• 【人髌骨血流变化的无创连续估计。】 复制标题 收藏 收藏
    DOI:10.1007/s11517-006-0070-0 复制DOI
    作者列表:Näslund J,Pettersson J,Lundeberg T,Linnarsson D,Lindberg LG
    BACKGROUND & AIMS: :A photoplethysmographic (PPG) technique to assess blood flow in bone tissue has been developed and tested. The signal detected by the PPG consists of a constant-level (DC) component-which is related to the relative vascularization of the tissue-and a pulsatile (AC) component-which is synchronous with the pumping action of the heart. The PPG probe was applied on the skin over the patella. The probe uses near-infrared (804 nm) and green (560 nm) light sources and the AC component of the PPG signals of the two wavelengths was used to monitor pulsatile blood flow in the patellar bone and the overlying skin, respectively. Twenty healthy subjects were studied and arterial occlusion resulted in elimination of PPG signals at both wavelengths, whereas occlusion of skin blood flow by local surface pressure eliminated only the PPG signal at 560 nm. In a parallel study on a physical model with a rigid tube we showed that the AC component of the PPG signal originates from pulsations of blood flow in a rigid structure and not necessarily from volume pulsations. We conclude that pulsatile blood flow in the patellar bone can be assessed with the present PPG technique.
    背景与目标: : 已经开发并测试了一种用于评估骨组织血流的光电容积描记 (PPG) 技术。PPG检测到的信号由恒定水平 (DC) 分量 (与组织的相对血管化有关) 和脉动 (AC) 分量组成,该分量与心脏的泵送动作同步。将PPG探针涂在髌骨上的皮肤上。探针使用近红外 (804 nm) 和绿色 (560 nm) 光源,并且两个波长的PPG信号的AC分量分别用于监测髌骨和上覆皮肤中的脉动血流。研究了20名健康受试者,动脉闭塞导致消除了两个波长处的PPG信号,而局部表面压力对皮肤血流的闭塞仅消除了560 nm处的PPG信号。在对具有刚性管的物理模型的并行研究中,我们表明PPG信号的AC分量来自刚性结构中的血流脉动,而不一定来自体积脉动。我们得出的结论是,可以使用目前的PPG技术评估pa骨中的脉动血流。
  • 【[中耳和岩骨继发性胆脂瘤的计算机断层扫描方面]。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Vasdev A,Boubagra K,Lavieille JP,Bessou P,Lefournier V
    BACKGROUND & AIMS: The authors present their experience of secondary cholesteatomas of the middle ear explored by computerized tomography (CT). Following a brief anatomicopathological description of secondary petrous bone cholesteatomas, and of the CT technique used for their exploration, they describe and illustrate the classical "bag-shaped" internal or external attical forms usually extended to the antrum and the mastoid process, and the less common locations often due to relapse or postoperative recurrences (anterior hypotympanic or posterior mastoidal). The holotympanic forms, usually due to "lamellar" cholesteatomas, create diagnostic problems with other opacities in the cavity, as also do certain forms that are evacuated spontaneously or by aspiration. One of the qualities of CT lies in the preoperative extension assessment. The lesion may extend towards the internal wall of the cavity (lateral semicircular canal, second portion of the facial nerve), towards the labyrinth to the petrosal apex and/or the geniculate ganglion, and above all towards the inferior labyrinth which might bring the cholesteatoma into contact with large vessels (e.g. jugular vein bulb for postero-inferior extensions, carotid canal for antero-inferior extensions). Extension into anfractuosities of the cavity walls (sinus tympani, subratubal fossette) must be systematically looked for in order to avoid postoperative recurrences.

