[Objective] To study the microstructure of ligamentum fiavum of the early dynamic imbalanced rats.[Methods]The dynamic imbalanced rat mode was established.The samples were taken and studied by electron microscopy at 3、5、15、30、60 days after operation.[Results]A large number of fibroblasts in the ligamentum flavum were found at 3 days after the neck muscles were resected.The fibroblasts had an active metabolism,and around them the collagen fibers were markedly increased at 5 days.The number of fibroblasts was reduced,but the matrices were increased at 15 days.At 30 days,fibroblasts became slender,and fibers looked like waves.At 60 days,the number and appearance of the fibroblasts of the ligamentum fiavum were similar to that of the control group.The fibers were regularly arranged and became larger than that of the colltrol group.[Conclusion]The number of fibroblasts and the collagen fibers in the ligamentum flavum of the dynamic imbanlanced rats has a regular change after operation.

Objective To study the effects of survivin antisense RNA on SGC7901 cell’s apoptosis and chemosensitivity to taxotere, and to investigate its effect on the expression of multi-drug resistance gene-1 (MDR-1). Methods Survivin antisense eukaryotic vector anti-pcDNA3-svv was transfected into SGC7901 cell lines by lipofectamine and positive clones were screened out then. Survivin protein and MDR-1 mRNA were measured by western blot and RT-PCR, respectively. Apoptosis that was induced by anti-pcDNA3-svv was observed by electronic microscope, and the sensitivity of SGC7901 cell to taxotere was examined by MTT. Results The expressions of survivin protein and MDR-1 mRNA in transfected SGC7901 cells both decreased more significantly than that of non-transfected cells (P

BACKGROUND: During xenogenic liver transplantation, major histocompatibility antigen can induce immunological rejection, and immunosuppressant can cause adverse effect on organism. Recently, treatment prior to transplantation induces immune tolerance, which is perspective for organ transplantation.OBJECTIVE: To investigate the correlation between thymus induction and immunological rejection during liver transplantation. METHODS: A total of 40 male SD rats of clean grade were selected as donors. Moreover, 30 male Wistar rats of clean grade and 10 male SD rats of clean grade were selected as recipients. The donor rats were divided into allogeneic gene transplantation, allotransplantation, cyclosporine, and thymus induction groups, with 10 rats in each group. The modified Kamada and improved two-cuff technique was used to establish a stable rat orthotopic liver transplantation model. The cyclosporine group was given cyclosporine (50 mg/kg) for 5 successive days. Thymus induction group was injected with major histocompatibility antigens (50 pL) for 5 successive days. Other groups were not given any interventions. Survival time of rats was recorded in each group. Pathological observation and mixed lymphocyte cultured were performed at days 3, 7, 14, 21, and 28 after transplantation. RESULTS AND CONCLUSION: Survival time was longer in the thymus induced group compared with other groups (> 60 days), damaged level was mild, local immunological rejection was reduced, and lymphocytes were decreased. The effect after liver transplantation was similar to allogeneic gene transplantation but superior to cyclosporine intervention (P < 0.05). This suggested that thymus induction relieved immunological rejection following liver transplantation.

