. As a result, lubrication contamination became entrapped at layer boundaries, preventing adequate bonding between layers.

11.
Clin Oncol (R Coll Radiol) ; 33(9): 567-578, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34266728

RESUMO

The standard of care for the definitive treatment of locoregionally advanced cervical cancer is external beam radiation therapy (EBRT) with concurrent chemotherapy followed by a brachytherapy boost. Historically, EBRT was delivered via a two-dimensional technique based primarily on bony landmarks. This gave way to three-dimensional conformal radiation therapy, which allows for dose calculation and adjustment based on individual tumour and patient anatomy. Further technological advances have established intensity-modulated radiation therapy (IMRT) as a standard treatment modality, given the ability to maintain tumoricidal doses to target volumes while reducing unwanted radiation dose to nearby critical structures, thereby reducing toxicity. Routine image guidance allows for increased confidence in patient alignment prior to treatment, and the ability to visualise the daily position of the targets and organs at risk has been instrumental in allowing safe reductions in treated volumes. Additional EBRT technologies, including proton therapy and stereotactic body radiation therapy, may further improve the therapeutic index. In the realm of brachytherapy, a shift from point-based dose planning to image-guided brachytherapy has been associated with improved local control and reduced toxicity, with additional refinement ongoing. Here we will discuss these advances, the supporting data and future directions.


Assuntos
Braquiterapia , Radiocirurgia , Radioterapia Conformacional , Radioterapia de Intensidade Modulada , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/radioterapia
12.
Nat Commun ; 12(1): 3960, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34172727

RESUMO

The Greenland Ice Sheet harbours a wealth of microbial life, yet the total biomass stored or exported from its surface to downstream environments is unconstrained. Here, we quantify microbial abundance and cellular biomass flux within the near-surface weathering crust photic zone of the western sector of the ice sheet. Using groundwater techniques, we demonstrate that interstitial water flow is slow (~10-2 m d-1), while flow cytometry enumeration reveals this pathway delivers 5 × 108 cells m-2 d-1 to supraglacial streams, equivalent to a carbon flux up to 250 g km-2 d-1. We infer that cellular carbon accumulation in the weathering crust exceeds fluvial export, promoting biomass sequestration, enhanced carbon cycling, and biological albedo reduction. We estimate that up to 37 kg km-2 of cellular carbon is flushed from the weathering crust environment of the western Greenland Ice Sheet each summer, providing an appreciable flux to support heterotrophs and methanogenesis at the bed.


Assuntos
Biomassa , Camada de Gelo/microbiologia , Carbono/análise , Ciclo do Carbono , Contagem de Colônia Microbiana , Groenlândia , Hidrologia , Camada de Gelo/química , Tempo (Meteorologia)
14.
Photochem Photobiol Sci ; 20(1): 1-67, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33721243

RESUMO

This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595-828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.

