OBJECTIVE: To investigate the influence of basic fibroblast growth factor (bFGF) on adhesion characteristics of osteoblasts, aimed at the important problem in bone tissue engineering of how to promote the adherence of osteoblasts to extracellular matrix materials. METHODS: 5 ng/ml, 10 ng/ml, 50 ng/ml, 100 ng/ml, 200 ng/ml bFGF were used to induce bone marrow stromal-derived osteoblasts of rabbit for 24 hours before incubation, and the common culture medium as the control. The attached cells were calculated with stereology method at 0.5 hour, 1st hour, 2nd hour, 4th hour, 8th hour after seeding. RESULTS: The number of attached cells was significant higher in the experimental group when induced by 10 ng/ml bFGF than that in the control group (P lt; 0.01); the number did not increase with the increase of bFGF concentration and there was no significant difference between the experimental group induced by 100 ng/ml bFGF and control group, and the number was even obviously lower in the experimental group when induced by 200 ng/ml than the control group (P lt; 0.01). CONCLUSION: bFGF can influence the adhesion characteristics of osteoblasts, 10 ng/ml bFGF can promote the adherence of osteoblasts to matrix materials, but 200 ng/ml bFGF may inhibit cell adhesion.
Objective To explore the expression of the vascular cell adhesion molecule 1 (VCAM1) in the acellular dermal matrix grafting in pigs. Methods Experimental models were established with 15 Inbred Strain mini pigs, 6 full-thichness skin defect wounds, 6 cm × 6 cm in size, were produced on both-side backs of the each pig, and then the pigs were randomly divided into 3 groups. In Group A (n=5, control) the thin auto-skintransplantation alone was made; in Group B (n=5), the grafting was performed in the acellular allo-dermal matrix combined with the thin auto-skins; in Group C (n=5), the grafting was performed in the acellular xeno-dermal matrixcombined with the thin auto-skins. The areas of the wounds were measured and the survival condition of the grafted skins was observed at 3, 9, 21 and 30 days after the grafting. The histological samples were harvested from the grafting area at 3, 6, 9, 12, 21 and 30 days after the procedure. The flow cytometry was employed to analyze the changes in the VCAM1 level in the sample at different time points after the grafting. Results In the 3 groups, the transplanted skin base was easily separated at 3 days after transplantation; the areas of the wound healing accounted for 94%±12%，92%±9%, and 91%±11%, respectively, at 21 days; good wound healing was achieved at 30 days. At 9 and 12 days after transplantation, there was an evidentlyincreased level of the VCAM-1 expression in the tissue samples in the composite skin grafting groups. Compared with the control group, the difference was significant (Plt;0.05); however, the VCAM-1 expression at 3 days was not statistically different between the composite skin grafting groups and the control group after transplantation. In contrast, the level of the VCAM-1 expression was significantly higher at 6 days in the control group than in the composite skin grafting groups (Plt;0.05). The levels of the VCAM-1 expression were significantly lower at 30 days than at 3 days after transplantation in all the 3 groups (plt;0.01). Conclusion The highest level of the VCAM-1 expression can be delayed in the composite skin grafting when compared with that in the thin auto-skins alone, which implies that the VCAM-1 expression may be correlated with angiogenesis and composite skin survival. The VCAM-1 expression is not different between the acellular allo-dermal matrix composite skin grafting groups and the acellular xeno-dermal matrix group.
ObjectiveTo explore the changes of focal adhesion kinase (FAK) in the fibrotic atrium of patients with valvular atrial fibrillation and explore its downstream signaling pathways.MethodsA total of 45 patients with mitral valve disease were included in this study and were divided into a valvular atrial fibrillation group (VAF, ≥6 months, 25 patients) and a sinus rhythm group (SR, 20 patients) based on having atrial fibrillation or not. The atrial appendage tissue was obtained during the operation , histopathological examination and Western blotting were performed. The degree of atrial fibrosis and changes in FAK and its downstream pathways in fibrotic myocardium were observed.ResultsThis study revealed a higher degree of atrial fibrosis in valvular atrial fibrillation and disordered cell arrangement. Expression of fibroblast differentiation marker alpha smooth muscle actin (α-SMA) was significantly increased in atrial fibrillation, and the expression of FAK and downstream AKT/S6K pathway proteins was up-regulated, while the other signal was observed, there was no significant change in ERK1/2 signaling pathway.ConclusionAtrial fibrosis in valvular atrial fibrillation is an important feature of atrial structural remodeling. We found overproduction of collagen fibers disrupted the continuity of atrial myocytes, leading to abnormal conduction and providing a matrix environment for the development of atrial fibrillation. The expression of focal adhesion kinase and downstream AKT/S6K signaling pathway in fibrotic myocardium may be involved in the process of atrial fibrosis, providing a basis for the study of its mechanism.
