单次化疗后荷瘤小鼠肿瘤细胞凋亡显像研究

目的探讨活体肿瘤细胞凋亡监测作为评价肿瘤对化疗反应的一种新方法的可行性.方法细胞凋亡分子探针99Tcm-HYNIC-Annexin Ⅴ经化学和放射化学合成获得.20～25 g昆明种小白鼠右前腋下皮下组织接种S-180肉瘤,建立荷肿瘤小鼠模型.荷瘤小鼠在环磷酰胺腹腔内给药化疗8 h、24 h、48 h、72 h后,分别尾静脉注射99Tcm-HYNIC-Annexin Ⅴ,1 h后进行单光子发射型计算机断层显像(SPECT)和体内生物分布测定,并与对照组进行比较.根据化疗后显像的最佳时间,给荷瘤小鼠尾静脉注射99Tcm-DTPA-HSA,测定体内各组织器官的血流分布情况.所有体内生物分布的实验结果应用SPSS 10.0统计学软件进行统计学分析.结果荷瘤小鼠在环磷酰胺腹腔内给药化疗后72 h进行SPECT显像时,肿瘤的显像效果最明显,且体内生物分布测定显示在化疗后72 h的肿瘤组织的放射性摄取值(1.87±0.58)最高,是对照组(1.18±0.128)的1.58倍(二者比较,P<0.05),与显像结果具有一致性.肿瘤/肌肉(T/M)放射性摄取率之比为5.83±0.799,肿瘤/血液(T/B)为1.03±0.258,与对照组比较均为P<0.05.化疗组和对照组的肿瘤组织对99Tcm-DTPA-HSA的摄取无明显差异(P>0.05).结论在进行单次环磷酰胺腹腔内给药化疗后72 h,荷瘤小鼠的肿瘤组织对 99Tcm-HYNIC-Annexin Ⅴ的摄取显著增加,细胞凋亡体内显像作为一种评价肿瘤对化疗反应的无创性的监测方法是有效、可行的.     

纽扣带袢钢板内固定治疗肩锁关节脱位短期临床分析

目的：分析肩锁关节脱位患者纽扣带袢钢板内固定治疗短期疗效。方法方便选取从2011年2月—2016年2月收治的60例肩锁关节脱位,随机分为对照组(30)与观察组(30),对照组采取锁骨钩钢板内固定,观察组采取纽扣带袢钢板内固定治疗,分析两组短期临床疗效。结果观察组优良率为96.67%,对照组为76.67%,观察组高于对照组(P﹤0.05)。并未发生喙突骨折、肩关节僵硬等并发症。结论采取纽扣带袢钢板内固定治疗肩锁关节脱位患者,短期疗效显著,该方法安全有效。     

不同种类固定矫治器在切牙排齐初始阶段的摩擦力对比研究

目的：比较4种不同类型固定矫治器在上颌切牙排齐初始阶段的动摩擦力和最大静摩擦力的变化。方法 Typodont模型上翻制上颌双侧侧切牙腭向水平3 mm异位的模型,随机分为4组,分别为A组（MDD）、B组（MBT ）、C组（Tip‐Edge）和D组（自锁）,每组5个样本。0.30 mm镍钛圆丝作为初始排齐弓丝,45℃恒温水浴30 min ,使用万能材料试验机对水浴前后各组模型进行动摩擦力和最大静摩擦力的测试并记录。结果4组矫治器水浴前最大静摩擦力和动摩擦力的力值排序为：D组＜ A 组＜C组＜B组,组间比较,差异有统计学意义（P＜0.05）。水浴后摩擦力降低率计算结果为：A组最小,D组最大,除B组与C组比较差异无统计学意义（ P＞0.05）外,其余各组间比较差异均有统计学意义（ P＜0.05）。结论 M DD矫治器在上颌切牙排齐初始阶段摩擦力较低,一定程度上影响牙齿排齐效果,其轻力矫治的特点有待进一步研究及临床验证。     

