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1.
Phys Chem Chem Phys ; 26(2): 1105-1112, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38098439

RESUMO

Millisecond-delayed photodissociation of gas-phase Sn22- clusters stored in a Penning trap is investigated as a function of excitation energy. Sn15- is the only significant charged fragment, indicative of the break-off of neutral heptamers. Fits of the time-resolved fragmentation require a distribution of decay constants, caused by the finite width of the internal energy distribution of the cluster ensemble prior to photoexcitation. A lower limit for the dissociation energy for the loss of Sn7 is determined to be 2.1(1) eV, a factor of two above literature quantum chemical calculations.

2.
Stroke ; 54(4): 1110-1119, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36876481

RESUMO

BACKGROUND: Spreading depolarizations (SDs) are believed to contribute to injury progression and worsen outcomes in focal cerebral ischemia because exogenously induced SDs have been associated with enlarged infarct volumes. However, previous studies used highly invasive methods to trigger SDs that can directly cause tissue injury (eg, topical KCl) and confound the interpretation. Here, we tested whether SDs indeed enlarge infarcts when induced via a novel, noninjurious method using optogenetics. METHODS: Using transgenic mice expressing channelrhodopsin-2 in neurons (Thy1-ChR2-YFP), we induced 8 optogenetic SDs to trigger SDs noninvasively at a remote cortical location in a noninjurious manner during 1-hour distal microvascular clip or proximal an endovascular filament occlusion of the middle cerebral artery. Laser speckle imaging was used to monitor cerebral blood flow. Infarct volumes were then quantified at 24 or 48 hours. RESULTS: Infarct volumes in the optogenetic SD arm did not differ from the control arm in either distal or proximal middle cerebral artery occlusion, despite a 6-fold and 4-fold higher number of SDs, respectively. Identical optogenetic illumination in wild-type mice did not affect the infarct volume. Full-field laser speckle imaging showed that optogenetic stimulation did not affect the perfusion in the peri-infarct cortex. CONCLUSIONS: Altogether, these data show that SDs induced noninvasively using optogenetics do not worsen tissue outcomes. Our findings compel a careful reexamination of the notion that SDs are causally linked to infarct expansion.


Assuntos
Isquemia Encefálica , Depressão Alastrante da Atividade Elétrica Cortical , AVC Isquêmico , Acidente Vascular Cerebral , Camundongos , Animais , Optogenética/métodos , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Infarto da Artéria Cerebral Média , Camundongos Transgênicos
3.
Stroke ; 54(10): 2640-2651, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37610105

RESUMO

BACKGROUND: Spreading depolarizations (SDs) occur in all types of brain injury and may be associated with detrimental effects in ischemic stroke and subarachnoid hemorrhage. While rapid hematoma growth during intracerebral hemorrhage triggers SDs, their role in intracerebral hemorrhage is unknown. METHODS: We used intrinsic optical signal and laser speckle imaging, combined with electrocorticography, to investigate the effects of SD on hematoma growth during the hyperacute phase (0-4 hours) after intracortical collagenase injection in mice. Hematoma expansion, SDs, and cerebral blood flow were simultaneously monitored under normotensive and hypertensive conditions. RESULTS: Spontaneous SDs erupted from the vicinity of the hematoma during rapid hematoma growth. We found that hematoma growth slowed down by >60% immediately after an SD. This effect was even stronger in hypertensive animals with faster hematoma growth. To establish causation, we exogenously induced SDs (every 30 minutes) at a remote site by topical potassium chloride application and found reduced hematoma growth rate and final hemorrhage volume (18.2±5.8 versus 10.7±4.1 mm3). Analysis of cerebral blood flow using laser speckle flowmetry revealed that suppression of hematoma growth by spontaneous or induced SDs coincided and correlated with the characteristic oligemia in the wake of SD, implicating the vasoconstrictive effect of SD as one potential mechanism of action. CONCLUSIONS: Our findings reveal that SDs limit hematoma growth during the early hours of intracerebral hemorrhage and decrease final hematoma volume.


