Objective To study the adhesion-preventing effect of basic fibroblast growth factor(bFGF) combined slow-releasing degradable membrane.Methods The bFGF combined slow-releasing degradable membrane was made from bFGF and the reagent which could promote fibrinogen synthesize. Sixty-six SD rats were divided into groups A,B,C randomly (22 rats each group). In group A, sutured achilles tendon were encapsulated with bFGF combined slow-releasing degradable membrane;in group B, sutured achilles tendon were encapsulated with degradable membrane without any drug; in group C, achilles tendon were only sutured. Ninety days later, light-microscope, electronmicroscopoe, figureanalysing, hydroxyproline content, extent of peritendon adhesion and biomechanic test were evaluated.Results ①The amount of fibroblast and fibrinogen inside the sutured tendon in group A was larger than that inits peripheral connective tissue and in groups B and C (P＜0.05). Thecontent of hydroxyproline and the ultimate tensile strength in group A was higher than those in groups B and C(P＜0.01).② The peripheral tissue in group A almostremains the formal loose connective tissue, but it became dense connective tissue in groups B and C and grew into the tendon. Moreover, the extent of adhesion in group A was lesser than that in groups B, C according to the mensuration of peritendon adhesion.Conclusion The bFGF combined slow-releasing degradable membrane can make the intrinsic healing of tendon faster than peripheral
ObjectiveTo investigate the effect of Smad4 on the fibrosis of tendon derived fibroblasts (TDFs) induced by transforming growth factor β1(TGF-β1) by targeted regulation of miRNA219-5P (miR219-5P). MethodsThe tendons donated by the volunteers were harvested to isolate and culture TDFs. The 3rd generation cells were used for experiment. Chemically synthesized miR219-5P mimics, miR219-5P inhibitor, and negative control sequences were transfected into TDFs. The gene expression of miR219-5P in TDFs was detected by real-time PCR, and the protein expression of Smad4 in TDFs was detected by Western blot at 48 hours after transfection. The combining sites of miR219-5P and Smad4 in 3'UTR district were predicted by informatics software. Wild type and mutant type reporter gene expression vectors were constructed and then targeted verification was carried out by the luciferase reporter gene test. Transfected TDFs were then induced by TGF-β1. The proliferation activity of the cells were measured by the cell counting kit 8 after culturing for 24, 48, and 72 hours. The expressions of fibrosis related proteins in TDFs were detected by Western blot at 72 hours. ResultsAfter TDFs were transfected by miR219-5P mimics, miR219-5P expression was significantly up-regulated, but the expressions of Smad4 was decreased subsequently (P<0.05). Intracellular expression of miR219-5P was inhibited by miR219-5P mimics inhibitor, however, the protein expression of Smad4 was significantly increased (P<0.05). Luciferase reporter gene test showed that luciferase activities were significantly decreased in pGL3-WT-Smad4+mimics group, but were significantly increased in pGL3-WT-Smad4+inhibitor group when compared with pGL3-WT-Smad4 transfected group (P<0.05), but no significant difference was found between GL3-MT-Smad4+mimics and pGL3-MT-Smad4+inhibitor groups (P>0.05). Cell proliferation and the fibrosis related proteins were increased in TGF-β1 induced TDFs, however, decreased in TGF-β1 induced TDFs after transfected by miR219-5P inhibitor (P<0.01). ConclusionmiR219-5P can significantly inhibit fibrosis of TDFs induced by TGF-β1 by down-regulating Smad4 expression.
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.
Objective To investigate the protective effects of endotoxin pretreatment on lung injury of rats with endotoxemia. Methods The rat model of acute endotoxemia was established by injecting lipopolysaccharide (LPS) intraperitoneally. Seventy-two male Wistar rats were randomly divided into three groups, ie. a saline control group (N, n=24) , a LPS-treated group (L, n=24) , and a LPS pretreated group ( P, n=24) . Each group was divided into 2 h, 4 h, 6 h, and 12 h subgroups. The rats in group P were firstly administered with introperitoneal injection of 0.25 mg/kg LPS. After 24 hours, they were subjected to the injection of 0.5 mg/kg LPS. The rats in group N and L received injection of equivalent amount of saline. After 72 hours, the rats in group L and P were challenged with intravenous injection of 10 mg/kg LPS, otherwise saline in group N. Six rats were killed at 2, 4, 6 and 12 hours respectively after injection of LPS in group L and P. The lungs were removed for detecting intercellular adhesion molecule-1 ( ICAM-1) , superoxide dismutase ( SOD) , and malondialdehyde (MDA) . Meanwhile the level of tumor necrosis factoralpha ( TNF-α) in serum was measured, and the pathological changes of lung were also examined. Results The contents of ICAM-1, MDA and TNF-α in the LPS-treated 4 h group were 75.07 ±0. 53, ( 3.93 ± 0.42) μmol/g, and (478.62 ±45.58) pg/mL respectively, significantly higher than those in the saline control group. The endotoxin pretreatment reduced the above indexes to 42.40 ±0.44, ( 2.89 ±0.49) μmol / g and ( 376.76 ±43.67) pg/mL respectively (Plt;0.05) . The content of SOD in the LPS-treated 4 h group was ( 6.26 ±0.31) U/mg, significantly lower than that in the saline control group. The endotoxin pretreatment increased SOD to ( 8.79 ±0.35) U/mg. Conclusion Endotoxin pretreatment can suppress the progress of lung injury in rats with endotoxemia and protect the lung tissue by down-regulating the inflammatory response and oxygen free radical production.
