Objective To study the effect of ketamine on L-type calcium currents (ICa-L) in guinea pig ventricular myocytes. Methods Adult guinea pigs of both sexes were anesthetized with pentobarbital. The hearts were immediately removed and ventricular myocytes were prepared by the technique described by Liu et al. The whole-cell patch clamp technique was used to study the ICa-L in isolated guinea pig ventricular myocytes. The changes in ICa-L produced by ketamine 100 ?mol?L-1 with different holding potentials or by different concentrations of ketamine with holding potential of + 10 mV were analyzed. Results Ketamine dose-dependently inhibited ICa-L evoked by a voltage step from a holding potential of - 40 mV to + 10 mV. The 4 concentrations of ketamine (100, 500, 1 000, 5 000 ?mol?L-1) reduced 1Ca-L by 28.7%?5.7% , 34.7%?1.4%, 58.7%?6.4% and 81.7%?6.7% respectively, with a mean IC50 concentration of 926.6 ?mol?L-1 . When the cells were exposed to ketamine 100 ?mol?L-1, the steady-state activation curve was not significantly affected, while the steady-state inactivation curve was shifted to more negative potentials.V1/2 decreased from ( - 14.8?0.8 ) mV to ( - 19.6?0.7) mV (P0.05) in control and drug-affected cells respectively. Ketamine slowed the rate of recovery from inactivation. Conclusion Ketamine can inhibit ICa-L in guinea pig ventricular myocytes in a concentration-dependent manner. This inhibitory effect of ketamine may explain its negative inotropic effect. Ketamine inhibits L-type calcium channel in its inactivated state.

Objective To study the effect of ketamine on inward rectifier potassium currents(I_k1)in isolated rat ventricular myocytes using whole-cell patch clamp technique.Methods Adult Wistar rats of both sexes were anesthetized with pentobarbital.The hearts were removed and ventricular myocytes were prepared by the technique described by Liu et al.Whole-cell patch clamp technique was used to study I_(k1) in isolated rat ventricular myocytes The changes in I_(KI) produced by 100 ?mol?L~(-1) with different holding potentials or by different concentrations of ketamine with holding potential of-120 mV were analyzed.Results Ketamine 100 ?mol?L~(-1) inhibited the Ira without any significant effects on reverse potential (-50--60 mV)and the shape of the Ⅰ-Ⅴ curve.Ketamine inhibited I_(k1) evoked by a holding potential of-120 mV in a dose-dependent manner with a mean IC_(50) value of (162.3?8.4)?mol?L~(-1).Conclusion Ketamine significantly inhibits I_(k1) in ventricular myocytes. This may explain the prolonged duration of action potential of ventricular myocyte produced by ketamine.

The purpose of this study was to investigate the effect of four kinds of different contact strength on the three-dimensional displacement of an implant-supported fixed bridge using digital laser speckle photography method. An in vitro model of beagle mandible with an implant-supported fixed bridge in its right premolar region was developed. The bridge was Au-Pt metal-ceramic. The contact was recovered to four different tightnesses, named 0, 1, 2, and 3. Different axial concentrated static load was applied to abutments and bridge respectively. The three-dimensional displacement of the implant-supported fixed bridge was measured using digital laser speckle photographic method. The results demonstrated that the influence of contact tightness was mainly on the mesio-distal and buccal lingual parts. When the contact tightness reached number 3, the regularity of displacement distribution was changed. The present study proved that digital laser speckle photography was an effective method of measuring the micro-displacement. One of the criterions of contact recovering decreased the implant displacement effectively without changing the regularity of displacement distribution.
Animals ; Dental Prosthesis, Implant-Supported ; Denture, Partial, Fixed ; Diagnostic Imaging ; methods ; Dogs ; Lasers ; Mandible ; Models, Animal ; Photography

Objective To determine the effect of cardiomyopeptidin on transient outward potassium current(I_(to) of rat ventricular myocytes and its action mechanism on the ion channels of myocardium.Methods Single ventricular myocytes of rats were obtained by enzymatic dissociation.The whole-cell patch-clamp recording technique was used to record the change of transient outward potassium current(I_(to) by different dosages of cardiomyopeptidin.Results Cardiomyopeptidin decreased I_(to) in a dose-dependent manner.Cardiomyopeptidin in dose of 10,50,100,250 and(500 mg/L) decreased I_(to %) by 4,13,22,32 and 38 respectively.Cardiomyopeptidin 50 mg/L moved the current density-voltage curve of I_(to) down,but the shape of the curve had no changes.Cardiomyopeptidin 50 mg/L did not change the steady state activation curve of I_(to).Conclusions Cardiomyopeptidin decreases the I_(to) of rat ventricular myocytes,which might be one of the mechanisms of its antiarrhythmic effect.

