Different mechanisms of spinal fusion using equine bone protein extract,rhBMP-2 and autograft during the process of anterior lumbar interbody fusion

To elucidate the molecular mechanisms of spinal fusion with different graft materials during an anterior lumbar interbody fusion, we examined the gene-expression profiles after implantation of equine bone protein extract, rhBMP-2 and autograft using microarray technology and data analysis, including hierarchical clustering, self-organizing maps (SOM), KEGG pathway and Biological process GO analyses in a porcine model. The results suggest that equine bone protein extract exhibited a more similar expression pattern with autograft than that of rhBMP-2. rhBMP-2 recruits progenitor cells, proliferation and differentiation possibly by inducing various factors including PGHS-2, IFGBP-2, VEGF and chemokines and then leads to preferable membranous ossification and bone remodeling. Conversely, equine bone protein extract results in endochondral ossification via upregulation of cartilage-related genes. Ossification by inducing direct osteoblastic differentiation and obviating the cartilaginous intermediate phases may increase spinal fusion rate.     

Effect of cadmium-polluted water on plasma levels of tumor necrosis factor-α, interleukin-6 and oxidative status biomarkers in rats: Protective effect of curcumin

The present study was designed to investigate the effect of CdCl₂-polluted drinking water (40 mg CdCl₂/L) on the level of TNF-α and IL-6, as well as oxidative status biomarkers in plasma of rats. The possible protective effect of oral administration of curcumin (50 mg/kg body weight/day) was assessed. Results illustrated that Cd exposure significantly elevated the plasma levels of TNF-α and IL-6 (p < 0.001) as compared to normal rats. Also, Cd administration resulted in a significant elevation in the lipid peroxidation and markedly reduction in the activities of SOD and catalase as well as the level of glutathione and total antioxidant capacity in plasma. The co-treatment of Cd with curcumin significantly reduced the levels of TNF-α and IL-6 and ameliorated the alteration in oxidative status biomarkers induced by Cd. Negative correlation between IL-6 or TNF-α was and the plasma activities of catalase, SOD and the level of total antioxidant capacity were found in rats exposed to Cd. Conclusion: Cadmium toxicity induced the release of TNF-α and IL-6 which is associated with systemic oxidative stress. This may be involved in the mechanism of the Cd toxicity. On the other hand, the findings suggest the curative action of curcumin against Cd toxicity.     

Feasibility study of a surface-coated lung model to quantify active agent deposition for preclinical studies

BackgroundMultiple drug resistance of a growing number of bacterial pathogens represents an increasing challenge in conventional curative treatments of infectious diseases. However, the development and testing of new antibiotics is associated with a high number of animal experiments.MethodsA symmetrical parametrized lung test rig allowing the exposure of air-passage surfaces to antibiotics was designed and tested to demonstrate proof-of-principle with aerosols containing allicin, which is an antimicrobial natural product from garlic. An artificial lung surface is coated with bacteria embedded in a hydrogel and growth inhibition is visualized by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, that is reduced from colourless to the dark blue formazan in the presence of metabolically active, living cells. A nebulizer is used to generate the aerosols.FindingsThe results show that allicin has an antibiotic effect as an aerosol and that the deposition pattern of the active agent occurred mainly around the carinal regions.InterpretationThe model represents an integral system for continuous, spatial detection of aerosol deposition and allows the analysis of bacterial behaviour and the toxicity of the active agent. Thus, the deposition of antimicrobial aerosols on the bronchial surfaces is characterized in preliminary tests without any animal experiments.     

Bilateral multidirectional jumps with reactive jump-landings achieve osteogenic thresholds with and without instruction in premenopausal women

BackgroundCurrently jump-landing ground reaction forces have only been quantified in the vertical direction as a stimulus for bone development. This study quantified the full-spectrum of jump-landing force magnitudes (body weight's) and rates of strain (body weights per second) of bilateral multidirectional jumps (star jump and stride jump) with reactive jump-landings (i.e. jumping immediately after initial jump-landing) among premenopausal women. It was also of interest to quantify the influence of instruction on the magnitude and rate of the jump-landing ground reaction forces.MethodsTwenty-one women [Mean (SD): 43.3(5.9)yr; 69.4(9.6)kg; 167(5.5)cm; 27.5(8.7)% body fat] performed a jump testing session ‘with instruction’ followed by a jump testing session performed one week later with ‘instruction withdrawn’.FindingsThe resultant magnitudes (3.90 to 5.38, body weights) and rates of strain (192 to 329, body weights per second) for the jump-landings, performed on a force plate, exceeded previously determined osteogenic thresholds (>3body weight's and >43body weights per second, respectively). An instruction effect was observed for resultant (↑8% and ↑12%; P ≤ .01) and vertical (↑8% and ↑7%; P ≤ .01) ground reaction force's (Newtons and body weight, respectively) indicating learning/practice effects for these exercises. A jump-landing effect was observed, with larger peak rates of strain (↑29%; P < .0001, body weight per second) and peak forces (↑12% to ↑48%; P ≤ .01, body weights) for the second jump-landing (post-reactive jump).InterpretationThese multidirectional bilateral jumps represent a unique training stimulus for premenopausal women and achieve osteogenic thresholds thought pre-requisite for bone growth and could be utilized in the development of osteogenic exercise programs.     

