Bone mesenchymal stem cell is a kind of multi-potential stem cells and can differentiate into osteoblast. The differentiation has membrane bone formation and enchondral bone formation two channels, and is regulated by numerous signal transduction pathways. According to related literatures, we review the signal transduction pathways of BMP/Smads, Runx2/osterix, Hedgehog, Wnt/β-Catenin and MAPK.

Purpose：To study the incidence of pneumonia, pathogenic bacteria and prognosis in patients with neoplasm after chemotherapy.Methods：Sputum culture was made by routine method. Then,to determine the kinds of bacteria bioMrieux ATB expression was used, and general drug-sensitivity test was done by Kirby-Bautr method.Results：Fever occured in 27.3% patients after chemotherapy, while pneumonia in 11.3% patients. 13 kinds of bacteria, 72 strains of bacteria and 2 kinds of fungi were found in 68 positive culture samples. The infection rates were 76.5% in infection of single bacteoia，23.5% in infection of two kinds of bacteria and 22.1% in bacteria with fungi. The infection rate of gram-negative bacteria is much higher than that of gram-positive ones (P＜0.01).Conclusions：The incidence of pneumonia in the hospital is higher in patients with neoplasm after chemotherapy. Most pathogenic bacteria are gram-negative and sensitive to aminoglycosides, piperacillin and norfloxacin.

Objective:To explore the influence of the veneering porcelain thickness on the compressive strength of zirconia all-ceramic crown.Methods:25 zirconia basement crowns with the thickness of 0.5 mm were made by CAD-CAMsystem,and then were divided into 5 groups randomly with the veneering porcelain thickness of 0.5(A),1.0(B),1.5(C),2.0(D)and 2.5 mm(E)respectively. The compressive strength of the samples was measured by a testing machine.Statistical analysis was conducted by SPSS13.0 software. The microstructure of the fractured bonding interface of the specimens was observed by scanning electron microscope(SEM).Results:The compressive strength in group A,B,C,D and E were:(1 279.96 ±42.85)N,(2 235.44 ±50.14)N,(2 216.38 ±48.97)N, (2 169.22 ±60.40)N and (2 028.70 ±47.37)N respectively(A or E vs B,C or D,P <0.01;A vs E,P <0.01;B vs C or D,P >0.05;C vs D,P >0.05).SEMobservation found that in group A and E the bonding interface was uneven and loose,the cracks and spores in veneering porcelain appeared more and larger,and had a more intensive distribution.Conclusion:When the veneering porce-lain is too thick or too thin,the compressive strength of zirconia all-ceramic crown decreases,the thickness of the veneering porcelain should be controled in an appropriate range.

Objective:To compare the fit of Co-Cr basal crowns fabricated by three kinds of technology. Methods:18 laser cured resin dies were divided into A, B and C groups(n=6) randomly. Co-Cr basal crowns of group A, B and C were made by traditional casting technology, CAD/CAM cutting metal technology and direct metal laser sintering technology( DMLS) respectively. The crowns were cemented to the corresponding dies and the basal crowns and dies were embedded in methyl acrylic. The thickness of the cement layer of the samples was measured under a stero microscope. Data were analyzed with SPSS13. 0 statistical software. Results:Marginal gap of group A, B and C was (66.08 ±3.90) μm, (29.21 ±3.31) μm and (24.96 ±2.99) μm respectively(P<0.01). Internal gap of group A, B and C was (114. 10 ± 27. 66) μm, (73. 69 ± 31. 31) μm and (79. 89 ± 33. 63) μm respectively(A vs B or C, P<0. 01, B vs C, P>0. 05). Conclusion:DMLS technology may make the best marginal fit, CAD/CAM and DMLS technology may pro-duce better internal fit. The marginal fit and the internal fit of the crowns prepared by the 3 methods can meet the clinical requirements.

