31 research outputs found

    Diesel Exhaust Inhalation Elicits Acute Vasoconstriction in Vivo

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    BACKGROUND: Traffic-related air pollution is consistently associated with cardiovascular morbidity and mortality. Recent human and animal studies suggest that exposure to air pollutants affects vascular function. Diesel exhaust (DE) is a major source of traffic-related air pollution. OBJECTIVES: Our goal was to study the effects of short-term exposure to DE on vascular reactivity and on mediators of vascular tone. METHODS: In a double-blind, crossover, controlled exposure study, 27 adult volunteers (10 healthy and 17 with metabolic syndrome) were exposed in randomized order to filtered air (FA) and each of two levels of diluted DE (100 or 200 μg/m3 of fine particulate matter) in 2-hr sessions. Before and after each exposure, we assessed the brachial artery diameter (BAd) by B-mode ultrasound and collected blood samples for endothelin-1 (ET-1) and catecholamines. Postexposure we also assessed endothelium-dependent flow-mediated dilation (FMD). RESULTS: Compared with FA, DE at 200 μg/m3 elicited a decrease in BAd (0.11 mm; 95% confidence interval, 0.02–0.18), and the effect appeared linearly dose related with a smaller effect at 100 μg/m3. Plasma levels of ET-1 increased after 200 μg/m3 DE but not after FA (p = 0.01). There was no consistent impact of DE on plasma catecholamines or FMD. CONCLUSIONS: These results demonstrate that short-term exposure to DE is associated with acute endothelial response and vasoconstriction of a conductance artery. Elucidation of the signaling pathways controlling vascular tone that underlie this observation requires further study

    Flow mediated dilation of the brachial artery: an investigation of methods requiring further standardization

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    BACKGROUND: In order to establish a consistent method for brachial artery reactivity assessment, we analyzed commonly used approaches to the test and their effects on the magnitude and time-course of flow mediated dilation (FMD), and on test variability and repeatability. As a popular and noninvasive assessment of endothelial function, several different approaches have been employed to measure brachial artery reactivity with B-mode ultrasound. Despite some efforts, there remains a lack of defined normal values and large variability in measurement technique. METHODS: Twenty-six healthy volunteers underwent repeated brachial artery diameter measurements by B-mode ultrasound. Following baseline diameter recordings we assessed endothelium-dependent flow mediated dilation by inflating a blood pressure cuff either on the upper arm (proximal) or on the forearm (distal). RESULTS: Thirty-seven measures were performed using proximal occlusion and 25 with distal occlusion. Following proximal occlusion relative to distal occlusion, FMD was larger (16.2 ± 1.2% vs. 7.3 ± 0.9%, p < 0.0001) and elongated (107.2 s vs. 67.8 s, p = 0.0001). Measurement of the test repeatability showed that differences between the repeated measures were greater on average when the measurements were done using the proximal method as compared to the distal method (2.4%; 95% CI 0.5–4.3; p = 0.013). CONCLUSION: These findings suggest that forearm compression holds statistical advantages over upper arm compression. Added to documented physiological and practical reasons, we propose that future studies should use forearm compression in the assessment of endothelial function

    Study of Healthcare Personnel with Influenza and other Respiratory Viruses in Israel (SHIRI): study protocol