延伸骨痂的骨化模式

在世界上曾经风迷一时的Ilizarov外固定方法因其较为安定的成绩,现在在骨科领域里已经成为规定的术式。然而在另一方面,人们对张压力效应和牵引性组织形成原理的理解程度,还有就其原理是否已被科学性地阐明都存有疑义。在此,根据多年来的动物实验结果以及文献的检索,就有关延伸骨痂的骨化模式的问题加以探讨。     

3D打印定位导航模板辅助置钉在脊柱畸形矫形术中的应用

目的 探讨3D打印定位导航模板辅助置钉在脊柱畸形矫形术中应用的可行性，并评估置钉的准确性与安全性。方法 回顾性分析2020年4月—2021年4月北京大学深圳医院收治的因脊柱畸形接受3D定位导航模板辅助置钉矫形术治疗的9例患者临床资料。通过术前规划确定钉道和螺钉尺寸，所有患者术中均使用3D打印定位导航模板辅助置钉，术后复查CT平扫及三维重建，采用Mobbs-Raley分级对螺钉位置进行评估，并分析置钉相关并发症发生情况。结果 所有手术顺利完成。共置入椎弓根螺钉118枚，其中34枚穿破椎弓根皮质，9枚穿破椎体外缘。0级螺钉75枚，1级螺钉24枚，2级螺钉19枚，置钉准确率为63.6%，置钉安全率为83.9%。所有患者均未发生神经、血管损伤等相关并发症，无患者行翻修手术。结论 3D打印定位导航模板辅助置钉在脊柱畸形矫形术中有良好的应用价值，置钉准确性和安全性较高。     

Inferior extended fixation utilizing porous titanium augments improves primary anti-rotational stability of the acetabular component

BackgroundThe primary anti-rotational stability is critical to preventing cup tilting failure following revision total hip arthroplasty, but is frequently compromised by severe ischial bone loss. A novel technique of “inferior extended fixation” was introduced by securing a porous metal augment into the deficient ischium. This study evaluated the effect of this technique on primary anti-rotational stability in revision total hip arthroplasty.MethodsComposite hemipelvis specimens, acetabular components and “lotus” augments were used to simulate total hip arthroplasty surgeries. Three different cementless operative settings of cup implantation were simulated: (1) native ischium without defects; (2) ischium with a defect not reconstructed; (3) ischial defect reconstructed with inferior extended fixation using a lotus augment. Lever-out testing was used to examine primary anti-rotational stability, which was measured as interface stiffness and yield moment.FindingsCompared with the native ischium setting, the mean interface stiffness decreased by 53.1% in the ischial defect setting (p < 0.001). In the inferior extended fixation setting, the mean value was 110% greater than that in the ischial defect setting (p = 0.014), and comparable to that in the native ischium setting (p = 1). Similar results were observed for the yield moment (declined by 63.1%, p < 0.001; 200% higher, p < 0.001; and p = 0.395; respectively).InterpretationIn revision total hip arthroplasty with severe ischial defects, inferior extended fixation with a lotus porous titanium augment restores anti-rotational stability of the acetabular component to the level of that with a native ischium, which provides the mechanical environment for bone ingrowth and prevents cup tilting failure.     

Ultrasound vibro-elastography for assessing mechanical properties of porcine reproductive tissues in an ex vivo model

BackgroundThe aim of this study was to use ultrasound vibro-elastography (UVE) for measuring surface wave speed and assessing mechanical properties of ex vivo porcine reproductive tissues, including the uterus, bladder, cornua and cervix.MethodsIn UVE, a 0.1-s harmonic vibration at low frequency was generated on the tissue surface with a handheld shaker. A linear-array ultrasound probe was used to measure the resulting surface wave propagation. Surface wave speeds of tissues were measured in the frequency range of 100–300 Hz. Mechanical properties of the tissue were calculated based on wave speed dispersion with frequency.FindingsThe obtained results showed that the surface wave speeds of porcine bladder, cervix, cornua and uterus increased with frequency. There were no statistically significant differences in the wave speeds or mechanical properties among the porcine bladder, cervix, cornua and uterus.InterpretationExperimental data obtained in this study may be used as a reference to study in vivo surface wave speed or mechanical properties for porcine or human reproductive tissues.