Microcarriers in application for cartilage tissue engineering: Recent progress and challenges.

Successful regeneration of cartilage tissue at a clinical scale has been a tremendous challenge in the past decades. Microcarriers (MCs), usually used for cell and drug delivery, have been studied broadly across a wide range of medical fields, especially the cartilage tissue engineering (TE). Notably, microcarrier systems provide an attractive method for regulating cell phenotype and microtissue maturations, they also serve as powerful injectable carriers and are combined with new technologies for cartilage regeneration. In this review, we introduced the typical methods to fabricate various types of microcarriers and discussed the appropriate materials for microcarriers. Furthermore, we highlighted recent progress of applications and general design principle for microcarriers. Finally, we summarized the current challenges and promising prospects of microcarrier-based systems for medical applications. Overall, this review provides comprehensive and systematic guidelines for the rational design and applications of microcarriers in cartilage TE.

CX3CL1 in the red bone marrow promotes renal cell carcinoma to metastasize to the spine by involving the Src-related pathway.

Spinal metastasis (SM) frequently occurs in renal cell carcinoma (RCC) patients. Our preliminary work showed that CX3CL1 plays a positive role in SM. The objective of the present study was to verify whether CX3CL1 activates the downstream pathway by binding to CX3CR1 in RCC cells, ultimately promoting RCC to metastasize to the spine. The expression of CX3CL1 and CX3CR1 in tissue samples was detected by immunohistochemistry and western blotting. ELISA was used to quantify the concentration of CX3CL1 in the serum. The expression level of CX3CR1 in RCC cell lines was also detected. The CellTiter-Glo assay and flow cytometry were used to analyze cell viability and apoptosis of RCC cells. Transwell and wound healing assay were used to analyze the effect of CX3CL1 on the invasion and migration ability of RCC cells. Specific inhibitors were used to interfere with key molecules in the signaling pathway to further explore the signal transduction in RCC cells after CX3CL1 stimulation. The expression of CX3CR1 in SM from RCC was higher than that in limb bone metastases. Among the five RCC cell lines, 786O cells expressed the highest level of CX3CR1. CX3CL1 neither inhibited the proliferation of 786O cells nor promoted the apoptosis of 786O cells. However, it promoted the migration and invasion of RCC cells. After CX3CL1 stimulation, Src and Focal adhesion kinase (FAK) phosphorylation levels increased in RCC cells. Bosutinib and PF-00562271 inhibited Src/FAK phosphorylation and cell motility and invasion triggered by CX3CL1 stimulation. CX3CL1 in the red bone marrow of spinal cancellous bone enhances migration and invasion abilities of RCC cells, thereby promoting RCC metastasize to the spine. The migration and invasion of RCC cells activated by CX3CL1 are at least partially dependent on Src/FAK activation.

[Prognostic analysis of plantar fasciitis treated by pneumatic ballistic extracorporeal shock wave versus ultrasound guided intervention].

OBJECTIVE: To compare the medium- and long-term effect of pneumatic ballistic extracorporeal shock wave versus ultrasound-guided hormone injection in the treatment of plantar fasciitis. METHODS: The clinical data were collected from patients with plantar fasciitis admitted to PLA General Hospital pain department from September, 2015 to February, 2017. The patients were randomly divided into ultrasound-guided drug injection group and shock wave group. The therapeutic parameters including the numerical rating scale (NRS) scores in the first step pain in the morning, American Orthopedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Scale, and thickness of the plantar fascia were monitored before and at 1 week, 1 month, 3 months, and 6 months after the treatment. The recurrence rate, effectiveness, and patient satisfaction were compared between the two groups at 6 months after the treatment. RESULTS: Thirty-nine patients were enrolled in shock wave group and 38 patients in ultrasound group. The NRS scores in the first step pain in the morning were lowered after treatment in both groups (P<0.05), and the scores were significantly lower in ultrasound group than in shock wave group at 1 week and 1 month (P<0.01), but significantly higher in ultrasound group than in shock wave group at 3 and 6 months after treatment (P<0.05). The AOFAS functional scores were increased in both groups (P<0.05) at 6 months after treatment, was significantly lower in ultrasound group than in shock wave group than group B (90.44∓13.27 vs 75.76∓21.40; P<0.05). The effective rates in shock wave group and ultrasound group were 92.31% and 76.32%, respectively (P<0.05). Recurrence was found in 1 patient (2.56%) in shock wave group and in 8 (21.05%) in ultrasound group (P<0.05). The patient satisfaction scores were significantly higher in shock wave group than in ultrasound group (8.13∓2.67 vs 6.63∓3.75, P=0.048). CONCLUSION: Pneumatic ballistic extracorporeal shock achieves better medium- and long-term outcomes than ultrasound-guided hormone injection in the treatment of plantar fasciitis.

