肝素在DMBA诱导地鼠颊囊粘膜癌变过程中的作用的初步研究

作者在ＤＭＢＡ诱导地鼠夹囊癌第７周起，于每次涂布ＤＭＢＡ前一小时用肝素加低分子右旋糖酐（５ｕ／ｍｌ）混合液给实验组地鼠腹腔内注射（０．４ｍｌ／１００ｇ），至第１８周，其过程中记录每只地鼠颊鼠癌时间（以粘膜出现三向平均直径为３ｍｍ肿瘤块的时间为准），并与对照组（单纯诱癌而不给抗凝处理）比较，结果实验组地鼠颊囊癌变时间平均比对照组延长３２．６天（Ｐ〈０．０１）。经血液流变和微循环检测证实，两组间有差异     

铸造义齿中网状支架的设计

铸造义齿中网状支架的设计李景辉，宋培智，陈官辉，季秋杰，卢玉春，高银凤在可摘局部义齿修复中，网状支架的合理设计既增加了义齿的强度，又具有传递咬力、分散力、保护口腔内软硬组织的功能［１］。常用形态为园孔形、方格形、楼梯的，网状形、三角形、倒锥形、栅栏形...     

Electromyographic activity of the masseter muscle after radiofrequency therapy in an animal model

Purpose

The purpose of this study was to examine changes in the electromyographic (EMG) activity of the masseter muscle after radiofrequency therapy (RF).

Methods

Twelve rabbits were used in this study: four in each group according to the number of RF applications. Preoperative EMG in the masseter muscle was used as the control. EMG was recorded at 1, 2, 3, and 4 weeks after RF in each rabbit. The recorded data were analyzed in terms of voltage and frequency, and changes in recorded variables were compared among the groups. The relative activity in peak voltage, root mean square of the action potential, area of voltage, and area of frequency were investigated.

Results

When compared to preoperative values, the variables at 3 or 4 weeks after RF application were significantly different in the single and quadruple therapy groups (P?<?0.05). There was no significant difference in the other groups (P?>?0.05). When the samples were regrouped as two groups like small number of application group (one or two point) and large number of application group (three or four points), the area of voltage and the area of frequency were significantly different between the groups at 4 weeks (P?<?0.05).

Conclusions

Masseter muscle activity after RF was significantly decreased compared to its preoperative state. The decreased activity was related to the number of applications and time elapsed after RF.     

Prevalence of Helicobacter pylori in the adolescent oral cavity

Background

Helicobacter pylori (HP) infection usually occurs in childhood. While there are various studies on the prevalence of HP in dental plaque, ours is the first to analyze its prevalence during orthodontic therapy and its interaction with competitive bacteria in adolescents.

Subjects and methods

The prevalence of HP was examined before and during the first 12?weeks of orthodontic therapy with fixed appliances in 11?patients with a mean age of 12.7?years. A total of 93?plaque samples were analyzed using PCR. The data acquired at every consultation were the following: PCR analysis of dental plaque and ¹³C urea breath tests for HP, quantitative analyses of saliva for Lactobacilli and Streptococcus mutans, the interproximal plaque index (API), and sulcus bleeding index (SBI).

Results

The prevalence of HP in plaque was 82% before orthodontic therapy, dropping to 54% during therapy (t test, p??0.05). In contrast to HP??s prevalence, the Lactobacilli count rose (p??0.05). The number of Streptococcus mutans bacteria in saliva decreased during orthodontic therapy (p??0.05).

Conclusion

The prevalence of HP in dental plaque amounted to 82%. Orthodontic treatment did not reduce its prevalence. The prevalence of Lactobacilli was inversely proportional to that of HP.     

Dentoalveolar distraction osteogenesis for rapid orthodontic canine retraction.