    背景与目标: 作者介绍了通过计算机断层扫描 (CT) 探索的中耳继发性胆脂瘤的经验。在对继发性岩骨胆脂瘤以及用于其探索的CT技术进行了简要的解剖学病理学描述之后,他们描述并说明了通常扩展到胃窦和乳突过程的经典 “袋状” 内部或外部形态,较不常见的位置通常是由于复发或术后复发 (前低潮或后乳突)。通常由于 “层状” 胆脂瘤引起的全鼓形式,会在腔内产生其他混浊的诊断问题,以及自发或通过抽吸抽空的某些形式。CT的质量之一在于术前扩展评估。病变可以向腔的内壁 (外侧半规管,面神经的第二部分) 延伸,向迷宫延伸到岩骨尖和/或膝状神经节,最重要的是走向下迷宫,这可能会使胆脂瘤与大血管接触 (例如颈静脉球用于后下方延伸,颈动脉管用于前下方延伸)。为了避免术后复发,必须系统地寻找延伸到腔壁的骨折 (鼓室窦,支气管下窝)。
  • 【骨髓衰竭综合征中的染色体不稳定性。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Babu Rao V,Colah RB
    BACKGROUND & AIMS: -2
    背景与目标: -2
  • 【骨髓嵌合体小鼠肿瘤浸润基质细胞的制备及功能分析。】 复制标题 收藏 收藏
    DOI:10.1111/j.1348-0421.2006.tb03830.x 复制DOI
    作者列表:Ishigaki H,Yamamoto Y,Ishida H,Kajino K,Itoh Y,Fujiyama Y,Ogasawara K
    BACKGROUND & AIMS: :Tumor-infiltrating stroma cells (TISC) as well as tumors themselves are thought to be involved in tumor-related immunosuppression, which is one of the critical mechanisms of tumor escape from immune surveillance. However, preparation of TISC is difficult because of the small proportion of TISC in established tumors. Thus, the cells thought to be involved in tumor-related immunosuppression are generally prepared from spleens or draining lymph nodes in tumor-bearing mice. In this study, we developed a method for directly preparing TISC from established tumors in order to analyze their function. Using green fluorescent protein (GFP) transgenic (Tg) mice and C57BL/6 mice transplanted with bone marrow (BM) cells of GFPTg mice, we detected three subpopulations of TISC: one is compatible with immature myeloid cells (ImC) derived from BM and the two other subpopulations, CD11b(+) cells and CD11b(-) cells, do not originate from BM. The TISC including these subpopulations but not each subpopulation independently after culturing with tumors in the presence of GM-CSF could suppress T cell proliferation induced by anti-CD3. In our system, tumors did not inhibit T cell responses directly, but unknown factors from tumors affected immunosuppression by TISC.
    背景与目标: : 肿瘤浸润的基质细胞 (TISC) 以及肿瘤本身被认为与肿瘤相关的免疫抑制有关,这是肿瘤逃避免疫监视的关键机制之一。然而,由于TISC在已建立的肿瘤中的比例较小,因此很难制备TISC。因此,被认为与肿瘤相关的免疫抑制有关的细胞通常是从荷瘤小鼠的脾脏或引流淋巴结中制备的。在这项研究中,我们开发了一种从已建立的肿瘤中直接制备TISC的方法,以分析其功能。使用绿色荧光蛋白 (GFP) 转基因 (Tg) 小鼠和C57BL/6小鼠移植了GFPTg小鼠的骨髓 (BM) 细胞,我们检测到了TISC的三个亚群: 一个与BM衍生的未成熟髓样细胞 (ImC) 相容,另外两个亚群,CD11b(+) 细胞和CD11b(-) 细胞不起源于BM。在gm-csf存在下用肿瘤培养后,包括这些亚群但不是每个亚群的TISC可以抑制anti-CD3诱导的T细胞增殖。在我们的系统中,肿瘤没有直接抑制T细胞反应,但是肿瘤的未知因素会影响TISC的免疫抑制。
  • 【骨髓来源的内皮细胞前体的生物学。】 复制标题 收藏 收藏
    DOI:10.1152/ajpheart.00662.2006 复制DOI
    作者列表:Schatteman GC,Dunnwald M,Jiao C
    BACKGROUND & AIMS: :Over the past decade, the old idea that the bone marrow contains endothelial cell precursors has become an area of renewed interest. While some still believe that there are no endothelial precursors in the blood, even among those who do, there is no consensus as to what they are or what they do. In this review, we describe the problems in identifying endothelial cells and conclude that expression of endothelial nitric oxide synthase may be the most reliable antigenic indicator of the phenotype. The evidence for two different classes of endothelial precursors is also presented. We suggest that, though there is no single endothelial cell precursor, we may be able to use these phenotypic variations to our advantage in better understanding their