BACKGROUND: Bracket dropping is often seen in clinic. Can these shed brackets be used again; what should be done to treat these brackets; is the bond strength of these recycled brackets different from those new ones, these questions are often concerned by orthodontists in their clinic and are the purpose of our study as well.OBJECTIVE: To evaluate the shear bond strength and compare two base-cure methods of recycled brackets. DESIGN: Grouping control study. SITTING: Department of Orthodontics, the Affiliated Hospital of Medical College, Qingdao University; Department of Materials, Dental School, Beijing University. MATERIALS: The teeth were collected from Oral Surgery, the Affiliated Hospital of Medical College, Qingdao University. The age was from 11 to 19 years. The gender was half male and half female. Intact enamel of the crown was required, but decayed, fracture, tetracycline pigmentation teeth or fluorosis teeth were excluded. Patients provided the confirmed consent for this experiment.METHODS: The experiment was carried out in Stomatology College of Peaking University in December 2005. Thirty ex vivo teeth were selected randomly from those prepared enamel surfaces, used as sample for rebounding. The edgewise brackets of swallow-tailed brackets were bonded on each tooth and rebonded after 24 hours. The teeth were cleaned and divided randomly into 3 groups. There were 10 teeth in each group. Group 1 was bonded with new brackets; group 2 with recycled brackets whose adhesive remnant were burned and got rid of; group 3 with recycled brackets whose adhesive remnant in the groove of the base were stored. Bracket was provided by Standard edgewise, Orsu Company, Hangzhou, China. After 24 hours, the shear bond strength was tested with material testing machine (Autogragh, Shimadzu, Japan). Adhesive remnant index (ARI) was added up. MAIN OUTCOME MEASURES: Shear strength of old metal bracket after rebonding and adhesive remnant.RESULTS: ① Shear bond strength: The shear bond strengths were (10.094±3.158 9) in group 1, (10.266±2.406 0) in group 2 and (8.898±1.365 9) in group 3. There were no statistically significant differences among the three groups (P > 0.05). ② ARI scores: ARI scores were 51.7%, 58.3% and 35.0% in the three groups, respectively. There were statistically significant differences between group 2 and 3. CONCLUSION: In vitro study indicates that the recycled metal brackets can reach good bond strength and that maybe there is chemical bond between new and old adhesive.

Objective By exploring the effects of recombinant human bone morphogenetic protein (rhBMP)2 and rhBMP13 on chondrocytes proteoglycan production and phenotype expression to establish the theoritical mechanisms for the treatment of disc degeneration with chondrocytes transplantation plus BMPs.Methods The dose-dependent effects of rhBMP2 and rhBMP13 on PG protein synthesis and gene expression were detected under different concentrations (0,25,125,and 625 ng/ml).The sulfated-glycosaminoglycan (s-GAG) in the culture media and the pericellular matrix was measured with a 1,9-dimethyl-methylene blue (DMMB) colorimetric assay.Reverse transcriptase polymerase chain reaction (RT-PCR) was performed respectively to quantify the relative abundance of aggrecan Mrna.Cell proliferation was examined by Hoechst Dye assay.Results All rhBMP2 and rhBMP13 in different concentrations could significantly increase s-GAG synthesis and gene expression in chondrocytes (P＜0.05).And at the same concentration.rhBMP2 was more potent than rhBMP13 on s-GAG synthesis.Hoechst Dye assay showed neither rhBMP2 nor rhBMP13 had significant effect on cell proliferation.Conclusion rhBMP2 and rhBMP13 are able to upregulate s-GAG synthesis,in addition,rhBMP2 is more potent than rhBMP13 on aggrecan gene expression regulation,but rhBMP2 and rhBMP13 do not have significant effect on chondrocyte proliferation.

