Purpose
To investigate the expression of intercellular adhesion molecules ICAM-1 and Mac-1，in epiretinal membanes (ERM) of eyes wi th proliferative vitreoretinopathy (PVR)．
Methods
Twenty epiretinal membranes were obtained from eyes undergone vitrectomy for retinal detachment complicated with PVR and observed by immunohistochemical examination．
Results
Expressions of ICMA-1 and Mac-1 were observed in 18 and 15 membranes respectively．Expression of both adhesion molecules in 12 membranes．
Conclusion
The findings indicate that adhesion molecules might be involved in the development of PVR．
(Chin J Ocul Fundus Dis，2000，16：71-138)
OBJECTIVE To investigate the adhesive interactions of cells with materials and the effects of material properties on cell adhesion in tissue engineering. METHODS By looking up the recent literatures dealt with adhesive interactions of cells with materials and reviewing previous work on the adhesion of tissue-derived cells to materials. RESULTS The adhesion characteristics of cells to materials not only depend on the nature of materials, including bulk and surface properties, surface modification, surface morphology, net charge, porosity and degradation rate, but also on the expression of cell surface molecules and their interaction with the material. CONCLUSION The quantitative measure and biophysical mechanisms of cell adhesion to materials might be very important in tissue engineering.
Fibrinogen (Fg) in human plasma plays an important role in hemostasis, vascular repair and tissue integrity. The surface chemistry of extracellular matrix or biological materials affects the orientation and distribution of Fg, and changes the exposure of integrin binding sites, thereby affecting its adhesion function to platelets. Here, the quantity, morphology and side chain exposure of Fg adsorbed on hydrophilic, hydrophobic and avidin surfaces were measured by atomic force microscopy (AFM) and flow cytometry (FCM), then the rolling behavior of platelets on Fg was observed through a parallel plate flow chamber system. Our results show that the hydrophobic surface leads to a large amount of cross-linking and aggregation of Fg, while the hydrophilic surface reduces the adsorption and accumulation of Fg while causing the exposure and spreading of the α chain on Fg and further mediating the adhesion of platelets. Fg immobilized by avidin / biotin on hydrophilic surface can maintain the monomer state, avoid over exposure and stretching of α chain, and bind to the platelets activated by the A1 domain of von Willebrand factor instead of inactivated platelets. This study would be helpful for improving the blood compatibility of implant biomaterials and reasonable experimental design of coagulation in vitro.
Objective?To evaluate the feasibility of Seprafilm anti-adhesion membrane, a hyaluronic acid (HA) derivative, on prevention of adhesion in acute injured tendon.?Methods?Eighteen 4-month-old Chinese white rabbits (half males and half females, weighing 2.0-2.5 kg) were made the laceration models of the bilateral second and third toes of hindpaw. According to different treatments, the rabbits were randomly divided into 4 groups (n=18). The second toe of right hindpaw was wrapped with Seprafilm anti-adhesion membrane (group A); the third toe of right hindpaw was wrapped with polylactic acid membrane (group B); the second toe of left hindpaw was coated with sodium hyaluronate gel (group C); and the third toe of left hindpaw did not treated, as control group (group D). The general condition was observed; the range of motion (ROM) of distal interphalangeal joint was measured; the gross observation and histological observation were performed at 1, 2, and 4 weeks, then the degree of adhesion was graded.?Results?All rabbits survived to the end of the experiment. There was no significant difference in ROM of distal interphalangeal joint between groups A and B at 1, 2, and 4 weeks (P gt; 0.05). ROM of group A was superior to that of groups C and D at 2 and 4 weeks (P lt; 0.05). The gross and histological observations showed the same result in the grading of adhesion. At 1 week, there was no significant difference in the grading of adhesion among 4 groups (P gt; 0.05); at 2 and 4 weeks, the grading of adhesion in group A was similar to that in group B (P gt; 0.05), and the grading of adhesion in group A was significantly slighter than that in groups C and D (P lt; 0.05).?Conclusion?Seprafilm anti-adhesion membrane composed of HA derivative can prevent tendon adhesion and improve the joint function in acute tendon injury of rabbits.
