Evidence-based medicine (EBM) has rapidly developed in recent years and is currently a hotspot in international medicine. The guiding principle behind EBM is that any medical decision should be determined based on objective clinical and scientific evidence, doctor's professional skills and experience, and patient's needs and desires. This paper introduces the concept and practice of EBM and explains how it can be used to solve the issues in stomatology.
Evidence-Based Medicine ; Humans ; Oral Medicine

Objective:To evaluate the effectiveness and treatment feature of maxillary incisor extraction in orthodontics.Methods:9 patients underwent orthodontic treatment with maxillary incisor extraction,5 female and 4 male,with an average age of 1 7.2 years at the start,were included.5 patients were treated by extraction of both upper incisors and lower first premolars,4 by extraction of the abnor-mal incisor and the first premolars in the other three quadrants.Cephalometric and Bolton index analysis were carried out.Results:Sat-isfactory treatment results were observed in all patients.Before treatment the predicted Bolton index of the patients of the anterior ratio and the overall ratio were 80.1 4% and 91 .3%,after orthodontic treatment 78.68% and 90.28%,respectively.Cephalometric analysis showed that U1 -NA(mm),U1 -NA,L1 -NB(mm),L1 -NB,U1 -SN,L1 -MP,UL-E and LL-E were decreased(P <0.05).Conclu-sion:Individual treatment plan based on Bolton index analysis and the corresponding techniques and methods,the patients with abnor-mal upper incisors can be effectively treated with the extraction of maxillary incisors.

It is a trend that clinical researchers overemphasize on hypothesis testing and the P value. However, P value has some limitations in the presentation of study results. Power is a tool for study design and results explanation, especially for negative results. Confidence interval contains more information for clinical results than P value. P value, power, and 95% confidence interval should be provided in the clinical reports to facilitate the interpretation of the results.

Objective To study the mechanisms of increasing amyloid [β1-42 (Aβ42) level by presenilin-1 (PS-1) mutation of V97L.Methods Expression level of neprilysin (NEP) in nontransfected, or mock vector, wild type (wt) PS-1 and V97L-PS-1-transfected SH-SY5Y cells were assessed by reverse transcriptional-polymerase chain reaction (RT-PCR) and Western blot.The level of Aβ42 was also assessed by enzyme linked immunosorbent assay (ELISA).Results The mRNA level of NEP was decreased significantly in PS-1 V97L transfected cells (0.650 ± 0.010) compared to that in normal cells (1.090 ± 0.015), wt PS-1 gene (1.040 ± 0.021) and mock (1.080 ± 0.020) stably transfected cell lines (t = 9.236, 10.452, 5.678; all P < 0.01).Although there was a decreased tendency in the protein expression of NEP in PS-Ⅰ V97L transfected cells (1.000 ± 0.126)compared to that in normal cells (1.020 ± 0.110), wt PS-1 gene (1.040 ±0.110), mock (2.130 ±0.130) stably transfected cell lines, nosignificant differences were found.The expression of Aβ42 was increased significantly in PS-1 V97L transfected cells compared to other cell lines (t = 2.109, 3.355, 3.976; all P < 0.01).Conclusions PS-1 V97L mutation can decrease the transcription of NEP, however, in contrast, this mutation also resulted in increased Aβ42.The mechanism needs further analysis.

Objective To evaluate the atrial structural remodeling of the canine model with chronic atrial fibrillation and the influence of captopril on it by acoustic quantification(AQ) technique. Methods Twenty-six healthy mongrel dogs were randomly divided into three groups, each dog in pacing group(n=11) and treating group(n=9) was implanted with permanent pacemaker(pacing at 400 beats/min) to pace the right atrial appendage for 8 weeks. In treating group all dogs were given captopril (50 mg,2 times a day) three days before pacing to 8 weeks after pacing. Echocardiography exam was performed before pacing and 1, 4, 8 weeks later to moniter the changes of the volume and area of biatria. No pacemaker was implanted in control group(n=6), but the exam was performed in the corresponding time with pacing and treating group. Results Monitered by AQ technique: in pacing group biatrial area was significantly enlarged after 1 week pacing, while biatrial volume began to increase 4 weeks later, 8 weeks after pacing both the area and the volume of biatria were enlarged further; in treating group no changes were found in area and volume of biatria after 1 week pacing, while 4 weeks later it tended to enlarge, 8 weeks later both the volume and the area of biatria showed slight increase compared with those before pacing. But the increase was not as much as the increase in pacing group(P

0.05). Conclusion Clopidogrel resistance may influence long-term prognosis in patients implanted with DES, and it may contribute to recurrence of ischemic events.

To investigate the effect of menopause on chemokine receptor CXCR2 expression on monocyte, 21 postmenopausal and 20 premenopausal women were enrolled in the present study. Fasting venous blood was collected, and plasma estrogen levels were determined with radio immunoassay. Monocytes were separated from peripheral blood with gelatin method. Protein expression of chemokine receptor was assayed with flow cytometry and mRNA concentration was measured with RT PCR. The results showed that the levels of plasma estrogen decreased, whereas protein and mRNA expression of chemokine receptor CXCR2 increased after menopause. The plasma estrogen levels were negatively correlated with chemokine receptor CXCR2 expression in monocytes. These data suggested that the changes in CXCR2 on monocytes might contribute to,at least partially,the increased risk of developing coronary heart disease associated with estrogen secretory changes.

Objective To investigate the relation between expression of P73 , P53, P21 waf1 ,PCNA protein in the different diseases of gastric mucosa and the malignant transformation of gastric mucosa epithelium and their correlation in gastric carcinoma and the relation to histological type , lymph node metastases, depth of invasion of gastric mucosa ,TNM stage in gastric carcinoma. Methods Immunohistochemical staining(S-P method) was used to detect the expression of P73, P53, P21 waf1 , PCNA protein in 39 cases of gastric carcinoma, 17 cases of chronic atrophic gastritis and 40 cases of chronic inflammatory polyp and a statistical analysis was made according to clinicopathogical data. Results The positive rate of P73 protein expression in gastric carcinoma was remarkably higher than that in chronic inflammatory polyp and that in chronic atrophic gastritis( P 0.05). there was negative correlation between expression of P21 waf1 protein and TNM stage, lymph node metastases( P 0.05). Conclusion Probably high expression of P73 gene is one hot spot gene alteration of gastric carcinoma and expression of P73 protein in gastric carcinoma may play an important role in the course of cancerous development. As one tumor suppressor gene, P73 has its tissular specificity. Cooperative expression of P73 and PCNA,and the correlation of expression to P73 and P53 、P21 waf1 protein could be an important index to judge the malignant transformation and clinicopathological process and prognosis. P21 waf1 may be an early signal of gastric carcinoma or one of indexes to judge prognosis.

Object To study the effects of different growth regulators and organic additives on rooting of regenerated shoots from Dendrobium huoshanense C Z Tang et S J Cheng protocorm like bodies Methods In order to induce root development, the regenerated shoots were cultured on MS medium containing 3% sucrose and 0 8% agar and supplemented with NAA, IBA, BA, KT, banana mud or amino acids at different concentrations During rooting induction, the development of roots was observed and the frequency of rooted shoots was scored Results The frequency and the process of root initiation were significantly influenced by different growth regulators or organic additives For initiation and development of roots, the suitable concentration of NAA, IBA, BA, KT, banana mud or amino acids was 0 2 , 0 1, 0 8, 0 8 mg/L, 20% and 0 1%, respectively Conclusion In all media tested, NAA, IBA or banana mud display greater effects on rooting of regenerated shoots of D huoshanense than others and KT enables shoots to keep green