Objective To observe the effect of glutamine （Gln） on intestinal permeability after surgery of children, also its influence on the plama level of interleukin-2（IL-2）, endotoxin and synthesize of protein through a random nutrition trial. Methods Twenty children suffered from congenital heart disease were divided into Gln group and control group with random number table, 10 cases in each group. They were all given isonitrogenous and isocaloric total paraenteral nutrition after 24 h postoperatively. In Gln group the Dipeptiven [-N （2）-L-alanyl-Lglutamine] was used with 2 ml/kg · 24h additionly. Before operation, 24h and 96 h after operation, intestinal permeability, serum level of endotoxin, IL-2, C-reaction protein, prealbumine were measured. Results Intestinal permeability increased in 24 h after cardiac surgery in two groups, while the concentration of endotoxin also increased, 96 h after surgery the intestinal permeability recovered, but the endotoxin level did not decrease in control group （P〈0. 01）. Conclusion Utilization of Gln can improve immune suppression, elevate the IL-2 level, decrease the endotoxin concentration, alleviate the infection, but has no effect on the protein synthesis after congenital cardiac operation of children.
ObjectiveTo determine the effects of different volume fluid resuscitation on intestinal injury and the permeability of intestine in hemorrhagic shock rats.
MethodsSprague-Dawley male rats(n=72) were randomly equally divided into 4 groups after the model establishment of blood pressure-controlled hemorrhage, 45, 30, and 15 mL/(kg·h) of fluid resuscitation were performed in high dosage of resuscitation(HLR), moderate dosage of resuscitation(MLR), and low dosage of resuscitation(LLR) group respectively, but rats of Sham group didn't accept fluid resuscitation. After resuscitation, ten centimeters ileum was harvested for testing intestinal permeability. Then 6 rats of each group were sacrificed at 24, 48, and 72 hours after fluid resuscitation respectively. Over the specified time interval, blood was collected for testing levels of lactic acid and plasma tumor necrosis factor-α(TNF-α). The ileums of 3 resuscitation groups were obtained for testing the ratio of wet weight to dry weight and observing the histological changes.
ResultsAfter resuscitation, the intestinal permeability was higher in HLR group(P<0.05). At 3-8 hours after resuscitation, rats of Sham group were all died, and the other rats of 3 groups were all alive. The level of plasma lactic acid was lower in LLR group than those of other 2 groups at 24 hours(P<0.05). The levels of TNF-α were higher in HLR group than those of other 2 groups at 24, 48, and 72 hours(P<0.05), and at 48 hours, level of TNF-α in LLR group was lower than MLR group(P<0.05). At 24 hours after resuscitation, ratio of intestinal wet weight to dry weight in LLR group was the lowest, and HLR group was the highest(P<0.05). According to the histopathology, intestinal injuries of the 3 groups were tend to be remission with the time, and at 48 and 72 hours after resuscitation, intestinal villus of LLR group appeared to be normal.
ConclusionLimited fluid resuscitation of 15 mL/(kg·h) could not only decrease the levels of lactic acid and TNF-α, but also moderate the intestinal permeability and the intestinal injury in early stage after shock and surgery.
OBJECTIVE To investigate the effect of the endoexpander pressure of continuous and constant pressure expansion on the drug permeability. METHODS The expanders were divided into two groups, the normal expansion and the continuous and constant pressure expansion (4.6 kPa). Each expander was filled with 0.2% Metronidazole, then the expanders were immersed wholly in normal saline and sealed totally. At several intervals over 72 hours, the surrounding saline was sampled and the drug concentration of the sample was measured respectively. RESULTS Both groups were permeable to the Metronidazole and the concentration outside the expander would reach the effective concentration in 48 hours. The drug concentration of the continuous and constant pressure expansion was higher than that of the normal one and there was significant difference between the two groups (P lt; 0.01). CONCLUSIO The endoexpander pressure in continuous and constant pressure expansion can enhance the drug permeability. In view of this, in the course of continuous and constant pressure expansion, 0.2% Metronidazole can be used to prevent and control the infection.
ObjectiveTo explore the effects of cytoskeleton depolymerizing agent and stabilizer on the clathrin/caveolae-mediated endocytosis, the expression of membrane vascular endothelial cadherin (VE-cad), and the vascular permeability by the transformation of cytoskeleton structure after lipopolysaccharide (LPS) treatment.
