280 research outputs found

    Proactive and politically skilled professionals: What is the relationship with affective occupational commitment?

    Get PDF
    The aim of this study is to extend research on employee affective commitment in three ways: (1) instead of organizational commitment the focus is on occupational commitment; (2) the role of proactive personality on affective occupational commitment is examined; and (3) occupational satisfaction is examined as a mediator and political skills as moderator in the relationship between proactive personality and affective occupational commitment. Two connected studies, one in a hospital located in the private sector and one in a university located in the public sector, are carried out in Pakistan, drawing on a total sample of over 400 employees. The results show that proactive personality is positively related to affective occupational commitment, and that occupational satisfaction partly mediates the relationship between proactive personality and affective occupational commitment. No effect is found for a moderator effect of political skills in the relationship between proactive personality and affective occupational commitment. Political skills however moderate the relationship between proactive personality and affective organizational commitment

    Modest effects of dietary supplements during the COVID-19 pandemic: Insights from 445 850 users of the COVID-19 Symptom Study app

    Get PDF
    OBJECTIVE: Dietary supplements may ameliorate SARS-CoV-2 infection, although scientific evidence to support such a role is lacking. We investigated whether users of the COVID-19 Symptom Study app who regularly took dietary supplements were less likely to test positive for SARS-CoV-2 infection. DESIGN: App-based community survey. SETTING: 445 850 subscribers of an app that was launched to enable self-reported information related to SARS-CoV-2 infection for use in the general population in the UK (n=372 720), the USA (n=45 757) and Sweden (n=27 373). MAIN EXPOSURE: Self-reported regular dietary supplement usage (constant use during previous 3 months) in the first waves of the pandemic up to 31 July 2020. MAIN OUTCOMES MEASURES: SARS-CoV-2 infection confirmed by viral RNA reverse transcriptase PCR test or serology test before 31 July 2020. RESULTS: In 372 720 UK participants (175 652 supplement users and 197 068 non-users), those taking probiotics, omega-3 fatty acids, multivitamins or vitamin D had a lower risk of SARS-CoV-2 infection by 14% (95% CI (8% to 19%)), 12% (95% CI (8% to 16%)), 13% (95% CI (10% to 16%)) and 9% (95% CI (6% to 12%)), respectively, after adjusting for potential confounders. No effect was observed for those taking vitamin C, zinc or garlic supplements. On stratification by sex, age and body mass index (BMI), the protective associations in individuals taking probiotics, omega-3 fatty acids, multivitamins and vitamin D were observed in females across all ages and BMI groups, but were not seen in men. The same overall pattern of association was observed in both the US and Swedish cohorts. CONCLUSION: In women, we observed a modest but significant association between use of probiotics, omega-3 fatty acid, multivitamin or vitamin D supplements and lower risk of testing positive for SARS-CoV-2. We found no clear benefits for men nor any effect of vitamin C, garlic or zinc. Randomised controlled trials are required to confirm these observational findings before any therapeutic recommendations can be made

    Monocyte Scintigraphy in Rheumatoid Arthritis: The Dynamics of Monocyte Migration in Immune-Mediated Inflammatory Disease

    Get PDF
    Background: Macrophages are principal drivers of synovial inflammation in rheumatoid arthritis (RA), a prototype immune-mediated inflammatory disease. Conceivably, synovial macrophages are continuously replaced by circulating monocytes in RA. Animal studies from the 1960s suggested that macrophage replacement by monocytes is a slow process in chronic inflammatory lesions. Translation of these data into the human condition has been hampered by the lack of available techniques to analyze monocyte migration in man. Methods/Principal Findings: We developed a technique that enabled us to analyze the migration of labelled autologous monocytes in RA patients using single photon emission computer tomography (SPECT). We isolated CD14+ monocytes by CliniMACS in 8 patients and labeled these with technetium-99m (99m-Tc-HMPAO). Monocytes were re-infused into the same patient. Using SPECT we calculated that a very small but specific fraction of 3.4x10(-3) (0.95-5.1x10(-3)) % of re-infused monocytes migrated to the inflamed joints, being detectable within one hour after re-infusion. Conclusions/Significance: The results indicate monocytes migrate continuously into the inflamed synovial tissue of RA patients, but at a slow macrophage-replacement rate. This suggests that the rapid decrease in synovial macrophages that occurs after antirheumatic treatment might rather be explained by an alteration in macrophage retention than in monocyte influx and that RA might be particularly sensitive to treatments targeting inflammatory cell retention

    Investigation of utilization of nanosuspension formulation to enhance exposure of 1,3-dicyclohexylurea in rats: Preparation for PK/PD study via subcutaneous route of nanosuspension drug delivery