Assuntos
Depressão Alastrante da Atividade Elétrica Cortical , Hemorragia Subaracnóidea , Camundongos , Animais , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Hemorragia Subaracnóidea/complicações , Eletrocorticografia , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/complicações , Hematoma/diagnóstico por imagem , Hematoma/complicações
4.
Invest New Drugs ; 39(3): 658-669, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33313978

RESUMO

Background Statins inhibit the cholesterol biosynthesis and are used as cholesterol-lowering agents in fat-metabolism disorders. Furthermore, several studies state that statins have supportive functions in breast cancer treatment. Therefore, simvastatin (SVA) as a potential radiosensitizer should be investigated on the basis of human breast cells. Methods First, an optimal concentration of SVA for normal (MCF10A) and cancer (MCF-7) cells was identified via growth and cytotoxicity assays that, according to the definition of a radiosensitizer in the narrower sense, enhances the effect of radiation therapy but has no cytotoxic effect. Next, in combination with radiation SVA's influence on DNA repair capacity and clonogenic survival in 2D and 3D was determined. Furthermore cell cycle distribution, expression of survivin and connective tissue growth factor (CTGF) as well as ERK1 map kinase were analysed. Results 1 µM SVA was identified as highest concentration without an influence on cell growth and cytotoxicity and was used for further analyses. In terms of early and residual γH2AX-foci, SVA affected the number of foci in both cell lines with or without irradiation. Different radiation responses were detected in 2D and 3D culture conditions. During the 2D cultivation, a radiosensitizing effect within the clonogenic survival was observable, but not in 3D. Conclusion The present study suggests that SVA may have potential for radiosensitization. Therefore, it is important to further investigate the role of SVA in relation to the extent of radiosensitization and how it could be used to positively influence the therapy of breast cancer or other entities.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Radiossensibilizantes/farmacologia , Sinvastatina/farmacologia , Mama/citologia , Neoplasias da Mama/metabolismo , Técnicas de Cultura de Células , Linhagem Celular , Fenômenos Fisiológicos Celulares/efeitos dos fármacos , Fenômenos Fisiológicos Celulares/efeitos da radiação , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/efeitos da radiação , Feminino , Histonas/metabolismo , Humanos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Survivina/metabolismo
5.
Phys Chem Chem Phys ; 23(33): 18197-18205, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34612283

RESUMO

Bacterial phytochromes are sensoric photoreceptors that transform light absorbed by the photosensor core module (PCM) to protein structural changes that eventually lead to the activation of the enzymatic output module. The underlying photoinduced reaction cascade in the PCM starts with the isomerization of the tetrapyrrole chromophore, followed by conformational relaxations, proton transfer steps, and a secondary structure transition of a peptide segment (tongue) that is essential for communicating the signal to the output module. In this work, we employed various static and time-resolved IR and resonance Raman spectroscopic techniques to study the structural and reaction dynamics of the Meta-F intermediate of both the PCM and the full-length (PCM and output module) variant of the bathy phytochrome Agp2 from Agrobacterium fabrum. In both cases, this intermediate represents a branching point of the phototransformation, since it opens an unproductive reaction channel back to the initial state and a productive pathway to the final active state, including the functional protein structural changes. It is shown that the functional quantum yield, i.e. the events of tongue refolding per absorbed photons, is lower by a factor of ca. two than the quantum yield of the primary photochemical process. However, the kinetic data derived from the spectroscopic experiments imply an increased formation of the final active state upon increasing photon flux or elevated temperature under photostationary conditions. Accordingly, the branching mechanism does not only account for the phytochrome's function as a light intensity sensor but may also modulate its temperature sensitivity.