Objective To investigate the status of Helicobacter pylori and “Helicobacter macacae” infection in rhesus and cynomolgus monkeys in China.Methods With the use of 16S rRNA specific primers for Helicobacter spp and Helicobacter pylori ( HP ) from published literatures, and new 16S rRNA specific primers designed for “Helicobacter macacae” ( HM ) , we investigated the infection status of these two Helicobacter spps in both of 45 rhesus and 90 cynomolgus monkeys by qPCR or conventional PCR on stool samples.Results All three primer sets for 16S rRNA exhibited excellently sensitivity and specificity.Both the infection rates of HP and HM were 100% among 45 young adult rhesus monkeys.The infection rate of HP and HM in 90 young adult cynomolgus monkeys were 100% and 97.8%, respectively.Conclusions Helicobacter pylori and “Helicobacter macacae” are present in almost every artificially bred adult rhesus and cynomolgus individuals which may adversely affect the health of laboratory monkeys and the accuracy of related animal experiments.

Objective To investigate the effect of remote ischemic postconditioning on brain injury after asphyxial cardiac arrest-resuscitation in rats.Methods Sixty-nine male Sprague-Dawley rats were randomly divided into 3 groups (n =23 each) using a random number table:sham operation group (group S),asphyxial cardiac arrest-resuscitation group (group CA-CPR),and remote ischemic postconditioning group (group RIPost).The animals were anesthetized with intraperitoneal 1％ pentobarbital 40 mg/kg,intubated and mechanically ventilated.Asphyxia was induced by occlusion of the tracheal tube and resuscitation was started 8 min later.In RIPost group,RIPost was produced by 3 cycles of 15 min occlusion of the right hind femoral artery-15 min release of the right hind femoral artery after restoration of spontaneous circulation (ROSC).Neurological deficits were evaluated and scored at 24 h,72 h and 7 days after ROSC.Neuron specific enolase (NSE) concentration in serum was assessed at 48 h after ROSC by ELISA.At 3 days after ROSC,the number of viable neurons in hippocampal CA1 region was recorded (by N issl's staining).Morris water maze test was used to quantify spatial learning and memory deficits after ROSC.Results Compared with group S,the neurological deficit score at each time point and the number of viable neurons in hippocampal CA1 region were significantly decreased,the NSE concentration in serum was increased,the escape lantency was prolonged,and the target quadrant residence time percentage and distance percentage were decreased in CA-CPR and RIPost groups.Compared with group CA-CPR,the neurological deficit score at each time point and the number of viable neurons in hippocampal CA1 region were significantly increased,the NSE concentration in serum was decreased,the escape lantency was shortoned,and the target quadrant residence time percentage and distance percentage were increased in group RIPost.The damage to neurons in hippocampal CA1 region was significantly mitigated in group RIPost as compared with group CA-CPR.Conclusion Remote ischemic postconditioning can reduce brain injury after asphyxial cardiac arrest-resuscitation in rats.

Objective:To compare the titanium-porcelain bonding strength between CAD/CAM and cast pure titanium.Methods:Pure titanium samples were prepaired by CAD/CAMand casting respectively and fused with porcelain.The bond strength between tita-nium and porcelain of the samples was measured with three-point test.The titanium-porcelain interface was investigated under scanning electronic microscope(SEM).Results:The bond strength of CAD/CAMpure titanium to porcelain was (35.95 ±3.74)MPa and cast pure titanium to porcelain was (28.37 ±1 .98)MPa(P <0.05).SEMobservation showed that there was thin transition layer between titanium substrate and ceramic in CAD/CAM bond interface,titanium and porcelain combined closely,no obvious pores.However, there was thicker transition layer and small pore in cast pure titanium to porcelain bonding interface.Conclusion:The bonding strength of porcelain to CAD/CAMpure titanium is greater than that of porcelain to casting pure titanium.

Objective:To compare the compressive strength of porcelain crown with Co-Cr,CAD/CAMpure titanium and CAD/CAM zirconia respectively.Methods:Metal models of simulating crown core of the ideal premolar were manufactured,digital data of the met-al model were obtained by CAD/CAMsystem,the basement crowns of Co-Cr,CAD/CAMpure titanium and CAD/CAMzirconia were respectively made(n =5),size of each crown was kept the same and the spcimens were set as group A,B and C respectively.Then masking porcelain and body porcelain were fired on basement crowns according to the instructions.The thickness of the porcelain was kept the same.All of the porcelain crowns were located on the Instron testing machine,the compression strength force values were measured.Data were statistically analysed by SPSS 1 3.0 software.The bonding surface of basement material and porcelain was observed by SEMafter compressive failure.Results:The compressive strength(N)of group A,B and C was 2 990 ±1 88,2 305 ±1 57,2 1 50 ± 1 31 ,A vs B or C,P <0.05,B vs C,P >0.05.Conclusion:All the 3 base materials with porcelain crown satisfy the clinical require-ments.The compressive strength of Co-Cr porcelain crown is stronger than that of CAD/CAMpure titanium porcelain crown and CAD/CAMzirconia porcelain crown.