MethodsCRL-2922 cells were used in the experiments. Indexes were tested at corresponding time point according to name of group, but in blank control group indexes could be tested at any time point. CRL-2922 cells were divided into blank control group, LPS-1 h group, and LPS-4 h group to observe cytoskeleton structure; CRL-2922 cells were divided into LPS-1 h group, Cyt D+LPS-1 h group, LPS-4 h group, and Jasp+LPS-4 h group to determine the expression of membrane VE-cad, and to determine the expression of its co-immunoprecipitation with clathrin and caveolin-1 (Cav1); besides, CRL-2922 cells were divided into blank control group, LPS-1 h group, Cyt D+LPS-1 h group, LPS-4 h group, and Jasp+LPS-4 h group to detect the cumulative infiltration rate.
Results①The cytoskeleton showed a dynamic change after LPS treat-ment, the F-actin polymerized and stress fibers formed at 1 hour after LPS treatment, but depolymerized at 4 hours after LPS treatment. ②Compared with LPS-1 h group, the level of co-immunoprecipitation of VE-cad with clathrin in Cyt D+ LPS-1 h group decreased (P<0.05), the level of co-immunoprecipitation of VE-cad with Cav1 increased (P<0.05), and expression level of VE-cad in plasma membrane decreased (P<0.05); compared with LPS-4 h group, there was no significant difference in the level of co-immunoprecipitation of VE-cad with clathrin of Jasp+LPS-4 h group (P>0.05), but the level of co-immunoprecipitation of VE-cad with Cav1 decreased in Jasp+LPS-4 h group (P<0.05), and expression level of VE-cad in plasma membrane increased (P<0.05). ③Compared with blank control group, the cumulative infiltration rates of LPS-1 h group and LPS-4 h group were both higher (P<0.05); compared with LPS-1 h group, the cumulative infiltration rate of Cyt D+LPS-1 h group was higher (P<0.05); compared with LPS-4 h group, the cumulative infiltration rate of Jasp+LPS-4 h group was lower (P<0.05).
ConclusionActin cytoskeleton shifts from polymerization to depoly-merization after LPS treatment, the structural change of actin cytoskeleton is an important reason for the transformation of VE-cad endocytosis pathway from clathrin-mediated to caveolae-mediated after LPS treatment.
【Abstract】ObjectiveTo investigate the influence of CO2 pneumoperitoneum on intestinal mucosa permeability in rats with liver cirrhosis. MethodsFifty rats were randomly divided into following groups: control group (n=5), cirrhosis group(n=5) and pneumoperitoneum group (n=40); the pneumoperitoneum group was further divided into 8 mm Hg group(n=20) and 13 mm Hg group (n=20). Four time points were chosen, including 0.5, 2, 6, and 12 hours after the end of pneumoperitoneum. After rat models with cirrhosis were established successfully, the abdominal cavity was insufflated with CO2 and maintained under the pressures of 8 mm Hg and 13 mm Hg respectively for two hours. The portal venous blood was collected and the levels of Dlactic acid and endotoxin were measured. ResultsThe levels of endotoxin and Dlactic acid in cirrhosis group were much higher than those of control group（P＜0.05）. The levels of serum endotoxin and Dlactic acid in pneumoperitoneum group were higher than those of cirrhosis group(Plt;0.05) regardless of pressure and time point. The endotoxin level in 13 mm Hg group was higher than that of 8 mm Hg group on different time points (F=5.466, P＜0.05), but there was no difference in Dlactic acid level between both of them（F=0.415,Pgt;0.05）.ConclusionThe intestinal mucosa permeability is increased in rats with liver cirrhosis. It can be further increased under CO2 pneumoperitoneum with certain pressure and time and in a pressuredependent manner. The permeability can decrease after removal of pneumoperitoneum.
The effect of parasitic ions on the results of ultraviolet A (UVA) cross-linking in iontophoresis was still not clear. In this work, the porcine sclera was cross-linked by riboflavin lactate Ringer’s solution (group A) and riboflavin normal saline (group B) in vitro, respectively. The concentration of parasitic ions in the solution was calculated. In addition, the average fluorescence intensity, penetration depth and concentration after the introduction of riboflavin and the mechanical properties of cross-linked sclera tissue were measured. The ranges of diffusion coefficient of the two solutions were also calculated, respectively. The results showed that more kinds of parasitic ions were detected in group A compared with group B, while the average fluorescence intensity, penetration depth and concentration of riboflavin and scleral elastic modulus in group B were significantly higher than those in group A when the penetration time was 10 minutes. Besides, the diffusion coefficient of riboflavin in group B was about 1.5 times larger than that in group A. The results suggested that the species of parasitic ions has a great impact on the permeability of riboflavin, and affects the mechanical properties of cross-linked sclera. The above results could provide a reference for improving the efficiency of riboflavin introduction and optimizing the formula of riboflavin in iontophoresis scleral cross-linking.