Assuntos
Agrobacterium/metabolismo , Proteínas de Bactérias/metabolismo , Luz , Fitocromo/metabolismo , Temperatura , Tetrapirróis/metabolismo , Agrobacterium/química , Proteínas de Bactérias/química , Fitocromo/química , Tetrapirróis/química
6.
Stroke ; 51(8): 2526-2535, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32640946

RESUMO

BACKGROUND AND PURPOSE: Spreading depolarizations (SDs) are recurrent and ostensibly spontaneous depolarization waves that may contribute to infarct progression after stroke. Somatosensory activation of the metastable peri-infarct tissue triggers peri-infarct SDs at a high rate. METHODS: We directly measured the functional activation threshold to trigger SDs in peri-infarct hot zones using optogenetic stimulation after distal middle cerebral artery occlusion in Thy1-ChR2-YFP mice. RESULTS: Optogenetic activation of peri-infarct tissue triggered SDs at a strikingly high rate (64%) compared with contralateral homotopic cortex (8%; P=0.004). Laser speckle perfusion imaging identified a residual blood flow of 31±2% of baseline marking the metastable tissue with a propensity to develop SDs. CONCLUSIONS: Our data reveal a spatially distinct increase in SD susceptibility in peri-infarct tissue where physiological levels of functional activation are capable of triggering SDs. Given the potentially deleterious effects of peri-infarct SDs, the effect of sensory overstimulation in hyperacute stroke should be examined more carefully.


Assuntos
Infarto Cerebral/fisiopatologia , Circulação Cerebrovascular/fisiologia , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Optogenética/métodos , Animais , Infarto Cerebral/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
7.
Stroke ; 50(5): 1210-1215, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31009358

RESUMO

Background and Purpose- Mechanisms contributing to acute hematoma growth in intracerebral hemorrhage are not well understood. Neuropathological studies suggest that the initial hematoma may create mass effect that can tear vessels in the vicinity by shearing, causing further bleeding and hematoma growth. Methods- To test this in mice, we simulated initial intracerebral hemorrhage by intrastriatal injection of a liquid polymer that coagulates upon contact with tissue and measured the presence and volume of bleeding secondary to the mass effect using Hemoglobin ELISA 15 minutes after injection. Results- Secondary hemorrhage occurred in a volume-dependent (4, 7.5, or 15 µL of polymer) and rate-dependent (0.05, 0.5, or 5 µL/s) manner. Anticoagulation (warfarin or dabigatran) exacerbated the secondary hemorrhage volume. In a second model of hematoma expansion, we confirmed that intrastriatal whole blood injection (15 µL, 0.5 µL/s) also caused secondary bleeding, using acute Evans blue extravasation as a surrogate. Anticoagulation once again exacerbated secondary hemorrhage after intrastriatal whole blood injection. Secondary hemorrhage directly and significantly correlated with arterial blood pressures in both nonanticoagulated and anticoagulated mice, when modulated by phenylephrine or labetalol. Conclusions- Our study provides the first proof of concept for secondary vessel rupture and bleeding as a potential mechanism for intracerebral hematoma growth.


Assuntos
Hemorragia Cerebral/complicações , Hemorragia Cerebral/patologia , Hemorragia/etiologia , Hemorragia/patologia , Doença Aguda , Animais , Anticoagulantes/administração & dosagem , Hemorragia Cerebral/tratamento farmacológico , Dabigatrana/administração & dosagem , Hemorragia/tratamento farmacológico , Masculino , Camundongos , Distribuição Aleatória , Varfarina/administração & dosagem
8.
Risk Anal ; 37(1): 173-192, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27164046

RESUMO

The objectives of this study are to understand tradeoffs between forest carbon and timber values, and evaluate the impact of uncertainty in improved forest management (IFM) carbon offset projects to improve forest management decisions. The study uses probabilistic simulation of uncertainty in financial risk for three management scenarios (clearcutting in 45- and 65-year rotations and no harvest) under three carbon price schemes (historic voluntary market prices, cap and trade, and carbon prices set to equal net present value (NPV) from timber-oriented management). Uncertainty is modeled for value and amount of carbon credits and wood products, the accuracy of forest growth model forecasts, and four other variables relevant to American Carbon Registry methodology. Calculations use forest inventory data from a 1,740 ha forest in western Washington State, using the Forest Vegetation Simulator (FVS) growth model. Sensitivity analysis shows that FVS model uncertainty contributes more than 70% to overall NPV variance, followed in importance by variability in inventory sample (3-14%), and short-term prices for timber products (8%), while variability in carbon credit price has little influence (1.1%). At regional average land-holding costs, a no-harvest management scenario would become revenue-positive at a carbon credit break-point price of $14.17/Mg carbon dioxide equivalent (CO2 e). IFM carbon projects are associated with a greater chance of both large payouts and large losses to landowners. These results inform policymakers and forest owners of the carbon credit price necessary for IFM approaches to equal or better the business-as-usual strategy, while highlighting the magnitude of financial risk and reward through probabilistic simulation.

