Thrombospondin-1 (TSP-1) is a matricellular protein that is present in negligible amounts in normal human vasculature but occurs in significant amounts in diseased vessels. In this study, we examined the effect of TSP-1 on DNA synthesis, proliferation, and migration in human vascular smooth muscle cells grown from saphenous vein. TSP-1 (0.1 to 30 micrograms/mL) elicited a concentration-dependent increase in DNA synthesis under serum-free conditions. In combination with platelet-derived growth factor, TSP-1 induced a synergistic effect on DNA synthesis that was significantly higher than the additive effect of both agents. In proliferation assays, TSP-1 increased cell numbers by 50% relative to the serum-free controls over 14 days. In migration assays, conducted using modified Boyden chambers, TSP-1 (> or = 10 micrograms/mL) elicited marked chemotaxis to a degree equivalent to platelet-derived growth factor. The chemotactic response to TSP-1 (10 micrograms/mL) was abolished by the GRGDSP peptide but unaffected by the control GRGESP peptide, whereas neither peptide inhibited DNA synthesis stimulated by TSP-1. Inhibition of tyrosine kinase activity with genistein or tyrphostin A23 abolished DNA synthesis induced by TSP-1, and a neutralizing antibody to platelet-derived growth factor had no effect on DNA synthesis. Similarly, migration in response to TSP-1 was largely inhibited by these tyrosine kinase inhibitors. TSP-1 is a strong mitogen and chemoattractant for human vascular smooth muscle cells under serum-free conditions. The novel finding that TSP-1 is mitogenic for human cells contrasts with previous studies that have not shown any significant effect of TSP-1 itself on the growth of animal-derived smooth muscle cells. TSP-1 may play an important modulatory role in the local regulation of vascular smooth muscle function in vascular pathologies in humans.
BackgroundThere is growing research on student use of podcasts in academic settings. However, there is little in-depth research focusing on student experience of podcasts, in particular in terms of barriers to, and facilitators of, podcast use and students' perceptions of the usefulness of podcasts as learning tools. This study aimed to explore the experiences of non-medical prescribing students who had access to podcasts of key pharmacology lectures as supplementary learning tools to their existing course materials.MethodsSemi-structured interviews were carried out with seven non-medical prescribing students (average age = 43 years), all of whom were nurses, who had access to seven podcasts of key pharmacology lectures. These podcasts took the form of downloadable audio lecture recordings available through the virtual learning environment WebCT. Low, medium and high users of the podcasts took part in the interviews in order to access a variety of student experiences. Interview data was analysed using thematic template analysis to identify key themes surrounding student experience of podcast availability, particularly in relation to barriers to and facilitators of podcast use, and students' experiences of podcasts as a learning tool.ResultsStudents used podcasts for a variety of reasons such as revisiting lectures, preparing for exams, to clarify or revise specific topics and, to a lesser extent, to catch up on a missed lecture. Barriers to podcast use centred mainly around technological issues. Lack of experience of the technology required to access podcasts proved a barrier for some students. A lack of access to suitable technology was also a reported barrier. Family assistance and I.T. assistance from the university helped facilitate students' use of the podcasts. Students found that using podcasts allowed them to have greater control over their learning and to gauge their learning needs, as well as helping them build their understanding of a complex topic.ConclusionsStudents used podcasts for a variety of reasons. Barriers to podcasts use were generally related to technological issues. Students often found that once assistance had been gained regarding these technological issues, they accessed the podcasts more easily. Students felt that access to podcasts added value to their learning materials by allowing them to better manage their learning and build their understanding. Podcasts represent a valuable additional learning tool for this specific group of older students.
Background: The shift away from a biological science to a social science model of nursing care has resulted in a reduction in pharmacology knowledge and understanding in pre-registration nursing students. This has a significant impact on nurse prescribing training where pharmacology is a critical component of the course from a patient safety perspective.
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