Objective:To evaluate the ability of calcium hydroxide removal using different irrigation methods and the effect on canal sealing.Methods:200 human single root canal premolar teeth were prepared.Divided the teeth randomly into 2 groups(each group 96 teeth,8 as control),one group filled with chemical calcium hydroxide and another filled with finished product calcium hydroxide.7 days after,divided each groups randomly into 6 subsets and remove the calcium hydroxide in the root canal(table1).Then each subset group choose 8 teeth randomly,observed by scanning electron microscope.Other specimens were obturated by lateral condensation of cold gutta-percha with a AH-Plus sealer,stained by Indian ink and then made into transparent teeth model.Results:At the same condition,there was no significant difference between group A and group B;the results of groups associated with ultrasonic were better than groups with injection syringe.The rinse solution EDTA was the best,distilled water was the worse.Dye penetration showed that the length of dye staining was no significant difference among all groups.Conclusion:Ultrasonic and sodium hypochlorite associate EDTA is the best method to remove the calcium hydroxide.But none of the methods and rinse solution used in this experiment can remove all of the calcium hydroxide.The calcium hydroxide remained influence on the root canal sealer is not predominance.

The marrow stromal osteoblasts from New Zealand rabbits were seeded on coral treated with L-polylysine, fibronectin and culture medium only, then the cells/coral composites were cultured in vitro. The cells/coral composites were observed for the process of cells growth and matrix formation at 7, 14 and 21 days after culture. With the aid of electron microscope,it was demonstrated that on the surface of the coral holes,which was treated with fibronectin, there were more adhering osteoblasts and matrix formation than those treated with both L-polylysine and culture medium after 7 and 14 days.Cell count in coral blocks was determined by doing a fluorimetric DNA assay. Although the samples treated with L-polylysine demonstrated higher cell count than the coral treated with culture medium after 7 days, there was no statistically difference between the two after 14, 21 days. At each time point, the samples treated with fibronectin showed higher cell count and alkaline phosphatase activity than the orals otherwise treated, and the cell count also increased with culture time. The study suggests that fibronectin has a significant effect on promoting the adhesion and proliferation of osteoblasts on the surface of coral.

Objective To observe the alteration of Bcl-2 and Fas-L at various intervals after traumatic brain injury and study the relationship between the alteration and the post-injury interval. Method The rat brain contusion was incurred by falling impact injury, paraffin section was cut after the test group rats were killed after various survival interval and stained with antibody of Bcl-2 and Fas-L, the hemotoxylin and eosin (HE) staining was carried out meanwhile. The staining results were measured quantitatively with computer imaging analysis system. Results Positive staining nerve celis were observed around the contusion area. At 30min after injury, a few Bcl-2 could be found around the wound, the intensity and the quantity of Bcl-2 positive celis increased significantly as post-injury interval extended. At 4h, the intensity came to a peak. Then the staining decreased. Although some Fas-L positive staining celis could be found around the wound at 30min after injury, the staining increased insignificantly from Ih to 4h after the injury. After 4h, the Fas-L positive staining cell increased significantly both in intensity and in quantity as post-injury interval extended. Conclusion There is a rule that the expression of Bcl-2 and Fas-L alters along with post-injury interval extension, which will be of value in time estimation of brain injury.

Objective To study the efficacy and safety of reboxetine and citalopram in treating retardant depression.Methods A total of 59 patients with retardant depression were randomly divided into reboxetine group(n=29)and citalopram group(n=30)for the treatment of 6 weeks.The patients were assessed with the Hamilton depression scale(HAMD)and treatment emergent symptom scale(TESS).Results At the end of 6 weeks,the total scores of HAMD in reboxetine(18.48±6.38)group and citalopram(11.60±4.46)group both significantly decreased(P＜0.001).Between two groups,the efficacy(82.8% and 56.7%)had significant differences(P＜0.05)but side effects had no statistical significance.Conclusion Reboxetine has significant curative efficacy,milder adverse effects and higher safety for treating patients with retardant depression.

