BACKGROUND:A new open“C”-shaped molar band with nanocoating (patent number:ZL201110057699.1) has been invented to overcome some weakness of traditional bands and buccal tubes, which is used for molar fixation. OBJECTIVE:Using three-dimension finite element analysis software to theoretical y prove that the new band comes up to clinic requirement. METHODS:We established a finite element model of alveolar bone-tooth-band, and node domains tensile and shear loading were given. Stress distribution of the new bands through numerical simulation was predicted and calculated. Simulation of 20 N orthodontic force was applied in medial direction, distal direction and vertical direction in the three-dimensional model of a new band buccal tube and traditional band, to analyze the stress state in different directions under the force of the binder. RESULTS AND CONCLUSION:By numerical simulation of three-dimensional finite element, the stress of the new band was higher than that of the traditional band, but it could not reach the clinical cracking limit of resin reinforced glass ionomer cement. So the new band could theoretical y satisfy the clinical requirements.

BACKGROUND: Imported self-locking brackets cost much. So it is necessary to develop low-cost and easy-to-operate domestic self-locking brackets.OBJECTIVE: To introduce a newly developed self-locking brackets, and investigate the frictional forces of the brackets. DESIGN, TIME AND SETTING: Biomechanical controlled analysis was performed in the Laboratory of Harbin Medical University in January 2004. MATERIALS: Self-made self-locking brackets and domestic conventional tie-wing stainless steel brackets; domestic Ni-Ti round wire, Australian stainless steel round wire, and domestic stainless steel rectangular wire. METHODS: Two kinds of brackets were combined with three kinds of arch wires. Under the drive of micromotor, pull sensor moved at 1 mm/min. An arch wire, which was ligated in the bracket, was dragged. Thus, teeth's shift was imitated.MAIN OUTCOME MEASURES: Waveshape was observed through the use of storage oscillograph and corresponding data were recorded. Frictional force was determined and compared.RESULTS: Under the same other conditions, no matter which kind of arch wires were combined with, tie-wing brackets produced greater frictional force than self-locking brackets (P < 0.001). Under the same other conditions, no matter which kind of brackets were combined with, Ni-Ti wire produced greater frictional force than Australian stainless steel round wire and domestic stainless steel rectangular wire (P < 0.001). In addition, domestic stainless steel rectangular wires produced greater frictional force than Australian stainless steel round wires (P < 0.001). CONCLUSION: Self-locking bracket produces low frictional force, so it is fit for orthodontic doctors to use the corrective force.

Objective:To observe the specific killing effect on tumor cells of the spleen cells in mice immunized with three tandem repeats of CEA minigene DNA vaccine pcDNA-triCEA625-667 and to evaluate the safety of the vaccine. Methods: The BALB/c mice were randomly divided into blank vector group ( pcDNA3. 0 ) , haploid vaccine group ( pcDNA-CEA625-667 ) and tandem repeats vaccine group (pcDNA-triCEA625-667). The mice received a total of 4 intramuscular immunization every 10 days once. The changes of body weight,survival state were recorded and the levels of serum ALT and serum creatinine were detected. The specific CTL killing activity of spleen cells in accinated mice on mouse hepatoma cells(H22-CEA+),gastric cancer cells(MFC-CEA+),colorectal cancer cells ( CT26-CEA+) with high expression of CEA and mouse hepatoma cells ( H22-CEA-) without expression of CEA was detected. Results:The two vaccines had strong killing activity on CEA positive liver cancer,gastric cancer and colon cancer cells,and the difference was statistically significant ( P<0. 01 ) compared with the PcDNA3. 0 group. And they had almost no effect on CEA negative tumor cells (H22-CEA-). The killing activity on liver cancer cell(H22-CEA+) and gastric cancer cell(MFC-CEA+) induced by pcDNA-triCEA625-667 was stronger than that induced by pcDNA-triCEA625-667(P<0. 05). The survival status,change of body weight and function of liver and kidney of the mice were not affected by the vaccine. Conclusion:There was no adverse reaction in the course of vaccine immunization. The minigene DNA vaccine derived from CEA can induce tumor specific CTL effect and the immune response level elicited by three tandem repeats of minigene DNA vaccine was superior to that elicited by haploid vaccine.

