经皮椎体成形术对骨质疏松性胸腰椎骨折患者生物力学的影响研究

目的:探讨经皮椎体成形术对骨质疏松性胸腰椎骨折患者生物力学的影响。方法:选取9具冻存新鲜尸体的胸腰段脊柱开展研究,并应用随机数字表法分为观察组、对照1组和对照2组,每组各3具。观察组、对照1组均制作成骨质疏松性胸腰椎骨折模型,观察组经椎弓根注入含有对比剂的低粘度骨水泥,对照1组置入椎弓根螺钉内固定,分别于术前和术后测量两组椎体的主要生物力学指标(最大抗压强度、刚度、高度),对照2组则作为参照,仅测量一次,对三组生物力学指标检测结果进行统计分析。结果:观察组椎体术前的最大抗压强度、刚度、高度与对照1组比较差异无统计学意义(P0.05),但两组术前最大抗压强度、刚度较对照2组降低,而高度较对照2组升高(P0.05)。观察组和对照2组术后的最大抗压强度、刚度均较对照1组升高,高度较对照1组降低(P0.05),而观察组术后的最大抗压强度、刚度、高度与对照2组比较差异无统计学意义(P0.05)。结论:应用经皮椎体成形术对骨质疏松性腰椎骨折患者实施治疗,能够有效恢复患者椎体生物力学,效果确切。     

经皮椎体成形术对老年骨质疏松性胸腰椎压缩骨折患者血清MMP-3、TIMP-1、IL-6及疗效的影响

目的:探讨经皮椎体成形术对老年骨质疏松性胸腰椎压缩骨折患者血清基质金属蛋白酶-3(MMP-3)、基质金属蛋白酶抑制因子-1(TIMP-1)、白细胞介素-6(IL-6)及疗效的影响。方法:选择60例2016年10月到2017年3月我院接诊的老年骨质疏松性胸腰椎压缩骨折患者,依照随机数表法分为实验组和对照组,每组30例,在都给予常规药物治疗的基础上,对照组给予复位枕垫和康复训练治疗,实验组采用经皮椎体成形术治疗。结果:治疗前,两组血清MMP-3、TIMP-1、IL-6水平无差异(P0.05);治疗后,两组血清MMP-3、IL-6水平均降低,实验组下降幅度更大,两组血清TIMP-1水平均升高,实验组上升幅度更大(P0.05);治疗前,两组患者VAS评分无差异(P0.05),治疗1周及治疗后,实验组患者VAS评分均低于对照组(P0.05);治疗前,两组患者Cobb角无差异(P0.05),治疗后,两组患者Cobb均明显下降,实验组较对照组下降更大(P0.05);治疗前,两组患者伤椎高度比无差异(P0.05),治疗后,两组伤椎高度比明显下降,实验组低于对照组(P0.05);治疗后,实验组有效率96.67%大于对照组的76.67%,差异显著(P0.05)。结论:经皮椎体成形术能有效降低患者血清MMP-3、IL-6水平,恢复TIMP-1水平,能显著提高治疗老年骨质疏松性胸腰椎压缩骨折的疗效     

Intrinsic disorder accelerates dissociation rather than association

The intrinsically disordered protein (IDP) has distinct properties both physically and biologically: it often becomes folded when binding to the target and is frequently involved in signal transduction. The physical property seems to be compatible with the biological property where fast association and dissociation between IDP and the target are required. While fast association has been well studied, fueled by the fly‐casting mechanism, the dissociation kinetics has received less attention. We here study how the intrinsic disorder affects the dissociation kinetics, as well as the association kinetics, paying attention to the interaction strength at the binding site (i.e., the quality of the “fly lure”). Coarse‐grained molecular dynamics simulation of the pKID‐KIX system, a well‐studied IDP system, shows that the association rate becomes larger as the disorder‐inducing flexibility that was imparted to the model is increased, but the acceleration is marginal and turns into deceleration as the quality of the fly lure is worsened. In contrast, the dissociation rate is greatly enhanced as the disorder is increased, indicating that intrinsic disorder serves for rapid signal switching more effectively through dissociation than association. Proteins 2016; 84:1124–1133. © 2016 Wiley Periodicals, Inc.     

Biomechanical assessment and clinical analysis of different intramedullary nailing systems for oblique fractures

The aim of this study is to evaluate the fracture union or non-union for a specific patient that presented oblique fractures in tibia and fibula, using a mechanistic-based bone healing model. Normally, this kind of fractures can be treated through an intramedullary nail using two possible configurations that depends on the mechanical stabilisation: static and dynamic. Both cases are simulated under different fracture geometries in order to understand the effect of the mechanical stabilisation on the fracture healing outcome. The results of both simulations are in good agreement with previous clinical experience. From the results, it is demonstrated that the dynamization of the fracture improves healing in comparison with a static or rigid fixation of the fracture. This work shows the versatility and potential of a mechanistic-based bone healing model to predict the final outcome (union, non-union, delayed union) of realistic 3D fractures where even more than one bone is involved.     

