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Objective To observe the effect of sustained release type Ⅰ collagen-vascular endothelial growth factor (VEGF) on healing of bone-tendon junction injuries.Methods Partial patellectomy was conducted in 72 rabbits divided equally into control group,type Ⅰ collagen group,and collagen type Ⅰ-VEGF group.The scaffold was planted into the bone-tendon interface.Animals were sacrificed at 4,8 and 12 weeks.New bone formation into the patella-patella tendon surface was detected using X-ray films and histological observations.Quality of bone healing was assayed using biomechanical testing.Results At postoperative 4,8 and 12 weeks,X-ray films showed bone formation of type Ⅰ collagen group [(4.1 ± 0.4) mm2,(12.1 ± 0.5) mm2,(13.0 ± 1.2) mm2 respectively] and of collagen type Ⅰ-VEGF group [(3.8 ± 0.4) mm2,(11.0 ± 0.5) mm2,(13.1 ± 1.0) mm2 respectively] were more than that of control group [(2.1 ± 0.6) mm2,(4.1 ± 0.3) mm2,(6.6 ± 0.6) mm2 respectively] (P ＜ 0.05).Histology identified few new bone,massive fibrocyte accumulation and disrupted alignment of tendon fiber in control group,massive new bone formation,neat and orderly alignment of collagen fiber tissues and massive aggrecan expression at postoperative 4 and 8 weeks (fibrous cartage repair in largely) in collagen type Ⅰ-VEGF group,and massive new bone formation but worse alignment of tendon collagen fibers and less aggrecan expression (fibrous repair in largely) in type Ⅰ collagen group.Biomechanical test showed the ultimate tensile strength increased over time in all groups,with significantly higher value at 12 weeks than that at 4 and 8 weeks.At the same time point,ultimate tensile strength ranged in an order as follows:collagen type Ⅰ-VEGF group ＞ collagen type Ⅰ group ＞ control group (P ＜ 0.05).Conclusion Sustained release type Ⅰ collagen-VEGF can accelerate early healing of bone-tendon junction injury and improve the histological and mechanical properties.
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Objective To investigate the effect of mixed-skin grafting with autologous microskin and allogenetic acellular dermal matrix microskin on wound healing in rats,and to make a further study on the related mechanism.Methods Wistar rats were served as a allogenetic acellular dermal matrix donor rats,and SD rats as acceptors with mould of full thickness skin defects on their back.The ninety SD rats were divided into 5 groups with 18 rats in each group.Group 1 was transplanted with autologous microskin,and group 2 with allogenetic acellular dermal matrix microskin.Groups 3,4 and 5 were grafted with mixed-skin ratio between autologous microskin and allogenetic acellular dermal matrix microskin 1 ∶ 1,1 ∶ 0.5 and 1 ∶ 0.25,repectively.The rate of wound healing was measured,wound samples collected,hematoxylin and eosin stain carried out,fibronectin (FN) and laminin (LN)detected,and intergroup comparison made,respectively,2,3 and 4 weeks after skin grafting.Results The wound healing rates and FN and LN expression of mixed-skin grafting groups were higher than those of the group with autologous microskin grafting.The group of 1 ∶ 0.25 obviously increased (P＜0.05 or P＜0.01).Conclusions The wound healing rate with mixed-skin grafting is higher than that with autologous microskin grafting.The best effect is achieved when the skin ratio between autologous microskin and allogenetic acellular dermal matrix microskin is 1 ∶ 0.25.It is possibly due to the increase of FN and LN on wound skin surface.
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ObjectiveTo establish rabbit knee joint cartilage injury models to evaluate effects of the type Ⅱ collagen sponge in repair of the articular cartilage.MethodsThe type Ⅱ collagen sponge was prepared according to previous method and the pore size of the sponges was measured based on the collagen autofluorescence characteristics.The type Ⅱ collagen sponge was transplanted into the injury lesions of the animal model for experimental study.The regeneration of the cartilage defects was observed by using MRI, histologic HE staining, Safranin O, sirius red polarized light staining, areas determination of the newly grown cartilage and immunohistochemistry of type Ⅱ collagen.ResultsAutofluorescent images of confocal microscope layer scanning showed that the pore size was (93.26 + 38.40) μm in diameter, suitable for chondrocyte growth.Comparison between MRI and H&E staining results showed quicker effusion absorption in the treatment groups than that in the control group, while the level of inflammatory response in the treatment group was lower than that in the control group.The sporadic cartilage signals first appeared at the 6th week.The newly formed cartilage with the expression of glycosaminoglycan and type Ⅱ collagen matrix was confirmed by Safranin O staining and immunohistochemical analysis.The sirius red polarized light staining showed that areas of the newly formed cartilage were significantly larger in the treatment group than that in the control group (P ＜ 0.01).Conclusion The type Ⅱ collagen sponge developed from purification can effectively repair the damaged cartilage tissues of the rabbit knee joints, as has been verified either by MRI or histology.