Objective To evaluate the clinical effects of total knee arthroplasty (TKA) in treatment of severe adults Kashin-Beck disease (KBD). Methods Sixteen cases of KBD patients underwent TKA in Shaanxi Provincial People's Hospital, including 2 males (2 knees) and 14 females (17 knees), aged 41 to 56 years, mean (56.38 ± 6.40) years, left knee in 8 cases and right knee in 11 cases, knee varus in 15 cases and valgus knees in 4 cases. Visual Analogue Scale/Score (VAS), Hospital for Special Surgery (HSS) scores, knee range of motion, varus deformity and postoperative complications were observed before and after TKA. Results In this group of TKA patients, the levels of VAS scores in pre-total knee arthroplasty (pre-TKA), 2 weeks post-total knee arthroplasty (post-TKA), 3 months post-TKA, and at the end of the follow-up were 7.51 ± 1.00, 3.56 ± 1.29, 1.83 ± 1.40 and 1.10 ± 0.87, respectively. The level of VAS scores in 2 weeks post-TKA was significantly lower than that in pre-TKA (P<0.01), and the VAS levels were continued to decrease in post-TKA (all P< 0.01). Total HSS score at the end of the follow-up post-TKA was 78.60 ± 5.30, which was significantly higher than that in pre-TKA (43.59 ± 10.08, t=19.21, P< 0.01). At the end of the follow-up post-TKA, in addition to the muscle strength, the levels of pain, knee function, activity, flexion deformity and stability (25.94 ± 4.17, 15.88 ± 3.70, 14.09 ± 1.03, 6.79 ± 2.25, 8.58 ± 1.30) were significantly higher than those in pre-TKA (11.56 ± 5.39, 7.56 ± 1.75, 9.86 ± 3.85, 3.05 ± 3.22, 5.00 ± 3.07, t= 16.00, 8.32, 6.43, 7.07, 6.95, all P< 0.01). At the end of follow-up post-TKA, the knee degree of extension [(3.05 ± 2.71)°] was significantly lower than that in pre-TKA [(15.11 ± 11.30)°, t= -5.40, P< 0.01], the knee degree of flexion [(115.79 ± 9.65)°] was significantly higher than that in pre-TKA [(93.95 ± 22.40)°, t=6.02, P< 0.01), the degree of varus [(2.40 ± 2.40)° ] and valgus [(3.75 ± 2.50)° ] deformity was significantly lower than those in pre-TKA [(11.33 ± 10.43)°, (18.00 ± 5.72)°, t = - 4.15, - 3.61, all P< 0.05]. One patient was diagnosed as knee tuberculosis in 6 months post-TKA. There was no complication in this group of patients. Conclusion The TKA in severe adults knee of KBD can significantly reduce knee pain, improve knee function, correct joint deformities and improve quality of life in patients, and shows good clinical results.

BACKGROUND:Intermittent negative pressure has been proven to promote the repairing of soft tissue and bone healing, but the effect of negative pressure on the tendon-bone healing after anterior cruciate ligament reconstruction has not been reported.
OBJECTIVE:To research the effect of intermittent negative pressure on tendon-bone healing after anterior cruciate ligament reconstruction and on the biomechanics of tendon grafts.
METHODS:A total of 24 New Zealand white rabbits were randomly selected to establish the models of anterior cruciate ligament reconstruction of autogenous semitendinosus. The hind leg of one side was selected randomly as the negative pressure group, and the joint of the negative pressure side was connected with the micro-negative pressure aspirator through drainage tube and maintained a low-intensity and intermittent negative pressure;the contralateral hind leg was as the control and connected with ordinary drainage tube. Drainage tubes of both sides were removed at the same time after 5 days. At 6 weeks after modeling, the joint fluid was drawn to detect the expression levels of interleukin-1β;femur-ligament-tibia complex was used for tension measurement of tendon graft, and histological observation of tendon-bone interface.
RESULTS AND CONCLUSION:One rabbit had joint infection, and final y 23 rabbits were included in the study. Tension measurement results showed that maximum load for breakage in negative group pressure was significantly greater than that in the control group (P<0.05). Histological observation found that the number of osteoblasts in the negative pressure group was significantly more than that in the control group, and the difference was statistical y significant (P<0.01). Detection of synovial fluid showed that iterleukin-1βcontent in synovial fluid of the negative pressure group was lower than that in the control group, and the difference was statistical y significant (P<0.01). Intermittent negative pressure may play an active role in tendon-bone healing and modeling of tendon graft after anterior cruciate ligament reconstruction.