9.
Environ Res ; 148: 475-483, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27136673

RESUMO

BACKGROUND: Although the health effects of long term exposure to air pollution are well established, it is difficult to effectively communicate the health risks of this (largely invisible) risk factor to the public and policy makers. The purpose of this study is to develop a method that expresses the health effects of air pollution in an equivalent number of daily passively smoked cigarettes. METHODS: Defined changes in PM2.5, nitrogen dioxide (NO2) and Black Carbon (BC) concentration were expressed into number of passively smoked cigarettes, based on equivalent health risks for four outcome measures: Low Birth Weight (<2500g at term), decreased lung function (FEV1), cardiovascular mortality and lung cancer. To describe the strength of the relationship with ETS and air pollutants, we summarized the epidemiological literature using published or new meta-analyses. RESULTS: Realistic increments of 10µg/m(3) in PM2.5 and NO2 concentration and a 1µg/m(3) increment in BC concentration correspond to on average (standard error in parentheses) 5.5 (1.6), 2.5 (0.6) and 4.0 (1.2) passively smoked cigarettes per day across the four health endpoints, respectively. The uncertainty reflects differences in equivalence between the health endpoints and uncertainty in the concentration response functions. The health risk of living along a major freeway in Amsterdam is, compared to a counterfactual situation with 'clean' air, equivalent to 10 daily passively smoked cigarettes.. CONCLUSIONS: We developed a method that expresses the health risks of air pollution and the health benefits of better air quality in a simple, appealing manner. The method can be used both at the national/regional and the local level. Evaluation of the usefulness of the method as a communication tool is needed.


Assuntos
Poluição do Ar em Ambientes Fechados/efeitos adversos , Exposição Ambiental/efeitos adversos , Poluição por Fumaça de Tabaco/efeitos adversos , Adulto , Carbono , Doenças Cardiovasculares/epidemiologia , Criança , Volume Expiratório Forçado , Habitação , Humanos , Recém-Nascido de Baixo Peso , Neoplasias Pulmonares/epidemiologia , Países Baixos/epidemiologia , Dióxido de Nitrogênio , Material Particulado , Medição de Risco , Aço , Local de Trabalho
10.
Environ Res ; 151: 721-727, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27644030

RESUMO

BACKGROUND: Air pollution episodes are associated with increased cardiopulmonary hospital admissions. Cohort studies showed associations of spatial variation in traffic-related air pollution with respiratory and cardiovascular mortality. Much less is known in particular about associations with cardiovascular morbidity. We explored the relation between spatial variation in nitrogen dioxide (NO2) concentrations and cardiopulmonary hospital admissions. METHODS: This ecological study was based on hospital admissions data (2001-2004) from the National Medical Registration and general population data for the West of the Netherlands (population 4.04 million). At the 4-digit postcode area level (n=683) associations between modeled annual average outdoor NO2 concentrations and hospital admissions for respiratory and cardiovascular causes were evaluated by linear regression with the log of the postcode-specific percentage of subjects that have been admitted at least once during the study period as the dependent variable. All analyses were adjusted for differences in composition of the population of the postcode areas (age, sex, income). RESULTS: At the postcode level, positive associations were found between outdoor NO2 concentrations and hospital admission rates for asthma, chronic obstructive pulmonary disease (COPD), all cardiovascular causes, ischemic heart disease and stroke (e.g. adjusted relative risk (95% confidence interval) for the second to fourth quartile relative to the first quartile of exposure were 1.87 (1.46-2.40), 2.34 (1.83-3.01) and 2.81 (2.16-3.65) for asthma; 1.44 (1.19-1.74), 1.50 (1.24-1.82) and 1.60 (1.31-1.96) for COPD). Associations remained after additional (indirect) adjustment for smoking (COPD admission rate) and degree of urbanization. CONCLUSIONS: Our study suggests an increased risk of hospitalization for respiratory and cardiovascular causes in areas with higher levels of NO2. Our findings add to the currently limited evidence of a long-term effect of air pollution on hospitalization. The ecological design of our study is a limitation and more studies with individual data are needed to confirm our findings.


