BACKGROUND:Human umbilical cord mesenchymal stem cel s are considered as novel seed cel s in bone tissue engineering. Cryopreservation is an effective method for storing cel s for a long time.
OBJECTIVE:To explore whether umbilical cord mesenchymal stem cel s of cryopreservation could be induced to differentiated into osteoblasts.
METHODS:Mesenchymal stem cel s were isolated from the Wharton’s jel y of human umbilical cord tissue by the tissue explant adherent method. Morphology of primitive cel s was observed by inverted microscopy. Immunophenotypes and cel cycle of umbilical cord mesenchymal stem cel s were measured using flow cytometry. After frozen storage for 6 months, the second passage of umbilical cord mesenchymal stem cel s was thawed and subcultured to passage 12. Upon induction with osteogenic inductive medium, the osteogenic ability of passage 12 of umbilical cord mesenchymal stem cel was evaluated by alkaline phosphatase activity, the immunofluorescent analysis of osteocalcin and bone sialoprotein and the assay of alizarin red staining separately.
RESULTS AND CONCLUSION:Primary umbilical cord mesenchymal stem cel s displayed a typical fibroblast-like morphology. Flow cytometry showed that the cultured cel s expressed high levels of the mesenchymal stem cel s surface markers CD73, CD105 and CD90, but did not express hematopoietic cel s surface markers CD34 and CD45. The survival rate of umbilical cord mesenchymal stem cel s after resuscitation was 90%. The cel cycle analysis indicated that 75%of the cel s of passage 8 were in G 0/G 1 phase and 25%in S+G 2 M phase. Passage 12 cel s treated with osteogenic inductive medium displayed a higher alkaline phosphatase activity compared with control cel s (P<0.01). Moreover, the cel s, induced in osteogenic inductive medium, were positive for osteocalcin and bone sialoprotein staining and formed the mineralized nodules. Umbilical cord mesenchymal stem cel s stil maintain their biological characteristics after cryopreservation, and can be induced into osteoblasts with osteogenic inductive medium.

Objective To investigate the feasibility and efifcacy of endoscopic submucosal dissection (ESD) for gastrointestinal neuroendocrine neoplasms (GI-NENs).Methods 52 patients with conifrmed histological diagnosis of GI-NENs performed ESD from January 2011 to December 2015 were included. The endoscopic morphology of tumor was summarized. Complete resection rate, complications, clinicopathological characteristics, and follow-up results were evaluated.Results There were 16 cases of stomach, 9 cases of colon and rectum 27 cases. Most of the lesions were submucosal uplift. A few of lesions looked like polyps. All the lesions were one-time whole diseased. 44 lesions were NET-G1, 8 lesions were NET-G2. Complete resection rate was 94.23%. 2 cases of rectal lesions infringemented intrinsic muscle layer, and got additional surgery. 1 case of rectal perforation, which was managed by endoscopic treatment and conservative treatment. All cases did not appear haemorrhage. During a mean follow-up period of 22.6 months, local recurrences occurred in 1 case of stomach, and treated with second line ESD. No cases lymph node and distant metastasis were found.Conclusion ESD appears to be a feasible, safe and effective treatment for GI-NENs with strict endoscopic treatment indications.

Objective:To analyze the risk factors for severe acute pancreatitis (SAP) complicated with infection and the effects on immune level.Methods:A total of 150 SAP patients admitted to Deyang People′s Hospital from February 2018 to April 2019 were divided into the infected group ( n=90) and the uninfected group ( n=60) according to whether SAP was complicated with infection or not; the changes of pathogenic bacteria in the infection focus, infection risk factors, blood inflammatory cytokines levels and T-lymphocyte subgroups were analyzed. Results:A total of 105 pathogenic bacteria were detected in 90 SAP patients with infection, among which 74(70.5%) were gram-negative bacteria, mainly escherichia coli, klebsiella pneumoniae and pseudomonas aeruginosa. There were 27 strains (25.7%) of gram-positive bacteria, mainly staphylococcus aureus, and 4 strains (3.81%) of fungi. Biliary causes, total parenteral nutrition time≥1 week, APACHEⅡ score≥11, surgical intervention, and respiratory mechanical ventilation were all independent factors for SAP infection (all P<0.05). At 24 hours after onset, blood IL-4(59.1±6.2)ng/L, IL-6(134.1±12.2) ng/L, IL-10(146.4±13.2)ng/L, TNF-ɑ(76.3±5.2)ng/L in infected group were all significantly higher than those in the uninfected group (all P values <0.05); at 30 days after the onset, blood IL-4(33.6±5.8)ng/L, IL-6(49.2±6.8)ng/L of the infected group, IL-10(80.7±8.8)ng/L, TNF-ɑ(28.7±5.5)ng/L in infected group were significantly lower than those in the uninfected group (all P values <0.05). At 24 hours after onset, the proportion of CD 4+ T lymphocytes in the infected group was significantly higher than that in the uninfected group [(45.3±5.5)% vs (32.3±5.2)%], and the proportion of CD 8+ T lymphocytes was significantly lower than that in the uninfected group [(20.6±4.2)% vs (29.7±4.8)%]; at 30 days after onset, the proportion of CD 4+ T lymphocytes in the infected group was significantly lower than that in the uninfected group [(21.6±3.7)% vs (40.2±2.5)%], and the proportion of CD 8+ T lymphocytes was significantly higher in the uninfected group [(48.4±4.1)% vs (32.8±4.0)%]; and all the differences were statistically significant (all P <0.05). Conclusions:The strains of concurrent infection with SAP were mainly gram-negative bacteria. Biliary causes, total parenteral nutrition time, surgical intervention and respiratory mechanical ventilation were all risk factors for concurrent infection with SAP. SAP infection may cause excessive inflammatory response and lead to immune cell damage, which should be paid attention to in clinical treatment.