15.
BJOG ; 128(10): 1635-1644, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33586324

RESUMO

OBJECTIVE: To determine the optimal total serum bile acid (TSBA) threshold and sampling time for accurate intrahepatic cholestasis of pregnancy (ICP) diagnosis. DESIGN: Case-control, retrospective cohort studies. SETTING: Antenatal clinics, clinical research facilities. POPULATION: Women with ICP or uncomplicated pregnancies. METHODS: Serial TSBA measurements were performed pre-/postprandially in 42 women with ICP or uncomplicated pregnancy. Third-trimester non-fasting TSBA reference ranges were calculated from 561 women of black, south Asian and white ethnicity. Rates of adverse perinatal outcomes for women with ICP but peak non-fasting TSBA below the upper reference range limit were compared with those in healthy populations. MAIN OUTCOME MEASURES: Sensitivity and specificity of common TSBA thresholds for ICP diagnosis, using fasting and postprandial TSBA. Calculation of normal reference ranges of non-fasting TSBA. RESULTS: Concentrations of TSBA increased markedly postprandially in all groups, with overlap between healthy pregnancy and mild ICP (TSBA <40 µmol/l). The specificity of ICP diagnosis was higher when fasting, but corresponded to <30% sensitivity for diagnosis of mild disease. Using TSBA ≥40 µmol/l to define severe ICP, fasting measurements identified 9% (1/11), whereas non-fasting measurements detected over 91% with severe ICP. The highest upper limit of the non-fasting TSBA reference range was 18.3 µmol/l (95% confidence interval: 15.0-35.6 µmol/l). A re-evaluation of published ICP meta-analysis data demonstrated no increase in spontaneous preterm birth or stillbirth in women with TSBA <19 µmol/l. CONCLUSIONS: Postprandial TSBA levels are required to identify high-risk ICP pregnancies (TSBA ≥40 µmol/l). The postprandial rise in TSBA in normal pregnancy indicates that a non-fasting threshold of ≥19 µmol/l would improve diagnostic accuracy. TWEETABLE ABSTRACT: Non-fasting bile acids improve the diagnostic accuracy of intrahepatic cholestasis of pregnancy diagnosis.


Assuntos
Ácidos e Sais Biliares/sangue , Colestase Intra-Hepática/diagnóstico , Complicações na Gravidez/diagnóstico , Diagnóstico Pré-Natal , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Colestase Intra-Hepática/sangue , Estudos de Coortes , Feminino , Humanos , Gravidez , Complicações na Gravidez/sangue , Estudos Retrospectivos , Sensibilidade e Especificidade
16.
BJOG ; 128(6): 1066-1075, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33063439

RESUMO

OBJECTIVE: To evaluate whether a particular group of women with intrahepatic cholestasis of pregnancy (ICP), based on their presenting characteristics, would benefit from treatment with ursodeoxycholic acid (UDCA). DESIGN: Secondary analysis of the PITCHES trial (ISRCTN91918806). SETTING: United Kingdom. POPULATION OR SAMPLE: 527 women with ICP. METHODS: Subgroup analyses were performed to determine whether baseline bile acid concentrations or baseline itch scores moderated a woman's response to treatment with UDCA. MAIN OUTCOME MEASURES: Bile acid concentration and itch score. RESULTS: In women with baseline bile acid concentrations less than 40 µmol/l, treatment with UDCA resulted in increased post-randomisation bile acid concentrations (geometric mean ratio 1.19, 95% CI 1.00-1.41, P = 0.048). A test of interaction showed no significance (P = 0.647). A small, clinically insignificant difference was seen in itch response in women with a high baseline itch score (-6.0 mm, 95% CI -11.80 to -0.21, P = 0.042), with a test of interaction not showing significance (P = 0.640). Further subgroup analyses showed no significance. Across all women there was a weak relationship between bile acid concentrations and itch severity. CONCLUSIONS: There was no subgroup of women with ICP in whom a beneficial effect of treatment with UDCA on bile acid concentration or itch score could be identified. This confirms that its routine use in women with this condition for improvement of bile acid concentration or itch score should be reconsidered. TWEETABLE ABSTRACT: PITCHES: No group of women with ICP has been found in whom UDCA reduces bile acid concentrations or pruritus.


Assuntos
Ácidos e Sais Biliares/sangue , Colestase Intra-Hepática , Complicações na Gravidez , Prurido , Ácido Ursodesoxicólico , Adulto , Colagogos e Coleréticos/administração & dosagem , Colagogos e Coleréticos/efeitos adversos , Colestase Intra-Hepática/sangue , Colestase Intra-Hepática/diagnóstico , Colestase Intra-Hepática/tratamento farmacológico , Colestase Intra-Hepática/fisiopatologia , Método Duplo-Cego , Feminino , Humanos , Avaliação de Resultados em Cuidados de Saúde , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/fisiopatologia , Prurido/diagnóstico , Prurido/tratamento farmacológico , Prurido/etiologia , Índice de Gravidade de Doença , Natimorto/epidemiologia , Avaliação de Sintomas/métodos , Reino Unido , Ácido Ursodesoxicólico/administração & dosagem , Ácido Ursodesoxicólico/efeitos adversos
17.
Int J Obes (Lond) ; 44(9): 1958-1969, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32678325

