赤峰兴隆沟遗址人类椎骨疾病的生物考古学研究

对赤峰兴隆沟遗址第一地点出土的人类椎骨上椎体的退行性关节病(DJD)和黄韧带骨化(OLF)进行了生物考古学研究,制订了这两种病症患病程度的分级记录标准,并对患病率和患病程度均值进行了统计分析。对两性的对比发现DJD的差异主要体现在男性颈椎患病较多而女性腰椎患病较多,OLF的主要差异则是男性胸椎患病率显著高于女性。通过与对比组的比较,发现兴隆沟组腰椎、颈椎DJD患病率相对较高,并再次验证了两性患病情况存在的明显差异;兴隆沟组OLF患病率与对比组也有显著差异。兴隆沟组的椎骨患病情况不一定与生业模式有关,只反映了脊柱承受负荷的情况,其差异暗示行为模式上的差异。建议开展其他方面研究以详细了解其行为模式,同时要重视建立统一的古病理研究标准的重要性。     

Inter- and intra-rater reliability of 3D kinematics during maximum mouth opening of asymptomatic subjects

Previous studies evaluated 3D human jaw movements using kinematic analysis systems during mouth opening, but information on the reliability of such measurements is still scarce. The purpose of this study was to analyze within- and between-session reliabilities, inter-rater reliability, standard error of measurement (SEM), minimum detectable change (MDC) and consistency of agreement across raters and sessions of 3D kinematic variables during maximum mouth opening (MMO). Thirty-six asymptomatic subjects from both genders were evaluated on two different days, five to seven days apart. Subjects performed three MMO movements while kinematic data were collected. Intraclass correlation coefficient (ICC), SEM and MDC were calculated for all variables, and Bland-Altman plots were constructed. Jaw radius and width were the most reproducible variables (ICC > 0.81) and demonstrated minor error. Incisor displacement during MMO and angular movements in the sagittal plane presented good reliability (ICC from 0.61 to 0.8) and small errors and, consequently, could be used in future studies with the same methodology and population. The variables with smaller amplitudes (condylar translations during mouth opening and closing and mandibular movements on the frontal and transversal planes) were less reliable (ICC < 0.61) and presented larger SEM and MDC. Although ICC, SEM and MDC showed less between-session reproducibility than within-session and inter-rater, the limits of agreement were larger in inter-rater comparisons. In future studies care must be taken with variables collected on different days and with mandibular movements in the frontal and transversal planes.     

山梨酸钾和D-异抗坏血酸钠联合作用HepG2细胞的生物学效应分析

该文研究食品添加剂联合作用人肝癌HepG2细胞后的多参数生物学指标,并探索可能存在的损伤机制。CCK-8法检测受试物山梨酸钾及D 异抗坏血酸钠0.13～ 2.00 g/L分别作用HepG2细胞24、48及72 h后的细胞增殖活力,显示山梨酸钾及D-异抗坏血酸钠均呈显著的时间、剂量依赖性的抑制HepG2细胞增殖,其24 h的IC50分别为1.35±0.11 g/L和1.58±0.17 g/L。高内涵分析结果表明,与单独组相比,联合组显著降低细胞数量和线粒体膜电位,增大细胞膜通透性及活性氧水平(P＜0.05);高剂量联合组(0.30+0.41 g/L)显著增加DNA损伤(P＜0.01),表现为协同作用。qRT-PCR和Western印迹法显示,山梨酸钾及D 异抗坏血酸钠可显著提高P53、Caspase 3、Bax、γ-H2AX表达,同时显著降低Bcl-2表达,从而抑制HepG2细胞增殖。     

Role of cartilage collagen fibrils networks in knee joint biomechanics under compression

Collagen fibrils networks in knee cartilage and menisci change in content and structure from a region to another. While resisting tension, they influence global joint response as well as local strains particularly at short-term periods. To investigate the role of fibrils networks in knee joint mechanics and in particular cartilage response, a novel model of the knee joint is developed that incorporates the cartilage and meniscus fibrils networks as well as depth-dependent properties in cartilage. The joint response under up to 2000 N compression is investigated for conditions simulating the absence in cartilage of deep fibrils normal to subchondral bone or superficial fibrils parallel to surface as well as localized split of cartilage at subchondral junction or localized damage to superficial fibrils at loaded areas. Deep vertical fibrils network in cartilage play a crucial role in stiffening (by 10%) global response and protecting cartilage by reducing large strains (from maximum of 102% to 38%), in particular at subchondral junction. Superficial horizontal fibrils protect the tissue mainly from excessive strains at superficial layers (from 27% to 8%). Local cartilage split at base disrupts the normal function of vertical fibrils at the affected areas resulting in higher strains.Deep fibrils, and to a lesser extent superficial fibrils, play dominant mechanical roles in cartilage response under transient compression. Any treatment modality attempting to repair or regenerate cartilage defects involving partial or full thickness osteochondral grafts should account for the crucial role of collagen fibrils networks and the demanding mechanical environment of the tissue.     

Assessing cranial plasticity in humans: The impact of artificial deformation on masticatory and basicranial structures

Artificial cranial deformations (ACD) are a widespread cultural practice found in numerous historical and prehistoric contexts. Their study can yield valuable insight into craniofacial growth, specifically into the interactions between neurocranial and basicranial modules. This study seeks to reinvestigate the presumed effect of ACD on basicranial and masticatory elements by applying a 3D geometric morphometric approach to CT scans. A total of 51 French and Bolivian skulls, representing anteroposterior and circumferential deformations and including undeformed individuals, were scanned, and 3D landmarks were submitted to between-group principal components analysis and two-block partial least-squares analysis. Our results illustrate changes in basicranial shape and in cranial base angles induced by ACD, as well as in masticatory geometry, namely in the relative position of the mandibular fossae. Furthermore, our findings highlight differential effects of the various deformation types, which suggest that patterns of covariation between modified vaults and their associated basicrania are more complex than previously assumed, thereby stressing the degree of plasticity in human craniofacial growth.     

