210 research outputs found

    TGF-b2 induction regulates invasiveness of theileria-transformed leukocytes and disease susceptibility

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    Theileria parasites invade and transform bovine leukocytes causing either East Coast fever (T. parva), or tropical theileriosis (T. annulata). Susceptible animals usually die within weeks of infection, but indigenous infected cattle show markedly reduced pathology, suggesting that host genetic factors may cause disease susceptibility. Attenuated live vaccines are widely used to control tropical theileriosis and attenuation is associated with reduced invasiveness of infected macrophages in vitro. Disease pathogenesis is therefore linked to aggressive invasiveness, rather than uncontrolled proliferation of Theileria-infected leukocytes. We show that the invasive potential of Theileria-transformed leukocytes involves TGF-b signalling. Attenuated live vaccine lines express reduced TGF-b2 and their invasiveness can be rescued with exogenous TGF-b. Importantly, infected macrophages from disease susceptible Holstein-Friesian (HF) cows express more TGF-b2 and traverse Matrigel with great efficiency compared to those from disease-resistant Sahiwal cattle. Thus, TGF-b2 levels correlate with disease susceptibility. Using fluorescence and time-lapse video microscopy we show that Theileria-infected, disease-susceptible HF macrophages exhibit increased actin dynamics in their lamellipodia and podosomal adhesion structures and develop more membrane blebs. TGF-b2-associated invasiveness in HF macrophages has a transcription-independent element that relies on cytoskeleton remodelling via activation of Rho kinase (ROCK). We propose that a TGF-b autocrine loop confers an amoeboid-like motility on Theileria-infected leukocytes, which combines with MMP-dependent motility to drive invasiveness and virulence

    Meaning in Life as a Mediator of Ethnic Identity and Adjustment Among Adolescents from Latin, Asian, and European American Backgrounds

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    Establishing a sense of life meaning is a primary facet of well-being, yet is understudied in adolescent development. Using data from 579 adolescents (53% female) from Latin American, Asian, and European backgrounds, demographic differences in meaning in life, links with psychological and academic adjustment, and the role of meaning in explaining associations between ethnic identity and adjustment were examined. Although no generational or gender differences were found, Asian Americans reported higher search for meaning than Latin and European Americans. Presence of meaning was positively associated with self-esteem, academic adjustment, daily well-being, and ethnic belonging and exploration, whereas search for meaning was related to lower self-esteem and less stability in daily well-being. Presence of meaning mediated associations between ethnic identity and adjustment, explaining 28–52% of ethnic identity’s protective effect on development. Ethnic identity thus appears to affect adjustment, in part, through its role in fostering a positive sense of meaning in adolescents’ lives

    Standard versus prosocial online support groups for distressed breast cancer survivors: a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>The Internet can increase access to psychosocial care for breast cancer survivors through online support groups. This study will test a novel prosocial online group that emphasizes both opportunities for getting and giving help. Based on the helper therapy principle, it is hypothesized that the addition of structured helping opportunities and coaching on how to help others online will increase the psychological benefits of a standard online group.</p> <p>Methods/Design</p> <p>A two-armed randomized controlled trial with pretest and posttest. Non-metastatic breast cancer survivors with elevated psychological distress will be randomized to either a standard facilitated online group or to a prosocial facilitated online group, which combines online exchanges of support with structured helping opportunities (blogging, breast cancer outreach) and coaching on how best to give support to others. Validated and reliable measures will be administered to women approximately one month before and after the interventions. Self-esteem, positive affect, and sense of belonging will be tested as potential mediators of the primary outcomes of depressive/anxious symptoms and sense of purpose in life.</p> <p>Discussion</p> <p>This study will test an innovative approach to maximizing the psychological benefits of cancer online support groups. The theory-based prosocial online support group intervention model is sustainable, because it can be implemented by private non-profit or other organizations, such as cancer centers, which mostly offer face-to-face support groups with limited patient reach.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01396174">NCT01396174</a></p

    Integrating Mindfulness into Positive Psychology: a Randomised Controlled Trial of an Online Positive Mindfulness Program

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    The purpose of the present study was to test the efficacy of an 8-week online intervention-based Positive Mindfulness Program (PMP) that integrated mindfulness with a series of positive psychology variables, with a view to improving wellbeing scores measured in these variables. The positive mindfulness cycle, based on positive intentions and savouring, provides the theoretical foundation for the PMP. The study was based on a randomised wait-list controlled trial; and 168 participants (128 females, mean age = 40.82) completed the intervention which included daily videos, meditations, and activities. The variables tested included wellbeing measures, such as gratitude, self-compassion, self-efficacy, meaning, and autonomy. Pre- and post- intervention data, including one month after the end of the intervention, were collected from both experimental and control groups. The post-test measurements of the experimental participants showed a significant improvement in all the dependent variables compared with the pre-test ones and were also significantly higher than those of the control group. One month after the intervention, the experimental group participants retained their improvement in 10 out of the 11 measurements. These positive results indicate that PMP may be effective in enhancing wellbeing and other positive variables in adult, non-clinical populations
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