The extraction rate in orthodontic practice changes from different ages,areas,doctors or patient groups.Every ways and means has its advantages and disadvantages,so has different indications.The discussion of extraction or nonextraction is always a focus in orthodontic practice.It is not only pure science but also has some relations with philosophy,ethics aesthetics,moral philosophy so we not only need professional knowledge and techniques,but also need to be responsible and serve the giant population.

Objective To investigate the effects of intrathecal (IT) ketamine on the synapsis remodeling in the spinal dorsal horn during devolopment of morphine tolerance in a rat model of neuropathic pain (NP). Methods Male SD rats weighing 200-250 g were used in this study. IT catheter was placed in the subarachnoid space according to Yaksh. Forty-eight SD rats in which IT catheter was successfully placed were randomly divided into 6groups (n=8 each): group sham operation (group S); group NP; group normal saline 20 μl IT(group NS);group morphine 20 μg IT (group M); group ketamine 50 μg IT (group K) and group morphine 20 μ g + ketamine 50 μg IT (group MK). NP was induced by compression of right L4,5 dorsal root ganglions with steel wire inserted through L4,5 intervertebral foramen in NP,M,K and MK groups. Normal saline or morphine and/or ketamine were injected IT once a day for consecutive 14 days. Paw withdrawal threshold (PWT) to mechanical stimulation and paw withdrawal latency (PWL) to a thermal nociceptive stimulus were measured on 0, 1, 3, 5, 7, 9, 11, 14 days during the consecutive 14 days of administration. The animals were sacrificed after the final IT administration. The lumbar segment of the spinal cord was removed for determination of the number of synapsis in the spinal dorsal horn by immuno-histochemistry in 4 animals in each group and observation of synaptic structure remodeling using electron microscope in another 4 animals in each group. Results Compared with group S, PWT was significantly decreased and PWL was shortened in the other 5 groups, and the number of synapsis was significantly increased and the synaptic structure was thickened in NP, NS, M and K groups (P ＜ 0.05). Compared with group NP,PWT was significantly increased and PWL was prolonged in M, K and MK groups, and the number of synapsis was significantly decreased and the thickness of synaptic structure was significantly reduced in group MK ( P ＜ 0.05).Compared with group M, PWT was significantly increased, PWL was prolonged, the number of synapsis was significantly decreased and the thickness of synaptic structure was significantly reduced in group MK ( P ＜ 0.05). Conclusion IT ketamine can inhibit the synaptic remodeling in the spinal dorsal horn during development of morphine tolerance in a rat model of NP.

Objective To evaluate clinically electroanatomical mapping and ablation of cardiac arrhythmias under the Carto system. Methods Fifty-six patients with various tachycardias indicated for electrophysiological study and radiofrequency ablation were included in this study, among of whom, 49 suffered from supraventricular tachycardia, and 7 ventricular tachycardia (VT). Carto system was utilized during ongoing tachycardia or sinus rhythm, 7F Navi-Star catheter was introduced into the interested cardiac chamber and underwent three-dimensional electroanatomical mapping. The mechanism and origin of cardiac arrhythmia were assessed by activation and propagation map, with which to guide radiofrequency ablation. Results The success ablation rate was 94.6% (53/56). One right accessory pathway (AP), one atrial tachycardia (AT) and one atypical atrial flutter (AF) had failed session. The procedure time was 128?59 minutes, and the fluoroscopic time 14?12 minutes. One patient had complcation of pneumothorax. No conduction block occurred. After follow-up of 1-14 months, one left AT recurred and had another succssful session. Conclusion The study demonstrates that Carto system is a safe and effective tool and may be applied for mapping and ablation of various tachyarrhythmias. It is helpful to guide catheter ablation and shorten fluorocopic time by its ability of associate intracardiac electrograms with their three-dimensional anatomic structure. It also lessen complication and recurrence by tagging the critical cardiac structures and utilize its location memory function. Our experience suggest that carto system has important role in the guidance of mapping and ablation in AT、AF、VT and complex or recurrent AP cases.