带线锚钉修复三角韧带损伤的效果及对患者踝关节功能的影响

目的:研究带线锚钉修复三角韧带损伤在踝关节骨折内固定治疗中的作用及对踝关节功能的影响。方法:回顾性分析2012年9月至2016年8月本院收治的72例裸关节骨折并三角韧带损伤患者并且行切开复位钢板置入内固定,及采取带线锚钉内固定方式修复三角韧带损伤视为观察组;另选取同期在本院进行踝关节骨折内固定治疗但不修复三角韧带的72例患者视为对照组。分析患者治疗前、治疗后1个月、3个月、6个月踝关节功能恢复情况,观察患侧内踝间隙和不良反应。结果:观察组在治疗后1个月、3个月、6个月的AOFAS评分显著高于对照组(P0.05)。观察组在治疗后6个月后的患侧内踝间隙显著小于对照组(P0.05)。结论:带线锚钉修复三角韧带损伤在踝关节骨折内固定治疗中,可明显降低患侧内踝间隙距离,可促进患者踝关节功能恢复,无严重不良反应,值得进一步广泛推广使用。     

水平基因转移介导抗菌素耐药性传播机制的研究进展

近几十年来,病原菌耐药性的出现和蔓延已上升为严峻的公共卫生问题。越来越多研究表明,抗菌素抗性基因(antibiotic resistance genes,ARGs)不仅仅见于临床所分离的病原体,而是包括所有的致病菌、共生菌以及环境中的细菌,它们都能在可移动遗传元件和噬菌体的作用下,通过水平基因转移(horizontal gene transfer,HGT)途径获得耐药性,进而形成抗菌素耐药基因簇(耐药基因组)。HGT可导致抗菌素的耐药性在环境共生菌和病原菌之间传播扩散,这可通过临床上一些重要的抗菌素耐药基因的传播证实。传统观念认为HGT的三种机制中,接合对ARGs的传播影响最大,最近研究表明转化和转导对ARGs播散起到不可忽视的作用。通过深入了解耐药基因组的传播及其在动员病原菌耐药中发挥的作用,对于控制这些基因的播散是至关重要的。将讨论耐药基因组的概念,提供临床相关的抗菌素抗性基因水平基因转移的例子,对当前已研究的促使抗菌素耐药性传播的各种HGT机制进行回顾。     

The efficacy of a video-based marker-less tracking system for gait analysis

Most clinical gait analyses are conducted using motion capture systems which track retro-reflective markers that are placed on key landmarks of the participants. An alternative to a three-dimensional (3D) motion capture, marker-based, optical camera system may be a marker-less video-based tracking system. The aim of our study was to investigate the efficacy of the use of a marker-less tracking system in the calculation of 3D joint angles for possible use in clinical gait analysis. Ten participants walked and jogged on a treadmill and their kinematic data were captured with a marker and marker-less tracking system simultaneously. The hip, knee and ankle angles in the frontal, sagittal and transverse planes were computed. Root Mean Square differences (RMS_diff) between corresponding angles for each participant’s support phase were calculated and averaged to derive the mean within-subject RMS_diff. These within-subject means were averaged to obtain the mean between-subject RMS_diff for the relevant joint angles in the two gait conditions (walking and jogging). The RMS_diff between the two tracking systems was less than 1° for all rotations of the three joint angles of the hip and knee. However, there were slightly larger differences in the ankle joint angles. The results of this study suggest a potential application in gait analysis in clinical settings where observations of anatomical motions may provide meaningful feedback.     

Evaluation of free or anchored antimicrobial peptides as candidates for the prevention of orthopaedic device‐related infections

The prevention of implant‐associated infection, one the most feared complications in orthopaedic surgery, remains a major clinical challenge and urges development of effective methods to prevent bacterial colonization of implanted devices. Alpha‐helical antimicrobial peptides (AMPs) may be promising candidates in this respect due to their potent and broad‐spectrum antimicrobial activity, their low tendency to elicit resistance and possible retention of efficacy in the immobilized state. The aim of this study was to evaluate the potential of five different helical AMPs, the cathelicidins BMAP‐27 and BMAP‐28, their (1–18) fragments and the rationally designed, artificial P19(9/G7) peptide, for the prevention of orthopaedic implant infections. Peptides were effective at micromolar concentrations against 22 Staphylococcus and Streptococcus isolates from orthopaedic infections, while only BMAP‐28 and to a lesser extent BMAP‐27 were active against Enterococcus faecalis. Peptides in solution showed activities comparable to those of cefazolin and linezolid, on a molar basis, and also a variable capacity to neutralize bacterial lipopolysaccharide, while devoid of adverse effects on MG‐63 osteoblast cells at concentrations corresponding to the MIC. The (1–18) BMAP fragments and P19(9/G7) were selected for further examination, based on better selectivity indices, and showed effectiveness in the presence of hyaluronic acid and in synovial fluid, while human serum affected their activity to variable extents, with BMAP‐27(1–18) best retaining activity. This peptide was immobilized on streptavidin–resin beads and retained activity against reference Staphylococcus epidermidis and Staphylococcus aureus strains, with negligible toxicity towards osteoblasts, underlining its potential for the development of infection‐resistant biomaterials for orthopaedic application. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.