Long-term Outcome of Multiple Small-diameter Drilling Decompression Combined with Hip Arthroscopy versus Drilling Alone for Early Avascular Necrosis of the Femoral Head.

BACKGROUND: Avascular necrosis of femoral head (AVNFH) typically presents in the young adults and progresses quickly without proper treatments. However, the optimum treatments for early stage of AVNFH are still controversial. This study was conducted to evaluate the therapeutic effects of multiple small-diameter drilling decompression combined with hip arthroscopy for early AVNFH compared to drilling alone. METHODS: This is a nonrandomized retrospective case series study. Between April 2006 and November 2010, 60 patients (98 hips) with early stage AVNFH participated in this study. The patients underwent multiple small-diameter drilling decompression combined with hip arthroscopy in 26 cases/43 hips (Group A) or drilling decompression alone in 34 cases/55 hips (Group B). Patients were followed up at 6, 12, and 24 weeks, and every 6 months thereafter. Radiographs were taken at every follow-up, Harris scores were recorded at the last follow-up, the paired t-test was used to compare the postoperative Harris scores. Surgery effective rate of the two groups was compared using the Chi-square test. RESULTS: All patients were followed up for an average of 57.6 months (range: 17-108 months). Pain relief and improvement of hip function were assessed in all patients at 6 months after the surgery. At the last follow-up, Group A had better outcome with mean Harris' scores improved from 68.23 ± 11.37 to 82.07 ± 2.92 (t = -7.21, P = 0.001) than Group B with mean Harris' scores improved from 69.46 ± 9.71 to 75.79 ± 4.13 (t = -9.47, P = 0.037) (significantly different: t = -2.54, P = 0.017). The total surgery effective rate was also significantly different between Groups A and B (86.0% vs. 74.5%; χ2 = 3.69, P = 0.02). CONCLUSION: For early stage of AVNFH, multiple small-diameter drilling decompression combined with hip arthroscopy is more effective than drilling decompression alone.

[Preparation of Platelet-Rich Plasma from the White Slurry and Its Effect on MSC Proliferation].

OBJECTIVE: To isolate platelet-rich plasma(PRP) from the white slurry(WS), a depleted fraction of the clinical blood supply, so as to provide an easier method to harvest PRP for related studies and clinical use. METHODS: The protocols preparing PRP from whole blood and WS were compared. The morphological characteristics of the different PRPs were observed under transmission electron microscope; the expression of the platelet markers CD41a and CD42b were detected by the flow cytometry. Moreover, the ingredients of the PRPs were measured by using cytoanalyzer. for detecting the physiological function of the PRP, the harvested PRP were added to MSC culture and the cell proliferation was detected by using CCK-8 method. RESULTS: a large amount of PRP from WS was easier harvested. the WS-derived PRP shared similar morphological characteristics and ingredients as compared with whole blood-derived PRP. Importantly, the WS-derived PRP exhibited a higher expression of CD41a and CD42b than that of traditional PRP, which indicate that the WS is a promising reservoir for PRP. CONCLUSION: The WS can be used to prepare PRP, and the novel PRP share similar biological characteristics as traditional PRP prepared from whole blood. The present study provides an easier and economical method to harvest PRP and this findings may be helpful for PRP related studies.

[Effects of Shock Wave on the Proliferation and Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells].

OBJECTIVE: To explore the effects of the shock wave on the capacity of mesenchymal stem cells(MSCs) to proliferate and differentiate into osteoblasts. METHODS: MSCs were isolated from the bone marrow of healthy donors. The human bone marrow MSCs(BM-MSCs) were divided into 3 groups including blank control group,osteoinduced group and shock wave group. The MSCs in blank control group were cultured with common mediam; the MSCs in osteoinduced group were treated with osteogenic agents and cultured; the MSCs in shock wave group were cultured with common medium and stimulated by shock wave. The morphology of MSCs in each groups were observed by micoscopy; the CCK-8 was used to detect the proliferation ability of MSCs; the alkaline phosphatase staining and von Kossa staining were used to evaluale the differentiation potential of MSCs in each groups. RESULTS: The results of CCK-8 revealed the shock wave could promote cell proliferation as compared with blank control group. The results of alkaline phosphatase and Von Kossa staining showed that the shock wave displayed a stronger ability to promote the human BMMSC differentiation into osteoblasts cells in comparison with the osteoinduced group. The blank control group was weakly positively stainined. CONCLUSION: The shock wave treatment can promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.

