Nowadays,stem cells are recognized as the most promising seed cells of tissue engineering due to their self replication ability and multilineage differentiation potential.In order to apply them to tissue engineering,a variety of physical and biochemical methods were tried to promote the proliferation,function and differentiation,and good effects were achieved.Recently,as a rising method of physical stimulation,electrical stimulation received more and more attention and had been proved to have good effects on stem cell proliferation and differentiation.This paper summarized the advances in promoting effects of electrical stimulation on stem cell proliferation and differentiation,and discussed the possible mechanisms of stem cell differentiation induced by electrical stimulation.

Objective To compare the surgical outcome of Lichtenstein,open preperitoneal technique and double-laver mesh technique in tension free repair of incarcerated inguinal hernia.Methods Totally 438 cases of indirect inguinal hernia in our hospital were retrospectively analyzed from January 2008 to January 2012,io which 154 patients received Lichtenstein,186 patients received open preperitoneal technique and 98 patients received double-layer mesh technique.Results The recurrence rates of these three groups were low,0.65％,0.54％,0,respectively,and there was no significant difference in the recurrence rate between these 3 groups (P ＞0.05),but significant difference in the foreign body sensation and postoperative pain between the open preperitoneal technique group and the other two groups(P ＜ 0.05),and the cost of the double-layer mesh technique group was ahout 2000 yuan higher than the other two groups.Conclusion The open preperitoneal technique can reduce the postoperative pain and foreign body sensation after surgery with low cost,and it is a good choice for inguinal hernia repair.

Cells and scaffolds are two key elements of tissue engineering,while the viabilitv of cells is mainly depended on the nature of scaffolds.A suitable scaffold should simulate the internal environment as well as possible,which is necessary for the growth of cells.The nanometer structured biomaterials have become more and more popular in the study of tissue engineering due to their ability to perfectly simulate the topography of the microenvironment.This paper summarized the advances in the application of nanometer structured materials in the in vitro cell cultures.The mechanisms of the promoting effect of nano.structured biomaterials on the cell growth and the application of nano-structured materials in liver tissue engineering are discussed.

Objective As an effective means of liver function support for acute liver failure, bioartificial liver has seen great progress in recent years. However, the development of this type of device is currently hindered by limited oxygen transport to cultured hepatocytes. In this study we try to resolve this problem by supplementing the circulating medium of the bioreactor with red blood cells.Methods Freshly isolated primary porcine hepatocytes were inoculated into our newly designed bioreactor and were divided into two groups: RPMI1640 was circulated in the control group and porcine red blood cells were added into the culture medium in the experimental group. The culture media in both groups were oxygenated through extra-corporeal membrane oxygenation, and the oxygen consumption rate (OCR) in the bioreactor was measured by a blood gas analyzer. Liver-specific functions and glucose consumption were also determined. Results The OCR of the experimental group was 1.5 fold that of the control group, and the glucose consumption rate was twice that of the control group. The liver-specific functions of the experimental group were significantly higher than those of the control group in terrns of albumin secretion and urea synthesis. Conclusion Supplementing the circulating medium of the bioreactor with red blood cells can significantly improve the oxygen supply in the bioreactor, thereby enhancing the glucose consumption and liver-specific functions of hepatocytes. This method is convenient and effective, and is expected to be an effective means to resolve the problems of oxygen supply in the bioreactor.

Objective To investigate the influence of membrane molecular weight cut off in our bioartificial liver(BAL)system.Methods Beagle dogs were used for a model of acute liver failure through D-galactosamine administration.The acute liver failure Beagles were divided into two groups by the membrane molecular weight cut off.Group A was treated with BAL containing 200 kDa retention rating membrane.Group B was treated with BAL containing 1200 kDa retention rating membrane.Each group underwent two six-hour BAL treatments that were performed on day 1 and day 21.BAL medium were examined and levels of IgG,IgM,and complement hemolytic unit of 50％(CH50)antibodies were measured in all Beagles and.Results BAL treatment was associated with a significant decline in levels of CH50.1200 kDa group experienced a significant increase in levels of IgG and IgM after two BAL treatments.Significant levels of canine proteins were detected in BAL medium from 1200 kDa group.Conclusions Xenogeneic immune response in the BAL system was influenced by membrane molecular weight cut off.

