Stereological study of the developing distal femoral growth plate

The distal femoral growth plate has a uniquely convoluted structure comprised of four mammillate processes. Factors contributing to the development of these processes and overall plate geometry were explored using three-dimensional image analysis of the canine distal femoral epiphysis. The growth plate at birth remains relatively flat until ossification of the epiphysis begins at 1 week of age. Epiphyseal ossification proceeds eccentrically, projecting in the medial-lateral and anterior-posterior directions. Growth plate activity indexed by [3H]thymidine labeling and plate thickness revealed regional differences in cell proliferation. This was measured as a decreased labeling index and thinning of the growth plate in areas capped by the ossifying epiphysis. The eccentric ossification pattern and associated variations in growth plate activity result in definition of an "intraphyseal" groove and medial-lateral oriented sulcus. The groove and sulcus bisect the plate into four quadrants, giving rise to a convoluted structure composed of four areas of plate elevations termed mammillary processes (MP). By 5 weeks, the pattern of ossification results in greater development of the MP in the anterior-medial quadrant and in decreasing order, in the posterior-medial, anterior, and posterior-lateral quadrants. By 10 weeks, a uniform rate of cell proliferation was observed coincident with completion of ossification of the epiphysis. The data suggest that localized variations in growth plate proliferation are associated with ossification of the epiphysis.(ABSTRACT TRUNCATED AT 250 WORDS)     

AO肩锁钢板钩治疗重型肩锁关节脱位

目的评估AO肩锁钢板钩治疗重型肩锁关节脱位的手术疗效.方法回顾性分析两年来27例手术病人的手术治疗和疗效.结果手术方法符合生理结构,手术时间平均30分钟,内固定牢靠.根据Murley和Constant[1]评分,优良率94%.结论 AO肩锁钢板钩治疗重型肩锁关节脱位,手术方法简单,疗效可靠,允许病人术后早期功能锻炼.     

单钉——沟槽柱翼钢板的生物力学实验研究

作者自行研究设计的单钉－沟槽柱翼钢板复位固定治疗腰椎滑脱症。预先采用６具成人尸体的Ｌ３－Ｓ３骨骼做成椎弓崩裂并滑脱模型，采用临床Ｉ型手术方法进行了复位固定，在每片钢板上粘贴６片电阻应变片，进行中心和偏心加载试验，同时进行了弯矩和扭矩试验，在５８６微机上进行了线性回归分析，求出了线性方程及线性相关系数ｒ，中心和偏心加载达到９００Ｎ未出现钢板松动，扭矩和弯矩在８３３Ｎ；ｃｍ和６６６．４Ｎ．ｃｍ以内左右     

System for inducible expression of cre-recombinase from the Foxa2 locus in endoderm, notochord, and floor plate.

We targeted the reverse tetracycline controlled transactivator (rtTA) to the Foxa2 locus (Foxa2(ITA)) to generate a system for regulating Cre-recombinase activity within Foxa2 expression domains, including the endoderm, notochord, and floor plate of early mouse embryos. The use of an internal ribosomal entry site to obtain rtTA expression preserves Foxa2 function of the targeted allele. Cre activity with this system reflects the level of endogenous Foxa2 activity and is also tightly controlled by doxycycline. The location of Cre activity within the broader Foxa2 expression domain can be restricted by altering the timing of doxycycline administration. Isolated floor plate expression can be obtained in this manner. This system will provide a useful tool for manipulating gene expression in endoderm, notochord, and floor plate, all of which are tissues with important structural and patterning functions during embryogenesis.     

Fluid Flow through Filtering Appendages of Insects

Many organisms use structures composed of arrays of cylindersto capture particulate food or molecules form the water or airaround them. The performance of such filters depends on thevelocity of fluid movement through them; hence, mathematicalmodels of flow through fibrous structures can provide insightsabout the functional morphology of biological filters. In thispaper, the authors address the case of feather-like biologicalfilters of finite width and assess several possible models forfluid motion through them by comparing model predictions withobservational data. Two examples of insect appendages are considered:the cephalic fans of black fly aquatic larvae that capture particulatefood and the antennae of adult male moths that catch sex-attractantmolecules released by female moths. The results suggest thatflow through such structures can be much slower than ambientcurrents, that the finest hairs in the structure are the morphologicalfeatures with the greatest effect on leakiness, and that thevelocity of movement (or of ambient flow), as well as the morphologyof such filters, can be critical in determining their performance.     

骨骺牵张与骨骺板的生物力学性质

本研究是对新西兰幼兔股骨远端骨骺进行体内和体外牵张实验.16只兔右股骨经5～10N力每3天一次牵张.4周后的股骨长度值明显大于左侧和0N组.形态学变化是受牵张的骺板增厚,软骨细胞增殖且无骨骺分离骨折.体外骺板抗断裂测试显示夸张后的骺板强度不低于未经牵张的对照侧.8只动物16根股骨于体外接受20～100N力的牵张,其骺板的塑性变形度随牵张力值的增高而增大,抗断裂强度亦不低于未经牵张的骨骺.这些结果表明适量的牵张力和/或低牵张速率是实现“软骨分离”或骨延长的关键.     

