Customized three-dimensionally printed mandibular external fixator

The advent of customized three-dimensional (3D) printing allows the affordable manufacturing of sophisticated medical devices, thereby providing swift and simple solutions to specific needs in modern healthcare. Meanwhile, certain devices such as industrial mandibular external fixators (EFs) have become less and less available from medical device companies because of decreased indications. What is more, their handling is often complex. The authors report, step by step, the original design and uneventful clinical use of a 3D-printed, customized mandibular EF. This device was designed together with a positioning and drilling guide for the fixation of a septic mandibular pseudarthrosis. It provided an adequate and satisfactory balance between lightness and rigidity. A simple, accurate and safe placement of the EF was achieved thanks to the skin-supported positioner and drilling guide, thereby making the procedure minimally invasive and time-efficient. To our knowledge, this is the first reported clinical use of a 3D-printed, customized mandibular EF to date. Because such 3D technology is becoming increasingly available to a large number of surgeons, the authors believe that the present innovation could become an alternative to reusable standard EFs.     

Standard versus customised locking plates for fixation of schatzker ii tibial plateau fractures

Aim3D-printed implants could improve the capture of fracture fragments for improved stability of tibial plateau fracture fixation. The aim of this study was to compare the biomechanical strength of fixation constructs using standard and customised 3D-printed proximal tibial locking plates for fixation of tibial plateau fractures.MethodsThis is a biomechanical study utilising six pairs of cadaveric tibiae. Fractures were created in an identical fashion using an osteotome and mallet, and fixed using either a standard, commercially-available proximal tibia locking plate or a customised 3D-printed plate. Design and production of the customised plates followed a “3D printing at point-of-care” model. Customised stainless steel 316 L plates were produced within a local additive manufacturing laboratory based upon pre-operative CT scans. Determination of implant choice within each cadaver pair was performed via simple randomisation. Following fracture fixation, the tibiae were skeletalised and biomechanically tested using a customised loading jig and a size-matched femoral knee prosthesis. The constructs were loaded cyclically from 100 N to approximately three times the cadaveric body-weight at 5 Hz for 10 000 cycles. Every 1000 cycles, the test was paused and the tibia was physically checked for failure. If failure had not occurred by the end of the testing cycle, the construct was loaded to failure and the load at which the construct failed was noted.ResultsFixation constructs using the 3D-printed plates performed comparably to those using the standard plates. There was no significant difference in the degree of fracture fragment displacement in both constructs. Overall longitudinal construct stiffness and load to failure was higher in the 3D-plates group but this did not reach statistical significance.ConclusionProduction of customised plates for proximal tibia fractures at point-of-care is feasible, however fixation constructs with these plates did not provide any biomechanical advantage over standard plates in terms of axial loading stiffness.     

中医药调控IL-1治疗肿瘤机制的研究进展

炎症已成为影响肿瘤细胞增殖转移的第七大因素,而白细胞介素-1(IL-1)是炎性微环境的重要因子之一。中医药在治疗肿瘤时具有多途径、多靶点的优势,同时炎性微环境致病特点与现代中医学"癌毒"的理论相吻合。查阅近年中医药调控IL-1家族分子治疗肿瘤机制的文献,对其进行梳理,并做出概括及评价,从中医药主要调控IL-1α、IL-1β和IL-18因子治疗肿瘤展开综述,为中医药更系统化治疗肿瘤提供参考。     

(-)-Epigallocatechin-3-gallate,reduces corneal damage secondary from experimental grade II alkali burns in mice

Background

Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.

Anisotropic Bladder Planning Target Volume in Bladder Radiation Therapy

Purpose

This study aimed to investigate 3 planning target volume (PTV) margin expansions and determine the most appropriate volume to be used in bladder preservation therapy when using daily cone beam computed tomography (CBCT). We aimed to establish whether a smaller PTV expansion is feasible without risking geographical miss.

3-磷酸甘油酸脱氢酶促进丝氨酸合成在肿瘤进展中的机制

丝氨酸生物合成途径活性的上调是许多癌症明显的共同特征。该途径的第一种限速酶3-磷酸甘油酸脱氢酶(PHGDH)在黑色素瘤、乳腺癌和肾癌等癌组织中高表达，对肿瘤细胞增殖、转移、侵袭有着重要作用。糖酵解中间产物3-磷酸甘油酸在PHGDH作用下，氧化为磷酸羟基丙酮酸并最终合成丝氨酸。丝氨酸转化为甘氨酸，然后在核苷酸、s-腺苷甲硫氨酸(SAM)和还原型谷胱甘肽(GSH)的合成中起着重要的作用。PHGDH 有望成为肿瘤治疗的新靶点。     

利用耳甲腔型小耳畸形残耳皮瓣及软骨改善再造耳颅耳沟效果观察

目的探讨对先天性耳甲腔型小耳畸形患者行全扩张法全耳再造术后，利用残耳皮瓣改善再造耳颅耳沟的效果。方法回顾分析 2012 年 1 月—2017 年 1 月收治的 150 例先天性耳甲腔型小耳畸形患者。其中男 92 例，女 58 例；年龄 6.5～35.0 岁，平均 11.1 岁。采用一期扩张器埋置、二期全扩张法全耳再造术后发现上部颅耳沟浅显；于 6～12 个月后行三期再造耳修整。将残耳垂通过“Z”字改型转移以再造耳垂。在残耳上部作蒂在轮屏切迹的残耳上部皮瓣，弧形切开松解并加深上部颅耳沟，将上部残耳皮瓣向颅耳沟创面旋转推进缝合以覆盖创面；将带皮下组织蒂的残耳软骨组织瓣插入支架底部形成的腔隙内，并缝合固定，以增加支架的高度；耳甲腔区其余残耳皮瓣用以覆盖耳甲腔创面。结果术后拆线时 1 例患儿皮瓣远端出现直径约 0.5 cm 的表皮水疱，经换药 2 周后愈合；其余患者皮瓣成活良好。患者均获随访，随访时间 6～12 个月，平均 9.6 个月。再造耳上部颅耳沟均明显加深，再造耳支架高度不同程度增加，双耳对称性佳，耳甲腔无明显挛缩变小，再造耳外观满意。再造耳上部表面毛发明显减少，耳周发际线上移。结论采用耳甲腔型小耳畸形的残耳皮瓣及残耳软骨瓣转移，不仅可加深颅耳沟，而且可增加上部支架的高度，术后颅耳沟变形较轻，再造耳与正常耳廓的对称性更佳。     

藿香正气汤抑制新型冠状病毒复制过程的有效成分及机制初探＊

目的 收集藿香正气汤的主要活性成分，通过分子对接及网络药理学探讨其防控新型冠状病毒肺炎（COVID-19）的有效成分及治疗机制。方法 通过基于配体-蛋白质相互作用的计算方法，以瑞德西韦为对照，探索藿香正气汤潜在治疗COVID-19的成分，并选出对接较好成分进行药理学机制预测，初探其药理学机制。结果 本研究筛选出5种与新冠病毒3CLpro结合能力强于瑞德西韦的小分子成分。网络药理学初步预测抗病毒途径可能是通过PI3K-Akt 信号通路影响病毒复制。结论 成分C1-C5与3CLpro结合良好，推测其可能是潜在的3CLpro的抑制剂，为抗病毒天然药物的开发提供了理论依据。