In order to improve tensile property of vascular scaffold, we blended silk fibroin with novel human-like collagen with the mass ratio of 9:1, 7:3 and 5:5 (W/W), and then fabricated blood vessel tubular graft by freeze-drying process. We studied microstructure, mechanical properties, elements composites, degradability and biocompatibility of vascular scaffolds. These results showed that tubular scaffold with mass ratio 7:3 exhibited interconnected porous structure with pore size at (60 +/- 5) microm and porosity of 85%; achieved the desirable mechanical property (strain of 50% +/- 5% and stress of 332 +/- 16 kPa); had relatively slow degradation rate; could enhance cell adhesion and proliferation and had superior biocompatibility.
Biocompatible Materials ; chemistry ; Biomechanical Phenomena ; Blood Vessels ; physiology ; Collagen ; chemistry ; Fibroins ; chemistry ; Humans ; Materials Testing ; Porosity ; Tissue Engineering ; methods ; Tissue Scaffolds

Objective:To investigate the effect of the timing of continuous renal replacement therapy (CRRT) administration on the prognosis of acute kidney injury (AKI) in children.Methods:The medical records of children with AKI who were admitted to the Intensive Care Unit of Hunan Children′s Hospital from March 2015 to February 2020 and underwent CRRT were prospectively analyzed.The children who met the criteria were divided into early group (defined as AKI 1 and 2) and delayed group (defined as AKI 3) according to AKI stage.The general conditions, indicators when CRRT was initiated, and prognosis of the children in two groups were recorded.Results:(1) A total of 39 children were included in the study, including 23 in the early group and 16 in the delayed group.There were no significant differences in age, gender, body weight and proportion of mechanical ventilation between two groups ( P>0.05). The score of critical cases in the early group was higher than that in the delayed group ( P=0.008). (2) There were no significant differences in serum potassium and bicarbonate when CRRT was initiated between two groups ( P>0.05). The urine output in the early group was higher than that in the delayed group ( P>0.001). The serum creatinine and urea nitrogen in the early group were lower than those in the delayed group ( P>0.05). (3) The 28-day survival rate and proportion of renal function recovery at 28 days in the early group were significantly higher than those in the delayed group ( P>0.05). The duration of CRRT, ICU stay and duration of mechanical ventilation in the early group were shorter than those in the delayed group ( P>0.05). Conclusion:Early initiation of CRRT at AKI stage 1 and 2 can improve the 28-day survival rate and renal function recovery of survivors when critically ill children are complicated with AKI.

Objective:To investigate the efficacy and safety of dexmedetomidine in noninvasive continuous positive airway pressure(NCPAP)for acute respiratory failure in children.Methods:Clinical data of children with acute respiratory failure who underwent NCPAP from January 2018 to March 2020 in PICU of Hunan Children′s Hospital were prospectively collected.They were randomly divided into dexmedetomidine group(group D)and midazolam group(group M), with a total of 100 children.We compared the sedation depth of the two groups at 7 time points after sedation at 0.5 h(t1), 1 h(t2), 2 h(t3), 6 h(t4), 12 h(t5), 24 h(t6), and 48 h(t7), time to reach proper sedation, NCPAP time, NCPAP failure rate, oxygenation index(P/F value)before sedation(T0)and 1h(T1), 24h(T2), and 48h(T3)after sedation, and the main vital signs and adverse reactions before sedation(T0)and 1h(T1), 24h(T2), 48h(T3)after sedation.Results:(1)The proportion of proper sedation at T4, T5, T6 and T7 after sedation in group D was higher than that in group M[98%(49/50)vs.84%(42/50), 94%(47/50)vs.90%(45/50), 96%(48/50)vs.88%(44/50), 90%(45/50)vs.88%(44/50), χ2=6.538, 8.043, 8.174, 7.678, all P<0.05]. Time to reach proper sedation in group D was shorter[(58.6±7.9)s vs.(66.7±9.3)s, t=4.682, P<0.01]. (2)The treatment time and failure rate of NCPAP in group D were lower than those in group M[(134.9±25.5)h vs.(147.8±24.3)h, 10%(5/50)vs.28%(14/50), all P<0.05]. P/F after NCPAP treatment in the two groups was improved as compared with that before treatment(all P<0.01), and the improvement was more significant in group D than in group M at T2 and T3 after sedation[(199.3±26.1)vs.(188.5±24.2)mmHg, (212.2±25.4)mmHg vs.(200.8±24.8)mmHg, t=2.132, 2.278, all P<0.05]. (3)There were no significant differences in heart rate(HR), mean arterial pressure(MAP), and respiratory rate(RR)before sedation between the two groups(all P>0.05). HR and RR after sedation in both groups decreased as compared with those before sedation( P<0.01). HR at T1, T2, and T3 after sedation in group D decreased more significantly than that in group M[(116.3±17.6)bpm vs.(124.8±14.1)bpm, (110.2±18.4)bpm vs.(121.9±15.2)bpm, (108.5±18.7)bpm vs.(117.6±12.8)bpm, t=0.479, -3.474, -2.840, all P<0.05]. There was no significant difference in RR after sedation between the two groups( t=1.872, 1.632, 1.675, all P>0.05). MAP at T1 in group D decreased as compared with T0( P<0.01). MAP at T1 in group D was lower than that in group M[(65.5±5.1)mmHg vs.(68.0±5.7)mmHg, t=-2.297, P=0.024]. (4)There was no significant difference in the incidence of total adverse reactions between the two groups[20%(10/50)vs.14%(7/50), P=0.595]. The incidence of bradycardia was higher in group D than in group M[16%(8/50)vs.2%(1/50), P=0.031]. Conclusion:The incidence of adverse reactions of dexmedetomidine and midazolam in the sedation of NCPAP in children with acute respiratory failure is similar, but the sedative effect of dexmedetomidine is better than that of midazolam in the improvement of pulmonary oxygenation.

Objective To explore the role of long non-coding RNA smad7(Linc-smad7)in invasion and migration of pancreatic cancer(PC)cells and its mechanisms.Methods The expression level of Linc-smad7 in PC tissues and cell lines was detected by qRT-PCR assays.Transwell assays were performed to observe the effect of Linc-smad7 overexpression on the migration and invasion abilities of PaCa-2 cells.Luciferase reporter analysis was made to detect the direct binding effect of Linc-smad7 on miR-125b and miR-125b on Sirtuin1(SIRT1).qRT-PCR assays were used to detect the regulatory effect of Linc-smad7 on miR-125b expression in PaCa-2 cells.qRT-PCR and Western blotting assays were used to detect the regulatory effect of miR-125b on SIRT1 expression.Results Linc-smad7 was significantly increased in PC tissues and cell lines.Paca-2 cells with overexpressed Linc-smad7 showed higher migration and invasion abilities,while miR-125b expression was decreased.After the expression of miR-125b was increased,the expression of SIRT1 was decreased significantly.Luciferase reporter assays results suggested that Linc-smad7 directly targeted with miR-125b,and miR-125b directly bound with SIRT1.Increased Linc-Smad7 or decreased miR-125b could reverse the effect of SIRT1 inhibition on invasion and migration of PaCa-2 cells.Conclusion Linc-smad7 promotes invasion and migration of PaCa-2 cells through miR-125b/SIRT1 axis.