Under physiological conditions, retinal pigment epithelium (RPE) is a cellular monolayer composed of mitotically quiescent cells. Tight junctions and adherens junctions maintain the polarity of RPE cells, and are required for cellular functions. In proliferative vitreoretinopathy (PVR), upon retinal tear, RPE cells lose cell-cell contact, undergo epithelial-mesenchymal transition (EMT), and ultimately transform into myofibroblasts, leading to the formation of fibrocellular membranes on both surfaces of the detached retina and on the posterior hyaloids, which causes tractional retinal detachment. In PVR, RPE cells are crucial contributors, and multiple signaling pathways, including the SMAD-dependent pathway, Rho pathway, MAPK pathways, Jagged/Notch pathway, and the Wnt/β-catenin pathway are activated. These pathways mediate the EMT of RPE cells, which play a key role in the pathogenesis of PVR. This review summarizes the current body of knowledge on the polarized phenotype of RPE, the role of cell-cell contact, and the molecular mechanisms underlying the RPE EMT in PVR, emphasizing key insights into potential approaches to prevent PVR.
To increase continuing education accessibility, nurses around the world are turning to Web-based instruction. However, for Internet education to be successful, particularly in developing countries, nurses must have access to computers and the Internet as well as positive attitudes toward this form of learning. As part of a distance education project for nurses of the Tianjin Municipality in China, a survey of nurses was conducted to examine their sources of professional knowledge as well as their computer and Internet access and attitudes. The attitudes of the nurses were generally positive, and there was evidence of rapidly increasing use of and access to computers and the Internet. This article reports the results of that survey and their implications for Web-based teaching of Chinese nurses.
Background: A descriptive survey examined continuing education experiences of hospital nurses working in Tianjin Municipality, the third largest municipality in The People's Republic of China.
Method: Fourteen hospitals and two hundred nurses were selected randomly.
Results: Over two thirds of the nurses had attended continuing education events in the previous few years. Learning experiences included on-site and off-site workshops; associate degree courses; and teaching strategies of mostly lectures, films and videos. Major barriers discouraging nurses from participating included lack of time, cost, distance, and being denied permission to attend. Nurses working in rural and suburban hospitals reported less access to continuing education opportunities than nurses in urban hospitals. Ninety-six percent of respondents reported they had made changes in their clinical practice as a result of the continuing education activities.
Conclusion: Strategies to reduce barriers to continuing education and future research examining the impact of continuing nursing education on clinical practice in China need to be developed.
Community health nursing in China is an emerging specialty. A multi-component collaborative endeavor between the Schools of Nursing of Tianjin Medical University, China, and the University of Ottawa, Canada is described. This project, funded by the Canadian International Development Agency, commenced in 1989. It has laid the groundwork for an expanded role for community health nurses in Tianjin, a municipality of 11 million people located in Northeast China. The historical context for the evolution of community health nursing in China and the emergence of community health nursing as a priority area within the project are described. Major project activities are highlighted, illustrating several underlying principles for strengthening the educational preparation of baccalaureate nurses who can apply community health skills. These include creating a critical mass of faculty who can teach community health nursing, modelling classroom and clinical teaching of community health nursing, bridging the gap between nursing in the community and nursing, in the hospital, and developing a prototype for baccalaureate community health nursing experience. Lessons learned from this initiative are summarized.
Mesenchymal stem cells (MSCs) may be easily isolated from the bone marrow, and possess multi-lineage differentiation potential and various therapeutic applications. The differentiation of MSCs into osteoblasts is a complex process that is regulated by multiple internal and external factors. In the present study, the differentiation of MSCs isolated from rabbit bone marrow into osteoblasts using different osteoblast inductive media in the presence of dexamethasone, bone morphogenetic protein 2 (BMP-2), 1,25-dihydroxyvitamin D3, transforming growth factor β (TGFβ), platelet lysate and cyclooxygenase 2 (COX2), respectively. Alkaline phosphatase (ALP) activity, mineralization, collagen type (Ct) I and osteocalcin activities, and the mRNA and protein expression levels of vascular endothelial growth factor (VEGF), BMP-2 and Ct II were measured during the differentiation process in MSCs treated with different inducers. Rabbit MSCs were successfully isolated and were observed to be predominantly circular in shape after culture for 24 h. Following subculture for 5 days, the cells demonstrated a spindle shape. ALP, Ct I and osteocalcin activities were higher in cells cultured in dexamethasone, BMP-2 and TGFβ compared with the activities in control cells. Following differentiation, the dexamethasone, BMP-2 and TGFβ groups demonstrated significantly enhanced mineralization of MSCs detected by Alizarin Red S staining. The mRNA and protein expression levels of VEGF, BMP-2 and Ct II were significantly increased in the same groups compared with the levels in the control group. In conclusion, rabbit MSCs were successfully isolated from bone marrow and differentiated into osteoblasts indicated by raised ALP, Ct I and osteocalcin activities, mineralization and expression of osteogenesis-inducing genes and proteins. The present study revealed that dexamethasone, BMP-2 and TGFβ have a positive effect on cell differentiation.
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