固定矫治与无托槽矫治治疗牙周病致前牙移位的疗效分析

目的分析和探讨固定矫治与无托槽矫治治疗牙周病致前牙移位的疗效。方法选取2012年3月至2019年3月在我院治疗的牙周病致前牙移位患者30例为研究对象,随机分为对照组和观察组,每组各15例。对照组采用固定矫治治疗,观察组采用无托槽矫治治疗,比较两组美观度、便捷性、语言功能及咀嚼功能评分、牙周指数、前牙覆盖距离、前牙覆深度。结果治疗后观察组美观度、便捷性、语言功能及咀嚼功能评分均高于对照组,差异有统计学意义(P0.05);治疗后观察组PLI、GI、SBI均低于对照组,差异有统计学意义(P0.05);矫治治疗后6个月、矫治结束时及保持3个月时,观察组前牙覆盖距离均低于对照组,差异有统计学意义(P0.05);矫治治疗后1个月、6个月、矫治结束时及保持3个月时,观察组前牙覆深度均低于对照组,差异有统计学意义(P0.05)。结论无托槽矫治治疗牙周病致前牙移位的疗效更佳,值得推广。     

Surgical correction of dorsally angulated distal radius malunions with fixed angle volar plating: a case series

PURPOSE: To report our experience using a fixed-angle volar plate in conjunction with a corrective osteotomy and cancellous bone graft for the treatment of distal radius malunions with dorsal angulation in 4 patients. METHODS: Four consecutive patients had a volarly based opening wedge osteotomy with a fixed angle volar plate and cancellous bone grafting for the treatment of a dorsally angulated distal radius malunion. Data collected retrospectively included a visual analog pain scale, grip strength, range of motion, radiographic parameters, and each patient's subjective functional outcomes as measured by the Disabilities of the Arm, Shoulder, and Hand questionnaire. Motion, strength, and radiographic values were compared with the contralateral arm for each patient. RESULTS: The average time from initial fracture to corrective osteotomy was 346 days. The average length of follow-up evaluation was 13.5 months. The flexion-extension arc of motion increased an average of 21 degrees to a value of 84% of the contralateral side; the pronation-supination arc of motion increased an average of 20 degrees to a value of 98% of the contralateral side. The average tilt of the radius improved from 26 degrees extension to 2 degrees extension; the average radial inclination improved from 22 degrees to 24 degrees; the average ulnar variance excluding the 1 patient who had a distal ulna resection improved from 5 mm to 1 mm. The average retrospective Disabilities of the Arm, Shoulder, and Hand score improved from 30 to 7; the average retrospective visual analog pain scale score improved from 4.5 to 1. The average grip strength increased from 20 to 29 kg, which corresponded to 73% of the contralateral extremity. CONCLUSIONS: The rigid characteristics of fixed angle volar plates can provide an alternative to the traditional techniques of distal radius osteotomy including structural bone grafting and dorsal plate fixation or external fixation. In addition these plates are strong enough to allow for early postoperative motion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

Volar fixed-angle plating of distal radius extension fractures: influence of plate position on secondary loss of reduction--a biomechanic study in a cadaveric model

PURPOSE: Treatment of extension fractures of the distal radius with volar fixed-angle plates has become increasingly popular in the past 2 years. It has been observed clinically that placement of the distal screws as close as possible to the subchondral zone is crucial to maintain radial length after surgery. The purposes of this study were (1) to evaluate radial shortening after plating with regard to plate position and (2) to evaluate whether plate position has an influence on the strength and rigidity of the plate-screw construct. METHODS: An extra-articular fracture (AO classification, A3) was created in 7 pairs of fresh-frozen human cadaver radiuses. The radiuses then were plated with a volar distal radius locking compression plate. Seven plates were applied subchondrally; 7 plates were applied 4.5 mm to 7.5 mm proximal to the subchondral zone. The specimens were loaded with 800-N loads for 2,000 cycles to evaluate radial shortening in the 2 groups. Each specimen then was loaded to failure. RESULTS: Radial shortening was significantly greater when the distal screws were placed proximal to the subchondral zone. The amount of shortening after cyclic loading correlated significantly with the distance the distal screws were placed from the subchondral zone. Rigidity of the plate systems was significantly higher in radiuses in which the distal screws were placed close to the subchondral zone. CONCLUSIONS: To maintain radial length after volar fixed-angle plating, placement of the distal screws as subchondral as possible is essential. The subchondral plate-screw-bone constructs showed significantly greater rigidity, indicating higher resistance to postoperative loads and displacement forces.     

