Tooth extraction is a common operation in oral surgery. Traditional-extraction instruments, such as bone chisel, elevator, and bone hammer, lead to not only severe trauma but also unnecessary complications, and patients easily become nervous and apprehensive if tooth extraction is performed using these violent instruments. In recent years, with the develop- ment of minimally invasive concept and technology, various micro-power instruments have been used for tooth extraction. This innovative technology can reduce the iatrogenic trauma and complications of tooth extraction. Additionally, this technology can greatly decrease the patient's physical and mental pressure. The new equipment compensates for the deficiency of traditional tooth extraction equipment and facilitates the gradual replacement of the latter. Diverse micro-power systems have distinct strengths and weaknesses, so some auxiliary instruments are still needed during tooth extraction. This paper focuses on the various micro-power systems for tooth extraction and tries to compare the advantages and disadvantages of these systems. Selection and usage of auxiliary equipment are also introduced. Thus, this paper provides reference for the proper application of the micro-power systems in tooth extraction.
Humans ; Tooth Extraction ; instrumentation

Background Retinal vascular recanalization is key to the treatment of retinal vascular occlusive disease.Studies confirmed that urokinase by intravitreal injection inhibits the expression of occludin protein at tight junction complexes among retinal capillary endothelial cells.Objective This study was to observe the effects of urokinase via eye local injection on the outward permeability of blood-retinal barrier by detecting the concentration of intravitreal Evans blue (EB).Methods Sixty healthy Sprague-Dawley (SD) rats were randomly assigned to four groups,and the right eyes of the rats were used as experimental eyes.Urokinase of 4 μl (350 U) and the equal volume of PBS (0.01 mol/L) was intravitreally injected separately in the intravitreal urokinase group and the intravitreal PBS group,and 10 μl urokinase (1000U) and the equal volume of PBS was injected via retrobulbar tissue respectively as the retrobulbar urokinase group and the retrobulbar PBS group.Twenty-four hours after injection of drugs,0.5％ EB 4 μl was intravitreally injected.Four hours later,the rats were sacrificed and the right eyeballs were excised for the extraction and drying.EB was extracted from dried vitreous by formamide.Then,the concentration of EB in formamide was determined by a formamide extraction-ultraviolet spectrophotometry method to calculate the concentration of EB in vitreous.The use and care of experimental animals followed the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission (2011 version).Results The rat vitreous body showed the light blue color in intravitreal urokinase group and the retinal vessels were visible under the microscope,and that in the retrobulbar urokinase group presented blue color.However,in the intravitreal and retrobulbar PBS group,rat vitreous exhibited the deeper blue color and retinas were invisible.Absorbance of EB in formamide was 0.181 ±0.008,0.450±0.017,0.330±0.009 and 0.436±0.012 in the intravitreal urokinase group,intravitreal PBS group,retrobulbar urokinase group and retrobulbar PBS group,respectively.The intravitreal EB concentrations in the intravitreal urokinase group were (0.266±0.014)g/L,which was lower than (0.667±0.026) g/L,(0.496±0.015) g/L and (0.657±0.017) g/L of the intravitreal PBS group,retrobulbar urokinase group and retrobulbar PBS group,showing significant different among the four groups (F =100.406,P＜0.01),and the intravitreal urokinase group showed the lowest value in comparison with other three groups (all at P＜0.01).Conclusions Local application of urokinase around eye can augment the outward permeability of blood-retinal barrier in rats.Intravitreal assay of EB after intravitreal injection is a feasible approach to the determination of outward permeability of blood-retinal barrier.

Objective To observe the changes of retinal sensitive cellular ultrastructure of rats in critical period of visual development.Methods Ten normal healthy Wistar rats were chosen,eight of which were neonatal rats and two were mature rats.The eight neonatal rats were randomized into four groups(n=2 in each group) and respectively sacrificed on postborn day 0,15,20,25.The eyeballs of the neonatal rats and the mature rats were resected and the retinas were observed by electron microscope.Results The rat retinal sensitive cellular ultrastructure on postborn day 0 was immature and the cellular arrangement was not clear.The organelle of sensitive cell in critical period developed mature gradually and the arrangement of them was very clear.Conclusion The retinal sensitive cell of rats develops and matures gradually in critical period.

The long-distance medical education in the health institution of Chinese People’s Armed Police Force is discussed. The function and actuality of medical service support of Chinese People’s Armed Police Force are analyzed in aspects of wide range of support, weak education basis and uneven medical resources. Problems are put forward and solutions are suggested so as to promote long distance education and support ability.

Objective To explore the telemedicine education by using operation live telecast system.Methods Multi-channel video and audio signals were collected by video camera and transmitter phone and were connected with telemedicine education web after matrix treating and controlling.Results Telecommunication of live telecast was realized.Conclusion Operations can be telecast more widely,and the level of telemedicine education is raised.

Objective To summarize the clinical experience of laparoscopic cholecystectomy(LC) for acute cholecystitis.Methods Clinical records of 58 cases of acute cholecystitis treated by LC from March 1998 to May 2004 were respectively reviewed.Results Intraoperative cholangiography was conducted in 6 cases,5 of which were found to have common bile duct stones.Of the 5 cases,2 underwent LC combined with choledoscopic choledochotomy, stone removal and T tube drainage; the other 3 cases had ill defined relationship of Calot′s triangle and underwent conversion to open choledochotomy with stone removal and T tube drainage.In 52 cases were diagnosed as simple gallbladder stones, LC was successfully accomplished in 50 cases and conversion to open surgery was required in 2 cases because of serious inflammatory adhesions.In this study 1 case had jaundice after operation and 3 cases had leakage of bile,and all recovered on conservative treatment . Conclusions LC can be performed safely in the majority of cases of acute cholecystitis.

