Conservative and functional surgery in the treatment of salivary gland tumours

The principle of modern oncological surgery is to conserve the functional organs or tissues as much as possible based on eradication of the tumour.For salivary gland tumours,conservative and functional salivary surgery,including partial sialoadenectomy as well as anatomical and functional preservation of the facial nerve,great auricular nerve,superficial musculoaponeurotic system (SMAS),and Stensen’s duct,has become increasingly popular.In the present review,we discuss the following aspects of conservative and functional surgery in the treatment of salivary gland tumours:(i) partial superficial parotidectomy (PP) to treat benign parotid gland tumours,(ii) modification of surgical incisions to improve cosmetic results,(iii) modification of the surgical approach to decrease complications,(iv) extracardial dissection to treat benign superficial parotid tumours,(v) partial sialoadenectomy to treat benign submandibular gland tumours,and (vi) 125I brachytherapy to preserve facial nerves.The majority of the operated parotid or submandibular glands are preserved,and surgical complications are also decreased.Conservative and functional surgery plays a significant role in maintaining normal salivary gland function and in improving patients’ quality of life during the treatment of salivary gland tumours and thus should be further promoted.

In vitro effect of iASPP on cell growth of oral tongue squamous cell carcinoma

iASPP is an inhibitory member of the apoptosis-stimulating proteins of P53 （ASPP） family. iASPP is over expressed in several malignant tumors and potentially affects cancer progression. However, the expression and potential role of iASPP in oral tongue squamous cell carcinoma （OTSCC） have not been addressed. In our study, we detected iASPP expression in OTSCC by immunohistochemistry, iASPP expression is up-regulated in OTSCC tissues. Moreover, in clinical pathology specimens, we found that increased iASPP expression correlates with poor differentiation and lymph node metastasis. Using multicellular tumor spheroids （MTS） and flow cytometry, we demonstrated that iASPP down-regulation arrests OTSCC cells at the G0/G1 phase, induces OTSCC cell apoptosis and inhibits OTSCC cell proliferation. These results indicate that iASPP plays a significant role in the progression of OTSCC and may serve as a biomarker or therapeutic target for OTSCC patients.

Anti-Cancer Effects of Cordycepin on Oral Squamous Cell Carcinoma Proliferation and Apoptosis in Vitro

Cordycepin is an active component of parasitic fungus, Cordyceps militaris, and investigated for its pharmacologic efficacy. Increasing evidence supports the anti-tumoral effects of Cordycepin in various types of human solid tumors. We sought to determine the effects of Cordycepin on oral squamous cell carcinoma in vitro and in vivo. Two oral squamous cell carcinoma cell lines, KB and HSC3, were used in this study. Cells were treated with Cordycepin or diluent, followed by determinations of proliferation by sulforhodamine method and apoptosis by TUNEL assay in vitro. For in vivo experiments, tumor cells were transplanted into nude mice, followed by treatment with Cordycepin or control diluent. In addition, cells were examined for expression of adenosine receptor isotypes, and tested whether cordycepin-induced effects were mediated through adenosine receptors by combinatorial treatment of cordycepin and antagonists specific to each isotype of adenosine receptors. Two cell lines expressed protein of all types of adenosine receptors stronger than normal oral keratinocytes. Cordycepin showed anti-proliferating effect and apoptotic effect on both cell lines in vitro in a dose dependent manner. However, any adenosine receptors did not reverse the effect of cordycepin. In our in vivo experiments, cordycepin failed to decrease the tumor volume significantly, and failed to induce more apoptosis of tumor cells. Cordycepin has anti-proliferating effect and induces apoptosis not mediated by adenosine receptor on oral squamous cell carcinoma cells in vitro. However, in vivo results suggest that cordycepin in itself has a limited value as a novel chemotherapeutic agent for oral squamous cell carcinoma.