ObjectiveTo study the effects of membrane molecular weight cut off on a novel bioartificial liver(BAL) system.MethodsHealthy beagles underwent 6-hour treatment with a BAL containing membrane with 200 kDa retention rating or 1200 kDa retention rating.The functional changes and cell viability were characterized.ResultsHepatocyte performance levels such as albumin secretion,urea synthesis and viability were significantly higher in the 200 kDa retention rating group when compared with the 1200 kDa retention rating group (P＜0.05).Significant levels of canine proteins were detected in the BAL medium from the 1200 kDa retention rating group.Fluorescence microscopy further verified that heavy deposition of canine IgG,IgM and complement (C3) on co-culture cells were obtained after BAL treatment in the 1200 kDa retention rating group.ConclusionsSmall membrane molecular weight cut off of BAL could reduce the transfer of xenoreactive antibodies into the BAL medium and improved the performance of the BAL.

Objective:To investigate the clinical efficacy of laparoscopic sleeve gastrectomy in obese adolescents.Methods:The retrospective and descriptive study was conducted. The clinical data of 37 obese adolescents who were admitted to Drum Tower Hospital Affiliated to Nanjing University Medical School between July 2016 and August 2020 were collected. There were 18 males and 19 females, aged 18(range, 13?19)years. All patients underwent laparoscopic sleeve gastrec-tomy. Observation indicators: (1) surgical and postoperative situations; (2) follow-up. The patients were followed up by outpatient review to detect body weight, blood glucose, blood lipid, blood pressure, nutrition situation and related complications at 3, 6 and 12 months after operation. The follow-up was up to August 2021. Measurement data with normal distribution were represented as Mean± SD. Repeated measurement data were analyzed by Repeated Measures Anova. Measurement data with skewed distribution were represented by M(range). Count data were expressed as absolute numbers or percentages. Results:(1) Surgical and postoperative situations. All 37 patients under-went laparoscopic sleeve gastrectomy successfully, the operative time was (50±7)minutes, the volume of intraoperative blood loss was (53±17)mL, and the duration of postoperative hospital stay was (3.0±0.5)days. Of the 37 patients, 2 cases had puncture infection. There was no complication such as bleeding occurred. (2) Follow-up. Of the 37 patients, 35, 31 and 22 cases were followed up at postoperative 3, 6 and 12 months, respectively. There was no anemia, malnutrition, trace element deficiency or other nutrition-related complications during the follow-up, and there was no death. The body mass, body mass index, homeostasis model assessment-insulin resistance, triglyceride, total cholesterol, systolic pressure, diastolic pressure, vitamin D, folate of the 37 patients were (117±19)kg, (40±5)kg/m 2, 6.59(range, 2.84?28.02), (1.6±0.7)mmol/L, (4.5±0.7)mmol/L, (141±22)mmHg (1 mmHg=0.133 kpa), (84±18)mmHg,(14±5)μg/L, (10±5)μg/L before the surgery, and (81±15)kg, (27±4)kg/m 2, 2.69(range, 1.08?9.71), (0.9±0.5)mmol/L, (4.5±0.7)mmol/L, (115±15)mmHg, (70±11)mmHg, (23±10)μg/L, (9±5)μg/L at postoperative 12 months. There were significant differences in the time effect of above indicators ( Ftime=214.14, 160.37, 12.66, 11.77, 2.90, 18.08, 11.32, 8.61, 5.04, P<0.05). The percentages of excess of body mass index lost of the 37 patients were 48%±19%, 77%±28% and 89%±24% at postoperative 3, 6 and 12 months, the percentages of excess weight loss were 42%±13%, 63%±17% and 75%±18%, the percentages of total body weight loss were 18%±5%, 26%±6% and 34%±7%, respectively. There were significant differences in the time effect of above indicators ( Ftime=83.96, 107.24, 109.06, P<0.05). The hemoglobin A1c was 4.8%, 5.0%, 5.1% and 4.9%, 5.2%, 5.2% in the 2 patients with type 2 diabetes at postoperative 3, 6 and 12 months, respectively, and they were relieved without drug treatment. Conclusion:Laparoscopic sleeve gastrectomy has definite short-term clinical efficacy in the treatment of adolescent obesity, which can effectively reduce excess body weight and improve the metabolic complications of insulin resis-tance, dyslipidemia and hypertension.