在兔下颌牵张成骨过程中依普拉芬对一氧化氮及一氧化氮合酶的影响

目的 讨论人工合成的植物雌激素依普拉芬对兔下颌骨牵张成骨一氧化氮及一氧化氮合酶的影响.方法 40只健康日本大耳白兔,随机分成对照组和实验组各20只.下颌骨牵张成骨术后实验组给予依普拉芬50 mg/(kg·d).并于牵张后1天、1周、2周、4周取材,进行血清NO浓度的测定,并采用免疫组织化学方法观察NOS在不同时间段的表达情况.结果 在牵张后1天、1周、2周、4周实验组NO浓度及eNOS阳性表达均高于对照组且差异有统计学意义(P<0.05),新骨形成早于同期对照组.结论 依普拉芬可以通过提高牵张成骨中血清NO的浓度有效的加速新骨的形成与矿化,缩短骨愈合时间.     

The Effects of botulinum toxin A on muscle histology during distraction osteogenesis

Distraction osteogenesis is a highly successful method of bone formation, yet muscle fibrosis and contractures can result in significant morbidity. In the current study, we investigate the efficacy of botulinum toxin A in preventing fibrosis and potentially increasing muscle development in distracted muscles. Fifteen New Zealand White rabbits underwent tibial distraction at 1.5 mm/day until a 20% gain was achieved. Treatment groups were divided by drug (saline or botulinum toxin) and target muscle (gastrocnemius or tibialis anterior). Two additional control animals received no treatment. Bromeodeoxyuridine was delivered continuously throughout the 8‐week experiment, and following muscle harvest. Tissues were stained for BrdU, Pax‐7, vimentin, and haematoxylin and eosin staining. Mitotic activity increased in all distracted animals; however, in the animals receiving botulinum toxin A injections into the gastrocnemius, the antagonist tibialis anterior suffered up to 9% less fibrosis than distraction alone (p = 0.024). Use of botulinum A toxin did not appear to promote or improve neogenesis of muscle fibers, nor did it decrease fibrosis in the injected muscles. It appears from this study, and a previously published study on the effects of this toxin on muscle function, that botulinum A toxin maybe of some benefit in decreasing morbidity in the antagonist muscle but not the muscle injected with the toxin. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:310–317, 2009     

Muscle response to leg lengthening during distraction osteogenesis

Continuous lengthening of intact muscles during distraction osteogenesis leads to an increase of sarcomeres and enhances the regeneration of tendons and blood vessels. A high distraction rate leads to an excessive leg and muscle lengthening and might cause damages of muscle fibers with fibrosis, necrosis, and muscle weakness. Complications like muscle contractures or atrophy after postoperative immobilization emphazize the importance of muscles and their function in the clinical outcome. In an animal model of distraction osteogenesis, 18 sheep were operated with an external fixator followed by 4 days latency, 21 days distraction (1.25 mm per day) and 51 days consolidation. The anatomical location (gastrocnemius, peroneus tertius, and first flexor digitorum longus muscle), dimension and occurrence of muscular defects were characterized histologically. The callus formation and leg axis was monitored by weekly X‐rays. Additionally, serum creatine kinase was analyzed during a distraction and consolidation period. Significant signs of muscle lesions in all three observed muscles can be found postoperatively, whereas normal callus formation and regular leg axis was observed radiologically. The peroneus tertius and first flexor digitorum longus muscles were found to have significantly more signs of fibrosis, inflammatory, and necrosis. Creatine kinase showed two peaks: 4 and 39 days postoperative as an indication of muscle damage and regeneration. The study implicates that muscle damages should be considered when a long‐distance distraction osteogenesis is planned. The surgeon should consider these muscle responses and individually discuss a two‐stage treatment or additional muscle tendon releases to minimize the risk of muscle damages. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 483–488, 2009     