Objective To describe the clinical application of microvascular anastomotic device in head and neck reconstruction.Methods From July,2013 to November,2013,microvascular free flaps were transferred to reconstruct the defects simultaneously after tumor resection of head and neck region in 12 cases in Department of Oral and Maxillofacial Surgery,Peking University School of Stomatology.Microvascular anastomotic coupling devices (MACD) were used in vascular anastomosis.The clinical data were collected and analyzed,including the selection of free flap,diameter of donor and recipient vessels,type of MACD,time of anastomosis,instant patency of anastomosis.The flap was monitored closely after operation and the final survival rate was calculated.Results Twelve microvascular free flaps were done in this series,including 6 fibula flaps,4 forearm flaps and 2 anterolateral thigh flaps.Totally 17 MACD were used by end-to-end anastomosis in this series,including 5 arterial anastomosis and 12 venous anastomosis.The anastomose time using MACD was from 4 to 10 minutes,with a median time 6.8 minutes.The instant patency rate of anastomosis was 100％.There were some blood leakages near the anastomotic stoma in 1 arterial anastomosis using MACD.It was resolved successfully by changing a new MACD.Conclusion Our primary clinical experience showed that the MACD was well suited to the microvascular reconstruction of head and neck defect.The feasibility and reliability was confirmed by our clinical cases.It should be recommended as a safe,fast and reliable adjuvant anastomotic instrument for free tissue transfer.

Objective To observe and identify the impact of a type of macro?pore bone block bioactive glass on osteo?blast in vitro. Methods Extract fluid of new bioactive glass was prepared withα?MEM culture medium as the bioactive medium group. And the concentrations of different ions were detected with Inductively Coupled Plasma?Atomic Emission Spectrometry in bioactive medium group andα?MEM medium group. MC3T3?E1 cells cultured in bioactive medium group were considered as ex?perimental group and cells cultured inα?MEM medium as control group. Giemsa and immunofluorescence staining was performed to detect the cell numbers, the karyoplasmic ratio and the average fluorescence intensity per cell. Cell proliferation and viability in different groups were detected by cell cycle analysis, MTT assay and BrdU assay, respectively. Total RNAs of cells in different groups were extracted and the expressions of ALP, OCN and collagenⅠwere measured by quantitative real time PCR. ALP stain?ing and alizarin red staining were performed to assess the differentiation and mineralization of MC3TC?E1 cells in different groups. Results The concentrations of Si and F were 40.02 ± 0.67 mg/L and 0.02 ± 0.001 mg/L in bioactive medium group, higher than 2.02±0.01 mg/L and 0.00 mg/L inα?MEM solution, and the concentration of Ca was lower than that inα?MEM solution. The con?centration of P and Na had no difference. In Giemsa staining, the cell number in 400 times field under a microscope was 106.0 ± 6.025 in bioactive medium group and 40.20 ± 3.639 inα?MEM medium group. In the immunofluorescence of vinculin, the karyo?plasmic ratio and the expression of vinculin were higher in bioactive medium group (40.85±5.720, 0.050 88±0.021 78) than inα? MEM medium group (21.93 ± 4.137, 0.023 60 ± 0.003 18). In cell cycle analysis, the proportion of cells retained in S and G2/M phase in the bioactive medium group was more than that in theα?MEM medium group after 72 hours of cell culture. In the BrdU and MTT assay, MC3T3?E1 cells in bioactive medium group both showed a higher proliferation rate with statistical significance. In MC3T3?E1 cells cultured with the bioactive medium, the expressions of osteogenesis?related genes were higher than those cultured with ordinaryα?MEM solution;in the ALP staining and alizarin red staining, the expression of ALP and the mineralization rate were higher in bioactive medium group (1.328%±0.015 36%, 2.953%±0.536 3%) than inα?MEM medium group (0.979%±0.030 59%, 1.000%±0.208 1%). Conclusion The bioactive medium promotes cell proliferation and osteoblastic differentiation of MC3T3?E1 cells, and has much more Si ions, which indicates that macro?pore bone block bioactive glass can promote cell proliferation and dif?ferentiation and has promising bioactivity.

