Pressure ulcers remain a challenge in clinical nursing. A new risk assessment model of pressure ulcers that is applicable to surgical patients is highly recommended.

Cancer stem cells are considered as the cell population which is responsible for chemoresistance and treatment failure in breast cancer patients. Therefore, it is urgent to explore the mechanism by which cancer stem cells survive under the treatment of chemotherapeutic drugs such as cisplatin. In this paper, we demonstrated significant decrease of miR-519d in breast cancer stem cells by quantitative RT-PCR analysis. Furthermore, we found the enforced expression of miR-519d in T-47D-cancer stem cells significantly increased their sensitivity to cisplatin through the apoptosis pathway. In addition, the gene of MCL-1, which is a member of pro-apoptotic Bcl-2 family, was found to be the target of miR-519d in T-47D-cancer stem cells. Our date demonstrated that enforced miR-519d expression enhanced the cisplatin-induced apoptosis through the MCL-1 dependent mitochondria pathway in breast cancer stem cells. Taken together, the present study suggests that miR-519d reduces chemoresistance in breast cancer stem cells, and understanding of miR-519d may be helpful for increasing the efficacy of chemotherapy.

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The expression of transgenes in mammalian cells is often at a low level mainly due to position effects from the neighboring chromatin context. To improve this, we have constructed a vector pCAM, which contains chloramphenicol acetyltransferase (CAT) reporter gene cassettes, driven by SV40 early promoter and flanked by two human beta-globin MARs in cis. We transfected this vector into the Chinese hamster ovary (CHO) cell line, and found that the level of CAT gene expression with MAR was effectively increased, about 5.493-fold higher than those without MARs. Moreover, the variations of CAT expression among individuals of transformants were decreased 2.670-fold. Our result also showed that MAR could increase the proportion of positive colonies in recombinants.