Assuntos
Poluentes Atmosféricos/análise , Doenças Cardiovasculares/epidemiologia , Exposição por Inalação/análise , Dióxido de Nitrogênio/análise , Admissão do Paciente/estatística & dados numéricos , Doenças Respiratórias/epidemiologia , Adolescente , Adulto , Idoso , Poluentes Atmosféricos/toxicidade , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/terapia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Exposição por Inalação/efeitos adversos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Dióxido de Nitrogênio/toxicidade , Doenças Respiratórias/induzido quimicamente , Doenças Respiratórias/terapia , Análise Espacial , Urbanização , Emissões de Veículos/análise , Emissões de Veículos/toxicidade , Adulto Jovem
12.
Lancet ; 383(9919): 785-95, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24332274

RESUMO

BACKGROUND: Few studies on long-term exposure to air pollution and mortality have been reported from Europe. Within the multicentre European Study of Cohorts for Air Pollution Effects (ESCAPE), we aimed to investigate the association between natural-cause mortality and long-term exposure to several air pollutants. METHODS: We used data from 22 European cohort studies, which created a total study population of 367,251 participants. All cohorts were general population samples, although some were restricted to one sex only. With a strictly standardised protocol, we assessed residential exposure to air pollutants as annual average concentrations of particulate matter (PM) with diameters of less than 2.5 µm (PM2.5), less than 10 µm (PM10), and between 10 µm and 2.5 µm (PMcoarse), PM2.5 absorbance, and annual average concentrations of nitrogen oxides (NO2 and NOx), with land use regression models. We also investigated two traffic intensity variables-traffic intensity on the nearest road (vehicles per day) and total traffic load on all major roads within a 100 m buffer. We did cohort-specific statistical analyses using confounder models with increasing adjustment for confounder variables, and Cox proportional hazards models with a common protocol. We obtained pooled effect estimates through a random-effects meta-analysis. FINDINGS: The total study population consisted of 367,251 participants who contributed 5,118,039 person-years at risk (average follow-up 13.9 years), of whom 29,076 died from a natural cause during follow-up. A significantly increased hazard ratio (HR) for PM2.5 of 1.07 (95% CI 1.02-1.13) per 5 µg/m(3) was recorded. No heterogeneity was noted between individual cohort effect estimates (I(2) p value=0.95). HRs for PM2.5 remained significantly raised even when we included only participants exposed to pollutant concentrations lower than the European annual mean limit value of 25 µg/m(3) (HR 1.06, 95% CI 1.00-1.12) or below 20 µg/m(3) (1.07, 1.01-1.13). INTERPRETATION: Long-term exposure to fine particulate air pollution was associated with natural-cause mortality, even within concentration ranges well below the present European annual mean limit value. FUNDING: European Community's Seventh Framework Program (FP7/2007-2011).


Assuntos
Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Exposição Ambiental/efeitos adversos , Material Particulado/toxicidade , Adolescente , Adulto , Idoso , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Causas de Morte , Criança , Pré-Escolar , Estudos de Coortes , Exposição Ambiental/análise , Europa (Continente)/epidemiologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Material Particulado/análise , Adulto Jovem
13.
Environ Res ; 140: 440-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25978345

RESUMO

Uncertainty about health effects of long-term ozone exposure remains. Land use regression (LUR) models have been used successfully for modeling fine scale spatial variation of primary pollutants but very limited for ozone. Our objective was to assess the feasibility of developing a national LUR model for ozone at a fine spatial scale. Ozone concentrations were measured with passive samplers at 90 locations across the Netherlands (19 regional background, 36 urban background, 35 traffic). All sites were measured simultaneously during four 2-weekly campaigns spread over the seasons. LUR models were developed for the summer average as the primary exposure and annual average using predictor variables obtained with Geographic Information Systems. Summer average ozone concentrations varied between 32 and 61 µg/m(3). Ozone concentrations at traffic sites were on average 9 µg/m(3) lower compared to regional background sites. Ozone correlated highly negatively with nitrogen dioxide and moderately with fine particles. A LUR model including small-scale traffic, large-scale address density, urban green and a region indicator explained 71% of the spatial variation in summer average ozone concentrations. Land use regression modeling is a promising method to assess ozone spatial variation, but the high correlation with NO2 limits application in epidemiology.