The Osteogenic Capacity of Human Amniotic Membrane Mesenchymal Stem Cell (hAMSC) and Potential for Application in Maxillofacial Bone Reconstruction <i>in Vitro</i>Study

Amniotic membrane of human placenta is a source of abundant mesenchymal stem cell (hAMSC) which makes it a potential source of allogeneic multipotent cell for bone healing. However, much has to be explored about its isolation procedure and the osteogenic differentiation potential. The aims of this study are to establish the procurement procedure of human amniotic membrane, the isolation and culture of hAMSC, the MSC phenotypic characterization, and the in vitro osteogenic differentiation of hAMSC. Results of the study are as follows. The quality of human amniotic membrane would be best if procured from Caesarean operation under highly aseptic condition to avoid fungal and bacterial contamination on the culture. Isolation procedure using modified Soncini protocol yielded large amount of MSC with high proliferative capacity in culture medium. Characterization of hAMSC showed that the majority of the target cells exhibited specific MSC markers (CD105 and CD90) with a small number of these cells expressing CD45, the marker of hematopoeitic cells. The in vitro osteogenic differentiation of hAMSC followed by Alizarin Red staining showed that osteoblastic differentiation was detected in a significantly high number of cells. This study concludes that hAMSCs isolated from human amniotic membrane have the capacity for in vitro osteogenesis which makes them be one of the potential allogeneic stem cells for application in maxillofacial bone reconstruction.

Pathological Changes of Small Blood Vessels in Maxillofacial Region Following High Velocity Missile Wound:an Experimental Study in Dogs

In order to provide an experimental foundation and pathological base for earlyreconstruction of maxillofacial tissues defects after firearms wound using microsurgicalmethods,an experiment,was made to study the microvascular pathological changesthrough light and electron microscopy observation.In the experiment we found somepathological changes of small vessels in wounded region,such as mierothrombi forma-tion,endothelial loss,internal elastic membrane break and some degenerations,necrosis within endothelial and smooth muscle cells of vessel.The nearer the woundededge was,the more evident injury was.The microvascular injurous range was 3 cm dis-tant from wounded edge,which recovered in 7 days later after wounding.The experi-ment indicated that if we used the vascularized free tissue transfer to repair defects ofmaxillofacial firearms wounds,the pedicles of flap should be anastomosed to distant re-cipient vesseles which could be chosen beyond 3 cm from wounded edge.Thereconstructive operation should be done 7 days later after wound.

One-Stage Repair and Reconstruction of Craniomaxillofacial Bone Defects

Objective: Severe craniomaxillofacial injuries and craniomaxillofacial tumors can lead to craniomaxillofacial bone defects and deformities. Seriously affect the patients’ appearance and quality of life. So one-stage repair and reconstruction of craniomaxillofacial bone defects is of great significance. The current study summarizes the clinical experience of one-stage repair and reconstruction of craniomaxillofacial bone defects. Material and Methods: Data in one-stage repair and reconstruction of?craniomaxillofacial bone defects performed on 13 patients were retrospectively analyzed out of 34 patients with?craniomaxillofacial injuries or tumors who received treatment at the outpatient department between January 2002 and March 2011. Surgical indications and approaches were explored after two typical cases were detected. Results: One-stage repair and reconstruction of bone defects was suitable for patients with craniomaxillofacial injuries and excised craniomaxillofacial benign tumors. Adjacent autogenous bones and artificial materials (such as titanium plates, titanium mesh, and so on) work well for the repair of the craniomaxillofacial bone frame and restoration of facial features. Conclusions: Surgical indications should be strictly selected in one-stage repair and reconstruction of craniomaxillofacial bone defects and deformities. Furthermore, the adoption of autogenous bones and artificial materials is a good choice in restoring the craniofacial features.

Human umbilical cord blood-derived mesenchymal stem cells promote regeneration of crush-injured rat sciatic nerves

Several studies have demonstrated that human umbilical cord blood-derived mesenchymal stem cells can promote neural regeneration following brain injury. However, the therapeutic effects of human umbilical cord blood-derived mesenchymal stem cells in guiding peripheral nerve regeneration remain poorly understood. This study was designed to investigate the effects of human umbilical cord blood-derived mesenchymal stem cells on neural regeneration using a rat sciatic nerve crush injury model. Human umbilical cord blood-derived mesenchymal stem cells （1 ~ 106） or a PBS control were injected into the crush-injured segment of the sciatic nerve. Four weeks after cell injection, brain-derived neurotrophic factor and tyrosine kinase receptor B mRNA expression at the lesion site was increased in comparison to control. Furthermore, sciatic function index, Fluoro Gold-labeled neuron counts and axon density were also significantly increased when compared with control. Our results indicate that human umbilical cord blood-derived mesenchvmal stem cells promote the functinnal r~.RcJv^rv nf P.n I^h-inillr^4 ~r^i~tit, n^r~e