Objective: To explore effects of large dose gamma globulin on cardiac function and immune regulation in patients with dilated cardiomyopathy (DCM) and heart failure (HF).Methods: According to random number table, a total of 90 DCM + HF patients were divided into routine treatment group (n=45) and gamma globulin group (n=45, received gamma globulin based on routine treatment, 400 mg kg-1 d-1 intravenous drip for 5d).After three months, therapeutic effect, cardiac function, levels of cardiac troponin T (cTnT), cTnI, N terminal pro brain natriuretic peptide (NT-proBNP) and anti-cardiac myosin heavy chain auto-antibodies (AMHCA) IgG titer before and after treatment, incidence of adverse reactions were observed and compared between two groups.Results: After three-month treatment, total effective rate of gamma globulin group was significantly higher than that of routine treatment group (80.00% vs.57.50%, P=0.02);compared with routine treatment group after treatment, there were significant reductions in levels of cTnT [(0.54±0.18) μg/L vs.(0.31±0.12) μg/L], cTnI [(1.35±0.18) μg/L vs.(0.72±0.13) μg/L], NT-proBNP [(758.34±64.28) pg/ml vs.(708.34±60.22) pg/ml], and significant rise in left ventricular ejection fraction [LVEF, (39.35±6.23)% vs.(47.32±6.10)%] in gamma globulin group, P<0.05 all;compared with before treatment and routine treatment group after treatment, there was significant reduction in AMHCA IgG titer [(0.099±0.047), (0.092±0.045) vs.(0.069±0.032), P<0.05 both] in gamma globulin group;incidence rate of adverse reaction in gamma globulin group was significantly higher than that of routine treatment group (22.22% vs.6.67%, P=0.04), but the symptoms were mild, and they recovered after symptomatic treatment.Conclusion: Large dose gamma globulin can significantly improve cardiac function and possesses good immune regulation effect in patients with dilated cardiomyopathy and heart failure.

AIM:To explore the improving effect of osteocalcin on obesity-related insulin resistance and in-flammation in the adipose tissue of obese mice .METHODS:The C57BL/6 mice were fed with high-fat diet for 12 weeks to obtain obese mice.Osteocalcin (30 ng/kg or 3 ng/kg) and saline solution (control) were intraperitoneally injected for other 4 weeks.The fat mass, body weight, serum triglycerides and serum free fatty acid were analyzed .Intraperitoneal glu-cose tolerance test and insulin tolerance test were carried out .Macrophage infiltration degree in the adipose tissue was ob-served by immunohistochemical staining .The mRNA expression of monocyte chemotactic protein-1 ( MCP-1 ) and CD68 was detected by real-time fluorescence quantitative PCR .RESULTS:Osteocalcin (30 ng/kg or 3 ng/kg) treatment for 4 weeks significantly reduced the body weight , fat mass and insulin level , and improved abnormal glucose tolerance and insu-lin resistance in the obese mice .Moreover, the macrophage infiltration decreased , and the mRNA expression of MCP-1 and CD68 was down-regulated in the adipose tissue of obese mice treated with osteocalcin at 30 ng/kg.CONCLUSION:Os-teocalcin at 30 ng/kg significantly reduces body weight and fat mass , and attenuates the severity of insulin resistance through down-regulating the mRNA expression of MCP-1 and CD68 and inbihiting macrophage infiltration in the adipose tis-sue of obese mice induced by high-fat diet.

BACKGROUND:Severely curved root canal preparation is the difficulty during clinical root canal preparation, and improper preparation may induce complications such as stage, root canal offset and apical open, which affect the quality of root canal preparation and apical closure. Therefore, it is important to choose a root canal preparation instrument which has the best cutting and forming ability. OBJECTIVE: To compare the shaping ability of Mtwo nickel-titanium rotary instruments, K3 nickel-titanium rotary instruments and stainless steel K-files for the preparation of curved root canals. METHODS:A total of 30 severely curved root canals of freshly extracted human maxilary molars were randomly divided into three groups, with 10 canals in each group. The canals were prepared by Mtwo instruments, K3 instruments and K-files, respectively. The instrument’s tip location in pre- and post-instrumentation radiographs of the three groups was recorded; the changes of root curvature, working length and working time in the three groups were measured and compared. RESULTS AND CONCLUSION:The root curvature showed no significant difference in the three groups before preparation (P> 0.05). The changes of root curvature after root preparation in Mtwo instrument and K3 instrument groups were significantly less than that in K-files group (P < 0.01), and no significant difference was found between Mtwo instrument group and K3 instrument group (P > 0.05). The root canal preparation time in the three groups showed significant differences (P < 0.01), which was the shortest in Mtwo instrument group and the longest in K-files group. The changes of working length after root preparation in the three groups showed no significant difference (P > 0.05). Mtwo nickel-titanium rotary instruments and K3 nickel-titanium rotary instruments are have high efficacy and strong shaping ability in preparing curved root canals.