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    Abstract Background The Study of Healthcare Personnel with Influenza and other Respiratory Viruses in Israel (SHIRI) prospectively follows a cohort of healthcare personnel (HCP) in two hospitals in Israel. SHIRI will describe the frequency of influenza virus infections among HCP, identify predictors of vaccine acceptance, examine how repeated influenza vaccination may modify immunogenicity, and evaluate influenza vaccine effectiveness in preventing influenza illness and missed work. Methods Cohort enrollment began in October, 2016; a second year of the study and a second wave of cohort enrollment began in June 2017. The study will run for at least 3 years and will follow approximately 2000 HCP (who are both employees and members of Clalit Health Services [CHS]) with routine direct patient contact. Eligible HCP are recruited using a stratified sampling strategy. After informed consent, participants complete a brief enrollment survey with questions about occupational responsibilities and knowledge, attitudes, and practices about influenza vaccines. Blood samples are collected at enrollment and at the end of influenza season; HCP who choose to be vaccinated contribute additional blood one month after vaccination. During the influenza season, participants receive twice-weekly short message service (SMS) messages asking them if they have acute respiratory illness or febrile illness (ARFI) symptoms. Ill participants receive follow-up SMS messages to confirm illness symptoms and duration and are asked to self-collect a nasal swab. Information on socio-economic characteristics, current and past medical conditions, medical care utilization and vaccination history is extracted from the CHS database. Information about missed work due to illness is obtained by self-report and from employee records. Respiratory specimens from self-collected nasal swabs are tested for influenza A and B viruses, respiratory syncytial virus, human metapneumovirus, and coronaviruses using validated multiplex quantitative real-time reverse transcription polymerase chain reaction assays. The hemagglutination inhibition assay will be used to detect the presence of neutralizing influenza antibodies in serum. Discussion SHIRI will expand our knowledge of the burden of respiratory viral infections among HCP and the effectiveness of current and repeated annual influenza vaccination in preventing influenza illness, medical utilization, and missed workdays among HCP who are in direct contact with patients. Trial registration NCT03331991 . Registered on November 6, 2017.https://deepblue.lib.umich.edu/bitstream/2027.42/146186/1/12879_2018_Article_3444.pd

    Selective Interaction of Syntaxin 1A with KCNQ2: Possible Implications for Specific Modulation of Presynaptic Activity

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    KCNQ2/KCNQ3 channels are the molecular correlates of the neuronal M-channels, which play a major role in the control of neuronal excitability. Notably, they differ from homomeric KCNQ2 channels in their distribution pattern within neurons, with unique expression of KCNQ2 in axons and nerve terminals. Here, combined reciprocal coimmunoprecipitation and two-electrode voltage clamp analyses in Xenopus oocytes revealed a strong association of syntaxin 1A, a major component of the exocytotic SNARE complex, with KCNQ2 homomeric channels resulting in a ∼2-fold reduction in macroscopic conductance and ∼2-fold slower activation kinetics. Remarkably, the interaction of KCNQ2/Q3 heteromeric channels with syntaxin 1A was significantly weaker and KCNQ3 homomeric channels were practically resistant to syntaxin 1A. Analysis of different KCNQ2 and KCNQ3 chimeras and deletion mutants combined with in-vitro binding analysis pinpointed a crucial C-terminal syntaxin 1A-association domain in KCNQ2. Pull-down and coimmunoprecipitation analyses in hippocampal and cortical synaptosomes demonstrated a physical interaction of brain KCNQ2 with syntaxin 1A, and confocal immunofluorescence microscopy showed high colocalization of KCNQ2 and syntaxin 1A at presynaptic varicosities. The selective interaction of syntaxin 1A with KCNQ2, combined with a numerical simulation of syntaxin 1A's impact in a firing-neuron model, suggest that syntaxin 1A's interaction is targeted at regulating KCNQ2 channels to fine-tune presynaptic transmitter release, without interfering with the function of KCNQ2/3 channels in neuronal firing frequency adaptation

    Partners No More: Relational Transformation and the Turn to Litigation in Two Conservationist Organizations