BACKGROUND: Most patients who underwent liver transplantation would suffer acute rejection or transplanted liver failure resulted by chronic rejection, therefore, inducing specific immune tolerance via varied pathways is the ideal method to solve this problem. OBJECTIVE: To treat rat transplanted liver by injecting transforming growth factor β1 (TGF-β_1) plasmid, and to analyze the relationship between TGF-β1 and allograft rejection from gene level. METHODS: A total of 30 male, Wistar rats were served as allogenic liver donors, and 10 male, SD rats served as syngeneic donors Totally 40 male SD rats were served as liver recipients, and divided into 4 groups by order number table: ailogenic transplantation, syngeneic transplantation, ciclosporin, and ciclosporin plus TGF--β_1 groups. In each group, rat orthotopic liver transplantation model was established by modified Kamada and improved two-cuff technique. After modeling, rats were received cyclosporine 1-5 days in the cyclosporine group, or intraperitoneal injected ciclosporin for 1-5 days, combined with TGF-β_1 plasmid 0-2 days in the cyclosporine plus TGF-β_1 group. No intervention was performed in the other groups. The survival time of rats were recorded, and the pathological changes was detected at days 3, 7, 14, 21, and 28 after transplantation, then the mixed lymphocyte culture was performed. RESULTS AND CONCLUSION: The survival time of rats in syngeneic transplantation group and cyclosporine plus TGF-1,β_1 group was more than 60 days, which was obviously greater than that of allogenic transplantation and cyclosporine groups (P< 0.05). The histopathologic slide showed that there was moderate and severe acute rejection, with evident intrahepatic inflammatory cell infiltration in the allogenic transplantation and cyclosporine groups. Few rejections were observed in the syngeneic transplantatior group, which was close to the normal lever tissues. Mixed lymphocyte culture of the cyclosporine plus TGF-β_1 group was superior to the syngeneic transplantation group or cyclosporine group (P < 0.05). The results demonstrated that cyclosporine combined with local injection of TGF-β_1 plasmid can relieve post-transplant immune rejection.

BACKGROUND: A small number of mesenchymal stem cells (MSCs) present in bone marrow, which would gradually drop with age. OBJECTIVE: To verify the effect of adherent method on culture of bone marrow-derived MSCs. METHODS: Under anaesthesia, bone marrow cells were obtained from femur and tibia of rats, cultured by DMEM containing calf serum, placed in an incubator containing 5% CO_2 at 37 ℃. The culture medium was renewed after 24 hours, and remained periodical medium change with once per week. The weakly adherent cells were passaged. The cell morphology, growth curve, and the expression of cell-surface markers were identified by flow cytometry and immunocytochemical staining. RESULTS AND CONCLUSION: After 24 hours of culture, the cells could adhere to the walls with fusiform or triangle shapes, proliferated faster after 2-3 days, and presented whirlpool-like or clustering. The cells reached a logarithmic growth phase after 2 days, and into the late stationary phase after 12 days, which covered the bottle after 15 days. The cultured cells were positive to CD90 and CD54. The results verified that bone marrow-derived MSCs can be isolated by adherent method. This method is easy operation, and can maintain cell activity preferably.

BACKGROUND:Calcium phosphate cement and recombinant human bone morphogenetic protein-2 both have bone osteoinductivity. Maybe both of them could promote repair of tendon-to-bone interface damage. OBJECTIVE:To evaluate the effect of calcium phosphate cement-II containing recombinant human bone morphogenetic protein-2 on tendon-to-bone interface healing after rotator cuff injury . METHODS: Twenty-seven adult healthy rabbits were enroled in the study. The tendon-to-bone interface of the bilateral shoulder joints was taken from three rabbits as normal group, and the bilateral shoulder joints of the other 24 rabbits were subjected to acute rupture of the rotator cuff and tendon-to-bone reconstructive surgery as experimental group (n=12) and control group (n=12). Rabbits in the experimental group were treated with calcium phosphate cement-II, while those in the control group treated with nothing. Specimens were colected at 2, 4, 8 postoperative weeks for biomechanical test. RESULTS AND CONCLUSION:The maximum tensile strength of the rotator cuff in the experimental group was higher than that in the control group (P < 0.001), but lower than that in the normal group (P < 0.001). At postoperative 8 weeks, the rigidity of rotator cuff of the experiment group was higher than the control group (P < 0.001) but lower than the normal group (P < 0.001). These findings indicate that calcium phosphate cement-II can improve the maximum tensile strength and rigidity of rabbit tendon-to-bone interface in the early postoperative period, enhance tendon-to-bone interface binding force, and promote tendon-to-bone interface healing.

