新型低弹性β钛合金关节表面微假体治疗犬膝关节软骨全层缺损的实验研究

目的 评价新犁低弹性β钛合金关节表面微假体治疗犬膝关节软骨面全层缺损的可行性与效果.方法 取8只成年家犬,制备舣侧股骨髁直径为7 mm的软骨面全层缺损,选用两种弹性模量钛合金材料制备关节表而微假体并植入软骨缺损区,左侧为低弹性模量组(弹性模量为42 GPa),右侧为高弹性模量组(弹性模量为110 GPa).3个月后取材,行X线片、显微CT扫描、骨计量学分析和组织学检测观察两组关节表面微假体的稳定性及周边骨与软骨的生长情况.结果 X线片示关节表面微假体钉帽周围软骨生长良好,完全填充钉帽周边软骨间隙,关节软骨面平整.显微CT三维重建及骨计量学分析显示低弹性模量组骨体积分数、骨小梁厚度、骨小梁数目及骨组织密度平均分别为0.389%±0.025%、(0.049±0.002)μm、(8.9±0.4)mm1、(652.7±12.6)mg/mm3,而高弹性模量组平均分别为0.253%±0.024%、(0.038 ±0.002)μm、(5.9±0.4)mm-1、(595.2±7.6)mg/mm3,以上指标两组间比较差异均有统计学意义(P<0.05).组织学观察显示低弹性模量组微关节表面假体固定钉周围有更多的新生骨小梁包绕,钉骨结合牢固,界面成骨量明显多于高弹性模量组.结论 新型低弹性β钛合金关节表面微假体治疗关节软骨面缺损是可行的,其低弹性模量的特点更有利干钉骨界面骨的形成.

Abstract：

Objective To assess the effect of a new β Ti alloy mini-prosthesis with low elastic modulus on resurfacing the full-thickness Surface defect of the knee joint in dogs.Methods A full-thickness osteochondral defect of 7 mm in diameter was created at the medial femoral condyle of both hind limbs in 8 healthy adult dogs.The titanium alloy mini-prostheses with high-modulus of elasticity were implanted on the right side(control group)and those with low-modulus of elasticity on the left side(experiment group)to repair the cartilage defects.After 3 months,all the 8 dogs were sacrificed to harvest the specimens.Radiographic,histologic and micro-CT examinations were conducted to observe stability of the mini-prostheses and growth of the bone and cartilage surrounding the implants. Results Radiographic evaluation revealed no indications of device disassembly or subsidence.Bone trabeculae surrounding anchoring screws in the experiment group was visibly more and denser compared with the control group.Micro-CT data revealed that the bone volume fraction,trabecular thickness,trabecular number and tissue mineral density were 0.389%±0.025%,0.049±0.002 μm,8.9±0.4 mm-1 and 652.7 ±12.6 mg/mm3 respectively in the experiment group,compare with 0.253%±0.024%,0.038±0.002 μm,5.9±0.4 mm-1 and 595.2±7.6 mg/mm3 in the control group,with statistically significant differences between the 2 groups(P<0.05).Cartilage around the cap grew well and the surface remained smooth.Periphery of the resurfacing implant was covered by an extension of the superficial cartilage emanating from the defect margins. Conclusions The new β Ti alloy mini-prosthesis with low elastic modulus is favorable toward resurfacing the articular surface defect.The low-modulus of elasticity can improve new bone formation on the implant-bone interface.     

Donor’s site evaluation after restoration with autografts or synthetic plugs in rabbits