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Objective To investigate the effect of 15d-PGJ2 on the expression of collagen type,CTGF and a-SMA in the hypertrophic scar in the rabbit ear,and the possibility of hypertrophic scar treated by 15d-PGJ2.Methods 18 New Zealand white rabbits were used to establish a hypertrophic scar model on the rabbit ear.The wounds were established as follows:2 cm × 3 cm wounds with total skin loses on the ventral side,2 wounds for each ear,totally 72 wounds.The wounds were randomly divided into the 15d-PGJ2 treatment group and NS control group.20μl 15d-PGJ2 or NS was injected into the ear scar once a day for 7 days.At 7,14 and 21 days after the injection,12 scars of each group were harvested.The expression of collagen type Ⅰ,CTGF and a-SMA was detected by immunohistochemical method.Results Excessive dermal scars on rabbit ears that were similar to human hypertrophic scar appeared in the two groups.Compared with the NS-treated scars group,the 15d-PGJ2-treated scars appeared to be smaller,softer,flatter and lighter in color.The expression of collagen type Ⅰ,CTGF and a-SMA in the 15d-PGJ2 group was significantly decreased as compared with that in the control group at different time points(P＜0.05).Conclusion 15d-PGJ2,the ligand of PPAR-r,can reduce the expression of collagen type Ⅰ,CTGF and a-SMA of hypertrophic scar in the rabbit ears and plays an important role in the prevention and treatment of hypertrophic scar.It may provide a new approach for the treatment of hypertrophic scar in clinical setting.
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Objective To discuss the value of Fisher discriminant analysis of serum progesterone and the growing rate of β-human chorionic gonadotropin in the prediction of early ectopic pregnancy. Methods 66 patients with ectopic pregnancy (11 cases were successfully treated expectantly and 55 cases were treated surgically including 40 cases of rupture of fallopian tube and 15 cases of tubal abortion) and 55 patients with intrauterine pregnancy and 50 patients with threatened abortion were chosen. Serum progesterone,β-HCG,48 hβ-HCG and the 48 h growing rate of β-HCG in each group were measured and a Fisher discriminant analysis was used. Results The serum progester-one was (30.27± 18.20) nmol/L in ectopic pregnancy group,( 108.44±23.27 ) nmol/L in intrauterine pregnancy group and (91.68±34.90) nmol/L in threatened abortion group. The first β-HCG was ( 3767.63 ± 3530.38 ) U/L in ectopie pregnancy group,(29 028.65 ± 10 874.01 )U/L in intrauterine pregnancy group and (13 457.47±16 367.65)U/L in threatened abortion group. The second β-HCG was (4349.24±3536.22)U/L in ectopic pregnancygroup,(56 139.46 ± 23 296.87 ) U/L in intrauterine pregnancy group and (23 270.63 ± 23 811.68 ) U/L in threat-ened abortion group. The growing rate of β-HCG ( β-HCG/the first serum β-HCG) was 1.29 ± 0.28 in ectopic preg-nancy group,1.93 ± 0.36 in intrauterine pregnancy group and 1.97±0.28 in threatened abortion group. There was significant difference in serum progesterone,the first β-HCG and the second β-HCG as well as the growing rate of β-HCG among the groups(P<0.05 or <0.01). Fisher discriminant analysis of combing progesterone and the growing rate of β-HCG were connected with diagnosis of ectopic pregnancy,however,the only one serum β-HCG was not con-nected with diagnosis of ectopic pregnancy. 98.5% of ectopic pregnancy,65.6% of intrauterine pregnancy and 64.0% of threatened abortion were correctly classified in the Fisher discfiminant analysis,with overall correct rate of 77.8%. Conclusion Fisher discriminant analysis of combing progesterone and the growing rate of β-HCG can bet-ter predict the early ectopic pregnancy.