Assuntos
Modelos Teóricos , Ozônio/análise , Sistemas de Informação Geográfica , Controle de Qualidade , Análise de Regressão , Estações do Ano
14.
Am J Respir Crit Care Med ; 189(6): 684-96, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24521254

RESUMO

RATIONALE: Prospective cohort studies have shown that chronic exposure to particulate matter and traffic-related air pollution is associated with reduced survival. However, the effects on nonmalignant respiratory mortality are less studied, and the data reported are less consistent. OBJECTIVES: We have investigated the relationship of long-term exposure to air pollution and nonmalignant respiratory mortality in 16 cohorts with individual level data within the multicenter European Study of Cohorts for Air Pollution Effects (ESCAPE). METHODS: Data from 16 ongoing cohort studies from Europe were used. The total number of subjects was 307,553. There were 1,559 respiratory deaths during follow-up. MEASUREMENTS AND MAIN RESULTS: Air pollution exposure was estimated by land use regression models at the baseline residential addresses of study participants and traffic-proximity variables were derived from geographical databases following a standardized procedure within the ESCAPE study. Cohort-specific hazard ratios obtained by Cox proportional hazard models from standardized individual cohort analyses were combined using metaanalyses. We found no significant associations between air pollution exposure and nonmalignant respiratory mortality. Most hazard ratios were slightly below unity, with the exception of the traffic-proximity indicators. CONCLUSIONS: In this study of 16 cohorts, there was no association between air pollution exposure and nonmalignant respiratory mortality.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Exposição Ambiental/efeitos adversos , Material Particulado/efeitos adversos , Doenças Respiratórias/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Estudos de Coortes , Exposição Ambiental/análise , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Material Particulado/análise , Modelos de Riscos Proporcionais , Análise de Regressão , Doenças Respiratórias/etiologia
15.
Biochim Biophys Acta ; 1831(4): 825-33, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23269286

RESUMO

Cholesteryl ester transfer protein (CETP) is a target of therapeutic intervention for coronary heart disease. Anacetrapib, a potent inhibitor of CETP, has been shown to reduce LDL-cholesterol by 40% and increase HDL-cholesterol by 140% in patients, and is currently being evaluated in a phase III cardiovascular outcomes trial. HDL is known to possess anti-inflammatory properties, however with such large increases in HDL-cholesterol, it is unclear whether CETP inhibition perturbs HDL functionality such as anti-inflammatory effects on endothelial cells. The purpose of the present study was to determine whether CETP inhibition by anacetrapib affects the anti-inflammatory properties of HDL. HDL was isolated from either hamsters treated with vehicle or anacetrapib for 2weeks, or from normal human subjects treated either placebo, 20mg, or 150mg anacetrapib daily for 2weeks. Anacetrapib treatment increased plasma HDL cholesterol levels by 65% and between 48 and 82% in hamsters and humans, respectively. Pre-incubation of human aortic endothelial cells with HDL isolated from both control and anacetrapib treated hamsters suppressed TNFα induced expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin. Similar results were obtained with human HDL samples pre and post treatment with placebo or anacetrapib. Further, HDL inhibited TNFα-induced MCP-1 secretion, monocyte adhesion and NF-κB activation in endothelial cells, and the inhibition was similar between control and anacetrapib treated groups. These studies demonstrate that anacetrapib treatment does not impair the ability of HDL to suppress an inflammatory response in endothelial cells.


