METHODS: Cardiac organoids derived from the self-assembled human induced pluripotent stem cells were constructed by regulating the Wnt signaling pathway. Flow cytometry was used to detect the proportion of cardiomyocytes in the cardiac organoids, and RT-qPCR was employed to detect the mRNA expressions. Immunofluorescence staining was used to detect the protein expressions of TNNT2, CD31, and vimentin. The beating amplitude of the cardiac organoids was determined with calcium transient. In vitro myocardial injury models and ischemia-reperfusion models were established, and the cell injuries were examined using Masson staining. TUNEL staining and calcium transient detection were used to evaluate the adverse effects of doxorubicin and trastuzumab in the cardiac organoids. RESULTS: The cardiac organoids began to beat on the 8th day of culture and consisted of 32.4% cardiomyocytes with high expressions of the myocardial markers TNNT2, NKX2.5, RYR2 and KCNJ2. No significant differences in morphological size, beating frequency, proportion of cardiomyocytes, or myocardial contractility were observed in the cardiac organoids differentiated from different batches. These cardiac organoids could be maintained in in vitro culture conditions for at least 50 days. Captopril treatment could obviously alleviate liquid nitrogen-induced myocardial injury in the cardiac organoids. Hypoxia/reoxygenation induced ischemia-reperfusion injury and promoted myocardial fibrosis and apoptosis in the cardiac organoids. Treatment with doxorubicin for 24 h resulted in significantly increased cell death and reduced beating frequency and cell viability in the cardiac organoids in a dose-dependent manner. Trastuzumab significantly impaired the contractile and calcium handling abilities of the cardiac organoids. CONCLUSIONS Cardiac organoids derived from human induced pluripotent stem cells have been successfully constructed and can be used for cardiac disease modeling and drug evaluation.
Humans ; Induced Pluripotent Stem Cells/cytology* ; Organoids/cytology* ; Myocytes, Cardiac/cytology* ; Cell Differentiation ; Heart Diseases

Objective:To investigate the training willingness of nursing management qualification certification of hospital nursing managers, so as to provide reference for relevant departments and personnel.Methods:The convenient sampling was used to conduct a self-designed questionnaire survey on nursing managers and training intentions of nursing management qualification certification in secondary and above hospitals in Beijing from March 2019 to January 2020, and its influencing factors were analyzed. In this study, 100 questionnaires were distributed in the pre-experiment, and 98 valid questionnaires were recovered, with an effective recovery rate of 98.0%. During the formal study, 930 questionnaires were distributed and 920 valid questionnaires were recovered, with an effective recovery rate of 98.9%.Results:A total of 920 nurse managers were investigated. Only 212 (23.0%) managers mastered or were proficient in nursing management, and most of them were greater than or equal to 35 years old (χ 2=12.326, P<0.01) , worked for more than 20 years (χ 2=22.376, P<0.01) , and chief head nurse or above position levels (χ 2=7.079, P=0.008) . 722 (78.5%) managers were in great demands of nursing management knowledge, especially those under the age of 35 (χ 2=4.064, P=0.044) , with bachelor 's degree or above levels (χ 2=4.520, P=0.033) , working within 20 years (χ 2=9.332, P=0.002) , and chief head nurse or above position levels (χ 2=5.499, P=0.019) . 879 (95.5%) managers were willing to participate in nursing management qualification certification training, especially those with a bachelor 's degree or above levels (χ 2=6.372, P=0.012) and worked within 20 years (χ 2=18.174, P<0.001) . Conclusions:Hospital nursing managers, especially those with low seniority, have high demand for nursing management knowledge and desire for qualification certification training. Nursing management qualification certification training courses should be set up scientifically, ensure quality and authority and be appropriately adjusted according to the training objects.

OBJECTIVE: To establish an HPLC method for the determination of chloramphenicol content in chloramphenicol vaginal soft capsule.METHODS: The sample was separated on Kromasil C18 column with 0.1% sodium heptanesulfonate solution-acetonitrile(77∶23) as mobile phase at a flow rate of 1.0 mL?min-1.The detection wavelength was set at 272 nm;The sample size was 10 ?L and the column temperature was maintained at 30 ℃.RESULTS: The linear range of chloramphenicol was 0.079～0.113 mg?mL-1(r=0.999 6) and its average recovery rate was 99.38%(RSD=0.42%).CONCLUSION: The method was proved to be specific,sensitive,accurate in results and suitable for the determination of chloramphenicol content in chloramphenicol vaginal soft capsule.