Objective To study the protective effects of human umbilical cord-derived mesenchymal stem cells (ucMSCs)against severe acute pancreatitis (SAP) in rats.Methods A total of 135 Sprague-Dawley male rats were randomly divided into Sham group,SAP group and SAP+ucMSCs group (45 each).SAP+ucMSCs group:Severe acute pancreatitis was induced by injecting 5％ sodium taurocholate (0.1ml/100g) into the common bilio-pancreatic duct and then CM-DiI-labeled ucMSCs at 1 × 107cells/kg were injected via the tail vein.All the rats were sacrificed 12,24 and 72 hours after SAP.The 72h death rate was counted.Pathological changes in the pancrease were detected by HE staining and pathological score was graded,ucMSCs colonization was observed by fluorescence microscopy.The serum levels of amylase,lipase,TNF-α,IL-1β,IL-4 and IL-10 were determined by ELISA.Results ucMSCs colonize the injured area of pancreatic tissue,the 72h death rate was reduced,and the serum amylase and lipase were also reduced significantly.Moreover,ucMSCs significantly reduced the pathological score of the pancrea and the level of proinflammatory cytokines (TNF-α and IL-1β),but the levels of anti-inflammatory cytokines were increased (IL-4 and IL-10).Conclusion Transplantation of ucMSCs can reduce the severity of pancreatic injury and inflammation in SAP rats.

BACKGROUND: A few devices have been reported to be used for studies on trauma, but these devices are unavailable for establishing the animal models of trauma because of their limited application range. OBJECTIVE: To develop a multifunctional impact system and evaluate its application effect, thus paying ways for establishing the animal models of trauma and basic experiments.METHODS: The multifunctional impact system was designed based on the theory of energy storage device, simple multifunctional impact device and impact parameter measuring equipment, and its effectiveness and stability were detected. The rat chest and different visceral organs were subjected to the closed impact experiment using a 5 cm2 impact at the predetermined parameter of 200, 300, 400, 500 kPa, respectively. Afterwards, the rats were sacrificed for morphological observation.RESULTS AND CONCLUSION: The multifunctional impactor was successfully developed, of which the maximum impact stress could be adjusted from 0 to 200 kg and compressive and extrusion stress also could be continuously adjusted from 0 to 100 kg. The experimental results showed that the impactor made certain damage to the rat lung, liver and spleen suggesting its favorable effectiveness (P < 0.05) and repeatability (P > 0.05). These findings suggest that the impactor is easy to operate in various ways and holds good effectiveness and stability, and its impact parameters can be detected in real time. Therefore, the impactor is suitable for both establishing the animal model of trauma and basic experiments.

Nitric oxide synthase (NOS) is a key enzyme for production of nitric oxide (NO) in vivo.With the deepening of study on biochemical and molecular characteristics of NOS,the intervention of NOS-NO pathway playing an important role in gastrointestinal motility disorder is appreciated.This article reviewed the progress of research on relationship between neuronal nitric oxide synthase (nNOS) and gastrointestinal motility disorders.