Assuntos
Anti-Inflamatórios/farmacologia , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Lipoproteínas HDL/farmacologia , Oxazolidinonas/farmacologia , Células Cultivadas , Selectina E/metabolismo , Humanos , Molécula 1 de Adesão Intercelular/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Molécula 1 de Adesão de Célula Vascular/metabolismo
16.
Lancet Oncol ; 14(9): 813-22, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23849838

RESUMO

BACKGROUND: Ambient air pollution is suspected to cause lung cancer. We aimed to assess the association between long-term exposure to ambient air pollution and lung cancer incidence in European populations. METHODS: This prospective analysis of data obtained by the European Study of Cohorts for Air Pollution Effects used data from 17 cohort studies based in nine European countries. Baseline addresses were geocoded and we assessed air pollution by land-use regression models for particulate matter (PM) with diameter of less than 10 µm (PM10), less than 2·5 µm (PM2·5), and between 2·5 and 10 µm (PMcoarse), soot (PM2·5absorbance), nitrogen oxides, and two traffic indicators. We used Cox regression models with adjustment for potential confounders for cohort-specific analyses and random effects models for meta-analyses. FINDINGS: The 312 944 cohort members contributed 4 013 131 person-years at risk. During follow-up (mean 12·8 years), 2095 incident lung cancer cases were diagnosed. The meta-analyses showed a statistically significant association between risk for lung cancer and PM10 (hazard ratio [HR] 1·22 [95% CI 1·03-1·45] per 10 µg/m(3)). For PM2·5 the HR was 1·18 (0·96-1·46) per 5 µg/m(3). The same increments of PM10 and PM2·5 were associated with HRs for adenocarcinomas of the lung of 1·51 (1·10-2·08) and 1·55 (1·05-2·29), respectively. An increase in road traffic of 4000 vehicle-km per day within 100 m of the residence was associated with an HR for lung cancer of 1·09 (0·99-1·21). The results showed no association between lung cancer and nitrogen oxides concentration (HR 1·01 [0·95-1·07] per 20 µg/m(3)) or traffic intensity on the nearest street (HR 1·00 [0·97-1·04] per 5000 vehicles per day). INTERPRETATION: Particulate matter air pollution contributes to lung cancer incidence in Europe. FUNDING: European Community's Seventh Framework Programme.


Assuntos
Adenocarcinoma/epidemiologia , Poluição do Ar/efeitos adversos , Carcinoma de Células Escamosas/epidemiologia , Neoplasias Pulmonares/epidemiologia , Material Particulado/efeitos adversos , Adenocarcinoma/etiologia , Adulto , Idoso , Carcinoma de Células Escamosas/etiologia , Exposição Ambiental , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Humanos , Incidência , Neoplasias Pulmonares/etiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos
17.
Rev Sci Instrum ; 95(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38341722

RESUMO

The Greifswald multi-reflection time-of-flight setup has been extended with a magnetron sputtering gas aggregation source for the production of atomic cluster ions with sizes ranging from a single to thousands of atoms. This source, combined with a newly added quadrupole mass filter and a linear Paul trap, opens up the possibility of many new atomic-cluster studies not feasible with the setup before. The new components and their interfacing with the previous setup are described, and benchmarking as well as the first experimental results are presented. The capability of the system to handle singly charged ions with masses of several ten thousand atomic mass units is demonstrated.

18.
J Mol Biol ; 436(5): 168375, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38092286

RESUMO

Rhodopsin guanylyl cyclases (RGCs) belong to the class of enzymerhodopsins catalyzing the transition from GTP into the second messenger cGMP, whereas light-regulation of enzyme activity is mediated by a membrane-bound microbial rhodopsin domain, that holds the catalytic center inactive in the dark. Structural determinants for activation of the rhodopsin moiety eventually leading to catalytic activity are largely unknown. Here, we investigate the mechanistic role of the D283-C259 (DC) pair that is hydrogen bonded via a water molecule as a crucial functional motif in the homodimeric C. anguillulae RGC. Based on a structural model of the DC pair in the retinal binding pocket obtained by MD simulation, we analyzed formation and kinetics of early and late photocycle intermediates of the rhodopsin domain wild type and specific DC pair mutants by combined UV-Vis and FTIR spectroscopy at ambient and cryo-temperatures. By assigning specific infrared bands to S-H vibrations of C259 we are able to show that the DC pair residues are tightly coupled. We show that deprotonation of D283 occurs already in the inactive L state as a prerequisite for M state formation, whereas structural changes of C259 occur in the active M state and early cryo-trapped intermediates. We propose a comprehensive molecular model for formation of the M state that activates the catalytic moiety. It involves light induced changes in bond strength and hydrogen bonding of the DC pair residues from the early J state to the active M state and explains the retarding effect of C259 mutants.