AIM: To investigate the effect of ligustrazine on hydrogen sulfide (H_2S) system in pulmonary hypertension induced by hypoxic hypercapnia in rats. METHODS: Thirty Sprague-Dawley rats were randomly divided into 3 groups: control group (C), hypoxic hypercapnia group (HH), and hypoxic hypercapnia+ligustrazine group (HH+L). The change of hemodynamics was measured. The ratio of vessel wall area and total area of arteriae pulmonalis were observed under light microscope. The apoptosis of arteriae pulmonalis was tested with TdT-mediated dUTP nick end labeling (TUNEL), and the apoptosis index was calculated. Plasma level of hydrogen sulfide and activity of hydrogen sulfide generating enzymes in homogenates of rat lung tissue were evaluated by sensitive modified sulfide electrode method. Cystathionine-γ-lyase (CSE) mRNA in lung tissues was determined by RT-PCR. RESULTS: The level of mean pulmonary arterial pressure, the ratio of vessel wall area/total area and the right ventricle/left ventricle+septum were significantly higher in HH group than those in C group, and the value was obviously lower in HH+LTZ group than that in HH group (all P<0.01). The mean carotid arterial pressure of 3 groups had no significant difference (P>0.05). The apoptotic index of arteriae pulmonalis in HH group and HH+LTZ group was significantly lower than that in C group, and that in HH+LTZ group was significantly higher than that in HH group (P<0.05 or P<0.01). Plasma level of H_2S, the activity of H_2S generating enzymes in homogenates of rat lung tissue, cystathionine-γ-lyase (CSE) mRNA in lung tissues in HH group were significantly lower than those in C group (all P<0.01), and those in HH+LTZ group were significantly lower than those in HH group (all P<0.01). CONCLUSION: Ligustrazine up-regulates the expression of cystanthionine-γ-splitting enzyme (CSE), enhances the activity of CSE and increases the level of H_2S to prevent pulmonary hypertension induced by hypoxic hypercapnia.

Objective:To observe the effect of tannic acid on renal morphology and function of diabetes mellitus model rats ,and to explore the mechanism of improving effect of tannic acid from oxidative stress , nitrosative stress angle.Methods: 8 rats were randomly selected from 68 6-week-old male Wistar rats as normal control group and the remaining 60 rats accepted high-sugar and high-fat diet for 4 weeks, then were injected streptozotocin ( STZ, 52 mg/kg ) intraperitoneally in order to manufacture a diabetic rat model.Further the diabetic rats were randomly divided into model group ,aminoguanidine group ,low-dose of tannic acid group and high dose of tannic acid group.The rats in aminoguanidine group were injected aminoguanidine [AG,40 mg/(kg· d)] intraperitoneally, those in low-dose of tannic acid group were injected tannic acid [TA,20 mg/(kg· d)] and those in high-dose of tannic acid group were injected tannic acid [TA,30 mg/(kg· d)].The rats in normal control group and model group were injected normal saline [NS, 30 mg/(kg· d)] and all rats were sacrificed and tissues were derived at the end of the week 10.Morphologic changes of kidney in diabetic rats were observed by HE staining and correlative biochemical indices of renal function were detected by biochemical analyzer.8-hydroxy deoxyguanosine (8-OHdG) and 3-nitrotyrosine (3-NT) content of renal tissue in rats in different groups were detected by ELISA method.Mesangial cells cultured in vitro were treated with high concentration of glucose (30 mmol/L) and AGEs (250 mg/L) and at the same time with different concentration of tannic acid (10,20,40 and 80μmol/L) on the basis of setting corre-sponding control group.The contents of 8-OHdG and 3-NT in the culture supernatant were measured by ELISA method after 48 hours.Results:Tannic acid can effectively improve the renal pathological changes and improve renal function of diabetic rats .The contents of 8-OHdG and 3-NT in kidney tissue homogenate of diabetic rats and in the supernatant of GMC cultured with high glucose or AGEs were all significantly increased and can be reduced by tannic acid.Conclusion:Tannic acid improving the structure and function damage of kidney in diabetic rats might be achieved by oxidative stress and nitrosative stress mechanism .

