RESUMEN
A deeper understanding of the detailed mechanism of in vivo tissue healing is necessary for the development of novel regenerative therapies. Among several external factors, environmental pH is one of the crucial parameters that greatly affects enzyme activity and cellular biochemical reactions involving tissue repair and homeostasis. In this study, in order to analyze the microenvironmental conditions during bone healing, we first measured the pH in vivo at the bone healing site using a high-resolution fiber optic pH microsensor directly in femur defects and tooth extraction sockets. The pH was shown to decrease from physiological 7.4 to 6.8 during the initial two days of healing (inflammatory phase). In the same initial stages of the inflammatory phase of the bone healing process, mesenchymal stem cells (MSCs) are known to migrate to the healing site to contribute to tissue repair. Therefore, we investigated the effect of a short-term acidic (pH 6.8) pre-treatment on the stemness of bone marrow-derived MSCs (BMSCs). Interestingly, the results showed that pre-treatment of BMSCs with acidic pH enhances the expression of stem cell markers (OCT-4, NANOG, SSEA-4), as well as cell viability and proliferation. On the other hand, acidic pH decreased BMSC migration ability. These results indicate that acidic pH during the initial stages of bone healing is important to enhance the stem cell properties of BMSCs. These findings may enable the development of novel methods for optimization of stem cell function towards tissue engineering or regenerative medicine.
Asunto(s)
Ácidos/farmacología , Regeneración Ósea/genética , Osteogénesis/efectos de los fármacos , Ingeniería de Tejidos/métodos , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Regeneración Ósea/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Microambiente Celular/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno/efectos de los fármacos , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones , Proteína Homeótica Nanog/genética , Factor 3 de Transcripción de Unión a Octámeros/genética , Medicina Regenerativa , Antígenos Embrionarios Específico de Estadio/genética , Células Madre/citología , Células Madre/efectos de los fármacos , Cicatrización de Heridas/genéticaRESUMEN
Studies of physician-nurse relationships have focused mainly on nurses' perceptions. Few studies have explored physicians' perceptions and related factors. This study had two aims: to describe physicians' perceptions of physician-nurse collaboration in Japan by focusing on attitudes toward collaboration and collaborative practice and to examine the effect of physicians' experiences related to collaboration on their perceptions of collaboration. A cross-sectional survey was conducted. Of the 520 physicians from four hospitals, 248 completed the survey. The survey included the Jefferson Scale of attitudes toward physician-nurse collaboration, the collaborative practice scales, learning experiences related to collaboration with nurses and experiences of joint activities with nurses. Multiple regression analysis revealed that learning experiences in undergraduate and out-of-hospital education and experiences of joint committee work were significantly associated with higher collaborative practice scores. Although participants' attitude scores had a strong association with practice scores, there were no variables significantly associated with the attitude score. This study supported the importance of education in undergraduate courses and suggested that it should be ongoing after qualification. Joint activities other than daily practice, such as continuous quality improvement, might also be effective. Factors that improve physicians' attitudes toward collaboration should be further explored.
