Influence of bone marrow on membrane-guided bone regeneration of segmental long-bone defects in rabbits

Defects 10 mm long were created in long bone in the diaphysis of both radii of 18 rabbits (test and control side). On the test side, ingrowth of bone marrow into the defects was hindered or delayed by: plugging the opening of the cut bone ends with gutta-percha points (n = 7); plugging with Gelfoam (n = 6); or by removing the bone marrow by flushing with saline (n = 5). The defects on both test and control side were covered with an expanded polytetrafluoroethylene membrane, shaped as a tube. Healing was followed with radiographs for four to five months, after which the animals were killed and ground sections of the areas of the defects were prepared for histological examination. On the control side, nine of 18 animals had complete osseous bridging of the defect, and a small transverse non-mineralised zone remained in the centre of the healed defect in the other animals. This zone consisted of loose connective and cartilagenous tissue as well as connective tissue obviously derived from the outside of the membrane. By preventing or delaying the ingrowth of bone marrow we retarded the regeneration of mineralised bone, particularly in the gutta-percha and flushed bone marrow groups. The principle of guided tissue regeneration may be used to achieve regeneration of extensive long-bone defects. Any attempts to delay or prevent bone marrow ingrowth into the defects did retard regeneration of segmental long-bone defects.     

BONE-INDUCTIVE EFFICACY OF RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN-2 EXPRESSED IN ESCHERICHIA COLI: AN EXPERIMENTAL STUDY IN RAT MANDIBULAR DEFECTS

Because to our knowledge the efficacy of prokaryotically expressed recombinant human bone morphogenetic proteins (rhBMP) to promote orthotopic osteogenesis has not previously been investigated, our aim was to test the efficacy of rhBMP-2 produced in Escherichia coli to promote bone healing in a standardised experimental bone healing model in rat mandibles. Different doses of rhBMP-2 were delivered in an absorbable collagen sponge carrier, and microporous barrier membranes were placed over half the number of defects in each treatment group, thereby making intraosseous cells the only recruitment source for new osteogenic cells. Results were evaluated by computerised image analysis after 12 and 24 days. The relative efficacy of rhBMP-2 preparations of different purity was also compared. E coli-produced rhBMP-2 stimulated bone healing, but its efficacy was estimated to be about one order of magnitude less than that of rhBMP-2 expressed in eukaryotic cells. We conclude that bacterially expressed rhBMP-2 is osteogenic in vivo, although higher doses will be required than of rhBMP-2 expressed in mammalian cell lines.     

Congenital Defect In The Abdominal Wall In An Adult: A Case Report

We describe a rare case of a woman aged 38 who presented with an untreated omphalocele in association with a duplication of the vena cava and malposition of the right kidney. An aesthetic and functional reconstruction of the abdomen was achieved with local flaps and the creation of a neo-umbilicus.     

EXPANDED POLYTETRAFLUOROETHYLENE AS TENDON REPLACEMENT: AN EXPERIMENTAL STUDY IN CHICKENS

We designed an experimental animal model (in chickens) to assess the potential applications, above all in hand surgery, of an expanded polytetrafluoroethylene (e-PTFE) graft as a replacement for a natural tendon. The results of macroscopic, histological, and functional observations made five weeks, and three, four, five, and six months after implantation showed that the e-PTFE seemed to be a good replacement for tendons, because it integrated well with surrounding tissue and permitted good functional recovery within a reasonable time period.     

自体神经组织匀浆修复面神经缺损的实验研究

目的：观察聚四氟乙烯膜管内植入自体神经组织匀浆桥接兔面神经缺损的修复效果，寻找修复面神经的新方法。方法：36只成年新西兰大白兔，均制成双侧面神经颊支8mm缺损的模型，用聚四氟乙烯膜管内植入自体神经组织匀浆桥接每只动物右侧面神经缺损作为实验组，单纯膜管桥接左侧为对照组。分别于术后4、8、12周行神经电生理测试后，处死动物，切取再生的神经组织标本进行大体观察、HE染色，普通光镜观察。结果：电生理测试显示，匀浆组术后4周，电刺激通过神经缺损区可引起肌收缩，空管组未引出肌动作电位。术后8、12周两侧均有动作电位引出，但匀浆组的神经传导速度明显大于空管组。光镜观察，匀浆组在术后各个时期神经再生情况均优于对照组，术后8周匀浆组管内充满再生神经纤维和髓鞘，排列较规则、整齐，呈束状分布，束间新生血管丰富；空管组有极少量再生神经纤维通过缺损区，纤维排列较紊乱。结论：自体神经组织匀浆进行神经再生室内移植．可获得比空膜管桥接面神经缺损更好的修复效果。     

E-PTFE补片增强眶隔膜在东方人下睑眼袋整复中的运用

目的报道一种Hamra下睑成形术的改良术式，通过临床病例分析探讨运用补片增强眶隔膜在整复东方人下睑眼袋及沟槽中的意义。方法在经下睑皮肤径路的下睑袋整形术中，当完成弓状缘释放、眶隔重置后．将修剪成月牙形的E—PTFE补片植入眶隔膜和眼轮匝肌下筋膜之间，适当固定以增强眶隔膜和眼睑中层。结果在本组102例中。对92例（其余10例失访）进行了随访，其中89例术后效果满意，维持时间长，2例术后发生了较长时间的水肿，约经2月自行消退。1例因为复发而再次手术。结论在Hamra术式中。通过E-PTFE补片植入增强眶隔膜．可有效地增加眼睑中层结构的力量．并调整和控制释放的眶脂量．防止眼袋复发。     

膨体聚四氟乙烯联合硅胶假体在隆鼻术中的应用

目的：探讨膨体聚四氟乙烯与固体硅胶假体联合植入进行隆鼻的方法.方法：将雕塑好的膨体聚四氟乙烯固定在L形硅胶假体鼻尖部,形成膨体-硅胶假体联合体,进行鼻背筋膜下隆鼻.结果：本组71例受术者经6个月～1年随访,均出现极大程度的外形改善,所有患者均未出现假体外露,感染,鼻尖皮肤破溃等并发症,均获得满意临床效果.结论：应用膨体聚四氟乙烯联合硅胶假体隆鼻操作简单、有效,适合推广应用.