139 research outputs found

    Plasma from Volunteers Breathing Helium Reduces Hypoxia-Induced Cell Damage in Human Endothelial Cells-Mechanisms of Remote Protection Against Hypoxia by Helium.

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    PurposeRemote ischemic preconditioning protects peripheral organs against prolonged ischemia/reperfusion injury via circulating protective factors. Preconditioning with helium protected healthy volunteers against postischemic endothelial dysfunction. We investigated whether plasma from helium-treated volunteers can protect human umbilical vein endothelial cells (HUVECs) against hypoxia in vitro through release of circulating of factors.MethodsHealthy male volunteers inhaled heliox (79% helium, 21% oxygen) or air for 30 min. Plasma was collected at baseline, directly after inhalation, 6 h and 24 h after start of the experiment. HUVECs were incubated with either 5% or 10% of the plasma for 1 or 2 h and subjected to enzymatically induced hypoxia. Cell damage was measured by LDH content. Furthermore, caveolin 1 (Cav-1), hypoxia-inducible factor (HIF1α), extracellular signal-regulated kinase (ERK)1/2, signal transducer and activator of transcription (STAT3) and endothelial nitric oxide synthase (eNOS) were determined.ResultsPrehypoxic exposure to 10% plasma obtained 6 h after helium inhalation decreased hypoxia-induced cell damage in HUVEC. Cav-1 knockdown in HUVEC abolished this effect.ConclusionsPlasma of healthy volunteers breathing helium protects HUVEC against hypoxic cell damage, possibly involving circulating Cav-1

    Effect of helium pre- or postconditioning on signal transduction kinases in patients undergoing coronary artery bypass graft surgery

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    Background: The noble gas helium induces pre- and postconditioning in animals and humans. Volatile anesthetics induce cardioprotection in humans undergoing coronary artery bypass graft (CABG) surgery. We hypothesized that helium induces pre-and postconditioning in CABG-patients, affecting signaling molecules protein kinase C-epsilon (PKC-epsilon), p38 mitogen activated protein kinase (p38 MAPK), extracellular signal-regulated kinase 1/2 (ERK-1/2) and heat shock protein 27 (HSP-27) within cardiac tissue, and reducing postoperative troponin levels. Methods: After ethical approval and informed consent, 125 elective patients undergoing CABG surgery were randomised into this prospective, placebo controlled, investigator blinded, parallel arm single-centre study. Helium preconditioning (3 x 5 min of 70 % helium and 30 % oxygen) was applied before aortic cross clamping; postconditioning (15 min of helium) was applied before release of the aortic cross clamp. Signaling molecules were measured in right atrial appendix specimens. Troponin-T was measured at 4, 12, 24 and 48 h postoperatively. Results: Baseline characteristics of all groups were similar. Helium preconditioning did not significantly alter the primary outcome (molecular levels of kinases PKC-e and HSP-27, ratio of activated p38 MAPK or ERK 1/2). Postoperative troponin T was 11 arbitrary units [5, 31; area-under-the-curve (interquartile range)] for controls, and no statistically significant changes were observed after helium preconditioning [He-pre: 11 (6, 18)], helium postconditioning [He-post: 11 (8, 15)], helium pre-and postconditioning [He-PP: 14 (6, 20)] and after sevoflurane preconditioning [APC: 12 (8, 24), p = 0.13]. No adverse effects related to study treatment were observed in this study. Conclusions: No effect was observed of helium preconditioning, postconditioning or the combination thereof on activation of p38 MAPK, ERK 1/2 or levels of HSP27 and PKC-e in the human heart. Helium pre-and postconditioning did not affect postoperative troponin release in patients undergoing CABG surgery

    Comparing the measurement of different social networks

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    __Background:__ Technological progress has enabled researchers to use new unobtrusive measures of relationships between actors in social network analysis. However, research on how these unobtrusive measures of peer connections relate to traditional sociometric nominations in adolescents is scarce. Therefore, the current study compared traditional peer nominated networks with more unobtrusive measures of peer connections: Communication networks that consist of instant messages in an online social platform and proximity networks based on smartphones' Bluetooth signals that measure peer proximity. The three social network types were compared in their coverage, stability, overlap, and the extent to which the networks exhibit the often observed sex segregation in adolescent social networks. __Method:__ Two samples were derived from the MyMovez project: a longitudinal sample of 444 adolescents who participated in the first three waves of the first year of the project (Y1; 51% male; Mage = 11.29, SDage = 1.26) and a cross-sectional sample of 774 adolescents that participated in fifth wave in the third year (Y3; 48% male; Mage = 10.76, SDage = 1.23). In the project, all participants received a research smartphone and a wrist-worn accelerometer. On the research smartphone, participants received daily questionnaires such as peer nomination questions (i.e., nominated networ

    The Impact of Social Media Influencers on Children’s Dietary Behaviors

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    Over the past years vlogs rapidly have become an attractive platform for food industries, sponsoring social media influencers to promote their products. As with more traditional media, social media influencers predominantly promote unhealthy drinks and foods that are high in sugar, fat, and salt – consumption of which may increase the risk of overweight, obesity, and non-communicable diseases. The aim of the current Brief Research Report is to examine the impact of vlogs on children’s unhealthy dietary behaviors. Drawing on longitudinal survey data from 453 8- to 12-year-old children, we analyzed the longitudinal relations between children’s frequency of watching vlogs and their consumption of unhealthy beverages and snacks. Structural path modeling analyses of three waves of data with 1-year intervals showed that children’s self-reported frequency of watching vlogs influenced consumption of unhealthy beverages 2 years later. The analyses did not yield significant relat