The microinjection of brain nuclei and potassium iontophresis induced tail flick were used to investigate the effect of injecting oxytocin (OT) or anti-oxytocin serum (AOTS) into locus ceruleus (LC) on the pain threshold (PT) and morphine analgesia. The result showed that OT injection into LC could enhance PT, while ATOS injection could reduce PT. The OT injection could strengthen morphine analgesia, but AOTS injection could antagonize this action. These results suggest that the OT analgesia and OT-enhanced morphine analgesia were related with the locus ceruleus.

A liquid chromatography-tandem mass spectrometry ( LC-MSMS ) method has been developed for the simultaneous determination of N3-methyladenine ( N3-MeA ) and N3-ethyladenine ( N3-EtA ) in calf thymus DNA. The DNA samples has been purified and enriched by cation exchange cartridge ( Waters Oasis MCX) . d3-N3-MeA and d5-N3-EtA were used as isotope internal standard. The DNA samples were injected with autosampler. The injected volume was 3 μL and analysis time was 13 min. The sample separation was carried out on hydrophilic interaction chromatograph ( Waters XBridge HILIC ) with 10 mmol/L ammonium formate-acetonitrile (5:92, V/V, pH=4. 0) as mobile phase. The flow rate was set at 250 μL/min. Mass spectrometry was performed by electrospray ionization ( ESI ) with multi-reactions monitoring ( MRM ) . The optimized operation conditions of MS were as follows: nebulizer gas 369 Pa; curtain gas 185 Pa, turbo ionspray temperature 400 ℃, ionspray voltage 5500 V, dwell time 40 ms. The limits of detection were 0. 043 and 0. 007 μg/L for N3-MeA and N3-EtA, respectively. The recoveries were between 87. 8% and 103. 0%for N3-MeA and N3-EtA. This method was successfully applied to the determination of N3-MeA and N3-EtA in calf thymus DNA by cigarette smoke condensate ( CSC) exposure. This method is appropriate for routine analysis and accurate quantification of N3-MeA and N3-EtA by CSC exposure.

BACKGROUND:Although drug treatment.physics-behavior therapy,and postoperative therapy have been commonly used to treat stress urinary incontinence(SUI),there is still no satisfactory treatment at present.OBJECTlVE:To build a stable animal model simulating stress urinary incontinence(SUI)by bilateral transaction of pudendal nerve and nerves innervating pelvic floor muscles,including iliococcygeous muscle and pubococcygeous muscle.METHODS:A total of 18 6-week-old female SD rats weighing(1 99.44±8.41)g were randomly divided into 3 groups:normal,model,and sham-surgery groups,with 6 rats in each group.Rats in the model group underwent bilateral transaction of pudendal nerves and nerves innervating iliococcygeous/pubococcygeous muscles,while rats in the sham-surgery group had same procedures except nerve transaction.The normal group did not undergo any operation.Each rat was subjected to measure leak point pressure(LPP)at 2 weeks after the operation.After the measurement of LPP,cross sections of connection area of bladder and urethra were sent to histology.RESULTS AND CONCLUSION:One rat in the sham-surgery group died at 1 week after the operation.The LPP of model group decreased significantly by approximately 33%compared with the normal group(P＜0 05):however,there was no significant difference in LPP between sham-surgery and normal groups(P＞0.05).The results of histology showed loosely arrangement and atrophy of urethral sttriated muscle fibers in rats of the model group.Bilateral transaction of pudendal nerves and nerves innervating to iliococcygeous/pubococcygeous muscles resulted in SUI in rats stably.

ObjectiveTo explore the effects of myoblast formation around the urethra of stress urinary incontinence (SUI) rats after treated with bone marrow mesenchymal stem cells(BMSCs) or musclelike cells/calcium alginate composite gel injection therapy.MethodsIsolation,cultivation and identification of Sprague-Dawley rat bone marrow mesenchymal stem cell were performed.5-azacytidine was introduced to induce muscle-like cells.Calcium alginate gel was initially prepared by 2％ sodium alginate and 1％ calcium chloride solution at a volume ratio of 5∶1.Compounds of stem cells or muscle-like cells were mixed with gel,respectively,and were prepared for microinjection.SUI was produced in 72 6-week-old female Sprague-Dawley rats.The rats were then divided into 4 groups:Gel group,stem cell-gel group,muscle-like cell-gel group and mock control group.Each group was further divided into 3 groups.Submucosal injection of gel was performed at urethra and bladder neck.After preparation of cross sections of rat urinary tract at 4 weeks and 8 weeks after injection,HE staining,fluorescent tracing,staining of Desmin and α-skeletal muscle actin (α-SMA) were performed.OD values of positive rates were compared.ResultsAt 4 weeks and 8 weeks after injection in stem cell-gel group and muscle-like cell-gel group,growth of blood vessels gradually increased at gel edge,BMSCs and muscle-like cells gathered around the new blood vessels observed by fl(u)orescence tracer,muscle-like cells grew into elongated spindle-like cells.Desmin and α-SMA staining were positive in these groups,and the OD values in the stem cell-gel group and muscle-like cell-gel group was significantly higher than that from the gel only group and control group,but no difference was found between stem cell-gel group and muscle-like cell-gel group.ConclusionsCompound of BMSCs,muscle-like cells and calcium alginate composite gel has the potential to differentiate into muscle cells in the microenvironment of SUI rat model.In short term,the myoblast formation potential is the same whether the BMSCs was introduced into the micro-environment in vivo directly,or the BMSCs was implanted into microenvironment after the formation of the muscles cells induced by 5-azacytidine in vitro.