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Prostaglandin E2 Inhibits Histamine-Evoked Ca2+ Release in Human Aortic Smooth Muscle Cells through Hyperactive cAMP Signaling Junctions and Protein Kinase A
In human aortic smooth muscle cells (ASMC), prostaglandin E2 (PGE2) stimulates adenylyl cyclase (AC) and attenuates the increase in intracellular free Ca2+ concentration ([Ca2+]i) evoked by activation of histamine H1 receptors. The mechanisms are not resolved. We show that cAMP mediates inhibition of histamine-evoked Ca2+ signals by PGE2. Exchange proteins activated by cAMP (EPACs) were not required, but the effects were attenuated by inhibition of cAMP-dependent protein kinase (PKA). PGE2 had no effect on the Ca2+ signals evoked by protease-activated receptors, heterologously expressed muscarinic M3 receptors, or by direct activation of inositol 1,4,5-trisphosphate (IP3) receptors by photolysis of caged IP3. The rate of Ca2+ removal from the cytosol was unaffected by PGE2, but PGE2 attenuated histamine-evoked IP3 accumulation. Substantial inhibition of AC had no effect on the concentration-dependent inhibition of Ca2+ signals by PGE2 or butaprost (to selectively activate EP2 receptors), but it modestly attenuated responses to EP4 receptors, activation of which generated less cAMP than EP2 receptors. We conclude that inhibition of histamine-evoked Ca2+ signals by PGE2 occurs through ‘hyperactive signalling junctions’, wherein cAMP is locally delivered to PKA at super-saturating concentrations to cause uncoupling of H1 receptors from phospholipase C. This sequence allows digital signalling from PGE2 receptors, through cAMP and PKA, to histamine-evoked Ca2+ signals.This work was supported by the Medical Research Council [G0900049], Biotechnology and Biological Sciences Research Council [L000075] and the Wellcome Trust [101844]
Altered emotion regulation capacity in social phobia as a function of comorbidity
Social phobia (SP) has been associated with amygdala hyperreactivity to fear-relevant stimuli. However, little is known about the neural basis of SP individuals capacity to downregulate their responses to such stimuli and how such regulation varies as a function of comorbid depression and anxiety. We completed an functional magnetic resonance imaging (fMRI) study wherein SP participants without comorbidity (n ¼ 30), with comorbid depression (n ¼ 18) and with comorbid anxiety (n ¼ 19) and healthy controls (n ¼ 15) were scanned while completing an affect labeling emotion regulation task. Individuals with SP as a whole exhibited a reversal of the pattern observed in healthy controls in that they showed upregulation of amygdala activity during affect labeling. However, subsequent analyses revealed a more complex picture based on comorbidity type. Although none of the SP subgroups showed the normative pattern of amygdala downregulation, it was those with comorbid depression specifically who showed significant upregulation. Effects could not be attributed to differences in task performance, amygdala reactivity or right ventral lateral prefrontal cortex (RVLPFC) engagement, but may stem from dysfunctional communication between amygdala and RVLPFC. Furthermore, the particularly altered emotion regulation seen in those with comorbid depression could not be fully explained by symptom severity or state anxiety. Results reveal altered emotion regulation in SP, especially when comorbid with depression
Trapping and Wiggling: Elastohydrodynamics of Driven Microfilaments
We present a general theoretical analysis of semiflexible filaments subject
to viscous drag or point forcing. These are the relevant forces in dynamic
experiments designed to measure biopolymer bending moduli. By analogy with the
``Stokes problems" in hydrodynamics (fluid motion induced by that of a wall
bounding a viscous fluid), we consider the motion of a polymer one end of which
is moved in an impulsive or oscillatory way. Analytical solutions for the
time-dependent shapes of such moving polymers are obtained within an analysis
applicable to small-amplitude deformations. In the case of oscillatory driving,
particular attention is paid to a characteristic length determined by the
frequency of oscillation, the polymer persistence length, and the viscous drag
coefficient. Experiments on actin filaments manipulated with optical traps
confirm the scaling law predicted by the analysis and provide a new technique
for measuring the elastic bending modulus. A re-analysis of several published
experiments on microtubules is also presented.Comment: RevTex, 24 pages, 15 eps figs, uses cite.sty, Biophysical
Effects of self-transcendence on neural responses to persuasive messages and health behavior change