Objective To observe the effects of Yiqi Huoxue Tongluo Jiedu fang (YHTJF) on pneumocyte apoptosis after lung ischemia/reperfusion (I/R) injury (LIRI) in mice and to investigate whether c-Jun N-terminal protein kinase (JNK) is involved in the mechanism of apoptosis.Methods Seventy C57BL/6J male mice were randomly divided into seven groups:normal control group (C group),carboxyl methyl cellulose-Na+normal control group (CMC-Na+C group),CMC-Na+sham group (CMC-Na+S group),CMC-Na+I/R group (CMC-Na+I/R group) and CMC-Na+YHTJF-low,-middle,-high dose groups (CMC-Na+YL,CMC-Na+YM,CMC-Na+YH groups).C group did not undergo any processing;in CMC-Na+S group,only was chest opened without clipping the lung hilum;in the rest of the four groups,they all underwent opening of the chest and clipping the lung hilum for 30 minutes,then the clipping of artery was relieved and left lung reperfusion was carried out for 3 hours.After operation,the mice were sacrificed,the lung tissues were harvested.Under light and electron microscopes,the lung morphological and ultra-structural changes were observed,and the changes of index of quantitative evaluation for alveolar damage (IQA) were determined.The terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) was applied to evaluate the apoptosis index (AI) of the lung tissues.The protein and mRNA expressions of JNK and glucose regulating protein 78 (GRP78) in lung tissues were detected by Western Blot and reverse transcription-polymerase chain reaction (RT-PCR);the correlations between lung AI and the expressions of mRNA and protein of JNK and GRP78,IQA were analyzed.Results Compared with CMC-Na+S group,IQA,AI and mRNA and the protein expressions of JNK and GRP78 in CMC-Na+I/R group were obviously higher [IQA:(74.00 ± 7.31)％ vs.(7.00 ± 1.23)％,AI:(64.40 ± 11.97)％ vs.(5.60 ± 1.14)％,JNK mRNA (gray value):1.143 ± 0.284 vs.0.152 ± 0.128,GRP78 mRNA (gray value):0.897 ± 0.129 vs.0.284 ± 0.044,JNK protein (A value):0.428 ± 0.074 vs.0.073 ± 0.052,GRP78 protein (A value):1.075 ± 0.145 vs.0.589 ± 0.060].Compared with CMC-Na+I/R group,the IQA,AI,protein and mRNA expressions of JNK and GRP78 in CMC-Na+YL,CMC-Na+YM,CMC-Na+YH groups were all lower,and the degree of reduction in group CMC-Na+YM was the most remarkable,greater than that in CMC-Na+YL or CMC-Na+YH group [IQA:(26.20 ± 3.35)％ vs.(34.00±5.34)％,(41.20±9.18)％,AI:(29.40±3.05)％ vs.(48.20±3.83)％,(39.20±6.14)％,JNK mRNA (gray value):0.681 ± 0.130 vs.0.804 ± 0.153,0.938 ± 0.11,GRP78 mRNA (gray value):0.450 ± 0.105 vs.0.747 ± 0.231,0.566 ± 0.115,JNK protein (A value):0.188 ± 0.049 vs.0.261 ± 0.065,0.209 ± 0.063,all P ＜ 0.01],compared with the CMC-Na+I/R group,the expression of GRP78 protein was obviously higher in CMC-Na+YH,CMC-Na+YL,CMC-Na+YM groups and the most remarkably high was in CMC-Na+YH group (A value:1.429 ±0.226 vs.1.130±0.169,1.128 ±0.177,all P ＜ 0.01).The apoptosis of each group was mainly in the pulmonary vascular endothelial cells and alveolar epithelial cells,and brown particles were positive cells under light microscope.Under transmission electron microscope:nuclear pyknosis and margination under the nuclear membrane,cytoplasm condensed,lamellar bodies decreased and emptying increased,cell membrane microvilli decreased or disappeared,mitochondria swelling,inflammatory cells increased in alveolar septum and adhering onto the capillary walls could be seen in CMC-Na+I/R group.Compared with CMC-Na+I/R group,the lung tissue ultrastructural damage alleviated,ultrastructure of alveoli clearly seen,nuclear chromatin relatively uniform,cytoplasm increased,type Ⅱ alveolar epithelial cell surface microvilli relatively plenty,lamellar corpuscle number increased,mitochondria swelling ameliorated in CMC-Na+YH,CMC-Na+YL,CMC-Na+YM groups and the most remarkable one was CMC-Na+YM group.AI was significantly positive correlated with the mRNA and protein expressions of JNK,GRP78 and IQA (r =0.907,0.928,0.880,0.712,0.911,all P ＜ 0.01).Conclusions YHTJF may effectively alleviate the cell apoptosis in mice LIRI,and its mechanism may be related to the inhibition of JNK pathway.