电穿孔介导的基因治疗兔下颌骨牵引成骨模型的建立

目的 探讨电穿孔技术介导的重组质粒体内转染兔下颌骨牵引成骨的可行性.方法 以新西兰大白兔为实验动物模型,于术后3 d开始下颌骨牵引,每天0.8 mm,连续牵引7 d后,将实验动物分为3组:质粒+电穿孔组(A组),质粒组(B组),生理盐水组+电穿孔组(C组).各组动物分别于注射后3 h及1、3、7、14 d处死,切取牵引区组织0.4 cm×0.4 cm行冰冻切片检查,采用荧光显微镜观察绿色荧光蛋白(GFP)表达以检测外源基因的表达.检测兔血清肝功能指标丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)和肾功能指标尿素氮(BUN)、肌酐(Scr)和心、肝、肾组织学检查.结果 A组转染新西兰大白兔,3 h可观察到GFP的表达,1 d时GFP的表达增强,3 d时GFP的表达最强,其后开始逐渐下降,7 d后GFP的表达减少,14 d仍可观察到微弱GFP的表达.B组的GFP的表达时限与A组相同,但各时相点的GFP的表达强度明显弱于A组,C组在各时间段均未观察到GFP的表达.3组肝、肾功能指标两两比较差异无统计学意义(P>0.05).结论 电穿孔技术介导的带有荧光标记的重组质粒体内转染,可在兔下颌骨牵引区组织内表达,电穿孔能明显提高重组质粒的体内转染效率,提示电穿孔技术介导的重组质粒体内转染兔下颌骨牵引成骨的动物模型是可行的,用于体内试验是安全的.     

电穿孔介导的基因治疗对兔下颌骨牵引区新生骨骨密度与强度的影响

Objective To explore the effect of electroporation mediated gene therapy on bone mineral density and strength of new-formed bone in mandibular distraction gap, so as to enhance the osteogenesis and shorten the distraction term. Methods New-Zeland rabbits were employed. The distraction began after 3 days of latency period at the rate of 0. 8 mm per day for 7 days. After distraction, the rabbits were randomly divided into 5 groups to receive injection in the distraction gap with recombinant plasmid 2 μg(0. 1μg/μl)pIRES-hVEGF165-hBMP2 in group A, with recombinant plasmid pIRES-hBMP2 in group B, with recombinant plasmid pIRES-hVEGF165 in group C, with pIRES in group D, and with normal saline (NS) in group E. After injection, electroporation was performed in all the groups. After 1 week, 2 weeks, 4 weeks and 8 weeks of consolidation, all the animals underwent X-ray and quantitative computed tomography (QCT). The new-formed bone in distraction gap was selected as regions of interest (ROI) to measure the bone mineral density( BMD). Then the rabbits were sacrificed and the new-formed bone samples were harvested to detect 3-point crushing strength. Results BMD of newly formed bone in group A, B and C was markedly higher than that in group D and E (P < 0. 01 ). After 2 weeks of consolidation, BMD in group A was much higher than that in the other groups, but there was no difference between group B and C. After 4 weeks of consolidation, BMD in group A and B was markedly higher than that in group C, D and E ( P < 0. 01 ). After 8 weeks of consolidation, BMD in group A was markedly higher than that in the other groups. While the BMD was not significantly different between group B and C, but the BMD in group B and C was higher than that in group D and E ( P < 0. 01 ). After 4 weeks of consolidation, the 3-point crushing strength of newly formed bone in group A was markedly higher than that in group B,C, D and E ( P < 0. 01 ) , which was still the same after 8 weeks of consolidation. And the crushing strength in group B was higher than that in group C, D and E ( P < 0.05 ). Conclusions Electroporation-mediated transfection of recombinant plasmid pIRES-hVEGF165-hBMP2 could greatly enhance osteogenesis and calcification. A combination of VECF and BMP may promote osteogenesis and angiogenesis simultaneously, so as to magnify the effect of each growth factor, resulting a synergetic effect.     