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.
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 expression of nuclear factor (NF)-κB and intercellular adhesion molecule (ICAM)-1 in rat′s retina injured by ischemia-reperfusion, and the effect of pyrrolidine dithiocarbamate (PDTC) on the expression of NF-κB and ICAM-1. Method The model of retinal ischemia-reperfusion was set up in 60 SD rats, which were divided into two groups with 30 rats in each: ischemia-reperfusion group and ischemia-reperfussion with injection of PDTC group. The left cephalic artery of each rat was ligated, and the right side was the control. Every group was subdivided into group 1 hour, 6, 12, 24, 48, and 72 hours after ischemia-reperfusion injury, and with 5 rats in each group. mRNA of NF-κB and ICAM-1 mRNA was measured by in situ hybridization (ISH) method in rat′s retina. Every rat underwent electroretinography (ERG) at the corresponding time before executed by neck breaking. Results In ischemia-reperfusion group, expression of NF-κB and ICAM-1 was detected at the 6th hour after ischemia-reperfusion, reached the highest level at the 24th hour, and weakened gradually later. In ischemia-reperfusion with injection of PDTC group, expression of NF-κB and ICAM-1 was detected at the 12th hour after ischemia-reperfusion, and reached the highest level at the 24th hour but lower than that in ischemia-reperfusion group. No expression of NF-κB and ICAM-1 was found in the control group. The relative recovery rate of ERG a and b wave amplitude in ischemia-reperfusion groups was lower than that in ischemia-reperfusion with injection of PDTC group at every stage(P＜0.01 ). The lowest relative recovery rate of ERG a and b wave amplitude in different stages in both of the 2 groups was at the 24th hour(P＜0.01). Conclusions NF-κB and ICAM-1 may play an important role in retinal ischemia-reperfusion injury, as the inhibitor of NF-κB, PDTC may relieve the retinal ischemia-reperfusion injury. (Chin J Ocul Fundus Dis，2004，20：175-178)
Abstract: Objective To study the preventive effect of n-3 polyunsaturated fatty acids on allograft arteriosclerosis. Methods Arterial homeotransplant model were created with 480 rats which were divided into four groups. Control group, no n-3 lyunsaturated fatty acids were taken. Group A, n-3 polyunsaturated fatty acids were taken for two weeks before operation with the dose of EPA 600mg/kg. Group B, 300 mg/kg and group C 150 mg/kg were taken respectively. The recipient’s transplanted vessel was excised after 1,7,14,21and 28 days respectively. The tissue pathological variations, ultrastructure variations and expression variations of intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1（VCAM-1）, nuclear factorkappa B（NF-κB） had been observed. Results The pathological changes occurred 7 days after operation in control group and were most prominent on the 28th day, blood vessels were obstructed and the expressions of ICAM-1, VCAM1,NF-κB were markedly intensified than those of group A, B, C (Plt;0.05). The pathological variations of transplanted vessel in group A, B, C occurred later than those in control group. The nonobstruction rates in group A, B, C were better than that in control group. The expressions of ICAM-1， VCAM-1， NF-κB in control group were ber than those in group A， B， C (Plt;0.05). The expressions of ICAM-1， VCAM-1， NF-κB after 1 day or 7 days demonstrated no statistically significant change in group A， B， C （Pgt;0.05）. The preventive effect for allograft vessel atheromatosis in group A and group B was ber than that in group C after 14, 21 and 28d (Plt;0.05). There were no significant difference between group A and group B (Pgt; 0.05). Conclusion The n-3 polyunsaturated fatty acids can prevent the allograft vessel atheromatosis, the most effective dose of n-3 polyunsaturated fatty acids is 300 mg/kg.
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.
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 To study the relationship between expression of nm23, CD44 in gastric carcinoma and lymph-node metastasis and prognosis. Methods Expression of nm 23, CD44H and CD44V6 in 105 cases of gastric carcinoma were assayed by immunohistochemistry. Among them, 59 cases were followed up. Results The incidences of nm23, CD44H and CD44V6 protein positivity in gastric carcinoma were 44.8%, 54.3% and 48.6% respectively. The positive expression of nm23, CD44V6 protein in human gastric carcinoma tissues was related to the differentiation, depth of invasion, TNM stage and prognosis (Ｐ＜0.05), but expression of CD44H was not correlated with other clinicopathologic indices. The reactivity to these three antibodies were correlate with metastasis of lymph nodes (Ｐ＜0.01 for CD44V6 and Ｐ＜0.05 for nm23, CD44H). Conclusion Expression of the standard form of CD44 (CD44H) might be useful in observing the progression of the disease, wile CD44V6 and nm23 hold promise as a prognostic indicator.