Existing neuroregulatory techniques can achieve precise stimulation of the whole brain or cortex, but high-focus deep brain stimulation has been a technical bottleneck in this field. In this paper, based on the theory of negative permeability emerged in recent years, a simulation model of magnetic replicator is established to study the distribution of the induced electric field in the deep brain and explore the possibility of deep focusing, which is compared with the traditional magnetic stimulation method. Simulation results show that a single magnetic replicator realized remote magnetic source. Under the condition of the same position and compared with the traditional method of stimulating, the former generated smaller induced electric field which sharply reduced with distance. By superposition of the magnetic field replicator, the induced electric field intensity could be increased and the focus could be improved, reducing the number of peripheral wires while guaranteeing good focus. The magnetic replicator model established in this paper provides a new idea for precise deep brain stimulation, which can be combined with neuroregulatory techniques in the future to lay a foundation for clinical application.
In order to establish a bone scaffold with good biological properties, two kinds of new gradient triply periodic minimal surfaces (TPMS) scaffolds, i.e., two-way linear gradient G scaffolds (L-G) and D, G fusion scaffold (N-G) were designed based on the gyroid (G) and diamond (D)-type TPMS in this study. The structural mechanical parameters of the two kinds of scaffolds were obtained through the compressive simulation. The flow property parameters were also obtained through the computational fluid dynamics (CFD) simulation in this study, and the permeability of the two kinds of scaffolds were calculated by Darcy's law. The tissue differentiation areas of the two kinds of scaffolds were calculated based on the tissue differentiation theory. The results show that L-G scaffold has a better mechanical property than the N-G scaffold. However, N-G scaffold is better than the L-G scaffold in biological properties such as permeability and cartilage differentiation areas. The modeling processes of L-G and N-G scaffolds provide a new insight for the design of bone scaffold. The simulation in this study can also give reference for the prediction of osseointegration after the implantation of scaffold in the human body.
ObjectiveTo explore the mechanism of liver capillary permeability in rats with severe acute pancreatitis (SAP). MethodsTotally 40 healthy Sprague-Dawley (SD) rats were randomly divided into two groups: sham operation (SO) group and SAP group, SAP group were divided into four subgroups according to sampling time (3 h， 6 h, 12 h， and 24 h). The model was established by injecting 5% sodium taurocholate retrogradely into pancreaticobiliary ducts. The changes of tumor necrosis factor-α (TNF-α), pathohistology, and tissue moisture content were compared among different groups. Liver occludin protein expression was analyzed by immunohistochemistry method, and occludin mRNA was measured by RT-PCR. ResultsThere was no significant pathological changes of liver tissue in the SO group. Typical pathological changes of SAP， such as interstitial edema, vasodilatation, infiltration of inflammatory cells, were found in the SAP group. TNF-α level and tissue moisture content of each phase increased gradually, and the highest level appeared at 24 h within the observing period. The two above indicators at different time point in subgroups were significantly different from each other and higher than those in the SO group (Plt;0.05)． In the SAP group, the expression of occludin and it’s mRNA began to decrease at 3 h to the bottom at 6 h and rebounced significantly at 12 h, 24 h compared with those at 6 h (Plt;0.05), but still lower than those in the SO group (Plt;0.05). ConclusionUpregulation in TNF-α and subsequent downregulation in occludin protein and mRNA maybe bly related to the severe liver capillary permeability in rats with SAP.
Objective To evaluate the effect of hepatocyte growth factor(HGF) on intestinal permeability and bacterial translocation after small bowel transplantation in rats. Methods Twenty Wistar rats were as recptors and twenty SD rats as donors. After heterotopic intestinal grafting, cyclosporine A was administered at 6mg/kg·day intramuscularly for inhibiting rejection. The SD rats were divided into 2 groups(n=10). HGF was administered at 150 μg/kg·day (HGF group) and normal saline was administered at 150 μg/kg·day (controlgroup). Intestinal permeability and bacterial translocation to the mesenteric lymph nodes and portal vein were assessed at the 8th postoperative day. Results The lactulose and lactulose/ mannitol of control group (0.0931%±0.008 5% and 0.132± 0.021) were higher than those of normal reference value (0.015 0%±0.002 0% and 0.020±0.005)（Plt;0.05）. The lactulose and lactulose/ mannitol of HGF group (0.039 6%±0.009 0% and 0.056±0.013) were also higher than those of normal reference value（Plt;0.05）.The bacterial culture positive proportion of lymphaden in HGF group and control group were 10% and 60%, showing statistically significant difference（Plt;0.05）. The bacterial culture positive proportion of portal vein in HGF group and control group were 10% and 20% respectively（P＞0.05）. Conclusion HGF can decrease intestinal permeability and bacterial translocation from the lumen of the graft to the mesenteric lymph nodes,thus improve gut barrier function, may be of help to reduce the incidence of septic complications after intestinal grafting.