[Clinical research on suture anchor fixation for the treatment of avulsion fracture of tibial intercondylar eminence under arthroscopy].

OBJECTIVE: To evaluate the early clinical effects of suture anchor fixation for the treatment of avulsion fracture of tibial intercondylar eminence under arthroscopy. METHODS: From July 2012 to January 2015, 22 patients with the avulsion fracture of tibial intercondylar eminence were treated with arthroscopic suture anchor fixation. There were 12 males and 10 females, with an average age of 22.8 years old(ranged, 18 to 33 years old). Nine patients had the fractures in the right knee and 13 patients had the fractures in the left knee. The mean duration from injury to surgery was 6.8 days(ranged, 3 to 11 days). According to the improved Meyers-McKeever classification, 13 cases were type II, 7 cases were type III, and 2 cases were type IV. The clinical outcomes were evaluated by the range of motion, the Lysholm score, the IKDC 2000 subjective knee score, the axial shift test, and the anterior drawer test. RESULTS: All the incisions healed by first intention, and no complications occurred. All the patients were followed up, and the mean duration was 32.8 months (ranged, 18 to 42 months). The knee range of motion was improved from preoperative (49.37±7.69) ° to (126.38±5.58) °at the latest follow-up(P<0.01). Lysholm score was improved from preoperative 43.4±5.6 to 79.2±6.2 at the latest follow-up(P<0.01). And the IKDC 2000 score was improved from preoperative 52.6±6.2 to 81.4±5.7 at the latest follow-up(P<0.01). At the latest follow-up, the patient underwent physical examination. One patient had a positive result of axial shift test at the 18th month after operation with grade II laxity of anterior cruciate ligament. One patient had a weakly positive result of anterior drawer test at the 24th month after operation. CONCLUSIONS: Absorbable suture anchor fixation for the treatment of avulsion fracture of tibial intercondylar eminence under arthroscopy can provide accurate reduction and stable fixation, which can be applied to treat all types of fractures including comminuted fracture, and it is not necessary to remove the implant in the second operation.

[Clinical research of popliteal cyst excision combined with debridement of the knee under arthroscopy with local anesthesia].

OBJECTIVE: To evaluate the clinical effects of popliteal cyst excision combined with debridement of the knee under arthroscopy with local anesthesia. METHODS: From February 2009 to August 2014, 52 patients with popliteal cysts were treated in our hospital, including 34 males and 18 females with an average age of 43.6 years old ranging from 14 to 62 years old; 29 cases were on the right knee and 23 on the left knee. Preoperative diagnosis was performed according to MRI findings and to determine whether other knee disorders were associated with the disease, 52 patients were diagnosed as popliteal cyst before operation; 23 cases of simple meniscus injury or cartilage injury, 18 cases of osteoarthritis, 7 cases of cruciate ligament injury, 2 cases of gouty arthritis, 1 case of rheumatoid arthritis, 1 case of pigmented villonodular arthritis. The preoperative clinical manifestations involved knee swelling in 21 cases, knee joint pain in 16 cases, joint lock in 8 cases, leg weakness in 4 cases, and knee joint snapping in 4 cases. Cyst size was 4.0 cm× 3.3 cm to 6.2 cm× 5.3 cm. According to the Rauschning and Lindgren standards, 1 case was grade I, 9 cases were grade II, 42 cases were class III. The rehabilitation plan should be made according to the patient's specific injuries and intraoperative management. During the postoperative follow-up, the postoperative curative effect was evaluated by the standard grading of Rauschning and Lindgren of popliteal cyst. RESULTS: All the incisions healed by first intention, and no complications occurred. All the cases were followed up from 25 to 64 months (averaged 39.6 months). For the Rauschning and Lindgren grading, 43 cases were grade 0, 8 cases were grade I, 1 case were grade II. CONCLUSIONS: Local anesthesia under arthroscopy and popliteal cyst removal knee joint cavity debridement is effective, less trauma, quick recovery, short term effect is good. The recurrence rate is also low because of the primary disease of the knee joint is also treated. After the operation, the rehabilitation plan should be made according to the intraoperative treatment and actively trained so as to recover at an early date.