Objective To explore the application value of 64-slice spiral CT cardiac enhancement scanning in the morphological as-sessment of left atrial appendage(LAA).Methods Patients were selected retrospectively between April 16,2013 and May 1,2013, including 142 patients with sinus rhythms underwent MDCT coronary angiography,25 patients with atrial fibrillation underwent MDCT pulmonary vein-left atrial angiography.All images were post-processed,datas were measured and the morphology of left at-rial appendage were classified into different types.Results 167 patients were enrolled,including 88 males and 79 femals,age 53.7± 8.9 years.Anatomical relationship of the orifice of left atrial appendage to left superior pulmonary vein(LSPV)were classified as high type (superior to LSPV,2.4%),middle type(parallel to LSPV,86.2%),low type(inferior to LSPV,11.4%).LAA orifice could be classified into three types including oval(162,97%),round-like(3,1.8%)and drop-like(2,1.2%).LAA morphology could be classified in four types including Cauliflower(35,21%),Windsock(41,24.6%),Cactus(7,4.2%),Chicken-wing(84, 50.3%).Patients with atrial fibrillation have a larger LAA volume than who with sinus rhythm.Conclusion 64-slice spiral CT car-diac enhancement scanning can provide a vivid and intuitive reference to the anatomy of LAA and its adjacent structures,and it can also provide quantitative evaluation of LAA anatomical parameters,so it may have a nice significance in the direction of LAA occlu-sion.

A HPLC method for simultaneous determination of uridine, inosine, guanosine, adenosine and cordycepine
in Cordyceps sinensis was developed. The sample solution was prepared with 0.5% phosphoric acid solution by ultrasonic extraction. The separation was performed on a ZORBAX SB-AQ (150 mmí4.6 mm, 5 μm)column with gradient elution by 0.1% formic acid solution and acetonitrile, with column temperature 30℃, at a flow rate of 0.8 mL/min, and detected at wavelength of 260 nm. The result of method validation showed that the developed method had high accuracy and good repeatability. This method has been successfully applied for analysis of 5 kinds of nucleosides in different parts of C. sinensis. The results indicated that content of nucleosides in stroma is higher than that in insect body and whole C. sinensis.

Objective: To determine the protective effect of zero-balanced ultraifltration and modiifed ultraifltration on infants’ pulmonary function atfer cardiac surgery. Methods: Sixty infants with congenital heart diseases were randomly divided into 3 groups: a zero-balanced ultraifltration group (Z group), a modiifed ultraifltration group (M group) and a zero-balanced ultraifltrationwith modified ultrafiltration group (Z+M group). Oxygenation index (OI), difference of alveoli-arterial oxygen pressure (P(A-α)O2), static lung compliance (Cstat), and airway resistance (Raw) were measured before caridopulmonary bypass (CPB, T1), 20 minutes atfer the CPB (T2), 2 h atfer the operation (T3), 6 h atfer the operation (T4) and 12 h atfer the operation (T5). hTe time of mechanical ventilation was also monitored. Results:Atfer the CPB, OI and Cstat in all groups decreased signiifcantly, while Raw and P(A-α)O2 increased signiifcantly. At T3, T4 and T5, OI and Cstat in the Z+M group were signiifcantly higher than those in the Z group and the M group (P<0.05), Raw andP(A-α)O2 in the Z+M group were signiifcantly lower than those in the Z group and the M group (P<0.05). hTe ventilation time in the Z+M group was signiifcantly shorter than that in the Z group and the M group (P<0.05). Conclusion:Zero-balanced ultrafiltration and modified ultrafiltration can effectively promote the pulmonary function atfer cardiac surgery in infants.