AIM: To investigate donor site's area histological and immunohistochemical knee cartilage appearances after resurfacing iatrogenic defects with biosynthetic plugs orautografts. METHODS: Thirty New Zealand White rabbits were used in this study. A full-thickness cylindrical defect of 4.5 mm(diameter) × 7 mm(depth) was created with a hand drill in the femoral groove of every animal. In Group A(n = 10) the defect of the donor site was re-paired with a biosynthetic osteochondral plug, in Group B(n = 10) with an osteochondral autograft, while in Group C(control group of 10) rabbits were left untreated. RESULTS: Twenty-four weeks postoperatively, smooth articular cartilage was found macroscopically in some trocleas' surfaces; in all others, an articular surface with discontinuities was observed. Twenty-eight out of 30 animals were found with predominantly viable chondrocytes leaving the remaining two-which were found only in the control group- with partially viable chondrocytes. However, histology revealed many statistical differences between the groups as far as the International Cartilage Repair Society(ICRS) categories are concerned. Immunofluoresence also revealed the presence of collagen Ⅱ in all specimens of Group B, whereas in Group A collagen Ⅱ was found in less specimens. In Group C collagen Ⅱwas not found. CONCLUSION: The matrix, cell distribution, subchondral bone and cartilage mineralization ICRS categories showed statistically differences between the three groups. Group A was second, while group B received the best scores; the control group got the worst ICRS scores in these categories. So, the donor site area, when repairing osteochondral lesions with autografting systems, is better amended with osteochondral autograft rather than bone graft substitute implant.     

自体软骨碎屑回植对肋软骨修复再生的影响

Objective To investigate the influence on costal cartilage reparative regeneration by replanting the small blocks of autogeneic cartilage into the perichondrial pocket at the donor-site. Methods 16 rabbits (8-10 weeks old, 1.8-2. 2 kg) were randomly divided into four groups as three experimental groups and one control group. The 1.5 cm in length of costal cartilage defect was made in experimental groups with the perichondrium and costochondral junction left completely intact. The cartilage defect was cloesd by 3 methods as suturation directly, or replanting the small blocks of autogeneic cartilage, or plugging bioprotein jelly after cartilage replanting. Each experimental group was handled with two methods in two sides of costal cartilage. No operation was performed in control group. All the rabbits were sacrificed 16 weeks after operation. The appearance of thoracic cage and new-formed tissue at the defect site were examined grossly. Haematoxylin-eosin staining was performed to evaluate the characteristics of new-formed tissues and biomechanical detection was used to measure intension of new-formed tissues. Results The appearance of thoracic cage was normal in every experimental group. Histological study showed that the defect was filled with abundant fibrous tissue in each group. The chipping of cartilage survived effectively with little proliferation. Biomechanical detection showed that the intension of new-formed tissue in the non replanted group [( 193. 92 ± 41. 41 ) N] was obviously less than that in the replanted group [( 318. 88 ±28. 28)N] ,or bioprotein jelly group[(301. 00 ±39. 52) N] , or control group[(300. 54 ±38. 35) N] (P <0. 01). Furthermore, there was no statistical difference between the latter three groups ( P > 0. 05 ) . Conclusions Although replanting the chipping of cartilage can' t promote reparative regeneration of hyaline cartilage, it can definitively strengthen the intensity of new-formed tissue, reinforce thoracic stability. It may also indirectly decrease the incidence rate of postoperative chest wall deformity.     

自体软骨碎屑回植对肋软骨修复再生的影响

Objective To investigate the influence on costal cartilage reparative regeneration by replanting the small blocks of autogeneic cartilage into the perichondrial pocket at the donor-site. Methods 16 rabbits (8-10 weeks old, 1.8-2. 2 kg) were randomly divided into four groups as three experimental groups and one control group. The 1.5 cm in length of costal cartilage defect was made in experimental groups with the perichondrium and costochondral junction left completely intact. The cartilage defect was cloesd by 3 methods as suturation directly, or replanting the small blocks of autogeneic cartilage, or plugging bioprotein jelly after cartilage replanting. Each experimental group was handled with two methods in two sides of costal cartilage. No operation was performed in control group. All the rabbits were sacrificed 16 weeks after operation. The appearance of thoracic cage and new-formed tissue at the defect site were examined grossly. Haematoxylin-eosin staining was performed to evaluate the characteristics of new-formed tissues and biomechanical detection was used to measure intension of new-formed tissues. Results The appearance of thoracic cage was normal in every experimental group. Histological study showed that the defect was filled with abundant fibrous tissue in each group. The chipping of cartilage survived effectively with little proliferation. Biomechanical detection showed that the intension of new-formed tissue in the non replanted group [( 193. 92 ± 41. 41 ) N] was obviously less than that in the replanted group [( 318. 88 ±28. 28)N] ,or bioprotein jelly group[(301. 00 ±39. 52) N] , or control group[(300. 54 ±38. 35) N] (P <0. 01). Furthermore, there was no statistical difference between the latter three groups ( P > 0. 05 ) . Conclusions Although replanting the chipping of cartilage can' t promote reparative regeneration of hyaline cartilage, it can definitively strengthen the intensity of new-formed tissue, reinforce thoracic stability. It may also indirectly decrease the incidence rate of postoperative chest wall deformity.     