Objective To explore the influence of the clinical pathway to control on hospital stay and medical expenses of pediatric rotavirus enteritis.Methods 245 infants with IRE were randomly assigned into two groups,109 in research group,136 in control group.All were treated with conventional therapy,for research group with clinical pathway.136 patients with previous medical routine therapy patients in the control group were compared.Compared two sets of average day in hospital,cure rate and cost,expenses for medicine and checking expenses proportion.Results The results shwed that the observation group of children's average hospital stay was lower than the control group,the cure rate higher than that in the control group,each time of total cost,expenses for medicine,each day medicine reducing( P ＜ 0.05 ).Checking expenses proportion was increased ( P ＜ 0.05),as to therapeutic effect,there was significant difference between two groups( P ＜ 0.05 ).Both expenses of drug ratio and ratio of the average daily expenses of drug are reduced.Conclusion Clinical pathway is applied in pediatric rotavirus enteritis can improve recovery rate,reduce hospitalization time and lower hospitalization fees and expenses,charges,medicine and inspection charge proportion.And can improve health education effect and patient satisfaction.

Objective To evaluate the effect of sevoflurane anesthesia on cognitive impairment in rats with traumatic brain injury. Methods One hundred and and twenty healthy male Wistar rats, aged 2-3 months, weighing 190-220 g, were assigned into 4 groups ( n=30 each) using a random number table method: control group ( group C) , traumatic brain injury group ( group T) , sevoflurane anesthesia group ( group S) , and traumatic brain injury plus sevoflurane anesthesia group ( group T+S) . A 40 g hammer was freely dropped onto the left parietal bone window from a height of 20 cm to establish the traumatic brain inju-ry model in T and T+S groups. Twelve days later, S and T+S groups inhaled 3％ sevoflurane for 3 h, and C and T groups inhaled pure oxygen for 3 h. On 1 day before anesthesia and 3 and 7 days after anesthesia, 10 rats in each group were randomly selected for performing Morris water maze test. Rats were sacrificed af-ter the end of Morris water maze test, and the hippocampal tissues were obtained for determination of the apoptosis rate of hippocampal neurons, cytoplasmic calcium concentration [Ca2+]i (by flow cytometry), expression of glucose-regulated protein 78 ( GRP78) and CCAAT∕enhancer-binding protein homologous pro-tein ( CHOP ) ( by immunohistochemistry ) , and expression of caspase-3 and caspase-12 ( by Western blot) . Results Compared with group C, the escape latency was significantly prolonged, the number of crossing platform was decreased, the apoptosis rate of hippocampal neurons and [ Ca2+] i were increased, and the expression of caspase-3, caspase-12, GRP78 and CHOP in hippocampal tissues was up-regulated in S, T and T+S groups ( P<0. 05) . Compared with T and S groups, the escape latency was significantly prolonged, the number of crossing platform was decreased, the apoptosis rate of hippocampal neurons and [ Ca2+] i were increased, and the expression of caspase-3, caspase-12, GRP78 and CHOP in hippocampal tissues was up-regulated in group T+S ( P<0. 05 ) . Conclusion Sevoflurane anesthesia can accentuate cognitive impairment in rats with traumatic brain injury, and the mechanism may be related to aggravating the degree of endoplasmic reticulum stress-induced calcium overload and increasing the apoptosis rate of hip-pocampal neurons.