ABSTRACT
Objective:To study the performance of the elastic fixation with our self-designed Tightrope system for inferior tibiofibular syndesmosis (ITFS) diastasis.Methods:In this self-control study, 6 specimens of normal cadaveric ankle were used as a normal ITFS group while the models of the ITFS diastasis were constructed as a group of ITFS diastasis. On the models of ITFS diastasis, elastic fixation with transverse Tightrope system (transverse fixation group) or binding Tightrope system (binding fixation group) was applied. The reduction and stability of ITFS were compared between transverse fixation and binding fixation for ITFS diastasis in terms of ITFS parameters on X-Ray[tibiofibular clear space (TFCS) and medial clear space (MCS)] and on CT[inferior tibiofibular anterior clear space (ITFACS), inferior tibiofibular middle clear space (ITFMCS), inferior tibiofibular posterior clear space (ITFPCS), anterior inferior tibiofibular interval (AITFI) and fibular rotation (θfib)].Results:The transverse fixation with Tightrope system for ITFS diastasis on the models led to iatrogenic injury to the fibular and the ITFS interosseous ligaments and to the perforating peroneal artery, and malreduction as well while the binding fixation with Tightrope system caused no injury to the anterior or the posterior ITFS ligament or the superior peroneal retinaculum but fine reduction as well. In comparisons of TFCS, ankle MCS, ITFACS, ITFMCS and AITFI between the 4 groups, normal ITFS group<binding fixation group<transverse fixation group<ITFS diastasis group; in comparison of ITFPCS between the 4 groups, transverse fixation group<binding fixation group<normal ITFS group< ITFS diastasis group; in comparison of θfib between the 4 groups, normal ITFS group<binding fixation group< ITFS diastasis group< transverse fixation group. Significant differences were shown in all the pairwise comparisons ( P<0.05). Conclusion:The binding fixation with our self-designed Tightrope system may be superior to the transverse fixation in surgical approach and reduction and stability of ITFS.
ABSTRACT
BACKGROUND: The ulcer wound is hard to heal in diabetic patients,and it is believed to be caused by the microcirculatory disorder of wound and decreased contents of endogenous growth factors in patients with diabetes mellitus.OBJECTIVE: To observe the biological effects of adeno-associated virus (AAV) mediated transforming growth factor beta1 (AAV-TGFβ1) and vascular endothelial growth factor (AAV-VEGF) in promoting the dermal ulcer healing of diabetic rabbits.DESIGN: A randomized controlled animal experiment.SETTINGS: Medical College, Qingdao University; Affiliated Hospital of Medical College, Qingdao University.MATERIALS: The experiments were carried out in the gynecological laboratory, Affiliated Hospital of Medical College, Qingdao University from July 2004 to January 2006. Twenty-four healthy adult New Zealand rabbits were randomly divided into co-transfection group (n=12) and control group (n=12).METHODS: ① The dermal ulcer models of diabetic rabbits was established by injecting alloxan (130 mg/kg) via ear vein, and the ulcer wound was made by operation. ② In the co-transfection group, the wound was locally infiltrated, and injected with AAV-TGFβ1 virus and AAV-VEGF virus (the concentration was 9×106 virus granules/mL respectively). The rabbits in the control group were treated with injection of saline.MAIN OUTCOME MEASURES: ① The levels of TGFβ1 and VEGF gene transcription in the healing tissue were detected with polymerase chain reaction (PCR) at 1 month postoperatively. ② The capillary density in the wound margin was counted with microcirculation microscope at 3 weeks postoperatively. ③ The collagen Ⅰ and Ⅲ were isolated and detected with Western blotting by protein gel electrophoresis and semi-dry electrophoretic transfer. ④ The content of collagen in the ulcer healing issue was detected at 1 day, 1, 2 and 3 weeks, 1, 2, 3, 4, 5 and 6 months postoperatively. ⑤ The thickness, color and quality of the wound healing were observed postoperatively.RESULTS: All the 24 rabbits were involved in the analysis of results. ① The expressions of TGFβ1 and VEGF gene transcription in the co-transfection group were increased as compared with those in the control group. ② The capillary density at the wound margin in the co-translection group was higher than that in the control group [(19.18±3.56), (6.43±1.52)/mm2,t=3.21, P ＜ 0.05]. ③ The content of collagen Ⅰ in the ulcer healing tissue in the co-transfection group was obviously increased, and the proportion of collagen Ⅰ in the constituent ratio of collagen Ⅱ and Ⅲ was increased.④ The contents of collagen in the ulcer healing tissue at 1 day after transfection were close without significant difference between the two groups (t=1.55, P ＞ 0.05). After that, the contents of collagen in the cotransfection group were all significantly higher than those in the control group (P ＜ 0.05). ⑤ The ulcer healing in the control group was obviously lagged with bad quality.CONCLUSION: The combination of AAV-TGFβ1 and AAV-VEGF can efficiently transfect the dermal ulcer wound in diabetic rabbits, obviously increase the capillary density in ulcer tissue, markedly improve the proportion of collagen I in the constituent ratio of collagen Ⅰ and Ⅲ in healing tissue, and obviously ameliorate the condition of ulcer healing.