Mean wall thickness and formation periods of trabecular bone packets in corticosteroid-induced osteoporosis

Summary We have compared the mean wall thickness (MWT) and active formation periods (sigma_f(A)) of trabecular bone packets in iliac crest biopsies from 20 patients (7 male, 13 female) with corticosteroid-induced osteoporosis (CS-OP) and 20 age- and sex-matched controls. The trabecular bone volume (TBV) of the CS-OP patients (9.6%±2.2% [SD]) was significantly reduced compared to controls (19.3%±5.1%). The MWT of CS-OP patients (32.7±4.3 μm) was also significantly lower than the control value (48.0±6.2 μm). There was a positive correlation between MWT and TBV in both groups. The mineralization rate (M) of the CS-OP patients (0.54±0.25 μm/day) was within the normal range, and since there was no increase in osteoid seam thickness, so therefore was the osteoblastic appositional rate (OAR). The active formation period of trabecular bone packets (sigma_f(A)=MWT/M) was significantly lower in the CS-OP patients (55.9 ± 14.4 days) than in the control group (68.1 ± 9.4 days). MWT and sigma_f(A) both decreased with age in the control group, whereas in the CS-OP group they were independent of age. We conclude that corticosteroid therapy results in a reduction of the MWT of trabecular bone packets and, consequently, of TBV. In these patients, where the OAR was normal, the reduction in MWT was apparently caused by a shortening of the lifespan of the active osteoblastic population at the basic multicellular unit (BMU) level. This work is dedicated to the late Professor Rudolfo Amprino in appreciation of his great contribution to the field of bone research.     

软骨细胞与骨髓基质细胞共培养体外构建软骨组织的实验研究

Objective To investigate the feasibility of chondrogenesis in vitro with bone marrow stromal cells (BMSCs) induced by the co-cultured chondrocytes. Methods The BMSCs and chondrocytes were separated from pig and cultured. The supernatant of chondrocytes was used as the inducing solution for BMSCs from the 2nd generation. 7 days later, samples were taken and underwent immunohistochemistry and RT-PCR for detection of the expression of specific type Ⅱ cartilage collagen,type Ⅱ collagen and aggrecan mRNA. The cultured BMSCs and chondrocytes were mixed at a ratio of 8:2(BMSC: cartilage cell) and were inoculated into a polyglycolic acid/polylactic acid (PGA/PLA) scaffold at the final concentration of 5.0 × 107/ml. The cartilage cells and BMSCs were also inoculated seperately at the same concentration as the positive and negative control. Pure cartilage cells at 20% of the abovementioned concentration (1.0 × 107/ml) were used as the low concentration cartilage cell control group. Samples were collected 8 weeks later. General observations, wet weight, glycosaminoglycans (GAGs) determination and histological and immunohistochemistry examinations were performed. Results The expression of type Ⅱ collagen, type Ⅱ collagen and aggrecan mRNA were positive in induced BMSCs.In the co-cultured group and the positive control group, pure mature cartilage was formed after 8 weeks of culture in vitro, and the size and shape of the scaffold were maintained. The newly formed cartilage in the two groups were almost the same in appearance and histological properties. The immunohistochemistry results indicated that the cartilage cells of the two groups all expressed ample cartilage-specific type Ⅱ collagen. The average wet weight and GAG content in the co-cultured group reached more than 70% of those in positive control group. Only an extremely small amount of immature cartilage tissues was formed in local regions in pure BMSC group, and the scaffold was obviously shrunk and deformed. Although the wet weight of newly generated cartilage tissue in the low concentration cartilage cell group reached 30% of that in positive control group, the scaffold was obviously shrunken and deformed. Only regional and discontinuous cartilage tissues were formed, and the amount of newly formed cartilage was obviously less than that in the co-culture group and the positive control group. Conclusions Chondrocytes can provide a micro-environment for the formation of cartilage, and also effectively induce BMSC to differentiate into chondrocytes and form tissue-engineered cartilage in vitro.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