Self-transcendence refers to a shift in mindset from focusing on self-interests to the well-being of others. We offer an integrative neural model of self-transcendence in the context of persuasive messaging by examining the mechanisms of self-transcendence in promoting receptivity to health messages and behavior change. Specifically, we posited that focusing on values and activities that transcend the self can allow people to see that their self-worth is not tied to a specific behavior in question, and in turn become more receptive to subsequent, otherwise threatening health information. To test whether inducing self-transcendent mindsets before message delivery would help overcome defensiveness and increase receptivity, we used two priming tasks, affirmation and compassion, to elicit a transcendent mindset among 220 sedentary adults. As preregistered, those who completed a self-transcendence task before health message exposure, compared with controls, showed greater increases in objectively logged levels of physical activity throughout the following month. In the brain, self-transcendence tasks up-regulated activity in a region of the ventromedial prefrontal cortex, chosen for its role in positive valuation and reward processing. During subsequent health message exposure, self-transcendence priming was associated with increased activity in subregions of the ventromedial prefrontal cortex, implicated in self-related processing and positive valuation, which predicted later decreases in sedentary behavior. The present findings suggest that having a positive self-transcendent mindset can increase behavior change, in part by increasing neural receptivity to health messaging
Cartoons and collaboration in wartime China: the mobilization of Chinese cartoonists under Japanese occupation
The work of Chinese cartoonists who published their illustrations in the popular press in occupied China from 1937 to 1945 has largely escaped the attention of scholars of both the occupation itself and the broader field of cartoon history. This article seeks to fill this gap in the literature by analyzing how the very nature of the occupation, together with efforts undertaken by collaborationist governments such as that of Wang Jingwei, created a context in which a particular body of artists could continue to draw. In so doing, the article raises questions about the place of “collaborationist” cartoonists in the broader development of art and propaganda in China and about the very nature of collaboration in the Chinese context
Expanding the parameters of academia
This paper draws on qualitative data gathered from two studies funded by the UK Leadership Foundation for Higher Education to examine the expansion of academic identities in higher education. It builds on Whitchurch’s earlier work, which focused primarily on professional staff, to suggest that the emergence of broadly based projects such as widening participation, learning support and community partnership is also impacting on academic identities. Thus, academic as well as professional staff are increasingly likely to work in multi-professional teams across a variety of constituencies, as well as with external partners, and the binary distinction between ‘academic’ and ‘non-academic’ roles and activities is no longer clear-cut. Moreover, there is evidence from the studies of an intentionality about deviations from mainstream academic career routes among respondents who could have gone either way. Consideration is therefore given to factors that influence individuals to work in more project-oriented areas, as well as to variables that affect ways in which these roles and identities develop. Finally, three models of academically oriented project activity are identified, and the implications of an expansion of academic identities are reviewed
Key features of palliative care service delivery to Indigenous peoples in Australia, New Zealand, Canada and the United States: A comprehensive review
Background: Indigenous peoples in developed countries have reduced life expectancies, particularly from chronic diseases. The lack of access to and take up of palliative care services of Indigenous peoples is an ongoing concern.
Objectives: To examine and learn from published studies on provision of culturally safe palliative care service delivery to Indigenous people in Australia, New Zealand (NZ), Canada and the United States of America (USA); and to compare Indigenous peoples’ preferences, needs, opportunities and barriers to palliative care.
Methods: A comprehensive search of multiple databases was undertaken. Articles were included if they were published in English from 2000 onwards and related to palliative care service delivery for Indigenous populations; papers could use quantitative or qualitative approaches. Common themes were identified using thematic synthesis. Studies were evaluated using Daly’s hierarchy of evidence-for-practice in qualitative research.
Results: Of 522 articles screened, 39 were eligible for inclusion. Despite diversity in Indigenous peoples’ experiences across countries, some commonalities were noted in the preferences for palliative care of Indigenous people: to die close to or at home; involvement of family; and the integration of cultural practices. Barriers identified included inaccessibility, affordability, lack of awareness of services, perceptions of palliative care, and inappropriate services. Identified models attempted to address these gaps by adopting the following strategies: community engagement and ownership; flexibility in approach; continuing education and training; a whole-of-service approach; and local partnerships among multiple agencies. Better engagement with Indigenous clients, an increase in number of palliative care patients, improved outcomes, and understanding about palliative care by patients and their families were identified as positive achievements.
Conclusions: The results provide a comprehensive overview of identified effective practices with regards to palliative care delivered to Indigenous populations to guide future program developments in this field. Further research is required to explore the palliative care needs and experiences of Indigenous people living in urban areas
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