22 research outputs found
Effects of Cannabinoids on Caffeine Contractures in Slow and Fast Skeletal Muscle Fibers of the Frog
The effect of cannabinoids on caffeine contractures was investigated in slow and fast skeletal muscle fibers using isometric tension recording. In slow muscle fibers, WIN 55,212-2 (10 and 5 ΌM) caused a decrease in tension. These doses reduced maximum tension to 67.43 ± 8.07% (P = 0.02, n = 5) and 79.4 ± 14.11% (P = 0.007, n = 5) compared to control, respectively. Tension-time integral was reduced to 58.37 ± 7.17% and 75.10 ± 3.60% (P = 0.002, n = 5), respectively. Using the CB1 cannabinoid receptor agonist ACPA (1 ΌM) reduced the maximum tension of caffeine contractures by 68.70 ± 11.63% (P = 0.01, n = 5); tension-time integral was reduced by 66.82 ± 6.89% (P = 0.02, n = 5) compared to controls. When the CB1 receptor antagonist AM281 was coapplied with ACPA, it reversed the effect of ACPA on caffeine-evoked tension. In slow and fast muscle fibers incubated with the pertussis toxin, ACPA had no effect on tension evoked by caffeine. In fast muscle fibers, ACPA (1 ΌM) also decreased tension; the maximum tension was reduced by 56.48 ± 3.4% (P = 0.001, n = 4), and tension-time integral was reduced by 57.81 ± 2.6% (P = 0.006, n = 4). This ACPA effect was not statistically significant with respect to the reduction in tension in slow muscle fibers. Moreover, we detected the presence of mRNA for the cannabinoid CB1 receptor on fast and slow skeletal muscle fibers, which was significantly higher in fast compared to slow muscle fiber expression. In conclusion, our results suggest that in the slow and fast muscle fibers of the frog cannabinoids diminish caffeine-evoked tension through a receptor-mediated mechanism
Supernova remnants: the X-ray perspective
Supernova remnants are beautiful astronomical objects that are also of high
scientific interest, because they provide insights into supernova explosion
mechanisms, and because they are the likely sources of Galactic cosmic rays.
X-ray observations are an important means to study these objects.And in
particular the advances made in X-ray imaging spectroscopy over the last two
decades has greatly increased our knowledge about supernova remnants. It has
made it possible to map the products of fresh nucleosynthesis, and resulted in
the identification of regions near shock fronts that emit X-ray synchrotron
radiation.
In this text all the relevant aspects of X-ray emission from supernova
remnants are reviewed and put into the context of supernova explosion
properties and the physics and evolution of supernova remnants. The first half
of this review has a more tutorial style and discusses the basics of supernova
remnant physics and thermal and non-thermal X-ray emission. The second half
offers a review of the recent advances.The topics addressed there are core
collapse and thermonuclear supernova remnants, SN 1987A, mature supernova
remnants, mixed-morphology remnants, including a discussion of the recent
finding of overionization in some of them, and finally X-ray synchrotron
radiation and its consequences for particle acceleration and magnetic fields.Comment: Published in Astronomy and Astrophysics Reviews. This version has 2
column-layout. 78 pages, 42 figures. This replaced version has some minor
language edits and several references have been correcte
Freely Expressed Views: Methodological Challenges for the Right of the Child to be Heard
Characterizing gene coexpression modules in Oryza sativa based on a graph-clustering approach
âCompletely out-at-seaâ with âtwo-gender medicineâ: A qualitative analysis of physician-side barriers to providing healthcare for transgender patients
<p>Abstract</p> <p>Background</p> <p>Members of the transgender community have identified healthcare access barriers, yet a corresponding inquiry into healthcare provider perspectives has lagged. Our aim was to examine physician perceptions of barriers to healthcare provision for transgender patients.</p> <p>Methods</p> <p>This was a qualitative study with physician participants from Ontario, Canada. Semi-structured interviews were used to capture a progression of ideas related to barriers faced by physicians when caring for trans patients. Qualitative data were then transcribed verbatim and analysed with an emergent grounded theory approach.</p> <p>Results</p> <p>A total of thirteen (13) physician participants were interviewed. Analysis revealed healthcare barriers that grouped into five themes: Accessing resources, medical knowledge deficits, ethics of transition-related medical care, diagnosing vs. pathologising trans patients, and health system determinants. A centralising theme of ânot knowing where to go or who to talk toâ was also identified.</p> <p>Conclusions</p> <p>The findings of this study show that physicians perceive barriers to the care of trans patients, and that these barriers are multifactorial. Access barriers impede physicians when referring patients to specialists or searching for reliable treatment information. Clinical management of trans patients is complicated by a lack of knowledge, and by ethical considerations regarding treatmentsâwhich can be unfamiliar or challenging to physicians. The disciplinary division of responsibilities within medicine further complicates care; few practitioners identify trans healthcare as an interest area, and there is a tendency to overemphasise trans status in mental health evaluations. Failure to recognise and accommodate trans patients within sex-segregated healthcare systems leads to deficient health policy. The findings of this study suggest potential solutions to trans healthcare barriers at the informational levelâwith increased awareness of clinical guidelines and by including trans health issues in medical educationâand at the institutional level, with support for both trans-focused and trans-friendly primary care models.</p