Effect of rhBMP-2 sustained-release nanocapsules on the ectopic osteogenesis process in Sprague-Dawley rats

Objective:To explore the effect of sustained-release recombinant human bone morphogenetic protein-2(rhBMP-2) on ectopic osteogenesis in the muscle pouches of rats through preparing rhBMP-2 sustained-release capsules by wrapping morphogenesis protein bones-2(BMP-2)using chitosan nanoparticles,and compositing collagen materials.Methods:Twenty four SpragueDawley rats were randomly divided into four groups with six rats in each group,that is Group A(control group),Group B(only treated with collagen),Group C(rhBMP-2+collagen treated group) and Group D(rhBMP-2/cs+collagen treated group).The composite materials for each group were implanted in the bilateral peroneal muscle pouches in rats.The peroneal muscles were only separated without implanting any materials in control group.Rats were sacrificed 2 weeks and 4 weeks post treatment and samples were cut off for general observation,Micro CT scans and histological observation.Results:General observation showed no new bone formation in Groups A and B mice,while new bones were formed in Groups C and D mice.Two weeks after treatment Micro CT scans showed that The bone volume fraction(BVF),trabecular thickness(Tb. Th),bone mineral density(BMD) in Group C mice were all higher than that in Group D(P<0.05). At the fourth week,the BVK,Tb.Th and BMD were significantly higher than that at the second week(P<0.01).Conclusions:The slow-release effect of rhBMP-2/cs sustained-release capsules can significantly promote ectopic osteogenesis.Its bone formation effect is better than that of rhBMP-2 burst-release group.

Biodegradable magnesium wire promotes regeneration of compressed sciatic nerves

Magnesium（Mg） wire has been shown to be biodegradable and have anti-inflammatory properties. It can induce Schwann cells to secrete nerve growth factor and promote the regeneration of nerve axons after central nervous system injury. We hypothesized that biodegradable Mg wire may enhance compressed peripheral nerve regeneration. A rat acute sciatic nerve compression model was made, and AZ31 Mg wire（3 mm diameter; 8 mm length） bridged at both ends of the nerve. Our results demonstrate that sciatic functional index, nerve growth factor, p75 neurotrophin receptor, and tyrosine receptor kinase A m RNA expression are increased by Mg wire in Mg model. The numbers of cross section nerve fibers and regenerating axons were also increased. Sciatic nerve function was improved and the myelinated axon number was increased in injured sciatic nerve following Mg treatment. Immunofluorescence histopathology showed that there were increased vigorous axonal regeneration and myelin sheath coverage in injured sciatic nerve after Mg treatment. Our findings confirm that biodegradable Mg wire can promote the regeneration of acute compressed sciatic nerves.

Evaluation of mandibular reconstruction with free vascularized fibular flap

Objective： To evaluates mandible reconstruction by free vascularized fibular flap with special emphasis on the immediate complications. Methods：The clinical data of 63 patients were reviewed, 35 male and 28 female（age range 16 to 73 years）. Aesthetic and functional outcomes were evaluated by follow-up and/or telephone conversation. Results：Among the 63 fibular flaps, 29 were osteocutaneous flaps with one or two skin islands. All the flaps were surviving well and the success rate was 100%. Long term donor site disability was not recorded for any patient. Thirty-one patients responded for aesthetic and functional evaluation, 20 cases（64.5%） reported their facial appearance as excellent or good, 11 （35.48%） felt fair; 14 cases （45%） could eat unrestricted diet, 17（55%） could eat soft diet; 21 cases were（67.67%） speech normal, 10（22.33%） speech intelligible. Conclusion：Free fibular flap reflects good functional and esthetic results with a high degree of consistency, and acceptable level of complications, and we strongly believe the vascularized fibular flap is the first choice for mandibular reconstruction.