Abstract-Increased arterial wall tension stimulates growth and remodeling of arteries, but little is known about the effects of decreased wall tension, despite its developmental and pathological significance. Consequently, we cuffed 1 carotid artery in rabbits with a portion of the contralateral artery to off-load circumferential wall tension. The model produced rapid and extensive atrophy of the cuffed artery that yielded decreases in the DNA content of the cuffed artery (a measure of cell number) from 8.0Ϯ0.5 g/cm of in situ vessel length to 5.6Ϯ0.5 g/cm at 21 days postoperatively. The elastin content of the cuffed artery was also significantly reduced, from 399Ϯ17 to 283Ϯ17 g/cm, and collagen content was reduced from 468.0Ϯ59.0 to 154Ϯ24 g/cm (PϽ0.05) at 21 days postoperatively. Detection of DNA oligonucleosomes by gel electrophoresis implicated apoptotic cell death in remodeling due to cuffing. Upregulation of matrix metalloproteinases (MMPs), including MMP-2, MMP-9, and unidentified gelatinases, indicated that these enzymes may also be involved in remodeling. No further changes in wall structure were seen between 3 weeks and 6 months, and the excised artery that was used as a cuff exhibited normal medial morphology for at least 6 months postoperatively. We infer from these experiments that off-loading of arterial wall tension induces rapid and extensive atrophy of the arterial media.

Vasa vasorum are important sources of oxygen and nutrients to vascular tissues and their proliferation influences the pathogenesis of arterial disease; however, the regulation of their growth is poorly understood partly because of a lack of appropriate experimental models. We cuffed common carotid arteries of rabbits with segments of the contralateral carotid artery, a procedure that resulted in rapid and extensive elaboration of adventitial vasa vasorum and connective tissue. Endothelium-lined microvessels were observed at 1 week but vessels as large as 300 microm with an organizing media were common by 3 weeks. These vasa vasorum arose primarily from the vascular supply to contiguous tissues, but also from the carotid artery. This angiogenesis was accompanied by increased expression of the angiogenic factor, vascular endothelial growth factor (VEGF), in the invading connective tissue cells and increased expression of the transcriptional regulator of VEGF, hypoxia-inducible factor-1alpha (HIF-1alpha), in these connective tissues and in the cuffing artery. These findings are consistent with the hypothesis that upregulation of HIF-1alpha and VEGF expression drives angiogenesis of vasa vasorum in this model. This simple model may be amenable to the study of the development and elaboration of vasa vasorum, especially in the context of vascular pathologies.

Background The Do-Live-Well (DLW) framework is an occupation-focused health promotion approach. Occupational therapists (OTs) have been interested in training opportunities regarding this framework. Traditionally, in-person continuing educational interventions are the main way that OTs obtain knowledge, but web-based learning has become popular among health care professionals. However, its effectiveness and learners’ experience in web-based learning have not been well-studied in occupational therapy education. Objective This study aims to evaluate the effectiveness of the web-based and in-person educational DLW workshops for Canadian OTs and to understand their experiences in both workshop types. Methods An explanatory sequential mixed methods study design was used, where quantitative data were collected first, then qualitative data were used to explain the quantitative findings. A quasi-experimental design and interpretative description methodology were used in the quantitative and qualitative phases, respectively. Results Quantitative results were as follows: a total of 43 OTs completed pre-, post-, and follow-up evaluations (in-person group: 21/43, 49%; web-based group: 22/43, 51%). Practice settings of the participants varied, including geriatric, hospital, long-term, mental health, pediatric, and primary settings. The primary outcome was as follows: there were no statistically significant differences in knowledge changes at the 3 time points (P=.57 to P=.99) between the groups. In the web-based group, the knowledge scores at follow-up were lower compared with the posttest results, meaning that knowledge gain was reduced over time (P=.001). The secondary outcomes were as follows: there were statistically significant differences between the groups in factors influencing DLW adoption at posttest (P=.001) and in satisfaction with the workshop (P<.001) at posttest in favor of the in-person group. Qualitative results were as follows: a total of 18 OTs (9/18, 50% from each group) participated in an individual interview. Five themes were identified regarding learners’ workshop experiences: relevance to their practices and interests may improve learning, a familiar learning environment may facilitate learning, synchronous in-person interaction is valuable in the learning process, ease of access to learning should be considered, and flexibility in web-based learning can be both beneficial and challenging. Conclusions The quantitative results of this study reported no difference in knowledge acquisition between the in-person and web-based groups, indicating that web-based education is as effective as in-person workshops. However, participants’ satisfaction with the workshop was statistically significantly higher for the in-person workshop. The qualitative findings described the participants’ perceived benefits and challenges of each educational format. The participants in both the web-based and in-person workshop groups valued in-person interactions in learning, but the participants in the web-based workshop group expressed web-based learning lacked in-person-like interactions. Thus, adding synchronous in-person interactions to web-based learning may improve learners’ educational experiences in web-based occupational therapy and continuing education.