An integrative approach to CTL epitope prediction: a combined algorithm integrating MHC class I binding, TAP transport efficiency, and proteasomal cleavage predictions

Reverse immunogenetic approaches attempt to optimize the selection of candidate epitopes, and thus minimize the experimental effort needed to identify new epitopes. When predicting cytotoxic T cell epitopes, the main focus has been on the highly specific MHC class I binding event. Methods have also been developed for predicting the antigen-processing steps preceding MHC class I binding, including proteasomal cleavage and transporter associated with antigen processing (TAP) transport efficiency. Here, we use a dataset obtained from the SYFPEITHI database to show that a method integrating predictions of MHC class I binding affinity, TAP transport efficiency, and C-terminal proteasomal cleavage outperforms any of the individual methods. Using an independent evaluation dataset of HIV epitopes from the Los Alamos database, the validity of the integrated method is confirmed. The performance of the integrated method is found to be significantly higher than that of the two publicly available prediction methods BIMAS and SYFPEITHI. To identify 85% of the epitopes in the HIV dataset, 9% and 10% of all possible nonamers in the HIV proteins must be tested when using the BIMAS and SYFPEITHI methods, respectively, for the selection of candidate epitopes. This number is reduced to 7% when using the integrated method. In practical terms, this means that the experimental effort needed to identify an epitope in a hypothetical protein with 85% probability is reduced by 20-30% when using the integrated method.The method is available at http://www.cbs.dtu.dk/services/NetCTL. Supplementary material is available at http://www.cbs.dtu.dk/suppl/immunology/CTL.php.     

人工肱骨头置换与肱骨近端锁定钢板治疗老年复杂肱骨近端骨折的近期临床疗效分析

[摘要] 目的 对比分析人工肱骨头置换术和肱骨近端锁定钢板治疗老年复杂肱骨近端骨折的近期疗效。方法 回顾性分析本院骨科2012年1月~2014年6月采用人工肱骨头置换术和肱骨近端锁定钢板治疗的老年（年龄>65岁）NeerⅢ、Ⅳ部分肱骨近端骨折患者54例，人工肱骨头置换治疗（置换组）30例，肱骨近端锁定钢板内固定治疗（内固定组）24例。比较分析两组手术时间、术中出血量、随访Neer评分及Constant-Murley评分来评定两组临床疗效。结果 两组随访时间相仿，平均随访时间为19.5个月（12~36个月）。内固定组手术时间（101±13）分钟，术中出血量（237.9±32.4）mL，Neer评分（82.5±3.2），Constant-Murley评分（71.7±5.0）；置换组手术时间（98±11）分钟，术中出血量（246.0±39.8）mL，Neer评分（82.9±4.5），Constant-Murley评分（73.5±5.0）。两组手术时间、术中出血量、随访Neer及Constant-Murley评分比较差异均无统计学意义（P＞0.05）。内固定组有1例出现肩关节半脱位，肱骨头置换组有2例出现肩关节半脱位，通过三角巾悬吊后关节脱位均得到纠正。有1例四部分骨折患者，行内固定术后出现内固定松动、肱骨头坏死，改行人工肱骨头置换术。结论 人工肱骨头置换术和肱骨近端锁定钢板治疗老年肱骨近端复杂骨折的近期临床疗效相似，对不可修复的肱骨近端骨折宜行肱骨头置换术。     

Neuromuscular function and mechanical efficiency of human leg extensor muscles during jumping exercises

The influence of prestretch amplitude on the mechanical efficiency was examined with 5 subjects, who performed 5 different series of vertical jumps, each of which differed with respect to the mechanics of the knee joint action during the prestretch (eccentric) phase of the contact on the floor. Electromyographic activity was recorded from the major extensor muscles during the entire work period of 1 min per series. In addition, expired air was collected during the test and recovery for determination of energy expenditure. Mechanical work was calculated from the vertical displacement of the body during the jumps. The results indicated that high net efficiency of 38.7% was observed in condition where amplitude of knee bending in eccentric phase was small. In large range motion the corresponding net efficiency was 30.1%. In jumps where no prestretching of extensor muscles ocurred the net efficiency was 19.7%. The high efficiency of small amplitude jumps was characterized by low myoelectrical activity of the leg extensor muscles during the positive (concentric) work phase. In addition, the small amplitude jumps had shorter transition time in the stretch-shortening cycle, high average eccentric force and high stretching speed. Therefore the results suggest that the restitution of elastic energy, which was also related to the length change and stiffness of the muscles during stretch, plays an important role in regulating the mechanical efficiency of work.     

珍珠散协同爱宝疗治疗重度宫颈糜烂的临床疗效与药物经济学研究

目的观察中药珍珠散协同爱宝疗浓缩液治疗重度官颈糜烂临床疗效和药物经济学效益。方法将有生育要求的Ⅲ度官颈糜烂患者111例随机分为治疗组和对照组，治疗组用中药珍珠散联合爱宝疗浓缩液治疗，对照组则单用爱宝疗浓缩液治疗，均每3d治疗一次。45d后，比较两组疗效、疗程及治疗费用。结果治疗组治愈率明显高于对照组（67．9％vs36．4％），差异有统计学意义（P〈0．05）。治疗组费用明显低于对照组[（371．6±138．4）vs（483．6±36．6）]元（P〈0．01）。治疗组治疗时间比对照组显著缩短[（32．4±12．1）vs（44．0±3．3）]d（P〈0．01）。治疗组中提前结束治疗患者多于对照组（35／56vs6／55，P〈0．05）。治疗组与对照组均未见副作用发生。结论珍珠散协同爱宝疗浓缩液治疗重度官颈糜烂疗效好，药物经济学效益高，值得临床推广。