生物标志物的联合检测对矽肺早期辅助诊断的价值

目的：探讨联合检测生物标志物应用于矽肺早期辅助诊断的灵敏度和特异性。方法：采用立意抽样法，选取65例男性矽肺患者为病例组，以70例接触游离二氧化硅的在岗作业人员为对照组。清晨空腹采集外周血并分离血清，采用比色法测定对照人群和矽肺患者血清中超氧化物歧化酶（SOD）和丙二醛（MDA）水平；酶联免疫吸附法测定白细胞介素-6（IL-6）及肿瘤坏死因子-α（TNF-α）水平，以矽肺I期患者血清中有显著性变化的生物标志物（MDA、IL-6和TNF-α）检测数据为数据集，绘制受试者工作特征曲线（ROC）并建立Logistic回归模型，评估联合检测上述生物标志物对矽肺早期辅助诊断的价值。结果：与对照组相比，矽肺患者血清中SOD表达水平无显著变化（P > 0.05）；矽肺I期及Ⅱ期患者血清中MDA及IL-6表达水平显著升高（P < 0.05）；矽肺I期患者血清中TNF-α表达水平显著升高（P < 0.05）。回归模型结果显示，ROC曲线下面积排序为：3个指标联合检测（0.89） > IL-6（0.86） > MDA（0.81） > TNF-α（0.65）。结论：IL-6、TNF-α和MDA的联合检测可以提高矽肺早期辅助诊断的灵敏度和特异性。     

Evaluation of dowel space preparation on the apical seal using an image processing system

The effect of post preparation on the apical seal of endodontically treated specimens was studied. The canals prepared in bovine bone were instrumented and obturated using five obturation techniques: the silver point technique, the lateral condensation of gutta-percha technique, the warm vertical condensation of gutta-percha technique, the Hygenic Ultrafil injection system and the Obtura technique. In addition to these five control groups, the five experimental groups were also subjected to post preparation. In the latter group, the gutta-percha was removed with an engine-driven root canal reamer 48 hours after obturation. Both the control and experimental groups were suspended in a 0.5 per cent crystal violet solution for 48 hours. After dye penetration, the specimens were immersed in liquid nitrogen and then split longitudinally. Linear measurements of the resultant apical dye leakage were determined by image processing. For each obturation technique, all specimens in both the control and experimental groups were recorded if they showed leakage. Using Fisher's exact probability test, it was shown that there was no significant difference between the obturation techniques used.     

The influence of a flexible coating on the bone stress around dental implants

summary The influence of a three-layered flexible coating of Polyactive® on bone stress distribution was investigated by three-dimensional finite element models of mandibular bone, in which a titanium implant (coated or uncoated) was located. Poly-active® is a system of poly(ethylene oxide) poly(butylene terephthalate) segmented co-polymers with bone-bonding capacity. In the case of sagittal and transversal loading, the use of a Polyactive® coating reduced both the minimum principal stress in the bone and the compressive radial stress at the bone-implant interface. However, it raised the maximum principal and the tensile radial stress. In the case of vertical loading, the application of a flexible coating reduced the compressive radial stress at the bone-implant interface around the neck of the implant by a factor of 6.6 and the tensile radial stress by a factor of 3.6. Variations in composition and thickness of the coating did not affect the results significantly.     

Symptoms of the cervical spine in temporomandibular and cervical spine disorders

This study was performed to assess the prevalence of signs and symptoms related to cervical spine disorders (CSD) in subgroups of patients with temporomandibular disorders (TMD) and to compare TMD patients and CSD patients with regard to the results of orthopaedic cervical spine tests. One hundred and eleven consecutive patients with TMD and 103 consecutive patients with signs and symptoms of CSD were examined. The results indicated that there is a considerable overlap in the signs and symptoms of patients with TMD and patients with CSD. Signs and symptoms on neck extension occurred more often in CSD patients than in subgroups of TMD patients. No significant differences in upper cervical extension, neck flexion, and shoulder girdle function were found between CSD patients and subgroups of patients with TMD. Patients with CSD reported neck pain during active and passive movements of the neck more often than the subgroups of patients with TMD. TMD patients and CSD patients did not differ with regard to pain on shoulder girdle function and palpation of the shoulder girdle. Logistic regression analyses showed that orthopaedic tests of the cervical spine are of minor importance in discriminating between patients with TMD and patients with CSD. It is concluded that TMD with a myogenous involvement in contrast to TMD with only an arthrogenous involvement should no longer be viewed as a local disorder of the stomatognathic system. The upper quarter, including the stomatognathic system, cervical spine, and shoulder girdle, should be evaluated in patients with more complex or persistent symptoms in the head and neck region.