Assuntos
Blastocladiomycota , Guanilato Ciclase , Rodopsina , Blastocladiomycota/enzimologia , Blastocladiomycota/metabolismo , Guanilato Ciclase/química , Guanilato Ciclase/genética , Luz , Modelos Moleculares , Rodopsina/química , Rodopsina/genética , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Resusc Plus ; 18: 100612, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38590446

RESUMO

Background: Handovers during medical emergencies are challenging due to time-critical, dynamic and oftentimes unorderly and distracting situations. We evaluated the effect of distraction-reduced clinical surroundings during handover on (1) the recall of handover information, (2) the recall of information from the surroundings and (3) self-reported workload in a simulated in-hospital cardiac arrest scenario. Methods: In a parallel group design, emergency team leaders were randomly assigned to receive a structured handover of a cardio-pulmonary resuscitation (CPR) either inside the room ("inside group") right next to the ongoing CPR or in front of the room ("outside group") with no audio-visual distractions from the ongoing CPR. Based on the concept of situation awareness, the primary outcome was a handover score for the content of the handover (0-19 points) derived from the pieces of information given during handover. Furthermore, we assessed team leaders' perception of their surroundings during the scenario (0-5 points) and they rated their subjective workload using the NASA Task Load Index. Results: The outside group (n = 30) showed significant better recall of handover information than the inside group (n = 30; mean difference = 1.86, 95% CI = 0.67 to 3.06, p = 0.003). The perception of the surroundings (n = 60; mean difference = -0.27, 95% CI = -0.85 to 0.32, p = 0.365) and the NASA Task Load Index (n = 58; mean difference = 1.1; p = 0.112) did not differ between the groups. Conclusions: Concerning in-hospital emergencies, a structured handover in a distraction reduced environment can improve information uptake of the team leader.

20.
Eur Respir J ; 41(6): 1257-63, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23143551

RESUMO

Outdoor air pollution has been associated with decrements in lung function and growth of lung function in school-age children. Lung function effects have not been examined in preschoolers, with the exception of one study on minute ventilation in newborns. Our goal was to assess the relationship between long- and short-term exposure to traffic-related air pollution and interrupter resistance in 4-year-old children. Lung function was measured using the interrupter resistance method in children participating in a Dutch birth cohort study. Long-term average air pollution concentrations of fine particulate matter, nitrogen dioxide and soot at the residential address at birth were assessed using land-use regression models. Daily average air pollution concentrations on the day of clinical examination were obtained from the Dutch National Air Quality Monitoring Network. Significant associations were found between long-term average air pollution concentrations and interrupter resistance. Interrupter resistance increased by 0.04 kPa·s·L(-1) (95% CI 0.01-0.07) per interquartile range increase (3.3 µg·m(-3)) in fine particle concentration. Short-term exposure was not associated with interrupter resistance. Long-term exposure to traffic-related air pollution was associated with increased interrupter resistance in 4-year-old children, supporting previous birth cohort studies reporting effects of air pollution on subjectively reported respiratory symptoms in preschool children.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Emissões de Veículos/análise , Asma/fisiopatologia , Pré-Escolar , Estudos de Coortes , Exposição Ambiental , Monitoramento Ambiental/métodos , Feminino , Humanos , Masculino , Dióxido de Nitrogênio/análise , Material Particulado/análise , Análise de Regressão , Testes de Função Respiratória/métodos , Sons Respiratórios/fisiopatologia , Sensibilidade e Especificidade , Fuligem/análise
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