Advances and Applications in Gene Silencing / 昆明医科大学学报

Gene silencing is a phenomenon in which the specific genes in organisms are not expressed or reduced for various reasons. It is an important mechanism to control gene expression by epigenetic control. At present, scientists intend to explore the treatment of difficult diseases through gene silencing technology,and the research has become a hot spot. With the rapid development of gene engineering, gene silencing technology has been replaced by new technologies. This paper aims to introduce the ribozyme technology, antisense oligonucleic acid technology, gene knockout,RNA interference technology and their applications in gene silencing technology.

Treatment of enophthalmos after severe malar-maxillary complex fracture with titanium mesh and high density polyethylene (Medpor) / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the surgical management of enophthalmos after severe malar maxillary complex fracture.</p><p><b>METHODS</b>The X-ray and CT examination were performed before operation to diagnose the orbital fracture and intraorbital tissue displacement. The fractured orbital rim was repositioned intraoperatively, followed by implantation of shaped titanium mesh to rebuild the orbital floor. The Medpor was inserted above the titanium mesh to correct the enophthalmos.</p><p><b>RESULTS</b>From Sept. 2007 to Jan. 2009, 6 cases of enophthalmos after severe malar-maxillary complex fracture were treated. The enophthalmos was corrected or improved obviously in all the patients.</p><p><b>CONCLUSIONS</b>The enophthalmos after severe malar-maxillary complex fracture can be corrected or obviously improved. Shaped titanium mesh can be used to rebuild the orbital floor with the Medpor to reconstruct the intraorbital tissue volume.</p>

Clinical research of angle-splitting ostectomy based on three dimensional computed tomography true-up technique / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To illustrate the morphological changes of mandible after angle-splitting ostectomy.</p><p><b>METHODS</b>From January 2006 to April 2008, 10 cases had undergone mandibular angle-splitting ostectomy to reduce the width of the lower face. For each patient, CT datum of mandible at three stages (preoperative, immediate postoperative, 6 months postoperative) were collected. By the application software of reverse engineering (Surfacer V9) and true-up and dissection techniques based on three-dimensional spiral computed tomography (3D-CT), operative efficacy and bone regeneration at the operation area of angle-splitting ostectomy were evaluated 6 months postoperative.</p><p><b>RESULTS</b>1) Concavity could be seen at the angle-splitting ostectomy area 6 months postoperative, especially at the mandibular external oblique line region. Average cup depth was (3.64 +/- 1.67) mm by contrasted to preoperative. Diminution of bone volume was 55% +/- 9% for the local operative area 6 months postoperative. 2) Bone regeneration could be seen at the area that mandibular outer cortex had been removed. Compared with immediate postoperative, ratio of neoformative bone was 84.6% +/- 7.3% 6 months postoperative. The main region of bone regeneration was mandibular angle.</p><p><b>CONCLUSION</b>Mandibular angle-splitting ostectomy is an effective technique for reducing the width of the lower face. Masseter muscular movement should be restricted postoperative to prevent hyperostosis at the angle area.</p>

Comparative study of onlay bone graft absorption of outer cortex from mandible and cranium / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the value of application of mandibular outer cortex as bone graft by comparing its bone absorption with cranial outer cortex.</p><p><b>METHODS</b>8 minitype grown-up pigs at the age of 8 - 12 months underwent surgery of taking out the same size (2.5 cm x 1.0 cm) of outer cortex from mandible and craninium. The volume of the outer cortex was measured by volume-displacement method. Then the outer cortex of mandible and cranium were onlay grafted to the each side of the pig snout, respectively. 12 weeks later, 2 pigs were randomly selected for histological examination. The other 6 pigs were killed 24 weeks after surgery for measurement of the bone graft volume and histologic examination.</p><p><b>RESULTS</b>The bone graft absorption rate was (41 +/- 5)% for mandibular outer cortex and (46 +/- 12)% for cranial outer cortex, showing no significant difference between them (P = 0.51). The histologic examination results also had no marked difference in the bony healing and reforming between the two graft.</p><p><b>CONCLUSIONS</b>Mandibular outer cortex is a good donor site for onlay bone graft in craniofacial region.</p>

Experimental study about osteotomy of mandibular outer cortex / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the change of morphology, biomechanics and histology after osteotomy of mandibular outer cortex.</p><p><b>METHODS</b>The mandibular outer cortex that involves angle and part of body was removed at one side in 8 minitype pigs aged 8-12 months. 2 pigs were selected randomly for histologic examination 12 weeks after operation. The other 6 animals were killed 24 weeks after operation. The thickness of new-formed mandibular outer cortex was measured and compared with that of operated side. Biomechanical test was performed in bilateral angles. Histological observation was made in the operated side.</p><p><b>RESULTS</b>The thickness of outer cortex was (2.1 +/- 0.3) mm and (2.5 +/- 0.4) mm in the operated side and opposite side, respectively, showing a significant difference between them (P < 0.01). The maximum load was (401.76 +/- 204.91) N and (585.42 +/- 413.07) N in the operated side and opposite side, respectively (P > 0.05). The Rigidity was (2172.19 +/- 1174.73) N/mm and (2363.90 +/- 1547.48) N/mm (P > 0.05). There was no statistical difference in biomechanics between the two sides. The histologic study showed histologically complete regeneration of outer cortex 24 weeks after mandibular outer cortex osteotomy.</p><p><b>CONCLUSIONS</b>After resection of mandibular outer cortex, the histologic restoration is complete, but the new-formed outer cortex is thinner with local depression. Bone tubercle can be seen at the angle after bone regeneration. There is no obvious change in biomechanics after outer cortex osteotomy.</p>

Clinical research of craniofacial bone autograft using mandibular outer cortex / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To illustrate the volume changes of mandibular outer cortex after been grafted to different recipient sites of facies cranii.</p><p><b>METHODS</b>Six cases underwent onlay bone graft to the angle and body part of mandible and malar surface simultaneously by using mandibular outer cortex. Three dimensional computed tomography (3D-CT) datum of immediate postoperative and 6 months postoperative of each case were collected systematically. By true-up and dissection techniques based on 3D-CT, volume changes of bone graft at different recipient sites were observed and analyzed 6 months postoperative.</p><p><b>RESULTS</b>6 months after onlay bone grafted, bone resorption occurred. To different recipient sites, bone resorption rate was unequal. At the mandible area, bone resorption rate was 20.8% +/- 7.2%, the main site of resorption was at the lower and posterior border of mandible. At the anterior part of maxilla, bone resorption rate was 11.2% +/- 2.3%. Statistics showed significant difference of resorption rate between the two sites (P<0.05).</p><p><b>CONCLUSION</b>Bone resorption of mandibular outer cortex after onlay graft treatment is variant according to different craniofacial recipient sites. The difference of mechanical environment at variant recipient sites is considered to be an influencing factor. Quantization of bone resorption rate can guide a better clinical use.</p>