Objective·To investigate the immunotherapeutic effects of exosomes derived from leukemia cells with high expression of B7 molecules(co-stimulatory molecules CD80 and CD86)in tumor-bearing mice.Methods·L1210 leukemia cells were transfected with lentiviral vectors containing the CD80 and CD86 genes,and thereby the leukemia cells with high expression of CD80 and CD86 molecules were obtained.Exosomes LEX-8086 with high expression of CD80 and CD86 molecules were then isolated from the culture supernatant.The biological characteristics of LEX-8086 were analyzed by using transmission electron microscopy(TEM)and Western blotting.A DBA/2-leukemia tumor-bearing mouse model was established.The tumor-bearing mice were divided into LEX-8086 group and PBS group.The LEX-8086 group received intravenous injections of 500 μL LEX-8086(150 μg/mL)via the tail vein 7 d and 12 d after tumor cell inoculation,while the PBS group received injections of equal volumes of PBS at the same time points.Differences in body weight,tumor volume,tumor mass,and survival of the mice between the two groups were observed.Flow cytometry was used to analyze the changes in the immune cells in spleens and lymph nodes of the mice in both groups.Western blotting and real-time fluorescent quantitative PCR(qPCR)were used to detect the expression of markers for M1 and M2 macrophages in the spleens of the mice in both groups.Results·The exosomes LEX-8086 were isolated from the supernatant of L1210 cells overexpressing CD80 and CD86 molecules.TEM revealed that LEX-8086 exhibited a disc-shaped vesicular structure with a diameter of approximately 100 nm.Western blotting demonstrated the expression of exosome-specific markers.In the animal experiments,compared with the PBS group,the body weight of the LEX-8086 group showed no significant change,while both the tumor volume and the relative tumor mass ratio decreased significantly,and the survival was significantly prolonged(all P<0.05).Flow cytometry results indicated that the proportions of natural killer(NK)cells and CD4+T cells in the lymph nodes and spleens of the LEX-8086 group significantly increased(all P<0.05);as for CD8+T cells,they only increased in the lymph modes(P=0.012).Moreover,flow cytometry results showed that the proportion of M1 macrophages in the spleens of mice in the LEX-8086 group was significantly elevated(P=0.003),while the proportion of M2 macrophages remained unchanged.Western blotting and qPCR also revealed that the mRNA and protein expression levels of M1 macrophage markers interleukin-6 and tumor necrosis factor-α in the spleens of mice in the LEX-8086 group increased significantly(all P<0.05).Conclusion·Exosomes derived from leukemia cells with high expression of co-stimulatory molecules CD80 and CD86 can induce a therapeutic anti-leukemic effect,which may be achieved by increasing the proportions of NK cells,M1 macrophages,CD4+T cells,and CD8+T cells.

Objective·To investigate the immunotherapeutic effects of exosomes derived from leukemia cells with high expression of B7 molecules(co-stimulatory molecules CD80 and CD86)in tumor-bearing mice.Methods·L1210 leukemia cells were transfected with lentiviral vectors containing the CD80 and CD86 genes,and thereby the leukemia cells with high expression of CD80 and CD86 molecules were obtained.Exosomes LEX-8086 with high expression of CD80 and CD86 molecules were then isolated from the culture supernatant.The biological characteristics of LEX-8086 were analyzed by using transmission electron microscopy(TEM)and Western blotting.A DBA/2-leukemia tumor-bearing mouse model was established.The tumor-bearing mice were divided into LEX-8086 group and PBS group.The LEX-8086 group received intravenous injections of 500 μL LEX-8086(150 μg/mL)via the tail vein 7 d and 12 d after tumor cell inoculation,while the PBS group received injections of equal volumes of PBS at the same time points.Differences in body weight,tumor volume,tumor mass,and survival of the mice between the two groups were observed.Flow cytometry was used to analyze the changes in the immune cells in spleens and lymph nodes of the mice in both groups.Western blotting and real-time fluorescent quantitative PCR(qPCR)were used to detect the expression of markers for M1 and M2 macrophages in the spleens of the mice in both groups.Results·The exosomes LEX-8086 were isolated from the supernatant of L1210 cells overexpressing CD80 and CD86 molecules.TEM revealed that LEX-8086 exhibited a disc-shaped vesicular structure with a diameter of approximately 100 nm.Western blotting demonstrated the expression of exosome-specific markers.In the animal experiments,compared with the PBS group,the body weight of the LEX-8086 group showed no significant change,while both the tumor volume and the relative tumor mass ratio decreased significantly,and the survival was significantly prolonged(all P<0.05).Flow cytometry results indicated that the proportions of natural killer(NK)cells and CD4+T cells in the lymph nodes and spleens of the LEX-8086 group significantly increased(all P<0.05);as for CD8+T cells,they only increased in the lymph modes(P=0.012).Moreover,flow cytometry results showed that the proportion of M1 macrophages in the spleens of mice in the LEX-8086 group was significantly elevated(P=0.003),while the proportion of M2 macrophages remained unchanged.Western blotting and qPCR also revealed that the mRNA and protein expression levels of M1 macrophage markers interleukin-6 and tumor necrosis factor-α in the spleens of mice in the LEX-8086 group increased significantly(all P<0.05).Conclusion·Exosomes derived from leukemia cells with high expression of co-stimulatory molecules CD80 and CD86 can induce a therapeutic anti-leukemic effect,which may be achieved by increasing the proportions of NK cells,M1 macrophages,CD4+T cells,and CD8+T cells.