软骨细胞与骨髓基质细胞共培养体外构建软骨组织的实验研究

Objective To investigate the feasibility of chondrogenesis in vitro with bone marrow stromal cells (BMSCs) induced by the co-cultured chondrocytes. Methods The BMSCs and chondrocytes were separated from pig and cultured. The supernatant of chondrocytes was used as the inducing solution for BMSCs from the 2nd generation. 7 days later, samples were taken and underwent immunohistochemistry and RT-PCR for detection of the expression of specific type Ⅱ cartilage collagen,type Ⅱ collagen and aggrecan mRNA. The cultured BMSCs and chondrocytes were mixed at a ratio of 8:2(BMSC: cartilage cell) and were inoculated into a polyglycolic acid/polylactic acid (PGA/PLA) scaffold at the final concentration of 5.0 × 107/ml. The cartilage cells and BMSCs were also inoculated seperately at the same concentration as the positive and negative control. Pure cartilage cells at 20% of the abovementioned concentration (1.0 × 107/ml) were used as the low concentration cartilage cell control group. Samples were collected 8 weeks later. General observations, wet weight, glycosaminoglycans (GAGs) determination and histological and immunohistochemistry examinations were performed. Results The expression of type Ⅱ collagen, type Ⅱ collagen and aggrecan mRNA were positive in induced BMSCs.In the co-cultured group and the positive control group, pure mature cartilage was formed after 8 weeks of culture in vitro, and the size and shape of the scaffold were maintained. The newly formed cartilage in the two groups were almost the same in appearance and histological properties. The immunohistochemistry results indicated that the cartilage cells of the two groups all expressed ample cartilage-specific type Ⅱ collagen. The average wet weight and GAG content in the co-cultured group reached more than 70% of those in positive control group. Only an extremely small amount of immature cartilage tissues was formed in local regions in pure BMSC group, and the scaffold was obviously shrunk and deformed. Although the wet weight of newly generated cartilage tissue in the low concentration cartilage cell group reached 30% of that in positive control group, the scaffold was obviously shrunken and deformed. Only regional and discontinuous cartilage tissues were formed, and the amount of newly formed cartilage was obviously less than that in the co-culture group and the positive control group. Conclusions Chondrocytes can provide a micro-environment for the formation of cartilage, and also effectively induce BMSC to differentiate into chondrocytes and form tissue-engineered cartilage in vitro.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

可控微结构电子束熔化成形钛合金支架作为成骨细胞载体修复兔骨缺损的研究

Objective To evaluate effects of titanium alloy scaffolds with controlled internal architecture as an osteoblast carrier on bone response in models of rabbit defects. Methods Electron beam melting process was utilized to fabricate porous titanium alloy scaffolds with fully interconnected and controlled internal pore architecture. After osteoblasts were seeded on the scaffolds and cultured for up to 7 days, the growth of rabbit osteoblasts on the scaffolds was observed by scanning electron microscopy. The experiment was conducted in 4 groups to evaluate the bone formation in vivo: group A (cell/scaffold composite), group B (scaffold only), group C (left empty) and group D (autogenous bone implant) . The scaffolds were transplanted into the rabbit defects after cultured in vitro for 7 days. The animals were sacrificed at 4, 8, and 12 weeks after implantation. Bone formation in the scaffolds was investigated by gross observation, histology and histomorphometry of non-decalcified sections and fluorochrome markers. Results Confluent cell layers could be observed on the scaffold surface and in the internal pores after 7 days of incubation in vitro. New bone growth and revascularization could be observed not only at the margins of the scaffolds, but also inside the central pores of the scaffolds after 12 weeks. New bone formed along the controlled internal channels of the scaffolds. The scaffolds were filled fully with the new bone tissue and blood vessels. More extensive new bone formation was found to originate from the host bone towards the implant in group A than in group B (P ＜0. 05) . Conclusions The controlled scaffolds are well biocompatible enough to accelerate healing of rabbit defects and new bone formation. The controlled honeycomb-like architecture may guide and promote the formation of mineralized tissue.     