Objective To investigate clinical characteristics of patients with ST-elevation myocardial infarction (STEMI) and hypokalemia and the effects of hypokalemia on prognosis. Methods Consecutive 216 cases with STEMI who underwent emergency PCI were divided into group A (serum potassium ＜ 3.5 mmol/L) and group B (serum potassium＞3.5 mmol/L). Infarct site, infarct interrelated artery, peak level of CK-MB and cTnT were compared between two groups. Post-infarctional angina pectoris, arrhythmia, heart failure and cardiac death were compared. Results (1 )The percentage of anterior wall myocardial infarction , left anterior descending artery (LAD) lesions in group A were significantly higher than those in group B [61.2%(41/67) vs. 44.3%(66/149),55.2%(37/67)vs. 38.9%(58/149),P = 0.022,0.026]. The peak levels of CK-MB and cTnT in group A were significantly higher than those in group B [(194.39 ± 101.27) μg/L vs. (115.35 ±78.62)μg/L,(19.16 ±11.48)μg/L vs. (9.07 ±7.65) μg/L,P = 0.004,0.002].(2)Left ventricular ejection fraction in group A was significant lower than that in group B (P - 0.003). The incidence rates of post-infarctional angina pectoris, ventricular tachycardia, ventricular fibrillation and heart failure were significantly higher in group A [43.3%(29/67),32.8%(22/67), 11.9%(8/67),37.3%(25/67)] than those in group B [24.8%(37/149),18.1%(27/149),4.0%(6/149),20.8%(31/149)](P = 0.006, 0.017, 0.029, 0.010). Conclusions Hypokalemia is associated with infarct site and infarct interrelated artery. Hypokalemia has bad effect on prognosis of STEMI.

Objective To study whether the contrast volume and radiation dose can be reduced by automated contrast injection system(ACIS) in coronary angiography compared with manual contrast injection system(MCIS).Methods 200 patients undergoing coronary angiography with transradial approach in the People′s Hospital of Liaoning Province were enrolled in the study from January 2016 to June 2016.They were divided into the ACIS group (n=100) and the MCIS group (n=100).The clinical data, the net amount of contrast the total amount of contrast media consumed, number of angiographic views performed, fluoroscopy time, air kerma (AK) and dose area product (DAP) of the two groups were statistically analyzed.Results There were no statistical differences in the clinical data, the net amount of contrast used, number of angiographic views performed and fluoroscopy time between the two groups (all P>0.05).The total amount of contrast media used, AK, and DAP were less in the ACIS group than in the MCIS group (all P<0.05).Conclusions The volume of contrast consumption and radiation dose can be reduced by ACIS during coronary angiography with transradial approach compared to MCIS.

Objective To investigate the effect of hirudo micropowder on inflammatory factors in rats with cerebral ischemia-reperfusion injury.Methods Rats were randomly divided into sham-operation group,model group,coarse powder hirudo group,high-,middle-and low-dose micropowder hirudo groups.The corresponding drugs were given to the rats for 10 days by intragastric administration.Then middle cerebral artery occlusion(MCAO) model was made by suture method.The changes of inflammatory factors were observed.Results The level of intercellular adhesion molecule 1(ICAM-1) in high-dose micropowder hirudo group was lower than that in coarse powder hirudo group,and the level of platelet-derived growth factor(PDGF) in middle-and high-dose micropowder hirudo groups was also lower than that in coarse powder hirudo group obviously(P

