Additive manufactured push‐fit implant fixation with screw‐strength pull out

Additive manufacturing offers exciting new possibilities for improving long‐term metallic implant fixation in bone through enabling open porous structures for bony ingrowth. The aim of this research was to investigate how the technology could also improve initial fixation, a precursor to successful long‐term fixation. A new barbed fixation mechanism, relying on flexible struts was proposed and manufactured as a push‐fit peg. The technology was optimized using a synthetic bone model and compared with conventional press‐fit peg controls tested over a range of interference fits. Optimum designs, achieving maximum pull‐out force, were subsequently tested in a cadaveric femoral condyle model. The barbed fixation surface provided more than double the pull‐out force for less than a third of the insertion force compared to the best performing conventional press‐fit peg (p < 0.001). Indeed, it provided screw‐strength pull out from a push‐fit device (1,124 ± 146 N). This step change in implant fixation potential offers new capabilities for low profile, minimally invasive implant design, while providing new options to simplify surgery, allowing for one‐piece push‐fit components with high levels of initial stability. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 36:1508–1518, 2018.     

定量化Delaire头影测量分析法的研究进展及展望

定位头影测量方法是评价颅颌面骨骼结构特征的重要手段,广泛运用于颅面生长发育预测及颅颌面骨骼特征等研究^[1]。传统方法诸如Downs分析法、Steiner分析法、Tweed分析法、Wylie分析法、Wits分析法、Ricketts分析法等对颅颌面骨骼结构的评价主要基于角度、线距、比例等,因受面高、颌骨旋转、参照平面变异等影响以及准确度、适用条件等限制,不能充分满足临床需要,     

NCB-02(standardized Curcumin preparation)protects dinitrochlorobenzene-induced colitis through down-regulation of NFκ-B and iNOS

AIM:To evaluate the efficacy and mechanism of action of NCB-02,a standardized Curcumin preparation,against 2,4-dinitrochlorobenzene(DNCB)-induced ulcerative colitis in rats.METHODS:Ulcerative colitis was induced in male rats by sensitizing with topical application of DNCB in acetone for 14 d and intra-colonol challenge with DNCB on day 15.A separate group of animals with vehicle treatment in similar fashion served as control group.Colitis rats were divided into different groups and treated with NCB-02 at doses of 25,50 and 100 mg/kg b.wt p.o.for 10 d.Sulfasalazine at a dose of 100 mg/kg b.wt for 10 d served as a reference group.On day 10 after respective assigned treatment,all the animals were euthanized and the length of the colon,weight of entire colon and distal 8 cm of the colon were recorded.The distal part of the colon was immediately observed under a stereomicroscope and the degree of damage was scored.Further distal 8 cm of the colon was subject to the determination of colonic myeloperoxidase(MPO),lipid peroxidation(LPO)and alkaline phosphatase (ALP)activities.A small piece of the sample from distal colon of each animal was fixed in 10% neutral buffered formalin and embedded in paraffin wax and sectioned for immunohistochemical examination of NFκ-B and iNOS expression.RESULTS:NCB-02 showed a dose dependent protection against DNCB-induced alteration in colon length and weight.NCB-02 treatment also showed a dose dependent protection against the elevated levels of MPO,LPO and ALP,induced by DNCB.NCB-02 demonstrated a significant effect at a dose of 100 mg/kg b.wt.,which was almost equipotent to 100 mg/kg b.wt.of sulfasalazine.Treatment with sulfasalazine and curcumin at a dose of 100 mg/kg b.wt.inhibited the DNCB-induced overexpression of NFκ-B and iNOS in the colon.CONCLUSION:Curcumin treatment ameliorates colonic damage in DNCB-induced colitic rats,an effect associated with an improvement in intestinal oxidative stress and downregulation of colonic NFκ-B and iNOS expression.     

正颌患者对美学与功能评价的感知初步评价

目的:基于正颌外科手术患者的求治动机和公众的审美要求,评估正颌外科患者对面部美学和功能改善的感知和期望,引导患者树立正确审美观,提高患者对联合治疗的满意度.方法:采用基于SCL-90、SDS、SAS量表的综合问卷调查患者对面部美学的理解和对疗效的期望,涵盖面部外形,牙齿外观、口颌功能等,并结合患者情况进行综合分析.结果:颜貌改观是患者寻求正颌手术治疗的主要目的,患者期望术后不仅有整齐牙列,更具备良好的面部外形和口颌功能.正颌外科术后应结合功能重建训练,以到达更好地改善外形,恢复口颌功能.结论:在临床治疗中应合理引导患者审美观,遵循美学与功能相结合原则,以期达到容貌美和良好咬合关系的治疗效果,更好地维护、修复和再塑造患者容貌美.     

Synthesis and biological evaluation of morpholines linked coumarin–triazole hybrids as anticancer agents

A series of novel morpholines linked coumarin–triazole hybrids ( 6a–6v ) has been synthesized and evaluated for their anti‐proliferative potential on a panel of five human cancer cell lines, namely bone (MG‐63), lung (A549), breast (MDA‐MB‐231), colon (HCT‐15) and liver (HepG2), using MTT assay. Among all, the compound 6n {7‐((1‐(2,4‐dichlorobenzyl)‐1H‐1,2,3‐triazol‐4‐yl) methoxy)‐4‐((2,6‐dimethylmorpholino) methyl)‐2H‐chromen‐2‐one} showed significant growth inhibition against MG‐63 cells with an IC₅₀ value of 0.80 ± 0.22 μM. Further, induction of apoptosis by 6n of MG‐63 cells confirmed as a result of morphological changes, the sub‐G1 phase arrest, increased percentage of apoptotic cells, and decrease in mitochondrial membrane potential and increase in reactive oxygen species levels. The in vitro Gal‐1 expression in cell culture supernatant of MG‐63 cells treated with compound 6n showed dose‐dependent reduction. The binding constant (K_a) of 6n with Gal‐1 was calculated from the intercept value which was observed as 3.0 × 10⁵ M^?1 by fluorescence spectroscopy. Surface plasmon resonance showed that 6n binds to Gal‐1 with binding constant (K_a) of 1.29E+04 1/Ms and equilibrium constant KD value of 7.54E?07 M, respectively. Molecular docking studies revealed the binding interactions of 6n with Gal‐1.     

Integration of 60,000 exomes and ACMG guidelines question the role of Catecholaminergic Polymorphic Ventricular Tachycardia‐associated variants

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a highly lethal cardiac arrhythmia disease occurring during exercise or psychological stress. CPVT has an estimated prevalence of 1:10,000 and has mainly been associated with variants in calcium‐regulating genes. Identification of potential false‐positive pathogenic variants was conducted by searching the Exome Aggregation Consortium (ExAC) database (n = 60,706) for variants reported to be associated with CPVT. The pathogenicity of the interrogated variants was assessed using guidelines from the American College of Medical Genetics and Genomics (ACMG) and in silico prediction tools. Of 246 variants 38 (15%) variants previously associated with CPVT were identified in the ExAC database. We predicted the CPVT prevalence to be 1:132. The ACMG standards classified 29% of ExAC variants as pathogenic or likely pathogenic. The in silico predictions showed a reduced probability of disease‐causing effect for the variants identified in the exome database (p < 0.001). We have observed a large overrepresentation of previously CPVT‐associated variants in a large exome database. Based on the frequency of CPVT in the general population, it is less likely that the previously proposed variants are associated with a highly penetrant monogenic form of the disease.