Control design for magnetic suspension

Through proper design, it is possible to build an electromagnetic bearing system, using a ferromagnetic rotor, such that there exists an equilibrium position in the magnetostatic field which is unstable only in the axial direction. In order to achieve axial stability, a regulator may be employed to vary the current in the coils whenever the rotor is displaced from the equilibrium position. The idea is to vary the current in such a way that the resultant change in the magnetic, field produces a restoring force to the rotor. This study is devoted to an investigation of the relative merits of various control laws which could be implemented by the regulator. The rotor is to be maintained in the vicinity of the equilibrium point even if an external force is present which enters the system as an unknown but bounded function of the system state and time. Recent magnetic suspension systems have been designed using a regulator based on linear state variable feedback. It is shown here that asymptotic stability cannot be maintained for the system in the presence of an external force if linear feedback control is used. The effect of an unknown but bounded external force on the system is vividly demonstrated by using qualitative methods to find the boundary of the set reachable under this force. Linear state variable feedback can maintain partial controllability of the system to some neighbourhood of the equilibrium point provided a simple inequality relationship between the feedback parameters and the bounds on the external force is maintained. Finally, it is shown that a game theoretic approach may be used for a nonlinear regulator design which will result in an asymptotically stable system in the presence of an unknown but bounded external force.     

Steering controls for constrained controllability problems with application to magnetic suspension

A method is presented for determining a control which steers a system to a specified target when there are magnitude constraints on the control. The method is suitable for numerical computation since it only involves solving finite-dimensional optimization problems. The effectiveness of the technique is illustrated by applying it to the problem of suspending a ferromagnetic rotor in a magnetic field.     

Study of subcutaneous fat

The main goal of this article is to demonstrate that biochemically, metabolically, histologically, embryologically, and anatomically there are two totally different types of subcutaneous fat. This fact has clinical and surgical consequences including the concept of dynamic and surface anatomy.     

Centrally administered orexin A increases motivation for sweet pellets in rats

Rationale Centrally administered orexin A induces both feeding and locomotion in rats. Thus, the feeding response following orexin A administration may be secondary to general increases in activity rather than a specific motivation to eat. Objective The aim of the study is to determine whether orexin A increases the motivation to eat. Methods The effect of orexin A (0, 31.25, 62.5, 125, 250, and 500 pmol) on breakpoint was determined in male Sprague–Dawley rats with rostro-lateral hypothalamic cannulae under a progressive ratio of five schedule (PR5). The effect of orexin A (0, 31.25, 125, and 500 pmol) on pressing rate under a fixed ratio (20) schedule was obtained to analyze the time course of orexin-A-induced pressing. The effect of 24-h food deprivation on breakpoint under PR5 and the effect of orexin A (125 pmol) on free feeding (sweet pellets) and on open-field locomotor activity (0, 100, 500, and 1,000 pmol) were also tested. Results Orexin A significantly augmented free feeding of sweet pellets, open-field locomotor activity, rate of pressing (FR20 schedule), and breakpoint (PR5 schedule), although compared to 24-h deprivation, the effect of orexin A on breakpoint was mild. However, there was a differential dose response relationship and time course of stimulation between orexin A's effects on locomotion and lever pressing. Conclusion These data indicate that infusion of orexin A enhances free feeding by enhancing and possibly prolonging motivation to eat.