Objective To explore the interaction model of social capital, mental health,occupational burnout, turnover intention and the related influence factors on nurses. Methods By random cluster sampling, investigated 723 nurses with Nurses' Turnover Intention Inventory, the Maslach Burnout Inventory, Social Capital Questionnaire and Chinese Health Questionnaire, then explored the interaction model by path analysis. Results Nurses' position can influence their social capital(the path coefficient was 0. 124), social capital and occupational turnout can influence nurses' mental health(the path coefficient were -0. 231,0. 151), the mental health and occupational turnout both can influence nurses' turnover intention directly(the path coefficient were 0. 088,0. 151 ), the model is acceptable(CMIN/DF 1. 645, GFI 0. 984, AGFI 0. 966, IFI 0. 941, CFI 0. 937, RMSEA 0. 037).Conclusion Social capital can provide a new perspective for nurses' management, developing the social capital resources can relieve nurses' mental problems effectively; relieving the turnout and mental problem can decrease nurses' turnover intention finally.

Objective To describe the factors influencing medication compliance of patients with ulcerative colitis (UC) and provide a reference for health care workers developing effective response plans.Methods In-depth interview was conducted to 10 UC patients and the interview results were analyzed by phenomenology research method.Results There were five factors influence medication compliance of UC patients including drug affect,economic burden,living events,follow-up appointment and stigma.Conclusions The medication compliance of UC patients is mainly related to patients lacking of drugs knowledge,heavy burden on drugs cost and shortage of social support etc.The health education and medication supervision on UC patients should be strengthened and the social health insurance system on UC needed to be improved.

Objective To explore the function of chemotherapy and embolization of uterine artery in treating cervical gestation.Methods 11 cases with cervical gestation were emergently undergone intubation in bilateral uterine arteriae,then the perfusion of Methotrexate was performed through the catheters,after that,the embolization of bilateral uterine arteriae was carried out with grains of gelatin sponge.The uterine aspiration or curettage was carried out under B-ultrasound guided within a week.Results Chemotherapy and embolization of uterine artery were successfully executed in all cases.Within a week,the uterine aspiration or curettage was done smoothly with little hemorrhage in the process of the operation.Conclusion Chemotherapy and embolization of uterine artery provides the secure guarantee for the conservative treatment of patients with cervical gestation,and it's a kind of safe effective therapy.

BACKGROUND: The uterine arterial embolization which is a major method to treat hysteromyoma has bean widely used in clinic and achieved a satisfactory therapeutic efficacy. The study addressing the effect of trisacryl gelatin microspheres on uterine arterial embolization in a hysteromyoma guinea pig model has less bean reported yet. OBJECTIVE: To vedfy the feesibility of trisacryl gelatin microspheres to uterine arterial embolization in hysteromyoma guinea pig models. METHODS: A total of 30 adult female guinea pigs were randomly divided into two groups: pelvic cavity artery moulding group (n=10) was performed pelvic vascular casting mould to demonstrate the anatomical characteristics, such as source, running shape, length, diameter and branches; arterial embolization group (n=20) was induced hysteromyoma model using astrogen-progestogen replacement therapy and performed technical research and pathological analysis by bilateral uterine arterial embolization. RESULTS AND CONCLUSION: The trunks of uterine arteries were erupted from internal iliac arteries. The diameter of the trunks and its arcuate branches were (0.350±0.022) mm and (0.160±0.012) mm, respectively. The 20 guinea pigs of the arterial embolization group were succeeded in operating bilateral arterial embolization. The dosage of 40-120 pm and 100-300 μm trisacryl gelatin microspheras were (0.040t±0.005) mL and (0.017±0.002) mL respectively during the operation. The achievement ratio of establishing model was 75% in the arterial embolization group. On the pathological section, the microspheres could be found in the uterine arterial arcuate branches and second branches within the subsercsa and third branches. The myometrium Was thickening. The cells of the leiomyoma nodules arranged in palisade or weaving shapes. Ischemia and necrosis were evidently present in leiomyomas of guinea pigs after embolization, but the myometria and endometria had no pathological change of ischemia and necrosis. It is feasible to use trisacryl gelatin microspheres to operate uterine arterial embolization for hysteromyoma of guinea pigs and the embolization effects are satisfactory.