Objective To investigate the relationship between expression of retinal intercellular adhesion molecule-1 (ICAM-1) and blood-retinal barrier (BRB) rupture and therapeutic effect of intravitreous injection with triamcinolone acetonide (TA) on blood-retinal barrier rupture in rats with diabetes mellitus (DM). Methods Diabetic model of Wistar rats was induced and were divided into normal control group, DM-4-month group and DM-6-month group. Each group was subdivided into immunohistochemcial staining and BRB measurement groups. BRB measurement group was further divided into non-TA treatment group, 1-week-TA treatment group, and 2-week-TA treatment group. The rats were intravitreously injected with 5 mu;l TA. The digested retinal preparation was stained by immunohistochemcial method to observe the expression of retinal ICAM-1 and morphological changes. The mean optic density (A) value of endothelial cells was measured by image-analyzing software to quantify the expression of ICAM-1. BRB changes were measured by content test of retinal Evans blue (EB). Results In the immunohistochemcial staining groups, there was no significant positive expression of ICAM-1 in retinal capillary in control group. Compared with the control, there was significant positive expression of ICAM-1 in DM-4-month group (P＜0.001) with some morphological changes such as irregular width of capillary caliber, and there was enhanced positive expression of ICAM-1 in DM-6-month group (P＜0.001) with aggravated morphological changes and even acellular capillary. In the BRB measurement groups, there was no significant difference of EB content(P＞0.05) among control groups. The EB content in two DM groups significantly increased compared with that in the controls (Plt;0.001), and higher in DM-6-month group than that in DM-4-month group (Plt;0.01). In TA treatment groups, the EB content in all the DM groups significantly decreased (Plt;0.001) but with no significant difference among the groups(P＞0.05). EB content in DM-4-month group after 2-week treatment almost reached to normal value (P＞0.05) while was higher in the rest of TA treatment groups than that in the control group (Plt;0.05). Rectilinear correlation between A value of endothelial cells and the retinal EB content(r=－0.959)was found. Conclusion There is a positive relation between the expression of ICAM-1 and BRB rupture in retina of DM rats, and intravitreous injection with TA can effectively alleviate BRB rupture. (Chin J Ocul Fundus Dis, 2006, 22: 24-27)
Objective To observe whether Cyclo-RGDfK (Arg-Gly-Asp-D-Phe-Lys) could enhance the adhesion of myofibroblast to decellularized scaffolds and upregulate the expression of Integrin αVβ3 gene. Methods Myofibroblast from the rat thoracic aorta was acquired by primary cell culture. The expression of Vimentin and α-smooth muscle actin(α-SMA) has been detected by immunoflurescent labeling. Decellularized valves have been randomly divided into three groups (each n=7). Group A (blank control): valves do not receive any pretreatment; Group B: valves reacted with linking agent NEthylN(3dimethylaminopropyl)carbodiimide hydrochloride (EDC) for 36 hours before being seeded; Experimental group: Cyclo-RGD peptide has been covalently immobilized onto the surface of scaffolds by linking agent EDC. The fifth generation of myofibroblast has been planted on the scaffolds of each group. The adhesion of myofibroblast to the scaffolds was evaluated by HE staining and electron scanning microscope. The expression of Integrin αVβ3 was quantified by halfquantitative reverse transcriptionpolymerase china reaction (RT-PCR). Results We can see that myofibroblast has exhibited b positive staining for Vimentin and α-SMA. Besides, it has been shown that the expression of Integrin αVβ3 was much higher in the experimental group than that of the group A and group B(Plt;0.05). There was no statistically difference in group A and group B (P=0.900). Conclusion RGD pretreatment does enhance the adhesive efficiency of seeding cells to the scaffolds and this effect may be related to the upregulation of Integrin αVβ3.
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 preventive effect of carbachol on the formation of postoperative intra-abdominal adhesion. Methods Forty-four Wistar rats were randomly divided into sham operation group (SO group, n=12), operation group (n=16) and carbachol treated group (carbachol group, n=16, carbachol 50 μg/kg). Animal model of abdominal adhesion was established by rubbing the procussus vermiformis of cecum with dry sterile gauze, and by clamping and scuffing abdominal wall. Half of rats were separately killed on day 7 and day 14 after surgery, respectively. The degree of adhesion was evaluated according to Phillips 5-scale grade and the feature of this model. The histopathological changes of adhesive tissues were observed and the content of collagen type Ⅰ in the tissues was detected by immunohistochemistry. Results The scores of intra-abdominal adhesion were significantly lower in the carbachol group than those in operation group both on 7 d and 14 d (P＜0.01). Mild inflammatory changes and less fibrous proliferation were observed in carbachol group microscopically. The contents of collagen type Ⅰ detected by immunohistochemistry were significantly lower in the carbachol group than those in operation group both on 7 d and 14 d (P＜0.01). There was no significant difference of the score of abdominal adhesion and content of collagen type Ⅰ in the same group between 7 d and 14 d (Pgt;0.05). Conclusion Carbachol may take a significant role in the prevention of postoperative abdominal adhesion in rat.
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.
ObjectiveTo review the research progress of medicine biomaterials in prevention and treatment of adhesion after tendon injury, and to provide reference for clinical treatment.MethodsThe literature on the application of medical biomaterials in the prevention and treatment of tendon adhesions in recent years was reviewed, and the biological process, treatment methods, and current status of tendon adhesions were summarized.ResultsTendon adhesion as part of the healing process of the tendon is the biological response of the tendon to the injury and is also a common complication of joint dysfunction. Application of medical biomaterials can achieve better biological function of postoperative tendon by reducing the adhesion of peritendon tissues as far as possible without adversely affecting the tendon healing process.ConclusionThe use of medical biomaterials is conducive to reduce the adhesion of tendon after operation, and the appropriate anti-adhesion material should be selected according to the patients’ condition and surgical needs.