BACKGROUND:To date, it is stil unclear whether the intramuscular injection of heterogeneous umbilical cord mesenchymal stem cel s (UC-MSC) can cause cardiac ectopic pathological angiogenesis as wel as increase col agen synthesis to promote myocardial fibrosis. OBJECTIVE:To explore the effects of intramuscular injection of human UC-MSCs on myocardial micrangium and col agen expression in normal Wistar rats. METHODS:After 2 weeks of feeding, 60 male SPF Wistar rats were randomly assigned to receive intramuscular injection of PBS (normal group), DMEM (culture medium group), human UC-MSCs supernatant (supernatant group), 0.25×105, 1.0×105, 4.0×105 human UC-MSCs (low-, moderate-and high-dose groups), respectively (n=10 per group). Al the rats were subjected to second injection (same dose) at 4 weeks after first intramuscular injection. Then, the rats were kil ed under anesthesia at 4 weeks after second injection, to take heart tissues from the left ventricle for pathological observation, immunohistochemical examination and Masson staining. RESULTS AND CONCLUSION:No alteration of the response, activity, victualage, faeces, weight growth, and fur was found, and there was no death in rats during the experiment. Al the rats had no symptoms of molt, inflammation, skin ulcer, scleroma. Strong positive expression of CD34 for the micrangium in the myocardial tissue was observed, and positive expression of the col agen in the myocardial tissue observed by Masson staining. There were no significant differences in the microvessel density and col agen expression in the myocardium among the groups (F=0.110 and 0.585, P>0.05). To conclude, hUC-MSCs or its supernatant via intramuscular injection has no effect on the micrangium and col agen expression in normal rats.

Objective:To introduce a surgical method and clinical effect of using Masquelet technique combined with skin graft to cover chronic refractory wounds in elderly patients.Methods:From September 2020 to September 2022, 20 elderly patients with wounds of bone or tendon exposure in lower limbs were treated in the Department of Wound Repair, the Second Affiliated Hospital of Wenzhou Medical University. Due to the age and poor general condition of the patients, flap transfer for wound coverage were not allowed. Masquelet technique was therefore applied in the treatment of chronic wounds of such patients. Sizes of wounds were found at 4.5 cm×3.0 cm to 15.0 cm×6.0 cm and all accompanied with tendon and bone exposure, after thorough debridement. Wounds were then sealed with antibiotic bone cement several times. After having induced formation of membrane in wounds, free mesh skin graft was used to cover the refractory wounds. The patients were entered in follow up regularly after surgery at outpatient service, and telephone or video reviews. The wound healing of patients and whether there were related complications in the skin donor area were observed. The number of operation times in the first stage was 1-4 with an average of 1.3 times ± 0.7 times. Lower Extremity Function Scale (LEFS) was used to evaluate the recovery of lower limb function.Results:All 20 wounds healed well. The follow-up time was 3-12 months, with an average of 7.6 months. The appearance and texture of the skin in the wounds area were satisfactory. The mean LEFS was 69.83 point ± 10.82 point.Conclusion:Using Masquelet technique combined with free skin grafting to treat refractory wounds in the elderly patients can achieve satisfactory clinical outcomes. It is a simple and reliable supplement to the wound repair, and can reduce the surgical risk.

Objective: To survey the conduction and evaluate the effectiveness of extracorporeal membrane oxygenation (ECMO) therapy in pediatric intensive care unit (PICU) in China mainland. Methods: In a questionnaire-based survey, we retrospectively reviewed the application of ECMO in children's hospital and general hospital in China mainland to summarize and analyze the categories of diseases and prognosis of children treated with ECMO therapy. Results: By December 31, 2017, a total of 23 hospitals using ECMO, including 22 tertiary referral hospitals and 1 secondary hospital, among which 16 were children′s hospitals and 7 were general hospitals. Thirty-seven ECMO equipment was available. A total of 518 patients treated with ECMO, within whom 323 (62.4%) successfully weaned from ECMO and 262 (50.6%) survived to discharge. Among 375 pediatric patients, 233 (62.1%) were successfully weaned from ECMO and 186 (49.6%) survived to discharge. Among 143 newborn patients, 90 (62.9%) successfully weaned from ECMO, 76 (53.1%) survived to discharge. ECMO was applied in veno-arterial (VA) mode to 501 (96.7%) patients, veno-venous (VV) mode to 14 (2.7%) patients, and VV-VA conversion mode to 3 (0.6%) patients. Sixty-nine patients required extracorporeal cardiopulmonary resuscitation (ECPR), including 20 newborn patients (29.0%) and 38 pediatric patients (71.0%), who were all with cardiovascular disease. Neonatal respiratory distress syndrome (26/61), persistent pulmonary hypertension of the newborn (PPHN) (12/61), and meconium aspiration syndrome (MAS) (11/61) are the most common pulmonary diseases in newborn patients; among whom, infants with PPHN had highest survival rate (10/12), followed by MAS (9/11). Among newborn patients with cardiovascular diseases, those who admitted were after surgery for congenital cardiac disease were the most common (54/82), while those with septic shock had the highest survival rate (2/3). In pediatric pulmonary diseases, acute respiratory distress syndrome was the most common (42/93), while plastic bronchitis was with the highest survival rate (4/4), followed by viral pneumonia (13/16). Among pediatric cardiovascular diseases, congenital cardiac defect was the most common (124/282), while fulminant myocarditis had the highest survival rate (54/77). Conclusion The application of ECMO as a rescue therapy for children with severe cardiopulmonary failure has dramatically developed in China mainland.