Objective To evaluate the effects of hypothermic cardiopulmonary bypass (CPB) on rocuronium-induced neuromuscular blockade in the patients undergoing open heart surgery.Methods Twenty ASA physical status Ⅰ or Ⅱ patients,scheduled for elective open heart surgery,aged 18-45 yr,with body mass index of 18-25 kg/m2,were randomly assigned into 2 groups (n =10 each) using a random number table:room temperature group (group R) and hypothermia group (group H).The nasopharyngeal temperature was maintained at 30-31 ℃ during CPB in group H or at 36-37 ℃ during CPB in group R,and it was maintained at 36-37 ℃ before and after CPB in both groups.Anesthesia was induced with iv etomidate 0.3 mg/kg,fentanyl 2-4 μg/kg and rocuronium 0.3 mg/kg.The patients were tracheally intubated and mechanically ventilated.Anesthesia was maintained with iv infusion of sufentanil and intermittent iv boluses of midazolam and fentanyl.BIS value was maintained at 40-60.Neuromuscular block was monitored using TOF-WATCH SX accelerometer.Train-of-four stimulation (intensity 40 mA,frequency 2 Hz,wave length 0.2 ms,interval 12 s) of ulnar nerve was used.Rocuronium was infused intravenously using an automatic feedback control system to maintain T1 at 8％-12％.At 10 min after start of operation (T0),10 min after onset of CPB (T1),and 10 min after termination of CPB,blood samples were collected for determination of the plasma concentration of rocuronium (by HPLC).The infusion rate and consumption of rocuronium were recorded before,during and after CPB.Results Compared with group R,the plasma concentration of rocuronium was significantly decreased at T1,2,and the infusion rate and consumption of rocuronium were decreased before and after CPB in group H.Conclusion Hypothermic CPB enhances rocuroniuminduced neuromuscular blockade in the patients undergoing open heart surgery.

Objective To determine if fetal stem cells can enter the maternal circulation during pregnancy and re-pair the injuries of maternal heart.Methods C57 female mice at the age of 6-8 weeks were randomly assigned to three groups:sham control, surgery without pregnancy, and surgery with pregnancy ( n=8,eath group) .The control sham group was developed by opening and closing of the chest.The other two groups underwent heart surgery.The myocardial infarc-tion ( MI) model was induced by ligation of the left anterior descending coronary artery.Half of the surgical mice mated with e-GFP transgenic male mice, and another half group was not.Electrocardiogram ( ECG) and echocardiographic images were recorded at pre-operation, post-operation and postpartum.The collected data were used to evaluate the heart function. The GFP expression was detected by immunohistochemistry and q-PCR.Results When compared with the sham group, both the ischemia surgery groups with and without pregnancy, the ECG ST segment was significantly increased.This meas-urement indicated that the myocardial ischemia surgery was successful, and no significant difference in the ST segments be-tween two ischemia surgery groups was found.However, when ECG was measured in the surgical mice after postpartum, their myocardial ischemia was dramatically improved when compared with that of the ischemia surgery only mice.Echocar-diographic images also indicated that both the surgery groups had myocardial ischemia, however, no significant difference was observed in the pregnant mice before and after postpartum.The order of the cardiac function indexes from high to low was the sham group, surgery with pregnancy group, and surgery with no pregnancy group;in particular, the cardiac func-tion of pregnancy group was significantly enhanced compared with that of the surgery with no pregnancy group (P<0.05). More importantly, both immunofluorescence and q-PCR results showed that the embryonic stem cell translocation through circulation system with GFP expression in the heart of pregnancy group, while negative in other two groups.Conclusions Embryonic stem cells can be transferred into the maternal circulation of pregnant mice, and play a role in the repairing of their cardiac injuries.