Objecttive To investigate the possibility of repairing articular cartilage defects with the mesenchymal stem cells (MSCs)- seeded type Ⅰ collagen-glycosaminoglycan(CG) matrices after being cultured with the chondrogenic differentiation medium.Methods The adherent population of MSCs from bone marrow of 10 adult dogs were expanded in number to the 3rd passage. MSCs were seeded into the dehydrothennal treatment (DHT) cross-linked CG matrices; 2 × 106 cells per 9-mm diameter samples were taken.Chondrogenic differentiation was achieved by the induction media for 3 weeks. Cell contractility was evaluated by the measuement of the cell-mediated contraction of the CG matrices with time in culture. The in vitro formation of the cartilage was assessed by an assay employing immunohistochemical identification of type Ⅱ collagen and by immunohistochemistry to demonstrate smooth muscle actin (SMA).The cells seededing CGs were implanted into cartilage defects of canine knee joints. Twelve weeks after surgery, the dogs were sacrificed and results were observed. Results There was significant contraction of the MSCs-seeded DHT cross-linked CG scaffolds cultured in the cartilage induction medium. After 21 days, the MSC-seeded DHT cross-linked matrices were contracted to 64.4% ± 0.3%; histologically, the pores were fotmd to be compressed and the contraction coupled with the newly synthesized matrix, transforming the MSCsseeded CG matrix into a solid tissue in most areas. The type Ⅱ collagen staining was positive. The SMA staining was positive when these MSCs were seeded and the contracted CGs were implanted into the cartilage defects of the canine knee joints to repair the cartilage defects. The function of the knee joints recovered and the solid cartilaginous tissue filled the cartilage defects. Conclusion The results demonstrates that MSCs grown in the CG matrices can produce a solid cartilaginous tissue containing type Ⅱ collagen after being cultured with the chondrogenic differentiation medium and implanted into cartilage defects. We hypothesize that the following steps can be performed in the chondrogenic process: ①MSCs express SMA, resulting in matrix contraction, thus achieving a required cell density (allowing the cells to operate in a necessary society); ②Cells interact to form a type Ⅱ collagen-containing extracellular matrix (and cartilaginous tissue); ④Other factors, such as an applied mechanical stress, may be required to form a mature cartilage with the normal architecture.

BACKGROUND: Tibia open fracture is a common disease, and intramedullary fixation has become the first choice, but the high risk of postoperative infection limits its clinical application.OBJECTIVE: To investigate the early prevention effect of vancomycin-hydroxyapatite (VCM-HA) coated titanium intramedullary nail in a rabbit model of open femoral fracture combined with wound infection.METHODS: Titanium intramedullary nails coated with three different concentrations of VCM-HA were prepared using biomimetic deposition, and subsequently in vitro bacteriostasis experiment was performed. Forty healthy male New Zealand white rabbits were selected and the model of mid-femur open fracture with wound infection was prepared. The rabbit models were then divided into ordinary intramedullary nail, low-, middle- and high-concentration VCM-HA coated intramedullary nail groups (n=10 per group). The wound appearance of the animals was dynamically observed. The body mass, anal temperature, white blood cells and C-reactive protein contents in the venous blood were monitored. The pathological examination of the soft tissue around the fracture and injured limb X-ray were conducted regularly.RESULTS AND CONCLUSION: The prepared VCM-HA coated titanium intramedullary nail exerted obvious antibacterial effects in vitro. The anal temperature in the ordinary nail group was significantly higher than that in the other three groups at 3 days after modeling (P < 0.05). The white blood cells and C-reactive protein contents in the venous blood in the VCM-HA groups were significantly lower than those in the ordinary nail group at 3, 7, 14 and 28 days after modeling (P < 0.05). The hematoxylin-eosin staining of the peripheral tissues displayed the inflammatory response in the VCM-HA groups was milder than that in the ordinary nail group at each time point after modeling. The injured limb X-ray displayed that the callus grew slowly accompanied with sequestration in the ordinary nail group, while the callus growth in the VCM-HA groups was significantly better than that in the ordinary nail group. To conclude, the VCM-HA coated intramedullary nail can effectively reduce postoperative infection in an animal model of open femoral fracture combined with wound infection.

