Analysis of differentially expressed genes in fetal skin of scarless and scar-forming periods of gestational rats

Objective: To study the differences of gene expression between earlier gestational skin and later gestational skin of rats with the aids of single primer amplification (SPA) and high-density oligonucleotide DNA array to understand the molecular mechanism of scarless healing. Methods: Total RNAs were isolated from fetal rat skin of the scarless (E15) and scar-forming (E18) periods of gestation (term =21.5 days). The RNAs from earlier gestational skin (EGS) and later gestational skin (LGS) were both reversely transcribed to cDNAs, then labeled with the incorporation of fluorescent dCTP for preparing the hybridization probes by SPA method. The mixed probes were then hybridized to the oligonucleotide DNA arrays which contained 5 705 probes representing 5 705 rat genes. After highly stringent washing, these DNA arrays were scanned for fluorescent signals to display the differentially expressed genes between the 2 groups of skin. Results: Among 5 705 rat genes, there were 53 genes (0.93%) with differentially expressed levels between EGS and LGS groups, 27 genes, including fibroblast growth factor 2 ( FGF2 ) and follistatin were up-regulated (0.47%) and 26 genes were down-regulated (0.46%) in fetal skin during scarless period versus scar-forming period. Higher expressions of FGF2 and follistatin in EGS than those in LGS were also revealed by RT-PCR method. Conclusions: High-density oligonucleotide DNA array provided a powerful tool for investigating differential gene expression in earlier and later gestational fetal skins. This technology validates that the mechanism of fetal scarless healing is very complicate and the change of many gene expressions is associated with fetal scarless healing.     

跟骨丘部重建距下关节融合治疗跟骨骨折严重畸形愈合

目的介绍自体植骨丘部重建距下关节融台术治疗严重跟骨骨折畸形愈台的方法，探讨手术适应证及优、缺点。方法1998年11月～2002年8月．对17例21足跟骨骨折严重畸形愈台患者采用自体植骨丘部重建距下关节融台的方法进行治疗．男13例17足．女4例4足；年龄25～45岁，平均35.4岁；单侧跟骨骨折13侧13足，双侧4例8足．选择跟骨外侧改良“L”形切口行自体植骨丘部重建距下关节融合术，其中15例17足取髂骨植骨，1例2足分别取髂骨植骨和跟骨外膨的外侧壁植骨．1例2足取跟骨外膨的外侧壁植骨。所有跟骨外嘭的外删壁均做切除．结果15例18足获得随访。随访时间9～22个月，平均14．5个月。按Maryland方法评价术后功能：优7足，良9足，可2足；优良率为88．9%，X线片示Bohler角、Gissane角、距骨倾斜角、跟骨宽度及丘部高度基本恢复正常，结论自体植骨丘部重建距下关节融台术是治疗严重跟骨骨折畸形愈合的一种有技方法。可明显矫正跟骨畸形．恢复后足外形及功能。     

Effect of autocontrol micromotion intramedullary interlocking nail on fracture healing： an experimental study

Objective: To investigate the effect of autocontrol micromotion locking nail ( AMLN ) on experimental fracture healing and its mechanism. Methods: 16 goats undergoing both sides of transverse osteotomy of the femoral shafts were fixed intramedullary with AMLN and Gross-Kempf (GK) nail, respectively. The follow-up time was 7, 14, 28 and 56 days. Roentgenographic, biomechanical, histological, scanning electromicroscopic and biochemical analyses were done. Results: (1) The strength of anticompression, antiflexion and antitorsion in the fractural end in the AMLN-fixed group was higher than that of GK nail-fixed group; whereas, the rate of stress shelter in the fractured end decreased significantly (P<0.01). (2) The content of the total collagen, insoluble collagen, calcium and phosphate in the AMLN-fixed group was higher than that in the GK nail-fixed group (P<0.05). (3) Histological observation and quantitative analysis of calluses revealed that AMLN could promote the growth of bridge calluses and periosteum calluses. Hence the facture healing and remolding process achieved early, which was much better than traditional GK nail fixation. (P<0.05). (4) 7-14 days postoperation, the calluses of AMLN-fixed group was flourish and camellarly arranged and the collagen fibril formed constantly in the absorption lacuna of bone trabecula. 28-56 days postoperation, the collagen fibril was flourish around the absorption lacuna and was parallel to the bone's longitudinal axis. Active bony absorption and formation were seen, so was remolding and rebuilding. Haversian system was intact and the bony structural net was very tenacious because of the deposition of calcium salt. None of the above findings was observed in the GK nailfixed group. Conclusions: The design of AMLN accords well with the plastic fixation theory. As the geometry ametabolic system constituted by the intramedullary fixation instruments and the proximal and distal end of the fracture is very firm and stable, the disturbance to the physical stress distributed in the fractural end is light. The generation and conduct of the intermittent physical stress between the fractural parts could reach the balance between stress conduct and stress protection. The feature that the healing and remolding take place at the same time speeds up the fractural healing process.     