微创经皮钢板接骨术与Henry入路钢板内固定治疗桡骨远端骨折的疗效观察

目的:研究微创经皮钢板接骨术与Henry入路钢板内固定治疗桡骨远端骨折的疗效。方法:选取2013年2月到2014年2月我院收治的桡骨远端骨折患者86例,按照随机数字表法将患者分为Ⅰ组和Ⅱ组,每组43例,Ⅰ组患者给予微创经皮钢板接骨术治疗,Ⅱ组患者给予Henry入路钢板内固定治疗,术后随访患者1年,比较两组临床疗效。结果:Ⅰ组手术时间、术中出血量显著优于Ⅱ组,两组比较差异具有统计学意义(P0.05);Ⅰ组术后1年DASH评分显著优于Ⅱ组,两组比较差异具有统计学意义(P0.05);两组并发症比较无统计学意义(P0.05)。结论:微创经皮钢板接骨术治疗桡骨远端骨折具有较好的临床疗效,能缩短手术时间、降低术中出血量,改善患者上肢功能。     

胫骨螺旋形骨折合并后踝骨折与单纯踝关节骨折的区别

目的:比较后踝骨折两种不同类型的临床区别,为后踝骨折的临床诊治提供借鉴参考依据。方法:选取2010年1月-2013年1月我院收治的成人胫腓骨骨干骨折和单纯踝关节骨折患者3578例为研究对象,对两种骨折患者的后踝骨折发生率、后踝骨折合并外踝骨折的发生率等进行比较分析。结果:(1)TAF患者的后踝骨折发生率高于单纯踝关节骨折患者的后踝骨折发生率,差异具有统计学意义(P0.05);(2)TSPMF患者的外踝骨折发生率低于单纯后踝关节骨折的外踝骨折发生率,差异具有统计学意义(P0.05)。结论:胫骨螺旋形骨折与单纯踝关节骨折存在一定程度的差异,临床实践中应针对两种骨折的临床特点实施有针对性的治疗方案。     

Variation of folded polypeptide surface area with probe size

Three types of polypeptide surface area (contact, accessible, and molecular) have been studied as a function of the radius of a probe sphere used to map the surface. The surfaces are: (1) three alpha-helices, the H-helix of myoglobin, the E-helix of leghemoglobin, and an artificial polyalanine helix, each with 26 residues; (2) two globins, myoglobin and leghemoglobin, each with 153 residues; and (3) a two-center model system for which the three types of surface area have been calculated analytically. The two globin helices have almost identical surface areas as a function of probe size as do the two globins. The polyalanine helix surface area is smaller but similar in shape to the globin helix areas. All three helix contact areas tend to the same limit as the probe size increases, and the globin contact areas behave similarly. Fractal dimensions were calculated for the helix and globin contact and molecular surfaces. All fractal dimensions showed strong dependence on probe size. The contact fractal dimension peaks at larger values for both the helices and globins. Most residues do not make contact with large probes (15 A).     

The basal body-root complex ofChlamydomonas reinhardtii during mitosis

Summary The results of this work clarify several structural and temporal aspects of biogenesis of the basal body-root complex inChlamydomonas reinhardtii. The two phases of basal body development (probasal body assembly and conversion of probasal body into mature basal body) occur at identical mitotic stages in successive mitoses during multiple fission, which indicates a tight coupling between basal body development and the mitotic cycle. The two steps of basal body development are separated from one another in time,i.e. immature probasal bodies originate during an interval lasting ca. 5 min between mid-metaphase and early telophase, but mature after a quasi-dormant period only during early prophase of the next mitotic round. The duration of the dormant period depends on the interval between two mitoses: during synchronized vegetative growth there is an interval of ca. 20 h (interphase growth) between two rounds of multiple fissions, but only a maximum interval of 1.5 h between the successive mitoses of one round of multiple fissions.The microtubular root system, which is bisected at the same time as the basal body apparatus in a plane perpendicular to the distal connecting fiber during prophase, and whose roots seem to be reduced in length, starts duplication at early metaphase with the successive origin of two short bud-like partner roots just opposite the remnants. These initial roots elongate during subsequent phases by unilateral and radial growth from the basal bodies and along the cell's periphery, but exactly where they terminate is not known. The two-stranded roots opposite each other appear to be again connected as early as anaphase.The striation pattern of the distal connecting fiber is lost during early prophase thus indicating a partial breakdown of the fiber.Dedicated to Prof. Dr. C.-G. Arnold (Erlangen) on the occasion of his 60th birthday.     

Host plant finding in phytophagous insects: the case of the Colorado potato beetle

A short critical review is given on the literature of host plant finding in phytophagous insects with main emphasis on the Colorado potato beetle (Leptinotarsa decemlineata Say, col.: Chrysomelidae). The literature data are compared with the results of field experiments: (1) the foraging behaviour of adults was observed in a field arena on bare ground, and (2) adults were released in closed plant stands and recaptured by potted potato plants. It is concluded that host plant finding is a chance event in this species. The observed high directionality of move must be an adaptation increasing probability of host finding. Implications on population dynamics and agricultural practice are discussed.