A HPLC-QTOF MS method was established for analysis of components in Ophiocordyceps sinensis . The HPLC analysis was performed on an Agilent Zorbax SB Aq (150 mmí4.6 mm, 5 μm) with gr adient elution (5 mmol·L-1 ammonium acetate aqueous solution-acetonitrile), flow rate was 0.8 mL·min-1 and detection wave-length was 260 nm. The developed method was successfully applied in analysis of three different samples in-cluding O. sinensis, Hirsutella sinensis ( anamorph of O.sinensis) and Cordyceps militaris. Nine compounds were i-dentified in both O.sinensis and H.sinensis, which eight compounds were identified in C.militaris.

Objective We established a rapid detection method of Pasteurella spp.and provided a reference for microbiological quality control of laboratory animal .Methods According to the β subunit of bacterial RNA polymerase ( rpoB) protein multiple alignments of 13 different Pasteurella spp.published in NCBI .The degenerate primers were designed by CODEHOP designer online .CODEHOP PCR method was applied to detecting Pasteurella spp.after the specificity and sensitivity of the method had been evaluated by 21 reference strains .Results Standard strain amplified fragment were about 200 bp by degenerate primers PastF6/PastR5.The primers are able to distinguish between Pasteurella spp.and the other pathognic organisms of laboratory animal respiratory tracts .Sensitivity of this method were 0.2 pg/μL~2 pg/μL to different Pasteurella.The Pasteurella positive rate was 19.1% in 609 animal ' s respiratory samples .The accuracy of positive results was 100%through verifying by sequenced and blast .Conclusions The established method has good specificity and sensitivity .It can be used to detect Pasteurella spp.in animal samples .

Objective:To investigate the characteristics and significance of insulin-like growth factor 1(IGF- 1) and insulin-like growth factor binding protein 2 (IGFBP2) expressions in ankle cartilage of patients with Kashin-Beck disease (KBD).Methods:In this case-control study, 10 KBD patients who were hospitalized in the Department of Orthopedics of Shaanxi Provincial People's Hospital from January 2010 to December 2016 were selected as KBD group, and 10 patients with ankle fracture caused by trauma but without talus injury during the same period were selected as control group, the cartilage tissues of the two groups were collected. IGF-1, IGFBP2 positive cells, the mRNA and protein expressions of IGF-1, IGFBP2 in the cartilage tissues were detected by immunohistochemistry, real-time fluorescent quantitative PCR and Western blotting, respectively. According to the expressions of IGF-1 and IGFBP2 in ankle cartilage of KBD patients, a patient with amputation caused by trauma was selected in Shaanxi Provincial People's Hospital, and ankle joint cartilage was taken to prepare chondrocytes for in vitro cell verification experiments. The chondrocyte were divided into control group (0 ng/ml T-2 toxin), T-2 treatment group (20 ng/ml T-2 toxin) and T-2+ IGFBP2 silenced group (20 ng/ml T-2 toxin+ 50 nmol/L IGFBP2 siRNA), the MTT method and dimethyl methylene blue staining were used to detect the activity of chondrocyte and the secretion of sulfated glycosaminoglycan (sGAG). Results:In the control group and the KBD group, the number of IGF-1[(47.26 ± 8.97), (68.15 ± 7.42) cells] and IGFBP2 positive cells [(27.56 ± 5.40), (71.85 ± 7.62) cells] in the cartilage tissues were significantly different ( t = 4.487, 9.402, P < 0.01). Compared with the control group, the IGF-1, IGFBP2 mRNA and protein expression levels in KBD group were significantly higher, the differences were significantly different ( t = 3.340, 20.700, 4.684, 8.699, P < 0.05 or < 0.01). In cell experiment, the chondrocyte activitives and sGAG contents of the control group, T-2 treatment group, and T-2+ IGFBP2 silenced group were significantly different ( F = 226.70, 80.66, P < 0.01); among them, the cell activitives and sGAG contents of the T-2 treatment group and T-2+ IGFBP2 silenced group were lower than those of control group ( P < 0.05), and the T-2+ IGFBP2 silenced group were higher than those of the T-2 treatment group ( P < 0.05). Conclusions:The expressions of IGF-1 and IGFBP2 in the ankle cartilage of KBD patients are significantly higher. Silencing IGFBP2 gene can reduce the inhibitory effect of T-2 toxin on chondrocyte activity and the secretion of sGAG.