Liver is the most common metastatic site for colorectal cancer (CRC), there is no satisfied approach to treat CRC liver metastasis (CRCLM). Here, we investigated the role of a polycomb protein BMI-1 in CRCLM. Immunohistochemical analysis showed that BMI-1 expression in liver metastases was upregulated and associated with T4 stage, invasion depth and right-sided primary tumor. Knockdown

Objective:To construct a scientific and practical micro-course content framework of cross-cultural nursing hospice care from the perspective of attention, relevance, confidence and satisfaction (ARCS) model.Methods:The research team was established in November 2018. Using Delphi method, 16 experts in cross-cultural nursing, hospice care, nursing management, nursing education and other fields were consulted for 3 rounds of correspondence. According to scores of experts, the index weights were calculated to form micro-course content framework of cross-cultural nursing hospice care from the perspective of ARCS model.Results:The positive coefficient of experts surveyed by the questionnaire was 100%, the average value of expert authority coefficient was 0.81. The determined importance values of the first and second level indexes were all greater than 4.00. The coefficient of variation was 0 to 0.12, which were all less than 0.25 and met the requirements. In the end, a content framework containing 3 first-level indexes of professional concepts, professional knowledge and professional skills and 19 second-level micro-course content framework of cross-cultural nursing hospice care were formed.Conclusions:Based on the perspective of ARCS model, the construction process of content framework of the cross-cultural nursing hospice care micro-course is scientific and the setting is reasonable, which has a good guiding significance for the development of training for hospice care nurses.

Objective To investigate the application of 3D-printing and digital technology in the preoperative design of internal fixation for intra-articular calcaneal fractures.Methods Thin-layer CT images of bilateral calcanei were collected from 12 patients who had been treated for calcaneal fracture of Sanders type Ⅲ from November 2015 to October 2016.They were 7 men and 5 women,aged from 23 to 53 years (average,38.7 years).The images were uploaded into Mimics software for 3D reconstruction,virtual reduction and digital surgical design.Real-size calcaneal models and navigation modules were produced using 3D printing technology for plate preshaping and surgical simulation.The operations were carried out according to preoperative design.The postoperative calcaneal morphological parameters were evaluated.Comparisons were made between postoperative results and preoperative digital design.Results The operating time for the 12 patients ranged from 60 to 90 minutes,averaging 77.9 minutes.Their follow-ups ranged from 4 to 8 months,averaging 6.2 months.No complications affecting their soft tissues happened.The postoperative B(o)hler angle (32.6° ± 3.6°) and Gissane angle (123.9° ± 9.5°) were significantly improved compared with the preoperative values (12.4° ± 2.1° and 143.9° ± 7.8°) (P ＜ 0.001).The shape of postoperative calcaneus was similar to that of the preoperative reduction model.The internal fixation locations and nail directions were in agreement with the preoperative design.Their average Maryland score was 87.8 and excellent to good rate 91.7％.Conclusion This technique can transform a digital design for intra-articular calcanealfracture into real operation tools to help realize a precise surgical design for such fractures.