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To detect the cellular immunity state of New Zealand white rabbit immunized by pig type II collagen. The New Zealand white rabbit was immunized by type II collagen for sixty days. The plasma was collected at a regular interval and the anti-type II collagen antibodies were examined. At the sixtieth day, the peripheral circular lymphocytes and the lymphocytes separated from spleen cells of rabbit and lymph nodes were collected and were stimulated by type II collagen in vivo again. The regulation of reactive cellular proliferation caused by the stimulation was detected. The experiment samples were divided into two groups. The first group was the positive control group by adding different concentrations of PHA and the non-specific immunity was assayed. The different concentrations of type II collagen were added to the second group and the specific immunity was assayed. The lymphocytes of normal rabbits showed proliferation by PHA stimulation but no proliferation by the first stimulation of type II collagen. Obvious proliferation due to the stimulation of both PHA and type II collagen in the immunized rabbit were observed. It shows that certain concentration of heterogeneous collagen may cause an increase of anti-type II collagen antibody in immunized rabbit and may cause a proliferation of lymphocytes in rabbit spleen and peripheral blood. The heterogeneous type II collagen causes cellular immunity in vivo.
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Animais , Feminino , Masculino , Coelhos , Divisão Celular , Colágeno Tipo II , Alergia e Imunologia , Citotoxicidade Imunológica , Antígenos de Histocompatibilidade , Linfócitos , Biologia Celular , Alergia e Imunologia , Baço , Biologia Celular , Suínos , Transplante HeterólogoRESUMO
BACKGROUND: The repair of articular cartilage defect is always a problem that is dedicatedly solved by doctors of orthopaedics. Autologous perichondrium, periosteum or allografting of cartilage have been used previously; however, the source of the donor is limited, the fixation is difficult as well as the occurrence of endochondrial ossification and delamination between the inferior cartilage and reparative cartilage, etc. Type Ⅱ collagen, the main component of cartilage matrix, has certain effects in the repair of articular cartilage defect.OBJECTIVE: To investigate the effects of type Ⅱ collagen sponge filling on the repair of articular cartilage defect.DESIGN: A randomized controlled trial.SETTING and MATERIALS: The study was conducted in the Guangzhou Institute of Traumatic Surgery. Materials were 24 adult male purebred New Zealand Rabbits(48 knees), ordinary grade, with a body mass of (2.29 ±0. 25) kg. Animals were fed with standard feeding in separate cage.INTERVENTIONS: A full-thickness defect in articular cartilage was made on the femoral trochlear surface by a drill of 5 mm in diameter and 3 mm in depth. Rabbits were allocated into filling group(type Ⅱ collagen sponge was grafted into left keen joint defect) and control group(right knee joint defect site was set as control) according to random number table.MAIN OUTCOME MEASURES: Gross morphological and histological observation of the defect repair in each dual week within 12 weeks after operation.RESULTS: During 10 - 12 weeks, in cuntrol group: The defect area was repaired by white and soft tissue that had no resistance to press. The repaired tissue was still lower than the surrounding articular surface with clear boundary. By histological observation, it was found that the defect was repaired by the mechanism similar to inflammatory reaction and the defect is ultimately filled by the hyperplasia of hyaline degenerative fibrous tissues. In filling group: the defect was repaired by semi-transparent, smooth, textured tissues with polish that had resistance to press as well as elasticity. The repaired tissue was almost similar to the shape of the surrounding cartilage,difficult to be distinguished. After histological observation, it was found that there was no inflammatory reaction, but active hyperplasia of inner bonetissue and cartilage tissues; a lot of osteoid tissues and trabeculation were found. Newlborn cartilage was fused with surrounding cartilage tissue and connected with surrounding tissues. Type Ⅱ collagen had significantly promoting effects in the repair of articular cartilage defect, and the repaired cartilage was close to normal cartilage. CONCLUSION: The self-made high purity type Ⅱ collagen sponge has favorable promoting effects in the repair of articular cartilage defect with good histocompatibility but without obvious toxic side effect.