biology. We also discuss how a variety of genetic, epigenetic, and methodological differences can account for the seemingly contradictory findings on the physiological relevance of bone marrow-derived precursors in normal vascular maintenance and in response to injury. Data on the impact of tumor type and location on the contribution of bone marrow-derived cells to the tumor vasculature are also presented. These data provide hope that we may ultimately be able to predict those tumors in which bone marrow-derived cells will have a significant contribution and design therapies accordingly. Finally, factors that regulate bone marrow cell recruitment to and function in the endothelium are beginning to be identified, and several of these, including stromal derived factor 1, monocyte chemoattractant factor-1, and vascular endothelial growth factor are discussed.
    背景与目标: : 在过去的十年中,骨髓含有内皮细胞前体的旧观念已成为人们重新关注的领域。尽管有些人仍然认为血液中没有内皮前体,即使在那些内皮前体中也是如此,但对于它们是什么或它们做什么还没有共识。在这篇综述中,我们描述了鉴定内皮细胞的问题,并得出结论,内皮一氧化氮合酶的表达可能是表型最可靠的抗原指标。还提供了两种不同类型的内皮前体的证据。我们建议,尽管没有单个内皮细胞前体,但我们可能能够利用这些表型变异来更好地了解它们的生物学。我们还讨论了各种遗传,表观遗传和方法上的差异如何解释关于骨髓来源的前体在正常血管维持和对损伤的反应中的生理相关性的看似矛盾的发现。还提供了有关肿瘤类型和位置对骨髓来源细胞对肿瘤脉管系统贡献的影响的数据。这些数据提供了希望,我们最终可能能够预测那些骨髓来源的细胞将在其中做出重大贡献的肿瘤,并相应地设计治疗方法。最后,开始确定调节骨髓细胞对内皮的募集和功能的因素,并讨论了其中的几种因素,包括基质衍生因子1,单核细胞趋化因子1和血管内皮生长因子。
  • 【腰椎骨密度分布的纵向变化可能会增加楔形骨折的风险。】 复制标题 收藏 收藏
    DOI:10.1016/j.clinbiomech.2012.10.005 复制DOI
    作者列表:Giambini H,Khosla S,Nassr A,Zhao C,An KN
    BACKGROUND & AIMS: BACKGROUND:Trabecular bone strength diminishes as a result of osteoporosis and altered biomechanical loading at the vertebral and spinal levels. The spine consists of the anterior, middle and posterior columns and the load supported by the anterior and middle columns will differ across different regions of the spine. Stress shielding of the anterior column can contribute to bone loss and increase the risk of wedge fracture. There is a lack of quantitative data related to regional spinal bone mineral density distribution over time. We hypothesize that there is an increase in the posterior-to-anterior vertebral body bone mineral density ratio and a decrease in whole-body bone mineral density over time. METHODS:Bone mineral density was measured in 33 subjects using quantitative computed tomography scans for L1-L3 vertebrae, region (anterior and posterior vertebral body), and time (baseline and 6 years after). FINDINGS:Lumbar bone mineral density decreased significantly (Δ: ~15%) from baseline to the 6th year visit. Individual vertebra differences over time (L1: ~14%, L2: ~14%, L3: ~17%) showed statistical significance. Anterior bone mineral density change was significantly greater than in the posterior vertebral body region (Δ anterior: ~18%; Δ posterior: ~13%). Posterior-to-anterior bone mineral density ratio was significantly greater in the 6th year compared to baseline values (mean (SD), 1.33 (0.2) vs. 1.23 (0.1)). INTERPRETATION:This study provides longitudinal quantitative measurement of bone mineral density in vertebrae as well as regional changes in the anterior and posterior regions. Understanding bone mineral density distribution over time may help to decrease the risk of wedge fractures if interventions can be developed to bring spine loading to its normal state.
