Functional genomics of allergen gene families in fruits

Fruit consumption is encouraged for health reasons; however, fruits may harbour a series of allergenic proteins that may cause discomfort or even represent serious threats to certain individuals. Thus, the identification and characterization of allergens in fruits requires novel approaches involving genomic and proteomic tools. Since avoidance of fruits also negatively affects the quality of patients' lives, biotechnological interventions are ongoing to produce low allergenic fruits by down regulating specific genes. In this respect, the control of proteins associated with allergenicity could be achieved by fine tuning the spatial and temporal expression of the relevant genes.     

数字医学在骨科中的应用进展

当今社会,信息技术迅猛发展,随着信息技术对各个领域的不断渗透,数字医学应运而生。借助数字化技术手段,医学科研人员不断研究信息化条件下医学新理论、新知识、新技术和新方法,让数字医学成为本世纪医学科学技术的核心和发展方向,尤其在骨科领域取得了长足的进步。本文介绍数字医学的发展概况及其在骨科中的应用进展。     

Occupational chronic exposure to organic solvents

Summary A study was carried out among 20 workers employed in a printing, office at three different work places (methanol concentration: 85, 101, and 134 ppm) to determine whether the concentration of formic acid in blood or urine and the methanol content of alveolar air permit the estimation of methanol exposure.For this purpose blood, urine, and end expiratory air were collected at the beginning and the end of the shift. For comparison formic acid concentrations were determined in the morning and in the afternoon in blood and urine of 36 and 15 control persons, respectively.The concentration of formic acid in blood increased significantly from 3.2 ± 2.4 mg/l before to 7.9 ± 3.2 mg/l after the shift in the exposed workers (mean increase 4.7 ± 3.8 mg/l). The corresponding concentrations in urine were 13.1 ± 3.9 mg/l and 20.2 ± 7 mg/l, respectively, with a mean increase of 7.1 ± 5.3 mg/l. This difference is also significant. On the contrary, in the control groups there was a small but significant decrease of formic acid concentration in blood from 5.6 ±4.5 mg/l in the morning to 4.9 ± 4.2 mg/l in the afternoon. In urine, the formic acid concentrations in the morning (11.9 ± 6.4 mg/l) and in the afternoon (11.7 ±5.6 mg/l) were not significantly different. The increase of formic acid concentration in blood during the shift is the most useful parameter for monitoring methanol exposed persons. In contrast determinations of methanol concentrations in the ambient air or in the exhaled air are only crude estimates.(Direktor: Prof. Dr. G. Lehnert)     

3D打印技术辅助髋臼成形术治疗脑瘫儿童髋关节脱位

目的:探讨通过3D打印技术明确髋臼发育不良类型选择最合适的髋臼成形术治疗脑瘫儿童髋关节脱位的适应证和临床疗效。方法:自2019年7月至2019年12月,采用3D打印技术辅助髋臼成形术治疗7例脑瘫儿童髋关节脱位,其中男3例,女4例;年龄3~8岁;左侧3例,右侧2例,双侧2例;2例髋关节半脱位,5例髋关节脱位。患儿术前均行骨盆-双股骨全长CT扫描。通过3D打印重建技术,判断髋臼发育不良类型:前侧2髋,前外2髋,外上1髋,后侧2髋,后外1髋,无发育不良1髋(未做髋臼成形术)。对8髋分别进行Pemberton,Dega和San Diego手术模拟,寻找最合适的手术方式并手术。比较术前和末次随访外移比例(migration percentage,MP),髋臼指数(acetabular index,AI),中心边缘角(center-edge angle,CEA),Shenton线和粗大运动功能分级(gross motor function classification system,GMFCS)的变化,并记录其并发症情况。结果:术后患者伤口愈合良好,无并发症发生。7例患者获随访,时间18~24个月。8髋Ⅰ期行软组织松解+股骨近端内翻去旋转短缩截骨+髋关节复位+髋臼成形术;1髋Ⅰ期行软组织松解+股骨近端内翻去旋转短缩截骨+髋关节复位术。MP由术前的58%~100%降至末次随访时的0~17.9%。AI由术前的25.0°~47.6°降至末次随访时的11.1°~25.3°。CEA由术前的0°改善至末次随访时的21.1°~48.5°。Shenton''线均由中断变为连续。其中5例GMFCS分级下降1级,2例无变化。结论:脑瘫儿童髋关节脱位中髋臼发育不良的类型多样,髋臼成形术适用范围也有差异,借助3D打印技术计算机模拟手术可选择最合适的手术方式并判断治疗效果,对脑瘫儿童髋关节脱位做到个体化、精准化治疗。     

眼眶爆裂性骨折修复术中3D打印技术应用的效果观察

目的:观察眼眶爆裂性骨折修复手术中应用3D打印技术的效果。方法:回顾性分析北京大学国际医院2016年7月至2017年12月眼眶爆裂性骨折13例的临床资料。术前根据CT扫描的数据行三维重建,获得患侧眶壁骨折区的模型,依照对侧正常眶壁形状,通过镜像技术,获得患侧眶壁骨折区的解剖修复形状指导片模型,使用3D打印机打印眶骨折区和修复形状指导片模型。以此为模板,在手术中指导修复材料的塑形,使之契合骨折区,修复眶骨折。术后观察效果。结果:本组13例术后CT显示骨折修复效果满意,修复材料与骨折区契合,术后无视力下降,术后3个月双眼球突出度之差为(0.54±0.78)mm,5例术前复视者中1例残留轻微复视,其余4例恢复良好。结论:3D打印技术用于指导修复模片,能使眼眶骨折达到满意的修复效果。     