Promoting lumbar spinal fusion by adenovirus-mediated bone morphogenetic protein-4 gene therapy

Objective: To determine whether an adenoviral construct containing bone morphogenetic protein-4(BMP-4) gene can be used for lumbar spinal fusion. Methods: Twelve New Zealand white rabbits were randomly divided into two groups, 8 in the experimental group and 4 in the control group. Recombinant, replication-defective type 5 adenovirus with the cytomegalovirus (CMV) promoter and BMP-4 gene (Ad-BMP-4) was used. Another adenovirus constructed with the CMV promoter andβ-galactosidase gene (Ad-β-gal) was used as control. Using collagen sponge as a carrier, Ad-BMP-4 (2.9×108 pfu/ml) was directly implanted on the surface of L5-L6 lamina in the experimental group, while Ad-β-gal was implanted simultaneously in the control group. X-ray was obtained at 3, 6, and 12 weeks postoperatively to observe new bone formation. When new bone formation was identified, CT scans and three-dimensional reconstruction were obtained. After that, the animals were killed and underwent histological inspection. Results: In 12 weeks after operation, new bone formation and fusion were observed on CT scans in the experimental group, without the evidence of ectopic calcification in the canal. Negative results were found in the control group. Histological analysis demonstrated endochondral bone formation at the operative site and fusion at early stage was testified. Conclusions: In vivo gene therapy using Ad-BMP-4 for lumbar posterolateral spinal fusion is practicable and effective.     

新型多孔可吸收骨替代材料修复兔股骨缺损的实验研究

Objective To test the osteogenetic ability and biocompatibility of a new type of porous morsel blocks of resorbable bioglass bone graft substitute. Methods Thirty healthy New Zealand adult white rabbits were selected to establish bone defect models and randomly assigned into 3 even groups(with 20hind legs in each group)for 3 methods of repairing the defects.The 6 mm×10 to 12 mm defeets were made at the bilateral fenloral condyles of each rabbit.In group A,a porous morsel block of resorbable bioactive glass bone substitute was implanted;in group B,commonly used bioactive glass was implanted;in group C,nothing was implanted.Specimens were collected at 6 and 12 weeks after operation to evaluate the biodegradation and osteogenic properties by gross observation, radiography, Micro-CT and histopathological examinations.ResulIs No local adverse reaction was observed in each group.At 6 weeks.gradual growth of the new bone was observed inside the implants in groups A and B.The amount of new bone in group A was significantly higher than in group B.In group A,the porous morsel material was almost completely degraded,bone defects were completely repaired,and bone trabecula moulding reconstruction was completed.In group B,a great amount of material was not completely degraded in the central area of the graft,while bone defects were not healed in the group C.The percentages of new bone area were 0.30±0.02 in group A,0.17±0.03 in group B and 0.06±0.01 in group C,with significant differences(F=374.202,P<0.001).At 12weeks.the percentages of new bone area were 0.53 ±0.05 in group A,0.39±0.05 in group B and 0.07±0.01 in group C,with significant differences(F=317.243,P<0.001). Conclusion New porous morsel blocks of resorbable bioglass bone graft substitute show superior osteogenetic properties and biodegradability because of their good three dimensional structure.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