Objective To study the effect of p38MAPK activity on tumor necrosis factor-α （TNF-α） mRNA and intercellular adhesion molecule 1 （ICAM1） mRNA expressions of isolated rabbit liver during early stage of cold preservation and reperfusion period. Methods Based on the cold preservation and reperfusion model of isolated rabbit liver, the animals were divided into inhibition group （n=12） with 3 μmol/L SB202190 (p38MAPK specificity inhibitor) in perfusate and control group （n=12） with no SB202190 in perfusate. Liver tissue samples were harvested at the time points of before resection, end of cold preservation, and different reperfusion period (10, 30, 60 and 120 min). Protein expression and activity of p38MAPK were detected by Western blot and immunoprecipitation respectively, expression of TNF-α mRNA was detected by RT-PCR, and expression of ICAM1 mRNA was detected by in situ hybridization. Results There was no obvious change of expression of p38MAPK protein in liver tissue both in two groups during the total period （P＞0.05）， and there was no statistically significant difference between two groups （P＞0.05）. At time points of end of cold preservation, 10, 30 and 60 min of reperfusion, the activity of p38MAPK in control group was significantly higher than that at the time points of before resection and 120 min of reperfusion (P＜0.01), and was also significantly higher than that in inhibition group at the same time points (P＜0.01). There was no significant difference in activity of p38MAPK among all time points in inhibition group (P＞0.05). The expressions of TNF-α mRNA and ICAM1 mRNA at the time points of before resection, end of cold preservation, and 10 and 30 min of reperfusion were significantly lower than those in 60 and 120 min of reperfusion in both two groups (P＜0.05, P＜0.01); The expressions of TNF-α mRNA and ICAM1 mRNA in inhibition group were significantly lower than those in control group at the time points of 60 and 120 min of reperfusion (P＜0.01). The activity of p38MAPK of liver tissue during cold preservation and reperfusion period was significantly correlated with the level of TNF-α mRNA and level of ICAM1 mRNA expression （r=0.996, P＜0.01； r=0.985, P＜0.01）. Conclusions These results suggest that p38MAPK pathway may regulate the expressions of TNF-α and ICAM1 at the level of transcription and the activation of p38MAPK can up-regulate TNF-α and ICAM1 expressions, which may be one of the important mechanisms to cause ischemia-reperfusion injury of isolated liver during cold preservation and reperfusion period.
Objective To study the effect of the allogeneic bone sheet that has been treated by the freezedrying and radiation sterilization in preventing the epidural adhesion after laminectomy in sheep. Methods Laminectomy was performed on L3,4and L4,5 of 12 adult male sheep. Afteroperation, one site of L3,4 or L4,5was covered by the allogeneicbone sheet in “H” shape after the freeze-drying and radiation sterilization treatment; and the other site was used as a control. The sheep were killed and the specimens were retrieved at 4，8，12，16，20 and 24 weeks after operation to observe the scar formation process. X-ray andCT scan were performed in the segments of L3,4and L4,5at 4 and 24weeks. Results Four weeks after operation, the position and the shape of the allogeneic bone sheet were good in condition, and no lumbar spinal stenosis or compression of the dura was found in the experimental sections. Twentyfour weeks after operation theexamination on the experimental sections revealed that the vertebral canal reconstruction was completed, the allograft was absorbed almost completely, and inosculation with the lamina of the vertebra and the shape of the lumbar spine were good, with no fibroid tissues found in the epidural area. Compared with the control segment, the dura adhesion degree in the laminoplasty segment was significantly decreased (Plt;0.01), and the dura sac remained in a good shape. There was no obvious compression on the dura. Conclusion The allogeneic bone sheet after the treatment of freeze-drying and radiation sterilization can effectively reduce the scar formation after laminectomy and prevent postoperative recurrence of the spinal stenosis.
Objective
To understand etiology and available treatment of postoperative peritoneal adhesion.
Method
Domestic and overseas literatures in recent years about research progress of peritoneal adhesion were reviewed.
Results
As to the previous research, the operation was the main cause of peritoneal adhesion by the injury, inflammatory reaction, and hypoxia, which further affected the changes of the peritoneal microenvironment through the release of inflammatory cells, inflammatory mediators, cytokines, etc., then disturbed the balance of deposition and dissolution of fibrin and promoted the formation of extracellular matrix and microangiogenesis, resulted in peritoneal adhesion. The main treatment measures were optimizing surgical procedure and improving surgical technique, preventing fibrinolysis and promoting fiber protein degradation, some drug therapies involved molecules and genes, using biologic barrier treatment with drug barrier and mechanical barrier, and some other adjuvant therapies.