扩张力作用下大鼠腭中缝组织成骨现象的连续观察

目的：观察扩张力作用下大鼠腭中缝牵张成骨的组织形态学变化及新骨形成情况,探讨扩弓后腭中缝组织的反应和新骨形成方式。方法：选用4周龄健康雄性wistar大鼠55只,随机分为实验组5组、对照组6组,采用两眼簧后牙扩弓器扩张大鼠上颌腭中缝组织,分别于0d、实验1、2、4、7、11d取材,标本常规进行石蜡切片,行常规苏木精-伊红染色、Masson三色染色、骨钙素（OCN）免疫组化。结果：扩张1d后即可见腭中缝明显增宽,并可见成骨细胞的分化和成纤维细胞的增殖;扩张2d和4d后可见软骨细胞带外侧有新骨沉积;固定3d后可见骨缝边缘内外侧均有新骨沉积;固定7d后,可见两侧陈旧的软骨细胞带内侧有大量类骨质形成,两侧骨缘呈指状嵌合。结论：扩张的腭中缝新骨改建主要发生在腭中缝骨缘,并由软骨内成骨的方式向膜内成骨方式进行转变。     

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目的    探讨口内入路牵引成骨术配合语音治疗对唇腭裂术后继发上颌骨发育不良患者的治疗效果。方法    对2007—2009年在南昌大学口腔医院接受治疗的9 ~ 12岁唇腭裂术后继发上颌骨发育不良畸形患者21例采用高位Le Fort I型截骨术,将上颌骨完全断离,安装口内牵引器,术后3个月开始语音训练,定期接受发音指导和语音测评,记录结果并进行统计分析。结果    21例患者手术效果满意,未见严重并发症,通过语音治疗,发音改善明显。结论    骨牵引成骨术用于矫治唇腭裂术后继发上颌骨发育不良,可早期解除上颌骨畸形,在一定程度上改善患者的腭咽闭合功能,再配合语音治疗可有效提高语音效果。     

下颌三焦点牵张成骨过程中新骨组织骨形成蛋白的时空表达与影像学研究

目的 观察下颌三焦点牵张成骨过程中新骨组织骨形成蛋白的分布表达及影像学特征. 方法 选取4只成年恒河猴,通过下颌前分骨截除术形成颏部正中联合骨缺损.在两侧下颌体部各制备一个输送盘,用自行研制的多平面牵张装簧使双侧输送盘向前内方向缓慢移动并在颏部正中对接以修复颏部骨缺损.在牵张结束的第2、4、8与16周分别行X线或CT检查后处死,标本以抗骨形成蛋白(BMP)单抗免疫组化方法染色观察. 结果 免疫组化结果显示,牵张结束的第2周BMP广泛表达于牵开问隙的成骨细胞内,第4周成骨活跃,第8～16周BMP表达渐趋减弱.X线及CT影像显示新骨组织的钙化成熟是沿牵张方向逐渐发展,二者具有时相相关性. 结论 BMP在牵张成骨的早期起重要作用.X线及CT亦证明,在牵张弧形轨迹上,新骨组织从无到有,最终实现骨连续性及结构的恢复.     

Experienced surgeons can do more than one thing at a time: effect of distraction on performance of a simple laparoscopic and cognitive task by experienced and novice surgeons

