Objective To determine the minimum alveolar concentration(MAC)of sevoflurane for blunting the responses to removal of the laryngeal mask airway(LMA)in 50%anesthetized children.Methods Twenty-five ASA Ⅰ or Ⅱ children aged 3-8 yr undergoing elective surgery under general anesthesia weTe enrolled in this stuay.Anesthesia was induced with inhalation of 8%Sevoflurane.LMA was inserted when the children lost eyelash reflex and the lower jaw was relaxed.Anesthesia was maintained with 3%sevoflurane.All the children kept spontaneous breathing during operation.Assisted ventilation waw performed when necessary to maintain PET CO2 at 35-45 mm Hg.After the surgery the target end-tidal sevoflurane concentration was maintained for 10 min before LMA was removed.Up-and-down sequential allocation was used to determine山e MAC.The initial end-tidal concentration was 1%and was increased/decreased by 20%in the next patient if the extubation response was positive or negative.Limb movement,breath-holding,laryngosposm and hypoxemia(SpO2<95%)were considered to be the signs of positive response.The midpoint from positive response to negative response was made the balance point.and the mean value ofthe concentrations of sevoflurane at all the balance points were calculated as MAC.Results The end-tidal sevoflurane concentration for blunting the responses to removal of LMA was 0.98%.Conclusion The MAC of sevoflilrane for blunting the responses to removal of LMA in 50%anesthetized children(aged 3-8 yr)is 0.98%.

Objective:To study the stress distribution of the mandibular premolar cervix during clenching and mastication. Methods:Models of anisotropic enamel of the mandibular first premolar and the opposite maxillary first premolar crown were establishied. The stress distributions in the cervical region of the mandibular premolar were investigated in different loading conditions: simulating working, nonworking and vertical micromotions. In each case, the stroke was applied to the maxillary first mandibular premolar in a stepping procedure using nonlinear contact analysis. Results:The stress in the cervical region under loading condition simulating vertical micromotion was lower than that under loading conditions simulating working and nonworking micromotions. The stress was mainly concentrated near the buccal or the lingual cervical enamelo-dentinal junction under loading conditions simulating lateral excursion. Conclusion:The stress distribution in the cervical region is closely related to the pattern of occlusal force including location and direction.

Objective To evaluate the effect of preoperative intramuscular injection of of dextromethorphan in three dosages on fentanyl consumption in postoperative PCA in order to optimize its pre-emptive analgesia dose. Methods 80 ASA Ⅰ-Ⅱ patients underwent spine operations under general anesthesia were randomly divided into four groups, who respectively received intramuscular dextromethorphan 10mg (DM10 group), 20mg (DM20 group), 40mg (DM40 group), or normal saline (CON group) respectively. The PCA fentanyl consumption as well as VAS pain scores were observed 4h, 24h, and 48h after the operation. Results Although there was no significant differences in pain VAS score between the four groups, the fentanyl consumption was significantly lower in groups DM20 and DM40 compared with group CON and DM10. However, there was no significant difference between group DM20 and group DM40. Conclusion Preoperative IM dextromethorphan shows a dose-dependant fentanyl spare effect on postoperative PCA, and a dose of 20mg seems to be optimal for preoperative use.

Objective To study the effects of basic fibroblast growth factor gene in enhancing collateral vessel formation of coronary artery in the ischemic myocardium of swine.Methods All swines were distributed into the operation control group(n=6) and treatment group.The treatment group was further divided into 2 groups according to the route of injection either through the right coronary artery or the left coronary(n=6 respectively).The animal models of AMI were prepared by ligating the left circumflex(LCX) coronary artery.Two weeks after the operation,2?000 ?g of pcDNA_3-bFGF eukaryotic expression plasmid was directly injected into the coronary artery by catheter.Two weeks after the gene injection,evaluation of collateral circulation formation was made by means of coronary angiography and immuohistological staining ect.Results (1) Through immuotistological staining,the vessels count in both treatment groups was more than that in the control group;(2) Selective coronary angiography at 4 weeks after the operation showed that the number of newly formed collateral vessels in the bFGF gene treatment group was more than that in the control group.On the other hand,more collateral vessels were found in the group through left coronary injection compared with the group through right coronary injection.Conclusion Intra-coronary artery injection of bFGF gene can improve collateral vascular formation in the ischemic myocardium of swine.

Objective To study the expression of striatin(STRN) protein in brain tissue of paitents with drug-refractory epilepsy,and analyze the clinical significance of the expression.Methods Immunohistochemistry,immunofluorescence,cDNA array and Western blot were used to measure the levels of STRN cDNA and the protein in surgically removed temporal lobe tissues of patients with refractory epilepsy.Samples were retrieved from the brain bank of the authors' department(n=42),and the results were compared with that of the normal controls(n=12).Results STRN cDNA of STRN was abnormally expressed in the temporal cortex of the patients with epilepsy,the ratio of Cy5/Cy3 of STRN was 0.384.Moreover,the expression of STRN was significantly lower in neurons and glial cells of all epilepsy specimens.OD value in epileptic tissues determined by Immunohistochemical method was 0.310 8?0.108 7,which was significantly lower than that of control(0.421 0?0.120 2,P