Objective To investigate whether problem-based learning (PBL) is suitable for medical imaging and whether PBL is more enlightening than lecture-based learning (LBL) mode in teaching of medical imaging.Methods Thirty-two students of clinical medicine specialty in Sun Yat-sen University were selected as teaching objects and were divided into 6 groups (5 students in four groups and 6students in 2 groups).Chapters of urinary and digestive system were taught by PBL mode while the rest chapters by LBL mode.Questionnaires were handed out to teachers and students by Email after class and the valid questionnaires were analyzed qualitatively.Results Thirty-one students and 5 teachers thought they were suitable for PBL teaching; 30 students and 5 teachers were willing to continue PBL.Thirty-one students and 5 teachers thought that PBL mode could let students learn more knowledge and was more revealing.Twenty-three students thought PBL teaching spent too much time can not promote in all chapters.Three teachers worried that PBL mode would cause poor organization form and teaching plans.Conclusions PBL is suitable for medical imaging teaching.PBL could let students learn more knowledge and is more revealing compared with LBL,however,PBL is time-consuming and laborious,therefore LBL and PBL should be combined.

Objective To investigate the association of the LIPC-C480T (rs1800588) and lipid levels and dyslipidemia in different age-and-sex groups in Han Chinese population.Methods The serum TC,TG,LDL-C and HDL-C were detected by automatic biochemical analyzer in 2420 health adults (1527 men and 893 women).The genotypes of rs1800588 were detected by M ALDI-TOF MS.According to the age difference (≤44,45-59 and ≥60-year-old),the total samples were divided to young (241 men and 201 women),middle-aged (652 men and 360 women) and older (634 men and 332 women) groups.The effects of genotypes on 4 serum lipid indicators in each age-and-gender group were analyzed by one way analysis of variance (ANOVA),and the odd risk of genotypes on dyslipidemia was estimated by binary Logistic regression analysis.The P value less than 0.05 was considered statistically significant.Results The frequence of allele T for LIPC rs1800588 in this population is 39.4％.In each age group the lipid parameters are quite different between males and females.Compared with those with CC genotype,middle-aged and elder men with CT or TT genotype have higher TC and HDL-C levels,and elder men with TT genotype also have higher TC level ; young women bearing CT genotype have higher TC level,and the CT and TT genotypes have higher HDL-C levels,middle aged women with CT or TT genotype have higher TC and TG levels,and CT genotype also have higher HDL-C level,the elder women with TT genotype have higher HDL-C level.Compared with those CC genotype individuals,the risk for mixed hyperlipidemia and hypercholesterolemia increases 2.318 folds (P =0.004) and 2.571 folds (P ＜ 0.001) respectively,while the risk for low HDL-C decreases 1.908 folds (P =0.029) for TT genotypes individuals among elder males; the hypercholesterolemia risk increasc 1.688 (P =0.036) and 2.099 times (P =0.040) in CT and TT genotypes respectively,and the risks for hypertriglyceridemia and mixed hyperlipidemia are 2.060 (P =0.038) and 2.381 (P =0.019) times higher than those with CC genotype among middle-aged females.Conclusions The LIPC rs1800588 site associates with the lipid levels and dyslipidmia risk in Han Chinese in an age-and-sex model.This SNP site has higher impact on lipid levels and dyslipidemia among elder males and middle-aged females,and the T allele is the risk factor.

Objective To examine whether speckle tracking imaging(STI) could provide for the assessment of acute cardiac rejection. Methods Hearts from Brown Norway rats or Lewis rats were transplanted into other Brown Norway rats. Isografts and groups of allografts either untreated or treated with cyclosporin A (CsA) at a low dose (3 mg ·kg-1 ·d-1) or high dose (10mg · kg-1 ·d-1) from 1　day before transplantation were compared at posttransplantation day 7. Results Echocardiography-derived left ventricular post wall thickness was increased only in untreated allografts. The left ventricular eject fraction was significant lower in the allografts compared with isograft, but allografts treated without or with low-dose CsA showed similar results. The radial systolic radial strain rate showed a lower value in untreated allografts than other grafts,but there was no significant differences between allograft treated with high- or low-dose CsA and isografts. The circumferential strain and circumferential strain rate was comparable among the 4 groups. However the radial strain exhibited a clear gradient in these groups [(2. 8 ± 1.3)％ in untreated allografts, (5.2 ± 0.9)％ in allografts treated with low-dose CsA, (6.3 ± 1.8 )％ in allografts treated with high-dose CsA,and (12.7 ± 7.9) in isografts, P＜0.001]. The radial strain exhibited a clear correlation with the severity of rejection ( r =-0.812, P＜ 0.0000). Conclusions The radial strain decreased as the severity of rejection worsen. STI offers promise as a noninvasive method for detecting transplant allograft rejection.