3D打印截骨模块在全膝关节置换术中的应用研究进展

3D打印技术是基于计算机三维数字成像技术和多层堆叠打印技术的一种新兴应用技术。该技术改变了传统的减式材料制造模式,带来了制造工艺和生产模式的变革。该技术应用于人工膝关节置换领域,制作个体化的截骨模块,能够使手术获得精确的下肢力线,具有个体化、精准化、数字化、符合加速康复外科理念等诸多优点,可以对膝关节置换术起到良好的辅助作用。随着该技术在临床中的应用越来越广泛,其缺点和不足逐渐显现。近年来对于改进3D打印截骨模块在全膝关节置换术中应用的研究报道逐渐增多,本文就新研究和进展进行文献综述。     

Subsidence and fusion performance of a 3D-printed porous interbody cage with stress-optimized body lattice and microporous endplates - a comprehensive mechanical and biological analysis

BACKGROUND CONTEXTCage subsidence remains a serious complication after spinal fusion surgery. Novel porous designs in the cage body or endplate offer attractive options to improve subsidence and osseointegration performance.PURPOSETo elucidate the relative contribution of a porous design in each of the two major domains (body and endplates) to cage stiffness and subsidence performance, using standardized mechanical testing methods, and to analyze the fusion progression via an established ovine interbody fusion model to support the mechanical testing findings.STUDY DESIGN/SETTINGA comparative preclinical study using standardized mechanical testing and established animal model.METHODSTo isolate the subsidence performance contributed by each porous cage design feature, namely the stress-optimized body lattice (vs. a solid body) and microporous endplates (vs. smooth endplates), four groups of cages (two-by-two combination of these two features) were tested in: (1) static axial compression of the cage (per ASTM F2077) and (2) static subsidence (per ASTM F2267). To evaluate the progression of fusion, titanium cages were created with a microporous endplate and internal lattice architecture analogous to commercial implants used in subsidence testing and implanted in an endplate-sparing, ovine intervertebral body fusion model.RESULTSThe cage stiffness was reduced by 16.7% by the porous body lattice, and by 16.6% by the microporous endplates. The porous titanium cage with both porous features showed the lowest stiffness with a value of 40.4±0.3 kN/mm (Mean±SEM) and a block stiffness of 1976.8±27.4 N/mm for subsidence. The body lattice showed no significant impact on the block stiffness (1.4% reduction), while the microporous endplates decreased the block stiffness significantly by 24.9% (p<.0001). All segments implanted with porous titanium cages were deemed rigidly fused by manual palpation, except one at 12 weeks, consistent with robotic ROM testing and radiographic and histologic observations. A reduction in ROM was noted from 12 to 26 weeks (4.1±1.6° to 2.2±1.4° in lateral bending, p<.05; 2.1±0.6° to 1.5±0.3° in axial rotation, p<.05); and 3.3±1.6° to 1.9±1.2° in flexion extension, p=.07). Bone in the available void improved with time in the central aperture (54±35% to 83±13%, p<.05) and porous cage structure (19±26% to 37±21%, p=.15).CONCLUSIONSBody lattice and microporous endplates features can effectively reduce the cage stiffness, therefore reducing the risk of stress shielding and promoting early fusion. While body lattice showed no impact on block stiffness and the microporous endplates reduced the block stiffness, a titanium cage with microporous endplates and internal lattice supported bone ingrowth and segmental mechanical stability as early as 12 weeks in ovine interbody fusion.CLINICAL SIGNIFICANCEPorous titanium cage architecture can offer an attractive solution to increase the available space for bone ingrowth and bridging to support successful spinal fusion while mitigating risks of increased subsidence.     

3D打印技术建立山羊腰椎融合模型及实验围手术期管理

目的:探讨个体化3D打印技术建立山羊腰椎融合模型的可行性及围手术期管理的注意事项。方法 :根据10只雄性1~2岁、体重35~45 kg波尔山羊腰椎术前X线片及CT三维重建数据,术前确定理论撑开高度,再根据理论进钉点确定钢板长度、弧度、放置位置及上下位螺钉长度等参考值,设计并进行3D打印腰椎侧前路接骨板。全麻下切除山羊腰椎椎体及相邻椎间盘,将植骨后的钛笼植入山羊体内,使用3D打印侧路接骨板进行固定。术后进行饲养、补液、抗感染及术后并发症处理、呼吸消化围手术期管理等。结果:成功建模,10只山羊术后X线片及CT三维重建显示钛笼及接骨板位置较好,固定可靠。术后3个月山羊行腰椎CT三维重建及显微CT,观察脊柱融合情况。影像学检查显示,侧路接骨板固定钛笼植骨融合均在钛笼两端与椎体间形成致密的骨小梁。结论:该3D打印技术建立山羊腰椎融合模型,是一种有效,成功率高,融合可靠稳定的方法,围手术期管理其方法科学、实用,且更加人性化,对确保腰椎侧前方钉板内固定系统成功置入,并降低手术并发症的发生具有较强的指导意义。     

印字水松纸的毒性及致突变研究

目的对印字水松纸进行安全性评价。方法通过急性毒性试验、骨髓细胞微核试验、骨髓细胞染色体畸变试验、精子畸形试验、Ames试验和30d喂养试验对印字水松纸进行安全性评价。结果①急性毒性试验显示印字水松纸的LD50〉21．5g／kgBW；②骨髓细胞微核试验、骨髓细胞染色体畸变、精子畸形试验、Ames试验均为阴性结果；③30d喂养试验结果显示印字水松纸未见毒性反应。未见体内蓄积中毒。结论即字水松纸在所试务件下属无毒级，无致突变作用、无明显体内蓄积毒性。