牙列缺损的计算机三维建模

目的 建立牙列缺损的计算机三维模型。方法 采用表面绘制法,依据CT扫描头颅骨标本获得的二维断层图像数据在3D Studio Max中沿牙体长轴放样、微调并赋以材质,得到牙列缺损的计算机三维模型。结果 能在计算机中方便快速地模拟任意类型的牙列缺损,并可全方位地旋转、放大和缩小。结论 提供了一种牙列缺损三维建模的新方法,有利于三维义齿专家系统的开发和计算机辅助教学。     

经关节入路微创钢板固定技术治疗股骨远端C型骨折

目的探讨经关节入路微创钢板固定(MIPPO)技术治疗股骨远端C型骨折的临床疗效。方法2002年4月～2005年2月,应用MIPPO技术治疗股骨远端C型骨折14例,按AO/ASIF分类：C1型3例,C2型6例,C3型5例。先行关节内骨折切开复位、松质骨螺钉固定,再行髁上部分骨折间接复位、经关节内切口插入髁支撑钢板或LISS钢板桥接固定骨折。结果12例患者获得10～32个月(平均18．4个月)随访,骨折均获愈合,愈合时间10周～12个月,平均4．6个月。按Kolmert和Wulff的评价标准：优4例,良5例,可2例,差1例,优良率为75%。结论应用MIPPO技术治疗股骨远端C型骨折实现了微创操作,具有创伤小、软组织干扰少、骨折愈合快等优点,疗效满意。     

The relationship between active travel to school and health-related fitness in children and adolescents: a systematic review

Background  

Active travel to school (ATS) has been identified as an important source of physical activity for youth. However, the relationship between ATS and health-related fitness (HRF) among youth remains unclear.     

Identification and characterization of novel uroporphyrinogen decarboxylase gene mutations in a large series of porphyria cutanea tarda patients and relatives

Porphyria cutanea tarda (PCT) arises from decreased hepatic activity of uroporphyrinogen decarboxylase (UROD). Both genetic and environmental factors interplay in the precipitation of clinically overt PCT, but these factors may vary between different geographic areas. Decreased activity of UROD in erythrocytes was used to identify patients with UROD mutations among a group of 130 Spanish PCT patients. Nineteen patients (14.6%) were found to harbor a mutation in the UROD gene. Eight mutations were novel: M1I, 5del10, A22V, D79N, F84I, Q116X, T141I and Y182C. Five others were previously described: F46L, V134Q, R142Q, P150L and E218G. The new missense mutations and P150L were expressed in Escherichia coli. D79N and P150L resulted in proteins that were localized to inclusion bodies. The other mutations produced recombinant proteins that were purified and showed reduced activity (range: 2.3–73.2% of wild type). These single amino acid changes were predicted to produce complex structural alterations and/or reduced stability of the enzyme. Screening of relatives of the probands showed that 37.5% of mutation carriers demonstrated increased urinary porphyrins. This study emphasizes the role of UROD mutations as a strong risk factor for PCT even in areas where environmental factors (hepatitis C virus) have been shown to be highly associated with the disease.     

The Effect of Nutrient Intake on Bone Mineral Status in Young Adults: The Northern Ireland Young Hearts Project

Optimizing peak bone mass in early life may reduce osteoporosis risk in later life. Such optimization may be partly dependent upon diet. In the present study, nutrient intakes and selected lifestyle parameters were assessed in adolescent subjects (238 males, 205 females; aged 15 y) and again, in the same subjects, on one occasion in young adulthood (aged between 20 and 25 y). The extent of the relationships between these parameters and bone mineral density (BMD), dual energy X-ray absorptiometry (DXA), lumbar spine (L2-L4), and femoral neck measured concurrently with diet in young adulthood only, was assessed. Adjusted linear regression models were constructed. Variables included a measure of pubertal status (at age 15 y), age (at young adulthood), height, weight, physical activity, smoking, and mean daily intakes of energy, calcium, protein, vitamin D, phosphorus, total fat, and alcohol. In both sexes, body weight at adolescence and young adulthood was the only factor consistently positively associated with BMD at both measurement sites. Effects of nutrient intake on BMD were inconsistent. Vitamin D and calcium intakes reported by female adolescents showed significant positive relationships with BMD measured in young adulthood (vitamin D measured at the lumbar spine; calcium measured at the femoral neck). The positive relationship between vitamin D and BMD remained significant at young adulthood, but at the femoral neck rather than at the lumbar spine. Also in females, intakes of phosphorus and the calcium:phosphorus ratio (Ca:P) at adolescence were strongly negatively related to femoral neck BMD measured at young adulthood. In males, however, Ca:P reported at young adulthood had a significant positive relationship with lumbar spine BMD, whereas Ca:protein was negatively associated with BMD at the lumbar spine. Intakes of Ca reported by adolescent males also had a strong negative effect on lumbar spine BMD measured at young adulthood.     

The reconnaissance and siting of field hospitals

This paper describes the reconnaissance function for the siting of deployable field hospitals. It reports two levels of reconnaissance, theatre/operational and tactical. The paper describes the factors to be considered when conducting the reconnaissance and the format of the reconnaissance report.     

下肢骨肉瘤的MRI与X线对照研究

目的 对比分析下肢骨肉瘤的X线与MRI表现，探讨MRI对骨肉瘤的诊断价值。方法 收集经手术或病理穿刺活检证实的下肢骨肉瘤15例，男11例，女4例，均行MRI平扫及增强扫描（4例行CT扫描），并摄有X线平片，对其MRI征象与X线征象作逐一对比。结果 MRI及X线平片对下肢骨肉瘤的诊断准确率均为100％，MRI在显示病变范围、放射状骨针、Codman三角两层结构以及跳跃病灶等方面明显优于X线平片检查。结论 X线平片是诊断骨肉瘤最简便而实用的方法，但MRI可以更好的显示病变的范围，发现早期病变。     

头皮原发性皮肤神经节细胞瘤

神经节细胞瘤是一种神经内分泌肿瘤，其发生与自主神经系统的交感或副交感神经节有关。罕见发生于膀胱、前列腺和子宫。本文作者报道1例发生于儿童头皮的原发性皮肤神经节细胞瘤。对此肿瘤进行了组织学、免疫组化和超微结构研究。该病例可能代表神经嵴细胞向鳃弓发育过程中的一种异常迁移。此外，研究结果还强调在胚胎发育过程中神经嵴和鳃弓／裂之间有复杂的相互作用。