Alterations of biochemical and biomechanical properties of rat tail tendons caused by non-enzymatic glycation and their inhibition by dibasic amino acids arginine and lysine

Summary The influence of dibasic amino acids arginine and lysine on non-enzymatic glycation of tail tendon fibers from old (900-day-old) and young (61-day-old) rats was investigated in vitro. The biomechanical changes in tendon fibers of young rats after an incubation interval of 7 or 14 days in a glucose solution were abolished by the addition of arginine or lysine (molar ratio amino acid:glucose 110). Glucose incorporation into rat tail tendon fibers as well as Amadori product formation was decreased significantly in the presence of the amino acids. The inhibitory effect of arginine was further confirmed by measurement of the amount of ketoamine formed during the glycation reaction using soluble albumin as a protein target. The effective inhibition of non-enzymatic glycation by arginine or lysine suggests their potential use in vivo as a means of controling protein over-glycation.     

Determination and correlation of lower limb anatomical parameters and bone age during skeletal growth (based on 1005 cases)

The aim of this study was to evaluate bone age and its correlation with the lower limbs' developing skeletal anatomy during growth. 1005 children and young adults were evaluated for bone age and 14 different parameters measured on lower‐limb reconstructions from radiological examinations carried out with an EOS 2D/3D system in the course of routine orthopedic indicated diagnostic practice. Cervical vertebral morphology evaluation for bone age using the Hassel–Farman method, which describes six stages of maturity, was selected. Intra‐ and inter‐observer reliability tests for this method, and for the EOS 3D reconstructions were performed. Statistical analysis were performed using Spearman correlation, multiple linear regression, and t‐test. The intra‐ and inter‐observer reliability of the Hassel–Farman method and the EOS 3D lower‐limb reconstruction were found to be excellent. Interestingly one bone age stage could include individuals across a 12.1 year range, and conversely individuals of the same calendar age could be of one of 3.2 different bone age stages. In the prepubertal age groups all six bone stages could be observed. Bone age revealed a stronger relationship, lower standard deviations with groups and proved to be a better discriminating variable than the calendar age by collodiaphyseal angle, femoral, and tibial torsion, femorotibial rotation, and mechanical tibiofemoral angle. Bone age is an indicator of skeletal maturity and may more accurately describe the growth of some lower limb parameters. As a result we suggest the consideration of bone age when evaluating lower‐limb biomechanic‐anatomical parameters. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1431–1441, 2017.

     

镍钛形状记忆合金细胞相容性和生物力学兼容性的改进

镍钛记忆合金（ＮｉＴｉ）生物材料器件的发展，迫切要求研究和提高其细胞相容性和生物力学性能。依据美国材料测试标准协会（ＡＳＴＭ）的标准，我们研究表明：ＮｉＴｉ的细胞毒性比纯钛、Ｔｉ６Ａ１４Ｖ和３１６Ｌ不锈钢大，在ＮｉＴｉ表面作聚合四氟乙烯高离子（ＰＰＴＦＥ）喷涂。可降低ＮｉＴｉ合金的细胞毒性，提高其抗腐蚀力。各种热处理方法可改善其疲劳性能，循环拉伸强度试验可测出其超弹性性能的衰减。     

Production of Porous β-Type Ti–40Nb Alloy for Biomedical Applications: Comparison of Selective Laser Melting and Hot Pressing

We used selective laser melting (SLM) and hot pressing of mechanically-alloyed β-type Ti–40Nb powder to fabricate macroporous bulk specimens (solid cylinders). The total porosity, compressive strength, and compressive elastic modulus of the SLM-fabricated material were determined as 17% ± 1%, 968 ± 8 MPa, and 33 ± 2 GPa, respectively. The alloy’s elastic modulus is comparable to that of healthy cancellous bone. The comparable results for the hot-pressed material were 3% ± 2%, 1400 ± 19 MPa, and 77 ± 3 GPa. This difference in mechanical properties results from different porosity and phase composition of the two alloys. Both SLM-fabricated and hot-pressed cylinders demonstrated good in vitro biocompatibility. The presented results suggest that the SLM-fabricated alloy may be preferable to the hot-pressed alloy for biomedical applications, such as the manufacture of load-bearing metallic components for total joint replacements.     

益肾护骨方对废用性骨质疏松的改善作用

目的: 观察益肾护骨方对废用性骨质疏松大鼠的血尿生化水平、骨结构及股骨生物力学性能影响,探讨益肾护骨方对废用性骨质疏松的改善作用。 方法: 选取3月龄SD大鼠70只,随机分为正常组、假手术组、模型组、益肾护骨方高、中、低剂量组和阳性药物对照组（强骨胶囊）,每组10只。模型组、益肾护骨方高、中、低剂量组和阳性药物对照组行右侧坐骨神经切断术,假手术组的手术过程只分离显露坐骨神经后缝合切口。益肾护骨方高、中、低剂量组分别于造模后第2天予以益肾护骨方52,26,16.25 g·kg^-1,阳性药物对照组造模后第2天予以强骨胶囊0.25 g·kg^-1ig,用药4周。检测血尿生化、股骨生物力学、胫骨组织形态计量学指标。 结果: 血碱性磷酸酶（ALP）、血清骨钙素（BGP）、血抗酒石酸酸性磷酸酶（TRACP）、尿羟脯氨酸（HYP）/肌酐（Cr）、骨小梁节点数、游离末端数及股骨生物力学指标,模型组与假手术组相比显著升高或降低（P<0.01）;与模型组比较,益肾护骨方高、中、低剂量组血ALP,BGP,TRACP,尿HYP/Cr,骨小梁节点数、游离末端数及股骨生物力学指标均显著降低或升高 （P<0.01）。 结论: 益肾护骨方对废用性骨质疏松大鼠有不同程度的成骨作用,可以不同程度延缓或减轻大鼠废用性骨质疏松的发生。     

Biomechanical properties of the cornea measured by the Ocular Response Analyzer and their association with intraocular pressure and the central corneal curvature

Background: The aim of this study was to investigate the biomechanical properties of the cornea and their association with intraocular pressure (IOP), central corneal thickness (CCT) and the central corneal radius of curvature (Rc). Methods: Eighty‐three eyes were divided into two groups. The biomechanical properties of the cornea were measured in 63 normal eyes and in 20 post‐laser in situ keratomileusis (LASIK) eyes. The IOP, corneal hysteresis (CH) and corneal resistance factor (CRF) were measured by the Ocular Response Analyzer (ORA). The Rc and CCT were measured using the corneal topographer Medmont E‐300 and the Tomey SP‐100 Handy ultrasonic pachymeter. Other parameters measured by the ORA, such as TimeIn and TimeOut, were also studied. Results: A mean corneal hysteresis of 10.8 mmHg and CRF of 10.6 mmHg were recorded for the normal eyes. There was no significant association with central curvature. All parameters measured by the ORA showed a significant correlation with the CCT, except for the corneal‐compensated intraocular pressure (IOPcc). Both IOPs measured by the ORA had the same values for the mean CH and CRF. For the post‐LASIK eyes, the CH and CRF were lower than in the normal non‐operated eyes. The TimeIn and the TimeOut also presented lower values for the post‐LASIK eyes, suggesting that additional data can be obtained with the ORA measurements. Conclusions: The results of this study indicate that there is no correlation between the parameters measured with the Ocular Response Analyzer and central corneal radius of curvature. Some of the biomechanical properties of the cornea studied were found to differ in the normal eyes compared to the post‐LASIK eyes.