Mesenchymal Stem Cell-Derived Exosomes are Effective for Radiation Enteritis and Essential for the Proliferation and Differentiation of Lgr5+ Intestinal Epithelial Stem Cells by Regulating Mir-195/Akt/ß-Catenin Pathway.

BACKGROUND: Radiation enteritis (RE) is a common complication of abdominal or pelvic radiotherapy, which when severe, could be life-threatening. Currently, there are no effective treatments. Studies have shown that mesenchymal stem cells (MSCs)-derived exosomes (MSC-exos) exhibit promising therapeutic effects in inflammatory diseases. However, the specific role of MSC-exos in RE and the regulatory mechanisms remain elusive. METHODS: In vivo assay was carried out by injecting MSC-exos into the total abdominal irradiation (TAI)-induced RE mouse model. For in vitro assay, Lgr5-positive intestinal epithelial stem cells (Lgr5+ IESC) were extracted from mice, followed by irradiation along with MSC-exos treatment. HE staining was performed to measure histopathological changes. mRNA expression of inflammatory factors TNF-α and IL-6 and stem cell markers LGR5, and OCT4 were quantified by RT-qPCR. EdU and TUNEL staining was performed to estimate cell proliferation and apoptosis. MiR-195 expression in TAI mice and radiation-induced Lgr5+ IESC was tested. RESULTS: We found that the injection of MSC-exos inhibited inflammatory reaction, increased stem cell marker expression, and maintained intestinal epithelial integrity in TAI mice. Furthermore, MSC-exos treatment increased the proliferation and simultaneously suppressed apoptosis in radiation-stimulated Lgr5+ IESC. MiR-195 expression increased by radiation exposure was decreased by MSC-exos therapy. MiR-195 overexpression facilitated the progress of RE by counteracting the effect of MSC-exos. Mechanistically, the Akt and Wnt/ß-catenin pathways inhibited by MSC-exos were activated by miR-195 upregulation. CONCLUSION: MSC-Exos are effective in treating RE and are essential for the proliferation and differentiation of Lgr5+ IESCs. Moreover, MSC-exos mediates its function by regulating miR-195 Akt ß-catenin pathways.

Proposal and Efficacy of a Nurse-Led Pain Management Model for Neurointensive Care Based on the Precede-Proceed Model.

Objective: This study's objective is to establish a nurse-led pain management model for neurointensive care based on the Precede-Proceed model to provide a theoretical basis for clinical pain management in neurointensive care. Methods. ICU nurses were randomly divided into a control group (giving conventional routine pain care) and an experimental group (managed pain based on the Precede-Proceed model). The nurses from the experimental group were trained in the Precede-Proceed-based management. The nurses then treated a total of 410 critically ill patients, and the patients were randomly divided into a control and an intervention group (205 cases/nursing group), and the data were prospectively recorded. Before and after the intervention, the pain assessment ability, discomfort level, satisfaction degree, usage of the analgesic drug, and the incidence of delirium of the patients from the two groups were evaluated. Nurses from both groups also assessed their knowledge of pain, attitude, and pain nursing behaviors using indicated self-designed questionnaires. Results: Before the intervention, there was no statistical difference between the two groups of nurses in their baseline characteristics, pain knowledge, attitude, pain nursing behavior, and pain assessment ability for the patients. After the intervention, the nurses in the experimental group had better pain knowledge, attitude, pain nursing behavior, and pain assessment ability to patients than the nurses in the control group. Patients in the intervention group felt less discomfort, a higher satisfaction degree, reduced use of analgesics, and a lower incidence of delirium than patients in the control group. Conclusion. Pain management based on the Precede-Proceed model was beneficial in improving the care of neurointensive patients.

Application of Dynamic Enhanced Magnetic Resonance Imaging in the Diagnosis of Hematological Malignancies.

The use of dynamic enhanced magnetic resonance imaging technology can effectively explore the diagnosis and clinical application of hematological malignancies. This paper selected 60 patients with hematological malignancies from 2015 to 2019; all of whom were diagnosed with hematological malignancies, including 40 men and 20 women, aged between 40 and 77 years. The main clinical manifestations of the patient are hematological malignancies, fever, and other symptoms. We used Siemens 3.0T to perform MRI and dynamic enhanced MRI examinations on 30 patients with hematological tumors. The PACS system was used to collect and organize clinical data. All patients were pathologically confirmed and clinically diagnosed with hematological malignancies. Based on the clinical data of the patients, retrospective analysis and summary were conducted and the clinical manifestations of hematological malignancies were discussed. The results showed that the diagnostic accuracy of 30 cases of dynamic enhanced MRI was 100%, while the diagnostic accuracy of ordinary MRI was lower than that of dynamic enhanced MRI, P < 0.05, and the difference was statistically significant. In addition, compared with dynamic enhanced MRI and MRI, P > 0.05, the difference was not statistically significant. Therefore, the application of dynamic enhanced MRI in the diagnosis of hematological malignancies is valuable.