PURPOSE: We present a technique to reduce the overall orthodontic treatment time by means of dentoalveolar distraction osteogenesis. PATIENTS AND METHODS: Eleven patients who were planned to undergo orthodontic treatment with bilateral first premolar extractions and subsequent bilateral canine tooth distalization underwent osteotomy around the canine tooth. The first premolar was extracted, and the buccal bone was carefully removed. After wound closure, a special orthopedic device was mounted and cemented to the first molar and canine teeth. Distraction was started the same day at the rate of 0.4 mm twice a day and continued until adequate movement of the canine teeth was achieved. The device was then removed, and orthodontic therapy was continued with fixed appliances. RESULTS: The distraction rate and the device were well tolerated by all of patients. No anchorage loss in the second premolar and first molar teeth, root resorption, dental ankylosis, discoloration, or loss of vitality was detected. CONCLUSION: The concept of distraction osteogenesis for rapid orthodontic tooth movement is promising and feasible for clinical practice.     

变形链球菌母子传播与其对牙面初始粘附关系的研究

目的:探索变形链球菌母子传播与其对牙面初始粘附能力的关系。方法:首先以AP-PCR检测Mutans streptococci(MS)在20对3~4岁儿童和母亲之间的传播,并从母亲口腔中筛选出传播株和非传播株;再采用同位素标记法,检测传播株和非传播株对SHA的粘附差异,同时对其表面蛋白粘附功能区spap-a和spap-pv分别用限制性内切酶haeⅢ和AluⅠ进行RFLP分析。结果:传播株较非传播株具有较弱的粘附力(P<0.01),spap-a和spap-pv经酶切后分别呈现的3种和2种基因型在传播和非传播人群的MS中分布不同(P<0.01)。结论:初始粘附能力弱的菌株被传播的可能性较大,不同MS株传播能力的差异可能与其表面蛋白A区,PV区的基因多态性有关。     

Reconstruction of a cranial bone defect with hydroxyapatite and free flap transfer.

The authors report a successful reconstruction of an extensive frontotemporal bone defect after craniotomy, which was complicated with infection and necessitated removal of frontal and temporal bones. The large frontotemporal bone defect was reconstructed using prefabricated hydroxyapatite blocks in combination with the free vastus lateralis muscle flap. The patient's functional and cosmetic restoration has been maintained for 10 months' follow-up.     

Microbial complexes in supragingival plaque

Background/aims:  To examine microbial communities in supragingival biofilm samples.
Methods:  Supragingival plaque samples were taken from 187 subjects at baseline ( n  = 4745). Fifty-five subjects provided supragingival plaque samples at 1–7 days after professional tooth cleaning ( n  = 1456); 93 subjects provided 8044 samples between 3 and 24 months post-therapy. All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA–DNA hybridization. Microbial associations among species were sought using cluster analysis and community ordination techniques for the three groups separately.
Results:  Six complexes were formed for the baseline samples. Similar complexes were formed for the samples taken 3–24 months post-therapy. However, distinct changes were observed in microbial communities in samples taken during the 7 days of plaque redevelopment. The complexes related to clinical parameters of periodontal disease.
Conclusion:  There were specific microbial complexes in supragingival plaque that were similar to those found in subgingival plaque samples with a few minor differences. The relation of previously unclustered taxa to the complexes was also described.     

牙龈卟啉单胞菌对脐静脉血管内皮细胞产生sICAM-1的影响

目的：观察牙龈卟啉单胞菌（Porphyromonas gingivalis,P.gingivalis)对人类脐静脉血管内皮细胞（human umbilical vein endothelial cells,HUVECs)产生可溶性细胞间粘附分子－1（soluble intercellular adhesion molecule-1,sICAM-1)的影响。方法：应用厌氧袋法培养P.gingivalis，并用其感染HUVECs，采和酶联免疫吸附实验（enzyme-linked immunosorbent assay,ELISA)测定培养上清中sICAM-1的含量，结果：HUVECs基础表达少量的sICAM-1;P.gingivalis剂量依赖性增强HUVECs产生sICAM-1蛋白的水平；紫外线、超声波和65℃的热处理都不能抑制P.gingivalis的作用；sICAM-1蛋白水平在P.gingivalis刺激后的4h未见改变，增高的作用从刺激后的8h开始，在12h,16h和20h继续增加。结论：活的和灭活的P.gingivalis都剂量依赖性和时间依赖性地增强HUVECs产生sICAM-1,P.gingivalis可能同样诱导牙龈血管内皮细胞表达sICAM-1，升高的sICAM-1可能参与调节牙周病炎症反应和免疫反应过程。