BACKGROUND: The relationship between cellular morphosis and function is undetachable, but there is little investigation about ultrastructure of human umbilical cord mesenchymal stem cells (hUCMSCs).OBJECTIVE: To study the relationship between the functions of hUCMSCs and their ultrastructure obtained by atomic force microscope (AFM). METHODS: hUCMSCs were isolated, cultured, expanded after enzyme digestion. P3 cells were observed under AFM. Immunophenotype and cell cycle were analyzed by flow cytometry, as well as induction of the adipogenic, osteogenic differentiation of hUCMSCs were identified using Oil red O staining and alkaline phosphatase staining. RESULTS AND CONCLUSION: hUCMSCs at passage 3 were strongly positive for CD44 and CD29, weakly positive for CD106, but negative for hematopoietic marker CD34. Cells in G_0/G_1 phase accounted for 80%. Proliferation index was 19.9%. Following adipogenic induction, alkaline phosphatase staining demonstrated brown cytoplasm in cube and polygonal cells. AFM showed hUCMSCs were spindle shape, obvious cytoskeletal filament that connected into nets, which fit for the strong capacities for proliferation, migration and differentiation.

Objective:To investigate the enhancing effect of bone marrow stroma cell(BMSC)on the functional recovery of injured spinal cord by observing the formation of gliotic scar,cavity volume and the cascade of apoptosis of neural cells.Methods:Eighty spinal cord injury(SCI)rat models were made and randomly divided into two groups:group A(n=40),the control group without any treatment;group B(n=40),the injured animals treated with BMSC implantation.The behavioral evaluation was performed using Basso,Beattie and Bresnahan(BBB)scoring system.Scores were recorded at time points of 1,2,4,6 and 8 weeks after transplantation.After 8 weeks,rats were sacrificed.The immunoreactivity of Nogo-A,glial fibrillary acidic protein(GFAP)and the cavity area were measured.The cell apoptosis was detected by TUNEL methods at 1,2,3,7 and 14 days after injury.Results:Compared with control group,treated animals gained higher scores after 8 weeks of transplantation.The number and the size of reactive astrocytes,the average volume of cavity,TUNEL positive cells,the expression of Nogo-A and GFAP reduced significantly in group B compared with those of group A(P＜ 0.05).Conclusion:BMSC possess effects on repairing injured spinal cord and promoting functional recovery through various mechanisms.

Objective:To investigate the effect of smoking on surgical site infection (SSI) after spinal surgery, and to provide evidence-based information for preventing the occurrence of SSI after spinal surgery.Methods:Literature searches were independently conducted in PubMed, EMBASE, CNKI, Wanfang and other databases from January 2000 to June 2020 by two researchers. Stata13.0 software was used to analyze the included literatures. Statistical analysis and subgroup analysis were preformed based on different population, research types, and adjustments.Results:44 literatures were finally included, involving 79 601 samples including 3 016 cases in the infected group. Compared with non-smokers, the combined odds ratio ( OR) of SSI in smokers after spinal surgery was 1.45 (95% CI: 1.25~1.68). The results of subgroup analysis showed that the risk of SSI in the yellow population and smokers after spinal surgery was 1.69 times that of the control group (95% CI: 1.35~2.12), and no such association was found in the white population. Smokers in the case-control studies and cohort studies had a higher risk of SSI after spinal surgery than that of the control group. Regardless of whether the effect size was adjusted, smokers had a higher risk of SSI after spinal surgery than that of the control group. Conclusions:This study has the advantages of using the latest data, including more literature, and analyzing ethnicity for the first time. The results show that smokers have a higher risk of SSI after spinal surgery. Clinically, patients should be encouraged to quit smoking to reduce the risk of SSI after spinal surgery. However, when to quit smoking to achieve the maximum benefit still needs further research.