[Objective]To investigate the clinical value of different magnetic resonance(MR) pulse sequences in the diagnosis of bone contusion.[Method]Forty-five patients with bone contusion underwent magnetic resonance imaging(MRI).All cases underwent computed radiography(CR),digital radiography(DR)or computed tomography(CT)and no bone fracture were revealed.Complications included swelling、pain and limit activity.The sagittal,coronal and transversal scanning were performed by Siemens Novus1.5T magnetic resonance imaging.The body coil were used on spines and knee coil on knees.MR pulse sequences included spin echo T1WI,Turbo spin echo T2WI,fl-2d T2WI and fat suppressed sequence T2WI.[Result]In 45 cases with bone contusion,44 cases were revealed on spin echo T1WI(97.7%),37 cases on Turbo spin echo T2WI(82.2%),24 cases on fl-2d T2WI(75%),45 cases on fat suppressed sequence T2WI(100%).The fat suppressed sequence T2WI was superior to TSE T2WI(

BACKGROUND:Finite element contact analysis was performed in premolars of lower mandible with enamelo-dentinal junction defects, which provided biomechanical evidence for the prevention of wedge-shaped defect and occlusion treatment.
OBJECTIVE:To analyze the effects of undermining damage of the enamelo-dentinal junction on the stress distribution of sclerous tissues of dental cervix.
METHODS:Triangle defects were established and models of wedge-shaped defect were designed in mandibular premolar along the enamelo-dentinal junction. The stresses during tightly biting and masticatory movement were simulated. Nonlinear contact analysis was conducted in sclerous tissues of mandibular premolar in the buccal cervical region.
RESULTS AND CONCLUSION:By simulating the stresses during tightly biting and masticatory movement, the stresses were concentrated in the defected regions of mandibular premolar at the enamelo-dentinal junction. With the defect length increased in size, the stress value and the magnitude of the stress field both increased. These indicated that the destruction of enamelo-dentinal junction altered stress distribution in the buccal cervical region. In the clinic, wedge-shaped defect should be fil ed promptly.

Objective:To investigate characteristics of masticatory movement path in young adults with AngleⅡ1 malocclusion.Meth-ods:1 5 youths with normal occlusion(group Ⅰ)and 1 5 with AngleⅡ1 malocclusion(group Ⅱ)were included.Mandibular movement paths of the incisal point of the incisor during unilateral-sided gum-chewing were recorded by the BioEGN mandibular kinesiography an-alyzer.Both maximal distances and directions (FH-opening/closing angles)in sagittal plane were analyzed.The statistic analyses were performed with SPSS 1 3.0 software.Results:Lateral distances of left masticatory movement path in Group I and Group II were (8.24 ±1 .48)mm and (6.58 ±2.49)mm,those of right(8.05 ±1 .05)mm and (6.42 ±2.47)mm,respectively(P <0.05).The aver-age of FH-opening/closing angle of masticatory movement path in Group I was higher than that in Group II at each level(P <0.05)ex-cept 0.5 mm point in the left masticatory movement path.Conclusion:Maximal lateral distance and FH-opening/closing angle of mas-ticatory path in young adults with AngleⅡ1 malocclusion are less than those with normal occlusion.

Objective The aim of this study was to explore MMP-2 and TIMP-3 expression in the gastric cardia carcinoma and with the relationship between the pathological stages.Methods Gastric cardia carcinoma surgical resection speciments of 115 cases were for the trial group.paraneoplastic gastric noncancerous tissues of 40 cases (the distance to cancer border>5 cm) as normal controls.The expression of MMP-2 and TIMP-3 was detected by two-step immunohistochemical method.The relationship of MMP-2 and TIMP-3 between clinicopathological stages was analyze. Results MMP-2 in carcinoma of the gastric cardia and the paraneoplastic tissues of organizations positive expression rates were 57.4%(66/115) and 40.0%(16/40) (P<0.05).MMP-2 expression was positively correlated with tumor size,tumor invasion depth,lymphatic metastasis and stage of tumor, which was negatively correlated with the prognosis of gastric cardia carcinoma (P<0.05).TIMP-3 in carcinoma of the gastric cardia and the paraneoplastic tissues of organizations positive expression rates were 48.7%(56/115) and 95.0%(38/40) (P<0.05).TIMP-3 expression was negatively correlated with tumor size,tumor invasion depth,lymphatic metastasis and stage of tumor, which was positively correlated with the prognosis of gastric cardia carcinoma. Conclusion The over expression of MMP-2 and the lost of TIMP-3 may play an important role in the invasion and metastasis of gastric cardia carcinoma.Combined MMP-2 and TIMP-3 detection may help to judge gastric cardia carcinoma development and to assess the prognosis of patients.

Objective an experimental animal model of acute myoc ardial infarction (ANI) was established by opening chest and ligation of the left anterior descending (LAD) coronary artery． Methods a total of 20 rabbits were opened chest and ligated LAD under sterilization． Electrocardiogram (ECG) and myocardial-enzymes in blood serum were investigated． Results ECG of all rabbi t s showed normal before operation． Irmediately after and 1/2 hour after ligation , ST-segment elevated and ECG showed ambulatory changes for 7 and 9 rabbits respectively． Two hours after LAD ligation, the change of ECG for 2 rabbits wa s not typical and 2 of them died during experiment． Four weeks after operation, E CG of 18 rabbits showed the chest leads had pathologic Q waves． Twenty-four ho urs after LAD ligation, AST, LDH, LDH-1, CK and CK-MB in blood serum were significantly increased． There was significant difference compared with before operation (except LDH) (P<0. 0l)． Conclusions:The method was sim ple and well repeated． The formation of myocardial infarction was reliable and rabbits were maintained for a long time after operation． It provides a valuable animal mode l for the experiment study of coronary heart disease．