[Clinical research of treating the avulsed fracture of humerus greater tuberosity using an arthroscopic double-row suture anchor fixation technique].

OBJECTIVE: To evaluate the early clinical effects of treating the avulsed fracture of humerus greater tuberosity using the double-row suture anchor fixation technique. METHODS: Total 20 patients with the avulsed fracture of the greater tuberosity of the humerus were treated from September 2009 to January 2013. There were 12 males and 7 females, with an average age of 46.8 years old(24 to 69 years old). Eleven patients had injuries on right shoulder joint and 8 patients had injuries on left side. The injury mechanism included 10 cases of traffic accident, 6 cases of sports injury, and 3 cases of falls. The mean interval from injury to surgery was 34.9 d (ranged, 3 to 72 d). The affacted arm was suspended and fixed within 3 weeks after operation. The swing exercise of shoulder joint was performed from the 2nd day after operation. The strap was removed 3 weeks after operation, and painless active exercise was performed 6 weeks after operation. The patients were followed up in the outpatient department 6, 12 and 24 weeks after operation, and then every 6 months. AP and lateral X-ray films were taken at each follow-up time. At the latest follow-up, protractor was used to measure activity of patients; and VAS pain score, California University of Losangeles(UCLA) standard, American Shoulder and Elbow Surgeons (ASES) score were used to evaluate therapeutic effects. RESULTS: All the patients were followed up, with a mean duration of 35.2 months (ranged, 24 to 48 months). All the incisions were healed on the first stage without secondary acromion impingement and other complications. All the patients had bony union within 12 weeks. The movements of shoulder joints including flexion, abduction, external rotation, internal rotation were increased obviously(P<0.05). The UCLA score was increased from preoperative 15.2±5.3 to 35.6±6.1 at the latest follow-up. The ASES score was increased from preoperative 31.2±5.4 to 91.2±6.8 at the latest follow-up (P<0.05). CONCLUSIONS: It has satisfactory curative effects for the avulsed fracture of humerus greater tuberosity using the double-row suture anchor fixation technique, especially the cases of small or comminuted fractures. It has several advantages such as firm fixation, simple and secure operation as well as quick postoperative recovery. Finally, patient should take exercises actively after operations.

[Clinical research on arthroscopic treatment for cruciate ligament cysts of the knee].

OBJECTIVE: To evaluate the early clinical effects of arthroscopic treatment for cruciate ligament cysts of the knee. METHODS: From September 2008 to January 2014, 23 patients with cruciate cysts were treated with arthroscopic surgery. There were 11 males and 17 females, with an average age of 28.3 years old (ranged, 16 to 56 years old). Twenty patients had injuries on the right knee and 8 patients had injuries on the left knee. Eight patients had a history of injury,5 patients had a history of chronic injury,and the other 15 patients had no obvious reasons for the symptom. Before the operation, 24 patients were clearly diagnosed as the cruciate ligament cysts of knee joint,and 4 patients were diagnosed as other problems of the knee, but the diagnosis were corrected after the operation. According to the MRI before the surgery,all the patients could be divided into 3 types: 14 were type I, 6 were type II, 8 were type III. After the operation, the patients were suggested to have a rest for 2 weeks, and take exercises everyday at the same time. The knee range of motion, Lysholm score, International Knee Documentation Committee (IKDC) 2000 subjective score, GLASGOW criteria, and McMurray test, pivot shift test, and anterior drawer test were observed to evaluate clinical results. RESULTS: All the incisions healed at the first stage without complications. Twenty-five patients were followed up, and the duration ranged from 12 to 52 months, with a mean of 26.7 months. Three patients accepted the reconstruction of ACL or tightened elongated ACL using bipolar radio frequency. The Lysholm score increased from preoperative 59.80 +/- 6.58 to 75.32 +/- 6.49 at the latest follow-up; IKDC 2000 score increased from preoperative 65.36 +/- 6.26 to 81.00 +/- 5.76 at the latest follow-up. According to GLASGOW criteria,23 patients got an excellent result and 2 good. CONCLUSION: It has a satisfactory curative effect on ACL reconstruction using bipolar radio frequency. It has advantages of firm fixation, simple and secure operation as well as quick postoperative recovery. It's very important to check the MRI before operations, and carefully seek the cysts during the operations, avoiding the omission of any cysts,especially the cases of multiple cysts. Finally, patients should take exercises actively after operations.