Background While operating, surgeons are required to make cognitive decisions and often are interrupted to attend to questions from other members of the health care team. Technical automatization may be achieved by experienced surgeons such that these distractions have little effect on performance of either the surgical or the cognitive task. This study assessed the effect of adding a distracting cognitive task on performance of a basic laparoscopic skill by novice and experienced surgeons. Methods In this study, 31 novice (medical students in postgraduate years [PGYs] 1–2) and 9 experienced (fellows/attendants and PGYs 4–5) laparoscopic surgeons practiced the Fundamentals of Laparoscopic Surgery (FLS) laparoscopic peg transfer task until their scores stabilized. The mean normalized score after five repetitions then was recorded. The subjects also were tested on the number of mathematical addition questions they could answer in 1 min. This was repeated five times, with the mean number of questions attempted and the accuracy (% correct) recorded. The laparoscopic and addition tasks then were performed concurrently five times. Data, presented as mean ± standard deviation, were analyzed using Student’s t-test. A p value less than 0.05 was considered statistically significant. Results After practice to stable peg transfer performance, the baseline peg transfer score was higher in the experienced group (98 ± 6 vs 87 ± 12; p < 0.01). There were no baseline differences between the groups in the number of math questions attempted in 1 min (10 ± 2 vs 9 ± 2; p = 0.55) or the number of correct answers (9 ± 3 vs 8 ± 3; p = 0.36). The comparison of baseline performance and dual-task performance showed that the experienced surgeons had no decline in peg transfer score (98 ± 6 vs 97 ± 6; p = 0.48), number of questions attempted in 1 min (10 ± 2 vs 9 ± 3; p = 0.32), or number of correct answers (9 ± 3 vs 8 ± 3; p = 0.46). In contrast, dual-tasking among the novices was associated with a decrease in the number of questions attempted (9 ± 2 vs 8 ± 2; p < 0.01) and the number of correct answers (8 ± 3 vs 7 ± 2; p = 0.02), and with no change in the peg transfer score (87 ± 12 vs 88 ± 8; p = 0.38) compared with baseline. Conclusions Distraction significantly decreased a novice’s ability to process cognitively based math problems, whereas there was no effect on experienced subjects. This occurred despite the fact that the novice group had practiced to high-level peg transfer scores at baseline. This suggests that the experienced surgeons had achieved automatization of the peg transfer basic surgical skill to a level that cognitive distraction did not affect performance of either task. The experienced surgeons were able to attend equally to both tasks, whereas the novices attended to the surgical task at the expense of some aspects of cognitive task performance. Presented at the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), Las Vegas, Nevada, USA, April 2007     

Release of the transverse carpal ligament alone is associated with elevated pressure beneath the distal volar forearm fascia in a cadaver model of carpal tunnel syndrome

PURPOSE: The purpose of this study is to determine whether release of the distal volar forearm fascia (DVFF) is necessary at the time of median nerve decompression for carpal tunnel syndrome. METHODS: Five fresh-frozen cadaver specimens were mounted vertically with the hand dependent and a 2.27-kg weight suspended from the fingers. A pressure sensor wire was used to measure pressures starting just distal to the transverse carpal ligament (TCL). The wire was withdrawn proximally in 5-mm increments and into the forearm until pressure was below 10 mm Hg. An incision in the forearm was extended distally until the pressure sensor was found. The distance from this point to the distal volar wrist crease was measured. The TCL was released, keeping the DVFF intact, and the experiment was repeated. Paired t-tests determined whether there were statistically significant differences between measurements before and after TCL release. RESULTS: Average peak pressure under the intact TCL was 57.8 +/- 10.1 mm Hg. Average peak pressure under the DVFF with the TCL intact was 61.2 +/- 43.6 mm Hg. Following release of the TCL, average peak pressure beneath the TCL significantly decreased to 14.0 +/- 9.0 mm Hg, whereas average peak pressure at the intact DVFF increased to 64.8 +/- 48.7 mm Hg. Average locations where DVFF pressure became less than 10 mm Hg with an intact TCL and with released TCL were 4.30 +/- 1.8 cm and 4.00 +/- 1.8 cm proximal to the distal volar wrist crease, respectively. There was no significant difference between DVFF pressures before or after TCL release. CONCLUSIONS: In a cadaver model of carpal tunnel syndrome, release of the TCL alone is associated with persistent pressures >30 mm Hg in the region of the DVFF. Release of the TCL did not significantly change the location of the pressure drop-off under the DVFF.