    Get PDF
    1,3-Dicyclohexylurea (DCU), a potent soluble epoxide hydrolase (sEH) inhibitor has been reported to lower systemic blood pressure in spontaneously hypertensive rats. One limitation of continual administration of DCU for in vivo studies is the compound's poor oral bioavailability. This phenomenon is mainly attributed to its poor dissolution rate and low aqueous solubility. Previously, wet-milled DCU nanosuspension has been reported to enhance the bioavailability of DCU. However, the prosperities and limitations of wet-milled nanosuspension have not been fully evaluated. Furthermore, the oral pharmacokinetics of DCU in rodent are such that the use of DCU to understand PK/PD relationships of sEH inhibitors in preclinical efficacy model is less than ideal. In this study, the limitation of orally delivered DCU nanosuspension was assessed by a surface area sensitive absorption model and pharmacokinetic modeling. It was found that dosing DCU nanosuspension did not provide the desired plasma profile needed for PK/PD investigation. Based on the model and in vivo data, a subcutaneous route of delivery of nanosuspension of DCU was evaluated and demonstrated to be appropriate for future PK/PD studies

    Oleate but not stearate induces the regulatory phenotype of myeloid suppressor cells

    Get PDF
    Tumor infiltrating myeloid cells play contradictory roles in the tumor development. Dendritic cells and classical activated macrophages support anti- tumor immune activity via antigen presentation and induction of pro- inflammatory immune responses. Myeloid suppressor cells (MSCs), for instance myeloid derived suppressor cells (MDSCs) or tumor associated macrophages play a critical role in tumor growth. Here, treatment with sodium oleate, an unsaturated fatty acid, induced a regulatory phenotype in the myeloid suppressor cell line MSC-2 and resulted in an increased suppression of activated T cells, paralleled by increased intracellular lipid droplets formation. Furthermore, sodium oleate potentiated nitric oxide (NO) production in MSC-2, thereby increasing their suppressive capacity. In primary polarized bone marrow cells, sodium oleate (C18:1) and linoleate (C18:2), but not stearate (C18:0) were identified as potent FFA to induce a regulatory phenotype. This effect was abrogated in MSC-2 as well as primary cells by specific inhibition of droplets formation while the inhibition of de novo FFA synthesis proved ineffective, suggesting a critical role for exogenous FFA in the functional induction of MSCs. Taken together our data introduce a new unsaturated fatty acid-dependent pathway shaping the functional phenotype of MSCs, facilitating the tumor escape from the immune system

    Characterization of bone repair in rat femur after treatment with calcium phosphate cement and autogenous bone graft

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In this study, the biocompatibility, stability and osteotransductivity of a new cement based on alpha-tricalcium phosphate (alpha-TCP) were investigated in a bone repair model using a rat model.</p> <p>Methods</p> <p>The potential of alpha-TCP on bone repair was compared to autogenous bone grafting, and unfilled cavities were used as negative control. Surgical cavities were prepared and designated as test (T), implanted with alpha-TCP blocks; negative control (C - ), unfilled; and positive control (C + ), implanted with autogenous bone graft. Results were analyzed on postoperative days three, seven, 14, 21 and 60.</p> <p>Results</p> <p>The histological analyses showed the following results. Postoperative day three: presence of inflammatory infiltrate, erythrocytes and proliferating fibroblasts in T, C - and C + samples. Day seven: extensive bone neoformation in groups T and C + , and beginning of alpha-TCP resorption by phagocytic cells. Days 14 and 21: osteoblastic activity in the three types of cavities. Day 60: In all samples, neoformed bone similar to surrounding bone. Moderate interruption on the ostectomized cortical bone.</p> <p>Conclusions</p> <p>Bone neoformation is seen seven days after implantation of alpha-TCP and autogenous bone. Comparison of C - with T and C + samples showed that repair is faster in implanted cavities; on day 60, control groups presented almost complete bone repair. Alpha-TCP cement presents biocompatibility and osteotransductivity, besides stability, but 60 days after surgery the cavities were not closed.</p

    The Effect of Predictability on Subjective Duration

    Get PDF
    Events can sometimes appear longer or shorter in duration than other events of equal length. For example, in a repeated presentation of auditory or visual stimuli, an unexpected object of equivalent duration appears to last longer. Illusions of duration distortion beg an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? In other words, what entailments do duration distortions have with respect to other timing judgments? We here show that when a sound or visual flicker is presented in conjunction with an unexpected visual stimulus, neither the pitch of the sound nor the frequency of the flicker is affected by the apparent duration dilation. This demonstrates that subjective time in general is not slowed; instead, duration judgments can be manipulated with no concurrent impact on other temporal judgments. Like spatial vision, time perception appears to be underpinned by a collaboration of separate neural mechanisms that usually work in concert but are separable. We further show that the duration dilation of an unexpected stimulus is not enhanced by increasing its saliency, suggesting that the effect is more closely related to prediction violation than enhanced attention. Finally, duration distortions induced by violations of progressive number sequences implicate the involvement of high-level predictability, suggesting the involvement of areas higher than primary visual cortex. We suggest that duration distortions can be understood in terms of repetition suppression, in which neural responses to repeated stimuli are diminished
    corecore