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BACKGROUND: Fibronectin(FN) plays the role of repair in the inflammation. There is no confirmed conclusion whether it can be applied to the refractory corneal epithelial defect.OBJECTIVE: To observe the repair effect of the human plasma FN for the refractory corneal epithelial defect.DESIGN: A controlled experimental study.SETTING: Guangzhou Red Cross Hospital, Guangzhou First People's Hospital, Guangzhou Children's Hospital, Guangzhou Hospital of Traditional Chinese Medicine and Guangzhou Second People's Hos pital.PARTICIPANTS: Totally 383 eyes with the refractory corneal epithelial defect were chosen, of which 309 were in the therapy group, and 74 in the control group.METHODS: The therapy group: Human plasma FN was administered by dropping it into the eyes once every two hours. The controlgroup: 10 g/L celacol M was administered by its dribbling into the eyes once every two hours. Weilesheng was taken orally in both groups, two pills once, three times per day. According to the state of illness, both groups received anti-bacterial or anti-viral treatment and reexamination was given every day or every other day after administration. 10 g/L fluorescein sodium was used to observe the changes of cornea.MAIN OUTCOSE MEASURES: The symptoms, results of staining using fluorescein sodium as well as the corneal epithelial healing of both groups.RESULTS: The symptoms, the results from staining using the fluorescein sodium and the corneal epithelial healing were used for the evaluation. In the therapy group, 309 eyes were followed up and the cure rate was 69.9%. The average therapeutic period was 6.5 days, while those of the control group were 58.1% and 8.7 days respectively. The difference in the curative effect between the two groups was significantly different( P＜0.01 ).CONCLUSION: The application of FN for the refractory corneal epithelial defect displays a more significant effect than conventional treatment.
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BACKGROUND: Type Ⅱ collagen has been used as the carrier for chondrocyte transplantation in animal models, but whether type Ⅱ collagen may cause arthritis or mediate cytotoxicity remains unknown.OBJECTIVE: To detect the cellular immune functions of the New Zealand rabbits immunized by porcine type Ⅱ collagen.DESIGN: An exploratory comparative study based on the observations.SETTING: An institute of trauma surgery of a municipal hospital.MATERIALS: The study was conducted in the Institute of Trauma Surgery,Guangzhou Red Cross Hospital from August 1999 to February 2000. Six New Zealand rabbits, whose body mass ranged from 2.0 kg to 3.0 kg, were chosen of either gender.METHODS: The rabbits were immunized by porcine type Ⅱ collagen for 60days, during which the plasma was regularly taken for detection of type Ⅱ collagen antibody. On the 60th day, the peripheral blood as well as the spleens and lymph nodes were taken to separate the lymphocytes, which were subjected to secondary stimulation with type Ⅱ collagen in vitro to observe the reactive cell proliferation. The lymphocytes were randomly divided into two groups, and the first group was treated with phytohemagglutinin(PHA) of different concentrations to serve as the positive control, in which non-specific immunity was examined; The second group was treated with type Ⅱ collagen of different concentrations for examining specific immunity.peripheral blood lymphocytes of normal and immunized rabbits.RESULTS: On the 21st day, the titer of the antibody presented the first peak, and 40 days after the re-injection of the antigen the second peak appeared, which maintained for 20 days and then gradually descended. The lymphocytes of the normal rabbits proliferated in response to PHA stimulation but not to the first stimulation with the type Ⅱ collagen. The lymphocytes of the immunized rabbits exhibited significant proliferation upon stimulations with both PHA and type Ⅱ collagen. At the concentration of 25 mg/L, type Ⅱ collagen stimulation was sufficient to induce lymphocyte proliferation, the peak of which occurred when the collagen concentration reached 50 mg/L.CONCLUSION: Xenogenic type Ⅱ collagen at an adequate concentration may induce the increase of the type Ⅱ collagen antibody in immunized rabbits and proliferation of lymphocytes of the spleens and peripheral blood to cause cellular immune reaction and even immunological arthritis in relation to the transplantation.
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In search of the optimal preparation method for large-scale purification of human plasma fibronectin, we adopted affinity chromatography with gelatin and the Sepharose 4B activated with cyanogen bromide to purify fibronectin from type "C" plasma of healthy males, and scanned the best method under the conditions of different amount of plasma loading and different residence time in column. In a given column volume of gelatin, the absorbent was related with the plasma residence time in column and the total amount of plasma loaded. As a result, the optimal loading amount of plasma is 150 ml, and the residence time is 20 minutes. The preparation method, herein, has been proved to require small amount of plasma and yield large amount of fibronectin.