牙根发育不良疾病的研究进展

牙根发育不良疾病是牙齿根部生理性发育出现障碍的疾病。其发病率为1%~10%,乳、恒牙列均可发生,其结果可导致牙根缺如或短根,严重者可造成牙齿过早脱落。国外学者将该疾病统称为短根异常疾病。其发病因素有遗传性疾病、全身性疾病、外源性因素和医源性因素等。     

Histometric study of root resorption on human premolars following experimental replantation

Abstract – A histometric method was applied for evaluation of root resorption in 57 experimentally replanted teeth and 22 controls. Representative axiobuccolingual sections were selected for measurement of resorptions at a magnification of × 40. The frequency of root resorption in the control teeth was low. In replanted teeth marked resorptive activity elicited by the trauma appeared after 2 wk. The extent of active resorptions increased until the third postoperative week. On an average 14% of the root periphery was affected at this stage. After the sixth postoperative week progressive cement deposition took place in the resorption lacunae. Incidental ankylosis of the periodontal membrane also occurred from this observation time but there was no increase among the long-term groups.     

Real-time refinement of subthalamic nucleus targeting using Bayesian decision-making on the root mean square measure.

The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.     

暴露前牙龈下残根进行桩冠修复

本文综述了暴露前牙龈下残根进行桩冠修复的两种方法,即牵引法与牙冠延长术,并对两者进行了比较、总结,在临床上有指导意义。     

福参的苷类成分

目的 从福参Angelica morii提取分离活性成分。方法 采用乙醇提取，溶剂萃取，大孔树脂、聚酰胺、硅胶柱层析，LH-20、重结晶等纯化，对福参饮片进行系统提取分离；运用波谱学方法及理化常数对照进行结构鉴定。结果 从正丁醇和水部分分离到6个苷类化合物，分别为升麻索苷(prim-O-glucosylcimifugin，Ⅰ)、紫花前胡苷(marmesinin，Ⅱ)、芹菜素7-O-β-D-葡萄糖苷(apigenin 7-O0-β-D-glucoside，Ⅲ)、木犀草素7-O-β-D-葡萄糖苷(1ute—olin 7-O-β-D-glucoside，Ⅳ)，umbeliferone 7-apiosylglucoside(V)和胡萝卜苷(daucosterol，Ⅵ)。结论 6个化合物均为首次该植物中分得；化合物Ⅲ首次从当归属中分得。     

An imaging routine for assessing the efficacy of instruments used for scaling and root planning

Deposits of dental plaque or calculus are typically quantified using planimetric techniques. However, error is introduced into a quantitative analysis of plaque deposits using these methods, since they require a significant amount of human intervention. The purpose of this study is to describe and validate a computerized imaging routine which has the potential to objectively identify material on dental roots and measure the area covered by these deposits. Dentiform teeth with simulated plaque were videorecorded. A computer routine was developed based on a flood-fill algorithm which analyzed images of the dentiform teeth and determined the amount of simulated plaque on their root surfaces. Results showed that the dentiform teeth and their simulated plaque patterns are duplicated by the imaging routine in a rapid and reliable fashion. The system shows a high degree of accuracy with an average error factor of only 0.58%. As well, the system enables precise reproducibility with an average error factor of only 0.71%.     

A New and Alternative Leads Positioning for Complex Regional Pain Syndrome Treatment: Paraforaminal Stimulation

We present a case of a female patient suffering from type I complex regional pain syndrome (CRPS) who developed “mirror imaging” of her CRPS and was successfully treated with dual spinal cord stimulation (SCS) in the paraforaminal epidural space. This patient initially had unilateral pain that was unsuccessfully treated with midline SCS and single‐lead lateral epidural lead placement “paraforaminally.” One year later, because we believed that paraforaminal stimulation would preferentially stimulate primary sensitized afferents innervating the painful area, we reperformed SCS with two leads positioned laterally and paraforaminally close to the roots within the epidural space. After repositioning and after 1 year of paraforaminal stimulation, there was significant improvement in the patient's symptoms, resolving all unilateral and “mirrored” symptoms. We conclude that paraforaminal stimulation may be a valid therapeutic option for the treatment of CRPS.     

止咳枇杷冲剂中枇杷叶和桔梗的薄层色谱鉴别研究

研究止咳枇杷冲剂中枇杷叶和桔梗的薄层色谱鉴别方法。分别取枇杷叶和桔梗药材，制剂及阴性制剂的醋酸乙酯提取液，在硅胶板上前者以ψ（氯仿：甲醇：水）=2：2.25:1.5展开，后者以ψ（正已烷：氯仿：甲醇）=5：4：0.3展开，磷钼酸乙醇溶液显色，在两者供试吕色谱中与各自对照药材色谱相应位置上，分别有相同的蓝绿色特征斑点；阴性制剂色谱图中无此斑点，因此该方法可作为这两味中药的鉴别方法。     

备用根大鼠脊髓后角提取液中神经营养活性组分的分离及生物活性测定

制作备用根大鼠脊髓后角提取液，取其分子量大于10kD的组分进行SDS-聚丙烯酰胺凝胶电泳分析，发现手术侧和非手术侧的电泳区带数目大致相同，但手术侧样品的第四条蛋白质区带扫描的吸收峰面积百分比大于非手术侧样品的第四条区带，两者在量上可能有差别。将手术侧样品经交联葡聚精G-75凝胶层析，得到两个洗脱峰．第一峰洗脱液有促进体外培养的背根节神经元存活及其突起生长的作用，其电泳分析显示4条主带，分子量在40～80kD之间．实验结果提示部分去传入纤维支配的脊髓后角组织含有神经营养活性物质，该物质的分子量约在40～78kD之间．     

维持肢体正常的运动感觉功能所需最少神经根数的实验研究

目的 研究臂丛神经根单发断，２根切断（不同方式联合）及３根切断后对肢体的影响，为治疗臂丛根性撕脱伤寻找更多的潜在移位神经，方法 ２５２只ＳＤ大鼠随机分为１３组：（１）第１－５组（单根神经根切断组）；每组１２只大鼠。分别切断Ｃ５－８Ｔ１各神经根；（２）第６－１２组（２根神经根切断组）；每组２４只大鼠。分别切断相邻及不相邻２根神经根，即Ｃ５，６，Ｃ６，７，Ｃ７，８，Ｃ８Ｔ１，Ｃ５，７，Ｃ６，８和Ｃ７Ｔ