    Neighborhood Characteristics and Elevated Blood Pressure in Older Adults

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    IMPORTANCE: The local environment remains an understudied contributor to elevated blood pressure among older adults. Untargeted approaches can identify neighborhood conditions interrelated with racial segregation that drive hypertension disparities. OBJECTIVE: To evaluate independent associations of sociodemographic, economic, and housing neighborhood factors with elevated blood pressure. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, the sample included Health and Retirement Study participants who had between 1 and 3 sets of biennial sphygmomanometer readings from 2006 to 2014 or 2008 to 2016. Statistical analyses were conducted from February 5 to November 30, 2021. EXPOSURES: Fifty-one standardized American Community Survey census tract variables (2005-2009). MAIN OUTCOMES AND MEASURES: Elevated sphygmomanometer readings over the study period (6-year period prevalence): a value of at least 140 mm Hg for systolic blood pressure and/or at least 90 mm Hg for diastolic blood pressure. Participants were divided 50:50 into training and test data sets. Generalized estimating equations were used to summarize multivariable associations between each neighborhood variable and the period prevalence of elevated blood pressure, adjusting for individual-level covariates. Any neighborhood factor associated (Simes-adjusted for multiple comparisons P ≤ .05) with elevated blood pressure in the training data set was rerun in the test data set to gauge model performance. Lastly, in the full cohort, race- and ethnicity-stratified associations were evaluated for each identified neighborhood factor on the likelihood of elevated blood pressure. RESULTS: Of 12 946 participants, 4565 (35%) had elevated sphygmomanometer readings (median [IQR] age, 68 [63-73] years; 2283 [50%] male; 228 [5%] Hispanic or Latino, 502 [11%] non-Hispanic Black, and 3761 [82%] non-Hispanic White). Between 2006 and 2016, a lower likelihood of elevated blood pressure was observed (relative risk for highest vs lowest tertile, 0.91; 95% CI, 0.86-0.96) among participants residing in a neighborhood with recent (post-1999) in-migration of homeowners. This association was precise among participants with non-Hispanic White and other race and ethnicity (relative risk, 0.91; 95% CI, 0.85-0.97) but not non-Hispanic Black participants (relative risk, 0.97; 95% CI, 0.85-1.11; P = .48 for interaction) or Hispanic or Latino participants (relative risk, 0.84; 95% CI, 0.65-1.09; P = .78 for interaction). CONCLUSIONS AND RELEVANCE: In this cohort study of older adults, recent relocation of homeowners to a neighborhood was robustly associated with reduced likelihood of elevated blood pressure among White participants but not their racially and ethnically marginalized counterparts. Our findings indicate that gentrification may influence later-life blood pressure control

    Testing a Social Network Intervention Using Vlogs to Promote Physical Activity Among Adolescents: A Randomized Controlled Trial

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    There is a need to stimulate physical activity among adolescents, but unfortunately, they are hard to reach with traditional mass media interventions. A promising alternative is to carry out social network interventions. In social network interventions, a small group of individuals (influence agents) is selected to promote health-related behaviors within their social network. This study investigates whether a social network intervention is more effective to promote physical activity, compared to a mass media intervention and no intervention. Ad

    FDG-PET/CT for differentiating between aseptic and septic delayed union in the lower extremity

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    Background: 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) has proven to have a high diagnostic accuracy for the detection of bone infections. In patients with delayed union it may be clinically important to differentiate between aseptic and septic delayed union. The aim of this study was to evaluate the efficacy and to assess the optimal diagnostic accuracy of FDG-PET/CT in differentiating between aseptic and septic delayed union in the lower extremity. Methods: This is a retrospective study of consecutive patients who underwent FDG-PET/CT scanning for suspicion of septic delayed union of the lower extremity. Diagnosis of aseptic delayed union or septic delayed union was made based on surgical deep cultures following PET/CT scanning and information on clinical follow-up. FDG-uptake values were measured at the fractured site by use of the maximum standardized uptake value (SUVmax). Sensitivity, specificity and diagnostic accuracy of FDG-PET/CT were calculated at various SUVmax cut-off points. Results: A total of 30 patients were included; 13 patients with aseptic delayed unions and 17 patients with septic delayed unions. Mean SUVmax in aseptic delayed union patients was 3.23 (SD ± 1.21). Mean SUVmax in septic delayed union patients was 4.77 (SD ± 1.87). A cut-off SUVmax set at 4.0 showed sensitivity, specificity and diagnostic accuracy of FDG-PET/CT were 65, 77 and 70% to differentiate between aseptic and septic delayed union, respectively. Conclusion: Using a semi-quantitative measure (SUVmax) for interpretation of FDG-PET/CT imaging seems to be a promising tool for the discrimination between aseptic and septic delayed union

    Promoting water consumption among Dutch children: an evaluation of the social network intervention Share H2 O

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    Background: There is a need to develop and improve interventions promoting healthy drinking behaviors among children. A promising method could be to stimulate peer influence within children’s social networks. In the Share H2O social network intervention (SNI), peer influence was utilized by selecting a subset of influential children and training them as ‘influence agents’ to promote water consumption—as an alternative to SSBs. Previous research has mainly focused on the process of selecting influence agents. However, the process of motivating influence agents to promote the behavior has hardly received any research attention. Therefore, in the SNI Share H2O SNI, this motivation process was emphasized and grounded in the self-determination t
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