Virus-induced gene silencing-based functional verification of six genes associated with vernalization in wheat.

Vernalization requirement is an important characteristic in crop breeding. Wheat is a widely grown crop in the world that possesses enormous economic significance. To better understand the gene networks in vernalization process, we performed a high-throughput RNA sequencing analysis comparing the transcriptomes of spring and winter wheat cultivars, with and without vernalization (unpublished data). In this study, we selected six unigenes (CL14010, CL12788, CL176, Unigene 16777, CL8746 and Unigene10196) from our transcriptome analysis based on their expression differences to further characterize their function. Transient silencing of the six unigenes individually were achieved through virus-induced gene silencing (VIGS) using BSMV vector. The period from germination to spike differentiation were recorded and compared between plants underwent VIGS silencing and the control. Our result showed that VIGS of the six unigenes significantly shortened the period from seedling to double ridge (DR) stage. Resulting in SD period ranging from 59.8 ± 0.60 to 65.8 ± 0.48 days, compared to 85.0 ± 0.73 days in the control. The results indicated that these six unigenes function as suppressors in vernalization process and silence or down-regulation of these genes promoted flower development in wheat. Further characterization of these six unigenes and their function in vernalization and flowering control is needed.

Drift characteristics of miniscrews and molars for anchorage under orthodontic force: 3-dimensional computed tomography registration evaluation.

INTRODUCTION: Although miniscrews have been used as absolute anchorage for a long time, their behavior under orthodontic loading is still unclear clinically. Therefore, this study was designed to evaluate the behavior of miniscrews under loading by retrospective 3-dimensional registration. METHODS: Sixty adult patients who had miniscrews as anchorage for en-masse retraction of anterior teeth were studied. Computerized tomography scans were made before force application and after closure of the extraction spaces, respectively. The 3-dimensional reconstruction and registration of before and after computerized tomography data were performed to assess the displacement of the miniscrews, first molars, and maxillary central incisors. RESULTS: The miniscrews and the maxillary first molars drifted mesially 0.23 and 0.91 mm apically, and 0.23 and 0.92 mm coronally; the amounts of maxillary incisor retraction at the edge and the apex were 5.94 and 1.40 mm, respectively, with 1.84 mm of maxillary central incisor intrusion. CONCLUSIONS: Our results indicated that the miniscrews and the maxillary first molars were mesially displaced under orthodontic loading. A mesial site for miniscrews might be a better choice for long-term stability.

[Accuracy evaluation of computer aided design and computer aided manufacture template for implant placement].

OBJECTIVE: The computer aided design and computer aided manufacture (CAD/CAM) template was fabricated basing on CT data of completely edentulous jaws, and the accuracy of template was evaluated by assessment of the deviation between the actual and planning position of the implant after the registration of pre- and post-operative CT images. METHODS: The CAD/CAM templates for 4 completely edentulous jaws were designed and fabricated basing on the pre-operative CT data and the stone models of the jaws sample. And 14 implants were placed in the posterior region of the jaws aided by the CAD/CAM template. The pre- and post-operative CT was registered by the point to point method, and the deviation between actual and virtual implants was measured to assess the accuracy of the template. RESULTS: With the aid of CAD/CAM template, the deviations of the position at the tail of the implant, at the tip of the implant and the projected deviation of angle were (0.19 +/- 0.07) mm, (0.47 +/- 0.12) mm, and 1.790 +/- 0.68 degrees respectively, and the deviations of the position at the bucco-palatal, disto-mesial, vertical direction were (0.22 +/- 0.08) mm, (0.25 +/- 0.06) mm, (0.30 +/- 0.11) mm at the tip respectively. CONCLUSION: Within the limits of this study, the results verify the accuracy of CAD/CAM template and support its use for safety implant placement.

[Isolation, identification, culture and bionomics of skeletal muscles satellite cells from green fluorescent protein transgenic mouse in vitro].