Objective To evaluate the significance of weight-bearing lateral radiographs in evaluation of malunited frac-tures of the ankle. Methods 17 patients with malunited fractures of the ankle were treated by different reconstructive operations be-tween March 2010 and October 2012, including 9 females and 8 males, aged from 17 to 64 years. According to the Takakura classifi-cation of ankle arthritis, there were 7 patients in grade 1, 4 in grade 2 and 6 in grade 3. Simple open reduction and internal fixation were performed in 5 patients, supramalleolar tibial osteotomy in 5, lengthening osteotomy of the fibula in 2, supramalleolar tibial and fibular osteotomy in 5. Tibiofibular clear space on the anteroposterior radiograph. Medial clear space, tibiofibular clear space and tib-iofibular overlap on ankle mortise radiographs were compared preoperatively and at last follow-up. Tibial lateral surface angle (TLS), the offset of the center of talar rotation from the tibial axis, and the displacement of tibiotalar articular surface center on weight-bear-ing lateral X-ray were also compared preoperatively and at last follow-up. AOFAS score was used to evaluate the function of the ankle. Results The duration of follow-up was 9 to 32 months. Bone healing was observed in all patients, and the average healing time was 11 to 14 weeks. Ankle joint degeneration grade had no exacerbation. The medial clear space, tibiofibular clear space and tibiofibular overlap had no significant difference between the pre and postoperative. Statistically significant change was seen postoperatively in the values of TLS (76.9°±4.1° vs 80.9°±5.2°). The offset of the center of rotation from the tibial axis and the displacement of tibiotalar articular surface center were changed from 10.8 ± 2.1 mm to 2.0 ± 0.5 mm and 4.5 ± 1.5 mm to 2.2 ± 1.0 mm, respectively. The average AOFAS score was improved from 45.7 ± 15.9 points preoperatively to 82.0 ± 9.9 points postoperatively. Conclusion Weight-bearing lateral radiographs can be used to judge the ankle restoration. Even if the mortise radiograph had relative good realignment, it may ap-pear obvious deformity on lateral radiographs. Good reduction of lateral radiographs requires that the mid axis of the tibia should pass through the center of talar rotation and tibiotalar articular surface be parallel on the lateral radiograph.

Objective To investigate the clinical curative result of the new method of postermedial deepen of the fibular groove in the treatment of chronic peroneal tendon subluxation.Methods From March 2006 to October 2012,21 patients (15 male,6 female) with chronic peroneal tendon subluxation via a novel method of postermedial deepen of the fibular groove.In this group:Ⅰ grade 5 cases;Ⅱ grade 9 cases;Ⅲ grade 5 cases;Ⅳ grade 2 cases.All patients were followed up for at least 24 months.The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scale score and visual analogue score (VAS) were used to evaluate the clinical outcomes.Operation time,time to heal and complications were also recorded.Results The average operation time was 50 minutes (30-70 minutes).The blood loss was 30-60 ml,average 40 ml.All incisions healed after operation,no case of incision infection,skin necrosis and sural nerve,vascular injuryed.Mean AOFAS score was significantly increased from (55.2±7.1) preoperative to (93.6±5.6) postoperative.15 patients with excellent,good for 1 cases.The excellent and good rate was 100％ (16/16).VAS score by an average of (5.3±2.1) points down to (1.2±1.1) points postperative.All the patients can wear normal shoes postoperative,waking with normal gait.No patients had peroneal tendon tenosynovitis,tendon adhesion,fracture of lateral malleolus and other serious complications,no dislocation recurrent,strength of the peroneal muscle returns to normal.Conclusion The novel method of postermedial deepen of the fibular groove in the treatment of chronic peroneal tendon subluxation was safe and effective for ankle instability with a relatively short time.