Conclusions
Pathogenesis of peritoneal adhesion is complex and poorly understood currently. There is no effective clinical treatment and intervention for this disease. Research on aspects of cell and molecular of abdominal cavity microenvironment will be beneficial to precise treatment of peritoneal adhesion, and combined medication of multiple targets and multiple links and related interventions are expected to apply for peritoneal adhesion in future.
In order to decrease the risk of operation, complete release of scar tissue and reduce the recurrence after operation, from February 1994 to March 1997, seventy-three cases of severe cicatricical adhesion on the submental-thoracic region were treated with release and resection of scar tissue, and delay skin graft. The grafted skin was survived completely after operation. The result from the release of scar tissue of the cervical region was good. The physiological angle of submental-thoracic angle was recovered. It was thought that two-stage operation for submental-thoracic cicatricial adhesion would decrease the risk of operation and be advantageous to the release of contracted soft tissue of anterior cervical region and reduce the recurrence of contracture. The interval between the two stages of the operation was 2 to 3 days, which did not increase the rate of infection of the wound. The shortcomings including increase of pain to patient and prolong the time in hospital.
Objective The intercellular adhesion (ica) gene of Staphylococcus epidermidis (SE) is a key factor to bacterial aggregation, to analysis the genotype of iatrogenic SE and to explore the effect of iatrogenic SE ica operon on theformation of bacterial biofilm on the surface of polyvinyl chloride (PVC). Methods Fifty-six cl inical isolates of iatrogenic SEwere selected, and PCR and gene sequencing were used to detect the genes related with bacterial biofilm formation. The genes contained 16S rRNA, autolysin (atlE), fibrinogen binding protein (fbe), and icaADB. The bacteria suspension of 1 × 105 cfu/mL iatrogenic SE was prepared; according to the test results of target genes, the PVC material and the genotype of icaADB+, atlE+, fbe+ strains were co-cultivated as the ica positive group; the PVC material and the genotype of icaADB-, atlE+, fbe+ strains were co-cultivated as the ica negative group. The thickness of biofilm and bacterial community quantity unit area on PVC materials were measured by confocal laser scanning microscope, and the surface structure of biofilm formation was observed by scanning electron microscope (SEM) at 6, 12, 18, 24, and 30 hours. Results The positive rate of 16S rRNA of iatrogenic SE strains was 100% (56/56). The genotype of icaADB+, atlE+, and fbe+ strains accounted for 57.1% (32/56). The genotype of icaADB-, atlE+, and fbe+ strains accounted for 37.5% (21/56). The sequencing results showed that the product sequences of 16S rRNA, atlE, fbe, and icaADB were consistent with those in GenBank. With time, no significant bacterial biofilm formed on the surface of PVC in ica operon negative group. But in ica operon positive group, the number of bacterial community was gradually increased, and the volume of bacterial biofilms was gradually increased on the surface of PVC. At 24 hours, mature bacterial biofilm structure formed, and at 30 hours, the volume of bacterial biofilms was tending towards stabil ity. The thickness of biofilm (F=6 714.395, P=0.000) and the bacterial community quantity unit area on PVC materials (F=435.985, P=0.000) in ica operon positive groupwere significantly higher than those in ica operon negative group. Conclusion Iatrogenic SE can be divided into 2 types ofica operon negative and ica operon positive bacteria. The iatrogenic SE ica operon can strengthen bacterium biofilm formation capabil ity on PVC materials, bacterium community quantity, and thickness of biofilm, it plays an important role in bacterium biofilm formation on PVC materials.
ObjectiveTo investigate the synergetic effects of the combination methylene blue or/and aprotinin on preventing postoperative intestinal adhesions (POIA).MethodsFourtyeight rabbits were divided into control group (group A), methylene blue group (group B), aprotinin group (group C), methylene blue+aprotinin group (group D). Each group contained 12 rabbits and established models of intestinal adhesions through laporotomy. Fourteen days after operation, the rabbits were reoperated to see whether there were adhesions and the degree of adhesions. ResultsThe adhesions of group A was the most serious, then in sequence were group B, C, group D showed very light adhesion. Group A was much more severe than B, C, D group (Plt;0.01); group D was very different from B, C group (P＜0.05). ConclusionMethylene blue and aprotinin have significant effects on preventing POIA and the combination of the two drugs can have a synergetic effects on POIA.
