Melanotic neuroectodermal tumour of infancy: an immunohistochemical and ultrastructural study

Two cases of melanotic neuro-ectodermal tumour of infancy (MNTI)—a rare neoplasm arising in the first year of life—are reported, with the results of immunohistochemical and ultrastructural examination. The tumours consisted of a biphasic cell population in a fibrous stroma. The small, darkly staining cells comprising the first population stained positively for synaptophysin, showing them to be neuroblasts, and the large epithelioid cells comprising the second cell population stained positively with the antibodies HMB-45 and NKI-Beteb, showing them to be melanocytes. Ultrastructural examination of the second case confirmed the biphasic nature of the tumour cells, with secretory granules and neurofilaments in the neuroblastic population, and melanosomes in the epithelioid population. These results add to the evidence supporting the neural crest origin of MNTI and confirm its formation from two distinct cell lines. Both cases have responded to local excision, with no recurrence more than a year after initial treatment.     

Salivary clearance of sugar before and after insertion of fixed orthodontic appliances

This study was conducted for the purpose of establishing the possible influence of orthodontic therapy with fixed appliances on salivary clearance of sugar. Fifteen consecutive patients between the ages 12 and 17 years took part in the investigation. Unstimulated salivary flow rate, residual volume of saliva in the mouth after swallowing (RESID), and salivary clearance of sugar was determined on two occasions, before treatment commenced and after a minimum of 3 weeks of appliance wear. Analysis of the data showed that both RESID and salivary flow rate exhibited significantly increased levels during orthodontic therapy. The insertion of fixed appliances did not seem to have any effect on the rate of salivary clearance of sugar. It was assumed that this finding could be a consequence of the combined effects of the changes in salivary flow rate and RESID.     

非接触式三维图像检测系统测量牙齿咬合面磨损的初步研究

目的　使用新研制的非接触式三维图像检测系统对健康人牙齿咬合面的磨损情况进行定量测定。方法　选择 32名牙列完整的健康中老年人 5年前后的牙颌模型 ,用统一方法确定个体参照平面和上颌第一恒磨牙测量范围 ,用非接触式三维图像检测系统测量研究对象 5年内上颌第一恒磨牙咬合面的磨损量和平均磨损速度。结果　 5年内上颌第一恒磨牙咬合面的磨损情况 :以高度平均值变化为指标 ,平均磨损量为 0 2 93mm ,平均每年磨损速度为 0 0 5 9mm ;以体积变化为指标 ,平均磨损量为 97 881mm3 ,平均磨损速度为 19 5 76mm3 /年。结论　非接触式三维图像检测系统及相关的必要设置 ,可作为测量健康人牙齿磨损情况的有效工具。其个别设置条件尚待进一步改进     

胶囊粉对可见光固化复合树脂机械性能的影响

目的:改善光固化复合树脂的强度和抛光性能.方法:我们采用悬浮聚合法研制了微胶囊型复合填料粉(MCP),作为光固化改进型(VLC-Ⅱ型)复合树脂的填料.并对其性能进行了测试.结果:在复合树脂中加入15%的胶囊型填料粉,压缩强度可达232.1±9.1MPa,拉伸强度可达48.7±2.3MPa,70000次牙刷磨耗率为0.588%,表面粗糙度为2.8μm.结论:胶囊粉可以显著改善复合树脂的压缩强度,拉伸强度,磨耗及表面抛光性等机械性能.与其它同类产品比较,其机械性能、磨耗性能和表面抛光性能均较优越,且相差显著.     

中国人面神经神经电图正常值与影响因素的探讨

用调节刺激电流强度的方法８６例成年中国人的１７２条面神经电图。结果显示中国人神经电图中肌肉复合动作电位的波幅与潜伏期均呈正态分布，波幅值３．９４±１．０２ｍＶ，变异系数２５．８％；潜伏期３．１８±０．４２ｍｓ，变异系数１３．２％。是无明显差异。左右侧基本对称，作认为，鉴于个体差异较大，对神经电图的解释分析应以左右对称为基点。对影响常人面神经神经电图的各种因素作了较深入的探讨。     

GP-084泡沫硅橡胶和SY-1硅橡胶之间粘结性能的测定

目的:评价GP-084泡沫硅橡胶和SY-1硅橡胶之间的粘结性能。方法:分别测试有无Adhesive-AGP-084泡沫硅橡胶和SY-1硅橡胶之间的粘结强度;并采用电镜观察2种材料之间的粘结界面。结果:使用Adhesive-AGP-084泡沫硅橡胶和SY-1硅橡胶之间的粘结强度为(1.31±0.09)MPa,无Adhesive-AGP-084泡沫硅橡胶和SY-1硅橡胶之间的粘结强度为(1.29±0.11)MPa,2组测试结果的差异无统计学意义;电镜观察2种材料之间没有明显界面,完全融合在一起。结论:GP-084泡沫硅橡胶和SY-1硅橡胶2种材料之间具有良好的粘结效果,可以完全融合在一起,无明显界面形成。     

Overview of the oral HIV/AIDS Research Alliance Program

The Oral HIV/AIDS Research Alliance is part of the AIDS Clinical Trials Group, the largest HIV clinical trial organization in the world, and it is funded by the National Institute of Dental and Craniofacial Research, in collaboration with the National Institute of Allergy and Infectious Diseases. The alliance's main objective is to investigate the oral complications associated with HIV/AIDS as the epidemic is evolving-in particular, the effects of potent antiretrovirals on the development of oral mucosal lesions and associated fungal and viral pathogens. Furthermore, oral fluids are being explored for their potential monitoring and diagnostic role with respect to HIV disease and coinfections. This article presents an overview of the alliance, its scientific agenda, and an outline of the novel interventional and noninterventional clinical studies ongoing and developing within the AIDS Clinical Trials Group infrastructure in the United States and internationally.     

铸造力对铸钛全冠完整性的影响

本实验的目的是证实铸造力对铸造钛全冠完整性的影响.在树脂牙上进行全冠牙体预备,颊侧边缘为凹型,舌侧边缘为刃状.将18个全冠蜡型分为6组,用专用钛包埋材包埋,用Ohara钛铸造机铸造.1至6组所上的弹簧圈数分别为5、10、15、20、25和30圈,这样便产生逐渐增加的铸造力.第1组只铸出铸道,第2组铸出铸道和部分冠壁;第3、4组的冠大体铸出,但舌侧边缘圆钝并有小的缺损;第5、6组的冠基本完整,边缘锐利,只是舌侧边缘有少数很小的缺损.实验结果表明:①铸造钛金属时要有足够大的铸造力.②如果铸造技术未得到进一步改进,应避免为铸钛修复体设计刃状边缘.     

Comparison of Ileal Digested Production of Parental Rice and Rice Genetically Modified With Cowpeas Trypsin Inhibitor

INTRODUCTION With the rapid development of genetically modified foods in the world, the safety assessment of these novel foods is becoming the first task for governments, scientists, and consumers. At the same time, nutritional assessment is an important …