    背景与目标:
  • 【低水平激光治疗对链脲佐菌素诱导的糖尿病大鼠骨缺损愈合的影响: 组织学和形态计量学评估。】 复制标题 收藏 收藏
    DOI:10.1080/14764172.2017.1341048 复制DOI
    作者列表:Yildirimturk S,Sirin Y,Soluk Tekkesin M,Gurler G,Firat D
    BACKGROUND & AIMS: BACKGROUND:The aim of the present study was to evaluate the effects of low-level laser therapy (LLLT) on the healing of bone defects in rats with streptozotocin (STZ)-induced DM. METHODS:28 male Sprague-Dawley rats were used in this study. 14 animals received a single dose of STZ intraperitoneally (65 mg/kg) to induce Type I DM, whereas others were injected only with sterile saline solution. Four weeks later, standard bone defects were created in the tibiae of rats. Surgical wounds in one group from each of the diabetic and non-diabetic animals were irradiated with diode laser for every other day for 4 weeks and they were described as DM + LLLT and CONT + LLLT groups, respectively. Remaining two groups received no laser treatment. New bone formation, osteoblast and blood vessel counts were calculated in histologic sections. RESULTS:DM group had significantly smaller bone area and lower blood vessel count when compared to DM + LLLT, CONT and CONT + LLLT groups (p < 0.05 for each). CONT and CONT + LLLT groups had significantly larger bone area than DM + LLLT group (p < 0.05 for both). CONCLUSIONS:LLLT application promoted vascularization and new bone formation in animals with DM to a limited extent, since it was unable to support the healing process up to the level of non-diabetic animals.
    背景与目标:
  • 【骨的全基因组分析揭示了骨质疏松症和骨关节炎的差异甲基化区域。】 复制标题 收藏 收藏
    DOI:10.1002/art.37753 复制DOI
    作者列表:Delgado-Calle J,Fernández AF,Sainz J,Zarrabeitia MT,Sañudo C,García-Renedo R,Pérez-Núñez MI,García-Ibarbia C,Fraga MF,Riancho JA
    BACKGROUND & AIMS: OBJECTIVE:To determine genome-wide methylation profiles of bone from patients with hip osteoarthritis (OA) and those with osteoporotic (OP) hip fractures. METHODS:Trabecular bone pieces were obtained from the central part of the femoral head of 27 patients with hip fractures and 26 patients with hip OA. DNA was isolated, and methylation was explored with Illumina methylation arrays. RNA was extracted, pooled, and deep-sequenced to obtain the whole transcriptome. Differentially methylated regions were identified, and connections between genes with differentially methylated regions were explored by pathway and text-mining analyses. RESULTS:After quality control, methylation of 23,367 CpG sites (13,463 genes) was analyzed. There was a genome-wide inverse relationship between methylation and gene expression in both patient groups. Comparison of OP and OA bones revealed 241 CpG sites, located in 228 genes, with significant differences in methylation (false discovery rate<0.05). Of them, 217 were less methylated in OP than in OA. The absolute methylation differences were >5% in 128 CpG sites and >10% in 45 CpG sites. The differentially methylated genes were enriched for association with bone traits in the genome-wide association study catalog. Pathway analysis and text-mining analysis with Gene Relationships Across Implicated Loci software revealed enrichment in genes participating in glycoprotein metabolism or cell differentiation, and particularly in the homeobox superfamily of transcription factors. CONCLUSION:Genome-wide methylation profiling of bone samples revealed differentially methylated regions in OP and OA. These regions were enriched in genes associated with cell differentiation and skeletal embryogenesis, such as those in the homeobox superfamily, suggesting the existence of a developmental component in the predisposition to these disorders.