肩后入路内固定治疗不稳定性肩胛骨骨折

目的：探讨不稳定性肩胛骨系列骨折的手术适应证与开放复位内固定的治疗效果。方法：22例肩胛骨骨折，男18例，女4例，年龄25～65岁，平均35．5岁。根据术前X线片与CT扫描对骨折进行分型，确定手术指征，经肩后入路行切开复位，采用重建钢板、微型钢板、拉力螺钉内固定，术后早期功能锻炼。结果：22例均获9～28个月随访，平均17．5个月，疗效优14例，良5例，可2例，差1例，优良率86．4％。所有骨折平均在术后8．5周骨性愈合。结论：对不稳定性肩胛骨骨折行开放复位内固定、早期功能锻炼可恢复较好的肩关节功能。     

S-nitrosoglutathione-containing hydrogel accelerates rat cutaneous wound repair

BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization.     

Computed tomography and plain radiography in experimental fracture healing

We evaluated the relative contribution of plain radiographs and computed tomography to the assessment of fracture healing under experimental circumstances. In 15 sheep, we performed midshaft femoral osteotomies and internal fixation of the resultant segmental fractures. Radiographs were obtained preoperatively and immediately postoperatively. Animals were sacrificed at 3 weeks, 6 weeks, 12 weeks, 24 weeks, and 36 weeks after surgery, and the femoral specimens radiographed. After removal of the internal fixation devices, computed tomographic scans of the specimens were performed.By 3 weeks, callus was visible, but at 6 weeks, a trabecular pattern in the callus was seen on plain films but not on computed tomography. There was progressive organization of the callus on both studies. At 24 weeks, computed tomography demonstrated fracture lines not seen due to overlying callus on plain films and also more accurately showed incomplete union. By 36 weeks, healing was essentially complete according to both modalities, although there still were small gaps in the callus detectable on computed tomography but not on plain films.Computed tomography may be of value in the evaluation of fractures of long bones in those cases in which clinical examination and plain radiographs fail to give adequate information as to the status of healing.     

Evaluation of wound contraction and epithelialization after subcutaneous administration of Theranekron® in cows

Ten bulls (age 7 months, weight 302 ± 15 kg) were used in this study. After sterile preparation of skin, a full thickness wound (20 × 20 mm) was created in each bull. The bulls were randomly assigned into two groups: group 1 received 6 ml Theranekron subcutaneously and group 2 penicillin banzatine 10,000 IU/kg IM. These doses were repeated 6 days after initial wounding. At days 0, 3, 6, 10 and 14, digital photographs were taken from the wounds to calculate wound contraction and epithelialization using geometry. Chi-square test was performed for statistical analysis using SPSS 9 for Windows. There was no significant differences in wound contraction between trial groups (P > 0.05) but a statistical difference was seen in epithelialization between groups (P < 0.05). Epithelialization is one of the most important factors in wound healing. According to the results of the present study, Theranekron can significantly stimulate epithelialization in full thickness wounds in cows during the first 14 days of healing.     

Intraincisional antibiotic in addition to systemic antibiotic treatment fails to reduce wound infection rates in contaminated abdominal surgery

One hundred ninety patients with peritonitis at the time of abdominal surgery were allocated at random to systemic antibiotic treatment alone or systemic antibiotic treatment combined with topical application of antibiotics in the wound at the time of wound closure. The overall wound infection rate was 17 percent without significant difference between the two treatment groups (P>0.80).     

B超直方图检测骨愈合初步研究

Ｂ超直方图检测骨愈合初步研究中国铁道建筑总公司总医院（１０００４３）王连萍，陆应隆，石维强，武连芬，朱维萍，周建本研究旨在以Ｂ超直方图量化检查骨愈合过程，现将初步研究结果报告如下。资料与方法本院门诊及病房收治的２０例病人，３３处骨折，共检测９０余次。...     

The effect of radiation on the fracture repair process. A biomechanical evaluation of a closed fracture in a rat model

The effects of a single dose of irradiation on the biomechanical parameters of the fracture healing process were studied in a rat model. Intramedullary pinning was performed before production of a closed femoral midshaft fracture. The experimental group was exposed to 900 rad 3 days after fracture and was compared with a control group with a similar fracture that received no irradiation. Animals were killed at intervals ranging from 2-16 weeks after surgery and the bones were tested until failure in torsion. In the irradiated groups, a delay of 4 weeks was noted in the biomechanical parameters associated with fracture healing (torque to failure, torsional stiffness, angle to failure, and biomechanical stage). Despite this delay in the normal temporal progression, the staging and stiffness approached normal controls within an 8-week period. However, the torque to failure remained below normal levels at the conclusion of this study. These results differ from a previous study using an open fracture model.