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Objective To study the preparation and the in vitro and in vivo release profile of GH-Chitosan-Alginate microcapsules.Methods GH-Chitosan-Alginate microcapsules were prepared through impulsive electrostatic technique.The interrelated factors influencing the diameter and sphericity were studied through orthogonal experiments,and finally the statistic analysis made sure the optimum conditions to prepare microspheres.The morphology and size of the microcapsules were observed,and the content,encapsulation efficiency and recovery efficiency of the microcapsules were measured.Moreover,their in vitro and in vivo release experiments were carried out.Results The results showed that the diameter of needle was the most significant factor to the diameter of microspheres.The optimum conditions for the least diameter of microspheres were 450?m diameter of needle,2cm from needle tips to the gelation surfaee,1.5% alginate concentration,8ml/h speed of flowing-liquid and metal containers.The microcapsules had good sphericity morphology and distribution.The size of the microcapsules was in the range of 10-25?m with an average size of 47.93?m.The encapsulation efficiency and GH-load of the microcapsules were 94% and 11.24% respectively.The release kinetics of microcapsules was studied in false gastric and intestines juice.In false gastric juice,the GH of microcapsules was not released;in false intestines juice,it was released well,and TAM was completely released after about 12h.in vivo release profile made sure that the serum GH level of GH microcapsule group was at the highest value(98.59ng/ml) at 8h.The release profile was fitted well in both in vitro and in vivo conditions.Conclusion GH-Chitosan-Alginate Microcapsules have good morphology and sustained release effect.
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Objective To study the biological effects of pSNAV2-hTGF?1 and pSNAV2-hTGF?3 on the reversion of rabbit disc degeneration. Methods Rabbit nucleus pulpous and annulus fibrosus cells were isolated and cultured. The fluorescence labled pSNAV2 were used to detect the transfect rates of rabbit disc cells at first. Then, the pSNAV2-hTGF?1 and pSNAV2-hTGF?3 were transfected into the degenerated rabbit disc cells respectively. The biological effects of hTGF?1 and hTGF?3 on degenerated rabbit disc cells were detected with Western-bloting and 35S detection to analyze and compare the matrix synthesis of the tranfected cells. Results pSNAV2 could transfect degenerated disc cells effectively in the early stages. Both the pSNAV2-hTGF?1 and pSNAV2-hTGF?3 could stimulate the synthesis of collagen Ⅱ and proteoglycan of the rabbit disc cells. For the early stage of degenerated disc cells, the synthesis of collagen Ⅱ and proteoglycan were greater transfected with pSNAV2-hTGF?1 than transfected with pSNAV2-hTGF?3. The pSNAV2-hTGF?1 could promote the degenerated rabbit annulus fibrosus cells to synthesize collagen Ⅰ and pSNAV2-hTGF?3 could promote the degenerated nucleus pulpous cells of later stage to synthesize the collagen Ⅱ. Conclusion Both pSNAV2-hTGF?1 and pSNAV2-hTGF?3 can promote the degenerated rabbit disc cells of early stage to synthesize the matrix. pSNAV2-hTGF?3 can efficently promote the seriously degenerated nucleus pulpous cells to synthesize the collagen Ⅱ.