The purpose of this study was to research the three-dimensional displacements of implant-supported cantilever fixed partial denture (CFPD) under oblique loading. One Beagle dog was used in this experiment. Two immediate implants of ITI were inserted in the mandible of the dog, and the implant-supported CFPD which used the implants as abutments was made in vitro fresh mandible. Then the digital laser speckle technique was employed to measure the three-dimensional displacements of CFPD under different oblique loading. We found that when an oblique loading was exerted on the pontic, the displacement increased with increasing of load. Under equal loading, the displacement of the abutment near to the pontic was smaller than that of the pontic but greater than that of the abut-ment far from the pontic. When oblique loading was exerted on the abutment, the displacement of the direct loaded abutment was greater than that of the other abutment and the pontic. Under the.eeual loading, the displacement of implant-supported CFPD of loading on pontic was greater than that of loading on abutments. The experiments demonstrated that implant-supported cantilever fixed partial denture (CFPD) is an effective and advisable therapy for totally? or partially edentulous patients. However, it is also suggested that the clinicians should avoid exerting oblique loading, especially the obliqe loading of the pontic when th e CPDF is used.
Animals ; Bite Force ; Dental Implant-Abutment Design ; Dental Stress Analysis ; methods ; Denture Design ; Denture, Partial, Fixed ; Dogs ; Imaging, Three-Dimensional ; Male ; Tooth Mobility

[ ABSTRACT] AIM:To study the expression of WNT5B in the breast cancer and further to discuss the correlation between WNT5B and clinicopathologic characteristics of breast cancer.METHODS:The expression of WNT5B at mRNA and protein levels was measured by real-time PCR and Western blot in 67 cases of breast cancer and the tissue adjacent to carcinoma.In addition, the immunohistochemical method was used to detect the expression of WNT5B in the breast cancer and the tissue adjacent to carcinoma.The relationships between WNT5B expression and clinicopathologic indexes were also analyzed.RESULTS:The expression of WNT5B in the breast cancer was obviously lower than that in the tissue adjacent to carcinoma (P<0.05).The expression of WNT5B at mRNA and protein levels in 67 samples of breast cancer was in va-rious degrees.The expression of WNT5B in T≤20 mm group of human breast cancer was obviously higher than that in T>20 mm group (P<0.05).The expression of WNT5B had no obvious correlation with axillary lymph node metastasis, histo-logical grade and immunohistochemical indexes of ER, PR, c-ErBb-2, p53 and Ki67 ( P>0.05) in the breast cancer. CONCLUSION:The expression of WNT5B decreases obviously in breast cancer.The expression of WNT5B is related to primary tumor size, which provides new ideas for the diagnosis and treatment of breast cancer, suggesting that WNT5B may be a new molecular marker for prognosis of breast cancer.

Objective To evaluate the effects of dexmedetomidine on hemodynamics during induction of anesthesia in the patients with atrial fibrillation with rapid ventricular rate undergoing noncardiac surgery.Methods Fifty patients with rheumatic valvular heart disease complicated with atrial fibrillation,aged 45-64 yr,weighing 50-75 kg,with ventricular rate ≥ 90 bpm,of ASA physical status Ⅱ or Ⅲll (NYHA Ⅱ or Ⅲ),scheduled for elective surgery,were randomly divided into 2 groups (n =25 each) using a random number table:control group (group C) and dexmedetomidine group (group D).Dexmedetomidine 0.6 μg/kg was infused intravenously at 10 min prior to induction of anesthesia in group D.Anesthesia was induced with iv midazolam 0.06 mg/kg,sufentanil 0.6 μg/kg,and vecuronium 0.12 mg/kg.Tracheal intubation was performed when the BIS value≤≤ 55After admission to operating room (T0,baseline),immediately after the end of dexmedetomidine infusion (T1),immediately before intubation (T2),and at 1,3 and 5 min after intubation (T3-5),SP,DP,MAP and HR were recorded.The adverse cardiovascular events were recorded starting from induction of anesthesia to 5 min after intubation.Results Compared with the baseline value at T0,HR was significantly decreased at T2,5,while increased at T3,4 in group C,and HR was decreased at T1-5 in group D; SP,DP and MAP were decreased at T2,5,while increased at T3 in group C,and no significant changes were found in the indices mentioned above in group D.Compared with group C,the incidence of hypotension,hypertension and tachycardia was significantly decreased,and no significant changes were found in theincidence of bradycardia in group D.Conclusion Dexmedetomidine 0.6 μg/kg infused intravously is helpful in maintaining the hemadynamics stable during induction of anesthesia in the patients with atrial fibrillation with rapid ventricular rate underging noncardiac surgery.