OBJECTIVE: To investigate the green fluorescent protein (GFP) expression and the bionomics of skeletal muscles satellite cells (SMSCs) in vitro in GFP transgenic mouse. METHODS: The newborn transgenic mice were acquired to separate skeletal muscles satellite cells with enzyme digestion method. Cells were cultured and subcultured in vitro. Morphological observation, growth curve were investigated to evaluate the proliferation and differentiation characteristics of skeletal muscles satellite cells, fluorescence microscope was used to observe the GFP expression. The cells were identified by immunocytochemical stain. In the basis of identification of anti-sarcometric actin anti-body, the combination of anti-desmin antibody and DAPI (4, 6-diamidino-2-phenylindole) were used to detect the purification of skeletal muscles satellite cells. RESULTS: Immunocytofluorescence suggested the good retain of GFP fluorescence in skeletal muscles satellite cells. The cells showed strong proliferative ability and they were positive with immunocytochemical stain of anti-sarcometric actin antibody and anti-desmin antibody. The combination of anti-desmin and DAPI stain can be used to determine the purification of SMSCs. CONCLUSION: Skeletal muscles satellite cells cultured in vitro showed strong proliferation and differentiation ability. They are fit to construct the cell bank of tissure engineering and to be a useful tool to explore cells fate after transplantation since these cells retain the expression of GFP.

[Effect of different nanophase hydroxyapatite particles on osteoblasts metabolism].

PURPOSE: To compare two different structural nanophase hydroxyapatite(HA) particles on the proliferation activity and functions of osteoblasts. METHODS: Primary culture of osteoblasts from rat calvaria was established and then cultured on the coatings of different size of nano particles (groupI 20-40nm,group II 70-100nm), the HA coatings without nano-particles was used as control group. Proliferation activity, protein content and synthesis of alkaline phosphatase(ALP) by osteoblasts were examined by MTT assay, coomassic brilliant blue method and PNPP test, and statistical significance was assessed by multiple comparison (q test, SNK) in one-way analysis of variance (ANOVA) with SPSS10.0 software package. RESULTS: Osteoblasts grew well on HA coatings. MTT assay demonstrated that there was significant difference between group I and group II at 6th day and 8th day (P<0.05).At first half stage(5th day and 10th day) ALP activity test showed no significant difference between group I and groupII (P>0.05) and as the culture going on(15th day and 20th day), there was significant difference between the two groups (P<0.05). Coomassic brilliant blue method showed that there was significant difference between group I and group II from 5th day to 20th day (P<0.05). CONCLUSION: The diameter of nano-particles on the HA coatings could influence the proliferation activity and functions of the osteoblasts. The nano-particles of similar size with HA crystal in vivo showed better cytocompatibility.

[Effect of bone morphogenetic proteins-2 on mandibular distraction osteogenesis in rabbits].

OBJECTIVE: To investigate the Effect of recombinant adenovirus vectors containing human Bone morphogenetic proteins-2 (Ad-hBMP-2) on the for mandibular distraction osteogenesis (DO) in rabbits. METHODS: Twenty-four New Zealand white rabbits were randomly divided into experimental group, and control group and underwent mandibular distraction osteogenesis. After 5 days latency, the distracters were activated at a speed of 0.5 mm every 12 hours for 7 days, then on the first day in the consolidation period, the distraction gaps of experimental group were injected with 0.2 ml Ad-hBMP2 10(12) pfu/L, while the animals of control group were injected with 0.2 ml Ad-EGFP 10(12) pfu/L. At the 7 th and 28 th day of consolidation period, specimens were obtained, X-ray and histomorphology were performed. The bone density and the quantity of new bone formation in the distraction gaps were observed and compared between the two groups at different consolidation period. RESULTS: Ad-hBMP-2 treated specimens demonstrated an increased amount of new bone formation CONCLUSIONS: Adenovirally-mediated delivery of BMP-2 can locally increase bone deposition during DO, which may potentially shorten the consolidation period.

[Experimental study on the proliferation of postirradiated osteoblast transfected with Ad-hBMP-2].