RESUMO

Diet has important effects on normal physiology and the potential deleterious effects of high fat diets and obesity on male reproductive health are being increasingly described. We conducted a histological review of the effects of chronic high fat (HF) diet (using a mouse model fed a 45% fat diet for 21 weeks) with a discovery proteomic study to assess for changes in the abundance of proteins in the testis. Mice on a HF diet became obese and developed glucose intolerance. Using mass spectrometry, we identify 102 proteins affected in the testis of obese mice. These included structural proteins important for the blood testis barrier (filamin A, FLNA), proteins involved in oxidative stress responses (spermatogenesis associated 20, SPATA-20) and lipid homoeostasis (sterol regulatory element-binding protein 2, SREBP2 and apolipoprotein A1, APOA1). In addition, an important regulator protein paraspeckle component 1, PSPC-1, which interacts with the androgen receptor was significantly downregulated. Proteomic data was validated using both Western blotting and immunostaining which confirmed and localised protein expression in both mouse and human testis using biopsy specimens. This study focused mainly on the abnormalities that occurred at the protein level and as a result, we have identified several candidate proteins and conducted pathway analysis around the effects of HF diet on the testis providing novel insights not previously described. Some of the identified targets could be targeted therapeutically and future work is directed in this area.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Gorduras na Dieta/farmacologia , Obesidade/metabolismo , Proteoma/efeitos dos fármacos , Testículo , Animais , Humanos , Masculino , Camundongos , Testículo/efeitos dos fármacos , Testículo/patologia
18.
Photochem Photobiol Sci ; 19(5): 542-584, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32364555

RESUMO

This assessment, by the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP), one of three Panels informing the Parties to the Montreal Protocol, provides an update, since our previous extensive assessment (Photochem. Photobiol. Sci., 2019, 18, 595-828), of recent findings of current and projected interactive environmental effects of ultraviolet (UV) radiation, stratospheric ozone, and climate change. These effects include those on human health, air quality, terrestrial and aquatic ecosystems, biogeochemical cycles, and materials used in construction and other services. The present update evaluates further evidence of the consequences of human activity on climate change that are altering the exposure of organisms and ecosystems to UV radiation. This in turn reveals the interactive effects of many climate change factors with UV radiation that have implications for the atmosphere, feedbacks, contaminant fate and transport, organismal responses, and many outdoor materials including plastics, wood, and fabrics. The universal ratification of the Montreal Protocol, signed by 197 countries, has led to the regulation and phase-out of chemicals that deplete the stratospheric ozone layer. Although this treaty has had unprecedented success in protecting the ozone layer, and hence all life on Earth from damaging UV radiation, it is also making a substantial contribution to reducing climate warming because many of the chemicals under this treaty are greenhouse gases.


Assuntos
Mudança Climática , Ozônio Estratosférico , Raios Ultravioleta , Saúde Ambiental , Humanos , Microplásticos , Nações Unidas
19.
Oxid Med Cell Longev ; 2020: 5751768, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32318239