Objective:To evaluate the protective effect of pressure-controlled volume-guaranteed ventilation (PC-VG) combined with dexmedetomidine on the lung of pediatric patients undergoing laparoscopic surgery.Methods:Forty-eight pediatric patients of either sex, aged 2-6 yr, weighing 8-21 kg, scheduled for elective laparoscopic pyeloplasty, were divided into 3 groups ( n=16 each) using a random number table method: volume-controlled ventilation (VCV) group (V group), PC-VG group (P group), and PC-VG combined with dexmedetomidine group (PD group). In PD group, dexmedetomidine was intravenously infused for 15 min at a loading dose of 0.5 μg/kg starting from the time point before anesthesia induction followed by a continuous infusion of 0.2-0.5 μg·kg -1·h -1 until the end of operation. VCV mode was used in group V, and PC-VG mode was used in P and PD groups, ventilator settings were adjusted to the mode with a tidal volume 6-8 ml/kg, respiratory rate 15-25 breaths/min, inspiratory/expiratory ratio 1∶2, oxygen flow rate 2 L/min, fraction of inspired oxygen 60%, and P ETCO 2 was maintained at 35-40 mmHg during mechanical ventilation in three groups. At 5 min before pneumoperitoneum (T 0), 10, 60 and 120 min of pneumoperitoneum (T 1-3) and 10 min after release of pneumoperitoneum pressure (T 4), peak airway pressure (Ppeak), mean airway pressure (Pmean), compliance of lung (C L) and airway resistance (Raw) were recorded, alveolar-arterial oxygen partial pressure difference (PA-aO 2), oxygenation index (OI), and respiratory index (RI) were recorded. The occurrence of pulmonary complications was recorded within 7 days after operation. Results:Compared with V group, the Ppeak and Raw were significantly decreased and C L was increased at T 1-4, and PA-aO 2 and RI were decreased and OI was increased at T 3, 4 in P group and PD group ( P<0.05). Compared with P group, no significant change was found in the parameters of respiratory mechanics mentioned above at each time point ( P>0.05), and PA-aO 2 and RI were decreased and OI was increased at T 3, 4 in PD group ( P<0.05). There was no significant difference in the incidence of postoperative pulmonary complications among the three groups ( P>0.05). Conclusions:PC-VG combined with dexmedetomidine has a certain lung-protective effect in pediatric patients undergoing laparoscopic surgery.

Objective:To evaluate the role of nuclear factor kappa B (NF-κB)/NOD-like receptor thermoprotein structural domain-associated protein 3 (NLRP3) signaling pathway in hippocampal microglia in dexmedetomidine-induced improvement in long-term cognitive function after multiple sevoflurane anesthesia in newborn mice.Methods:One hundred SPF healthy male C57BL/6 mice, aged 6 days, weighing 3-5 g, were divided into 5 groups ( n=20 each) by a random number table method: control group (group C), multiple sevoflurane anesthesia group (group S), multiple sevoflurane anesthesia+ NF-κB inhibitor pyrrolidine dithiocarboxylate group (group SP), multiple sevoflurane anesthesia + dexmedetomidine group (group SD), and multiple sevoflurane anesthesia + NF-κB agonist phorbol 12-myristate 13-acetate (PMA) + dexmedetomidine group (group SPD). Anesthesia was induced by inhalation of 3% sevoflurane and maintained by inhalation of 60% oxygen and 3% sevoflurane for 2 h for 3 consecutive days in S, SP, SD and SPD groups. At 30 min before each sevoflurane inhalation, pyrrolidine dithiocarbamate 100 mg/kg was intraperitoneally injected in group SP, and dexmedetomidine 20 μg/kg was intraperitoneally injected in group SD. NF-κB agonist PMA 15 μg/kg was intraperitoneally injected at 1 h before each sevoflurane inhalation, and 30 min later dexmedetomidine 20 μg/kg was intraperitoneally injected in group SPD. The mice were sacrificed at the age of 11 days, and the hippocampal tissues were isolated for determination of the expression of phosphorylated NF-κB p65 (p-NF-κB p65) and NLRP3 (by Western blot). The co-staining area of NLRP3 and microglia-specific ionized calcium binding adaptor molecule 1 (Iba-1) double positive cells (NLRP3 + -Iba-1 + cells) was calculated by immunofluorescence. The open field test and novel object recognition test were performed at 29 days of age, and the Morris water maze test was performed at 30-34 days of age. Results:There were no significant differences in each parameter of the open field test among the five groups ( P>0.05). Compared with group C, the expression of p-NF-κB p65 and NLRP3 in hippocampal tissues was significantly up-regulated, the co-staining area of NLRP3 + -Iba-1 + cells was increased, the percentage of novel object exploration and discrimination index were decreased, the escape latency was prolonged, and the frequency of crossing the original platform was reduced in group S ( P<0.05). Compared with group S, the expression of p-NF-κB p65 and NLRP3 in hippocampal tissues was significantly down-regulated, the co-staining area of NLRP3 + -Iba-1 + cells was reduced, the percentage of novel object exploration and discrimination index were increased, the escape latency was shortened, and the frequency of crossing the original platform was increased in SP, SD and SPD groups ( P<0.05). Compared with SD group, the expression of p-NF-κB p65 and NLRP3 was significantly up-regulated, the co-staining area of NLRP3 + -Iba-1 + cells was increased, the percentage of novel object exploration and discrimination index were decreased, the escape latency was prolonged, and the number of crossing the original platform location was decreased in SPD group ( P<0.05). Conclusions:The mechanism by which dexmedetomidine improves long-term cognitive function after multiple sevoflurane anesthesia may be related to inhibiting the activation of NF-κB/NLRP3 signaling pathway in the hippocampal microglia of newborn mice.