口服补液对烧伤休克犬肺组织含水量和血管通透性的影响

Objective To investigate the effect of oral fluid resuscitation on pulmonary vascular per-meability and lung water content in burn dogs during shock stage. Methods Eighteen male Beagle dogs with catheterization of carotid artery and jugular vein for 24 hours were subjected to 50% TBSA full-thickness burn, then they were divided into non-fluid resuscitation(NR), oral fluid resuscitation (OR), intravenous fluid resuscitation (IR) groups, with 6 dogs in each group. Dogs in OR and IR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 hours after burn, while those in NR group were not given any treatment. Dogs in each group were then given intravenous fluid for further resuscitation after 24 post burn hours(PBH). Deaths were recorded within 72 hours after burn. Mean arterial pressure(MAP) , respiratory rate (RR) , PaO2, extravascular lung water in-dex (ELWI) and pulmonary vascular permeability index (PYPI) were determined before burn and at 30 mins and 4, 8, 24, 48, 72 PBH with the aid of PICCO. Dogs were sacrificed to collect lung tissue for deter-mination of water content at 72 PBH or just before death. Results All dogs died during 9-22 PBH in NR group, 3 dogs died during 25-47 PBH in OR group, and all dogs survived within 72 PBH in IR groups. Com-pared with those before burn, RR (44.0±5.0) times/min, ELWI (10.3±0.6) mL/kg and PVPI (6.6± 0.6) were markedly increased in NR group at 8 PBH, but PaO2 and MAP were obviously decreased (P<0.05). In OR group, RR (33.0±4.0) times/min, ELWI (8.9±0.3) mL/kg and PVPI (5.7±0.4) were significantly lower than those of NR group (P<0.05) , but higher than those of IR group [ RR (26.0± 3.0) times/min, ELWI (8.2±0.3) mL/kg, PVPI (4.2±0.4), P <0.05] at 8 PBH. PaO2 and MAP in OR group were higher than that in NR group (P<0.05). Lung water content showed no statistically signifi-cant difference between OR ang IR groups (P>0.05), which were lower than that in NR group ( P < 0.05). Conclusions Although the protective effect of oral fluid resuscitation with GES on the lung of burn dog at shock stage was inferior to intravenous fluid, it still can decrease pulmonary vascular permeabili-ty, alleviate pulmonary edema, and reduce pulmonary complication compared with no resuscitation with fluids.     

绿茶多酚改善环孢素A抑制血管舒张的作用

Objective To observe the alleviation effect of green tea polyphenols (GTP) on cyclosporine A (CsA)-induced inhibition of vasodilation, and to study the underlying mechanism. Methods Thirty SD rats were randomly divided into three groups: CsA group, control group and CsA + GTP group. Five weeks after the treatment, the body weight, kidney function (BUN, Cr) of the rats were measured. Then thoracic aorta rings were mounted on a bath system, and the Ach-induced vasodilation, the effect of L-NAME and indomethacin pretreatment on the vasodilation and the denuded vasodilation were evaluated. The contents of nitric oxide (NO) in the vascular tissues were measured. Results Five weeks later, the body weight of the rats in CsA group (253.2 ±8.1) g was lighter than that in control group (292.1 ±9.5) g (P < 0.05);the body weight in CsA + GTP group (287.9 ± 9.7) g was heavier than that in CsA group ( P < 0.05);The levels of BUN and Cr in CsA group were higher than in control group (P <0.05);The levels of BUN and Cr in CsA + GTP group were lower than in CsA group (P <0.05). The maximal response for Achinduced vasodilation in CsA group was (42.5 ±4.3)% , significantly lower than (81.2 ±7. 6)% in control group and (70.1 ± 6.5) % in CsA + GTP group (both/P < 0.05). After pretreatment with L-NAME, the vasodilation in CsA group and CsA + GTP group was (40.3 ±3.7)% and (45.8 ±4.2)% respectively, lower than in control group (79. 4 ± 6. 8)% ;After pretreatment with indomethacin, the vasodilation in control group and CsA + GTP group was higher than in CsA group (both P < 0.05). The vasodilation in the denuded groups was inhibited, but there was no significant difference between groups (P>0.05). In CsA group, the content of NO in vascular tissues was lower than that in control group and CsA + GTP group (both P < 0.05). Conclusion CsA might decrease the NO content in vascular tissues and induce abnormal endothelium-dependent vasodilation which is mediated by NO. The administration of GTP could increase the NO content and alleviate the CsA-induced inhibition of the endothelium-dependent vasodilation.