PURPOSE: To investigate the exact relationship at which Ad-hBMP-2 can exert its effects on postirradiated proliferation of osteoblasts in rats. METHODS: The osteoblasts used were isolated from the calvariae of neonatal (one-day-old) Wistar rats by sequential enzymatic digestion. The third passage of the cells were irradiated with X-ray at the doses of 0, 100, 300, 500,700 and 900 cGy. The medium was changed immediately and the Ad-hBMP-2 were added. After 6 days of culture the cells were examined and measured for proliferation ability by MTT test, and the data were analyzed with SPSS13.0 software package for Student's t test. RESULTS: After irradiation, the proliferation ability of osteoblasts was inhibited and the effects were more remarkable as the dose increased. Ad-hBMP-2 could counteract the inhibitory effects when irradiation dose was lower (100 cGy),and partially when the dose was higher (500 cGy). There was significant difference between the cells transfected with Ad-hBMP-2 and the cells of control groups (P<0.05). When the dose was over 700 cGy, the damages of the cells seemed irreversible and there was no significant difference between the two groups (P>0.05). CONCLUSION: Ad-hBMP-2 could increase the proliferation ability of postirradiation osteoblasts, and the effect depends on the dose of radiation.

[Mandibular keratocyst induced trigeminal neuralgia: report of one case].

Trigeminal neuralgia is very common in clinic, but the etiology is still unclear. This articles reported a case of trigeminal neuralgia induced by jaw keratocyst. The clinical manifestation, radiographic characteristic, pathologic diagnosis and treatment were discussed. It is concluded that jaw bone cavities may be one of the major etiologic factors of secondary trigeminal neuralgia. Surgical curettage of the lesion is the main treatment for this disease.

[Repair of mandibular central fissures in rabbits with hBMP-2 gene modified tissue engineered bone].

PURPOSE: To evaluate the effectiveness of the tissue engineered bone substitute loaded with periosteal-derived osteoblasts (POBs) transfected by adenovirus mediated human bone morphogenetic protein-2 gene (Ad-hBMP-2) in the repair of rabbit mandibular central fissures. METHODS: 45 rabbits with the soft tissue in the mandibular central fissures removed were randomly divided into 5 groups, group I: Ad-hBMP-2 transfected POBs/bioglass group (n=10); group II: adenovirus mediated enhanced green fluorescent protein (Ad-EGFP) gene transfected POBs/bioglass group (n=10); group III: untransfected POBs/bioglass group (n=10); group IV: single bioglass group (n=10); group V: control group (n=5). The above bone substitutes were implanted in the rabbit mandibular central fissures respectively except group V. The samples were studied by gross, X-ray, histomorphology, histomorphometrical analysis and biomechanics after 2, 4, 8, 12 weeks respectively. One-way ANOVA was used for statistical analysis. RESULTS: In gross view, the rabbit mandibular central fissures in group I were replaced by new bone including cortical bone from the 4th week. X-ray examination showed that the higher bone density was found in the rabbit mandibular central fissures of group I 4 to 8 weeks after implantation. Histomorphometrical analysis showed much more new bony callus in group I than in other groups (P<0.01). The maximal anti-bending load and bending rigidity of the implanted bone substitute of group I were significantly higher than those of group II, III and IV (P<0.01). CONCLUSION: The tissue engineered bone substitute loaded with POBs transfected by human BMP-2 gene could get the best result in the repair of rabbit mandibular central fissures, therefore, it is likely to be used in the repair of alveolar clefts.

[Evaluation of peri-implant augmentation with collected bone].

PURPOSE: To determine the amount of bone harvested from dental implant osteotomies with aspeo 12000 bone collector, to characterize the nature of the debris, and to evaluate the histological viability and clinical effect of peri-implant augmentation with immediate implantation of collected bone. METHODS: From May 2004 to Oct 2005, 15 recruited patients without peri-implant imperfections underwent 18 ITI implants installation. During the implant bed preparation, 18 samples of bone were collected using the instrument and an analysis of variance was used to determine if there were statistical differences between female versus male, maxilla versus mandible, anterior versus posterior alveolar bone. After decalcification, the material from each sample was fixed in paraffin wax and stained with haematoxylin and eosin, all sections were examined by optical microscope and the proportion of bone was established histomorphometrically. During the time, 12 defects occurred in 11 patients when 16 dental implants were installed, and all the defects were augmented with collected bone debris simultaneously. RESULTS: About 93% volume of 'wet' bone could be obtained from one dental implant osteotomy, and there were no statistical differences between female and male, maxilla and mandible, anterior and posterior alveolar bone. Histological observation showed that all samples contained bone and coagulum, the mean bone proportion was 94.2%. 3 to 6 months after surgery, the defects were successfully augmented, and during the secondary operation, bone growth was found over the defects. CONCLUSION: The use of bone collectors is a good method for obtaining material to fill small bone imperfections in dental implantation.