Objective To investigate the profile and antibiotic resistance of bacteria in patients with ascites infection in intensive care unit (ICU) patients in order to provide a reference for rational clinical use of antibiotics. Methods A retrospective analysis was conducted. The bacteria isolated from ascetic fluid patients admitted from January 1st, 2004 to October 31st, 2015 to ICU of the First Affiliated Hospital of Anhui Medical University were identified, and their susceptibility to antibiotics was analyzed. Patients, who were admitted from January 1st, 2004 to December 31st, 2009 were assigned to group A, and patients admitted afterwards were assigned to group B. Results A total of 637 specimens of ascetic fluid were examined, with 185 positive culture (29.0%) during the 12 years, and 203 strains of bacteria were found. Among them 126 strains (62.1%) of gram-negative bacteria (G-), 54 (26.6%) of gram-positive bacteria (G+) and 23 (11.3%) strains of fungi were found. Compared the result of group B with that of group A, the proportion of G- bacteria was increased [71.2% (99/139) vs. 44.2% (27/64)], and that of G+ decreased [17.3% (24/139) vs. 46.9% (30/64)] in group B. The difference was statistically significant (χ2 = 20.34, P = 0.001). The main pathogenic bacteria were G-, and Enterobacteriaceae was the most common pathogenic bacteria in intra-abdominal infection of ICU patients. The isolation rate of Escherichia coli and Klebsiella pneumoniae(35.7%, 10.3%) ranked in the first and third in G- bacteria, respectively. The resistant rate of Escherichia coli against penicillin and third generation cephalosporin were > 95.0% and > 73.3%, and it showed a sensitive rate of 70% to β-lactam/inhibitor, amikacin and minocycline, and a higher sensitivity to carbapenems and tigecycline (11.1%, 0). Forty-eight strains of non-fermentation bacteria were found with a rate of 23.7%. The positive rates of Acinetobacter baumannii in groups A and B were 7.8% (5/64) and 23.7% (33/139), respectively, and they ranked first among non-fermentation bacteria. Twenty strains (62.5%) multidrug-resistant Acinetobacter baumannii were found. Acinetobacter baumannii showed a resistance rate of 84.6% to cefoperazone/sulbactam, 35.3% to minocycline, and 53.3% to tigecycline. Candida albicans was the most commonly isolated fungus in intra-abdominal infections (87.5%). No strains resistant to common antifungal drugs were isolated. Conclusions G- bacteria was the main pathogen in intra-abdominal infection in patients with ascites. Non-fermenters showed an increasing trend of producing infection, and the proportion of multidrug-resistant Acinetobacter baumannii infection increased year by year, and more attention should be taken by attending doctors.

Background and Objectives The relationship between left atrial (LA) size and congestive heart failure (CHF) is well recognized;however, there is little information on the association of pulmonary vein (PV) diameter and CHF.The purpose of this study was to investigate the changes of PV and LA sizes in CHF patients by multislice computed tomography (MSCT) angiography using a new 64-slice scanner. Methods and Results We assessed diameters of PVs ostium and LA by 64-slice MSCT with three-dimensional reconstruction in 25 CHF patients and in 26 age- and sex-matched non-CHF controls. Compared with controls, CHF patients showed significant greater diameters of left superior pulmonary vein (LSPV) and right inferior pulmonary vein (RIPV) in both anteriorposterior(AP) and superior-inferior (SI) directions (P＜0.01), significant dilation of right superior pulmonary vein (RSPV) in AP direction (P＜0.05), as well as significant increase of LA transverse, AP, and SI diameters (P＜0.01). Conclusion Significant dilation of PVs with simultaneous LA enlargement was demonstrated in CHF patients. This anatomic and geometric changes may participate in the perpetuation of AF.