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    The rise in litigation against administrative bodies by environmental and other political interest groups worldwide has been explained predominantly through the liberalization of standing doctrines. Under this explanation, termed here the floodgate model, restrictive standing rules have dammed the flow of suits that groups were otherwise ready and eager to pursue. I examine this hypothesis by analyzing processes of institutional transformation in two conservationist organizations: the Sierra Club in the United States and the Society for the Protection of Nature in Israel (SPNI). Rather than an eagerness to embrace newly available litigation opportunities, as the floodgate model would predict, the groups\u27 history reveals a gradual process of transformation marked by internal, largely intergenerational divisions between those who abhorred conflict with state institutions and those who saw such conflict as not only appropriate but necessary to the mission of the group. Furthermore, in contrast to the pluralist interactions that the floodgate model imagines, both groups\u27 relations with pertinent agencies in earlier eras better accorded with the partnership-based corporatist paradigm. Sociolegal research has long indicated the importance of relational distance to the transformation of interpersonal disputes. I argue that, at the group level as well, the presence or absence of a (national) partnership-centered relationship determines propensities to bring political issues to court. As such, well beyond change in groups\u27 legal capacity and resources, current increases in levels of political litigation suggest more fundamental transformations in the structure and meaning of relations between citizen groups and the state

    A Generic and Unified Global-Gyrator Model of Switched-Resonator Converters

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    Increased activity of cell membrane-associated prothrombinase, fibrinogen-like protein 2, in peripheral blood mononuclear cells of B-cell lymphoma patients.

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    Fibrinogen-like protein 2, FGL-2, was reported to be overexpressed in various cancer tissues, where it acts as a transmembrane prothrombinase. This study aims to determine the prothrombinase activity of FGL-2 in peripheral blood mononuclear cells (PBMC) of patients with B-cell lymphoma. FGL-2 activity was determined in patients with B-cell lymphoma (n = 53), and healthy controls (n = 145). FGL-2 activity in patients at diagnosis increased 3 ± 0.3 fold (p < 0.001). Sensitivity and specificity of the test was established at 73.6% and 80.7%, respectively, using a cutoff of 150% activity over control. Moreover, FGL-2 activity in 10 of 11 patients in remission decreased by 76%. In contrast, no significant difference was observed in expression levels of fgl-2 gene in patients and controls. Taken together, our study indicates that FGL-2 prothrombinase activity in PBMC of lymphoma patients is increased in active disease and normalizes during remission, thus being a potential marker for follow up of lymphoma patients

    Coronavirus Disease 2019 (COVID-19)-Associated Hospitalization and Mortality in Patients with Psoriasis: A Population-Based Study

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    Background!#!The impact of immune-related conditions on the outcomes of coronavirus disease 2019 (COVID-19) is poorly understood. Determinants of COVID-19 outcomes among patients with psoriasis are yet to be established.!##!Objective!#!Th objective of this study was to characterize a large cohort of patients with psoriasis with COVID-19 and to identify predictors of COVID-19-associated hospitalization and mortality.!##!Methods!#!A population-based nested case-control study was performed using the computerized database of Clalit Health Services, Israel. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence (CIs) of predictors for COVID-19-associated hospitalization and mortality.!##!Results!#!The study population included 3151 patients with psoriasis who tested positive for COVID-19. Subclinical COVID-19 infection occurred in 2818 (89.4%) of the patients while 122 (3.9%), 71 (2.3%), 123 (3.9%), and 16 (0.5%) of the patients experienced a mild, moderate, severe, and critical disease, respectively. Overall, 332 (10.5%) patients were hospitalized and 50 (1.6%) patients died because of COVID-19 complications. Intake of methotrexate independently predicted COVID-19-associated hospitalization (adjusted OR 2.30; 95% CI 1.11-4.78; p = 0.025). Use of biologic agents was not associated with COVID-19-associated hospitalization (OR 0.75; 95% CI 0.32-1.73; p = 0.491) or mortality (OR 0.85; 95% CI 0.12-6.21; p = 0.870). Older age, the presence of comorbid cardiovascular diseases, metabolic syndrome, chronic obstructive pulmonary disease, and chronic renal failure independently predicted both COVID-19-associated hospitalization and mortality.!##!Conclusions!#!The use of oral methotrexate was associated with an increased odds of COVID-associated hospitalization, whereas the use of biologic drugs was not associated with worse outcomes of COVID-19 among patients with psoriasis
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