RESUMO

The causes of hypertension are complex and involve both genetic and environmental factors. Environment changes during fetal development have been linked to adult diseases including hypertension. Studies show that timed in utero exposure to the synthetic glucocorticoid (GC) dexamethasone (Dex) results in the development of hypertension in adult rats. Evidence suggests that in utero stress can alter patterns of gene expression, possibly a result of alterations in the topology of the genome by epigenetic markers such as DNA methyltransferases (DNMTs) and histone deacetylases (HDACs). The objective of this study was to determine the effects of epigenetic regulators in the fetal programming and the development of adult hypertension. Specifically, this research examined the effects of the HDAC inhibitor valproic acid (VPA) and the DNMT inhibitor 5-aza-2'-deoxycytidine (5aza2DC) on blood pressure (BP) and gene expression in prenatal Dex-programmed rats. Data suggest that both VPA and 5aza2DC attenuated the Dex-mediated development of hypertension and restored BP to control levels. Epigenetic DNMT inhibition (DNMTi) or HDAC inhibition (HDACi) also successfully attenuated elevations in the majority of altered catecholamine (CA) enzyme expression, phenylethanolamine N-methyltransferase (PNMT) protein, and elevated epinephrine (Epi) levels in males. Although females responded to HDACi similar to males, DNMTi drove increased glucocorticoid receptor (GR) and PNMT expression and elevations in circulating Epi in females despite showing normotensive BP.


Assuntos
DNA (Citosina-5-)-Metiltransferases/metabolismo , Dexametasona/farmacologia , Histona Desacetilases/metabolismo , Hipertensão/etiologia , Animais , Pressão Sanguínea/efeitos dos fármacos , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , DNA (Citosina-5-)-Metiltransferases/genética , Decitabina/farmacologia , Epigênese Genética , Epinefrina/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Hipertensão/induzido quimicamente , Hipertensão/enzimologia , Hipertensão/genética , Masculino , Feniletanolamina N-Metiltransferase/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Endogâmicos WKY , Fatores Sexuais , Ácido Valproico/farmacologia
20.
BJOG ; 127(7): 876-884, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32012415

RESUMO

OBJECTIVE: To determine maternal, obstetric and neonatal outcomes in a cohort of women with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). DESIGN: Retrospective cohort study. SETTING: Ten specialist centres managing pregnant women with liver disease. POPULATION: Women with a diagnosis of PBC and PSC and a pregnancy of ≥20 completed weeks of gestation. METHODS: Retrospective case notes review. MAIN OUTCOME MEASURES: Adverse outcomes were defined as: maternal - development of ascites, variceal bleeding, encephalopathy and jaundice; obstetric events - gestational hypertension, pre-eclampsia and postpartum haemorrhage; and neonatal - stillbirth, preterm delivery and admission to neonatal unit. The relationship of alanine transferase (ALT) and bile acid levels with gestation at delivery was studied. RESULTS: The first recorded pregnancies of 34 women with PSC and 27 women with PBC were analysed. There were 60 live births and one intrapartum stillbirth that did not occur in the context of maternal cholestasis. The overall median gestation of delivery was 38 weeks but the rate of preterm birth was 28% (17/61 deliveries), 76% (13/17) of which were spontaneous. Gestation at birth negatively correlated with maternal serum ALT concentration at booking (P = 0.017) and serum bile acid concentration during pregnancy (P = 0.016). There were no other significant correlations and maternal and neonatal outcomes were good. CONCLUSIONS: Pregnancy in PBC and PSC is well tolerated, but women should be counselled regarding the increased risk of preterm birth. Measurement of maternal ALT and bile acids may help identify women at risk of preterm delivery. TWEETABLE ABSTRACT: Pregnancy in women with PBC and PSC is well tolerated; however, rates of preterm birth are high and are related to maternal bile acid levels.


Assuntos
Colangite Esclerosante , Cirrose Hepática Biliar , Complicações na Gravidez , Nascimento Prematuro , Adulto , Colangite Esclerosante/complicações , Colangite Esclerosante/diagnóstico , Colangite Esclerosante/epidemiologia , Feminino , Humanos , Recém-Nascido , Cirrose Hepática Biliar/complicações , Cirrose Hepática Biliar/diagnóstico , Cirrose Hepática Biliar/epidemiologia , Testes de Função Hepática/métodos , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/epidemiologia , Resultado da Gravidez/epidemiologia , Nascimento Prematuro/etiologia , Nascimento Prematuro/prevenção & controle , Estudos Retrospectivos , Medição de Risco , Reino Unido/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...