    背景与目标:
  • 【电刺激通过肝素生物激活的导电支架调节成骨细胞的增殖和骨蛋白的产生。】 复制标题 收藏 收藏
    DOI:10.1002/bem.21766 复制DOI
    作者列表:Meng S,Rouabhia M,Zhang Z
    BACKGROUND & AIMS: :Electrical fields are known to interact with human cells. This principle has been explored to regulate cellular activities for bone tissue regeneration. In this work, Saos-2 cells were cultured on conductive scaffolds made of biodegradable poly(L-lactide) and the heparin-containing, electrically conducting polypyrrole (PPy/HE) to study their reaction to electrical stimulation (ES) mediated through such scaffolds. Both the duration and intensity of ES enhanced cell proliferation, generating a unique electrical intensity and temporal "window" within which osteoblast proliferation was upmodulated in contrast to the downmodulation or ineffectiveness in other ES regions. The favourable ES intensity (200 mV/mm) was further investigated in terms of the gene activation and protein production of two important osteoblast markers characterised by extracellular matrix maturation and mineralisation, that is alkaline phosphatase (ALP) and osteocalcin (OC). Both genes were found activated and the relevant protein production increased significantly following ES. In contrast, ES in the down-modulation region (400 mV/mm) suppressed the production of both ALP and OC. This work demonstrated that important osteoblast markers can be modulated with specific ES parameters mediated through conductive polymer substrates, providing a unique strategy for bone tissue engineering.
    背景与目标: 已知电场与人类细胞相互作用。已探索此原理来调节骨组织再生的细胞活性。在这项工作中,将Saos-2细胞培养在由可生物降解的聚 (L-丙交酯) 和含肝素的导电聚吡咯 (PPy/HE) 制成的导电支架上,以研究它们对通过此类支架介导的电刺激 (ES) 的反应。ES的持续时间和强度都增强了细胞增殖,产生了独特的电强度和时间 “窗口”,与其他ES区域的下调或无效相反,在该窗口内对成骨细胞增殖进行了上调。进一步研究了有利的ES强度 (200  mV/mm),即两种重要的成骨细胞标志物的基因活化和蛋白质生产,其特征是细胞外基质成熟和矿化,即碱性磷酸酶 (ALP) 和骨钙素 (OC)。发现两个基因都被激活,并且在ES之后相关的蛋白质产量显着增加。相反,下调制区域 (400  mV/mm) 中的ES抑制了ALP和OC的产生。这项工作表明,重要的成骨细胞标志物可以通过导电聚合物底物介导的特定ES参数进行调节,为骨组织工程提供了独特的策略。
  • 【植入腹股沟下旁路移植物的球囊扩张支架的挤压变形。】 复制标题 收藏 收藏
    DOI:10.1177/1538574417714396 复制DOI
    作者列表:Ahmed N,El-Khoury R,Sabri MN,White JV,Jacobs CE,Schwartz LB
    BACKGROUND & AIMS: :A 59-year-old man with critical claudication underwent left femoro-anterior bypass grafting, which was uneventful. The graft was tunneled medially across the knee, then anterior to the tibia. His symptoms recurred 1 year later and he was found to have critical stenosis of the vein graft just proximal to the anterior tibial arterial anastomosis. This was treated with scaffolded balloon angioplasty and implantation of a coronary, zotarolimus-eluting balloon-expandable stent, which was also uneventful. However, his claudication again recurred 1 year later. Diagnostic angiography revealed crush, deformation and restenosis of the balloon-expandable stent requiring surgical revision of the bypass graft.
    背景与目标: : 一名59岁的严重跛行男子接受了左股骨前旁路移植术,手术顺利。移植物在膝盖内侧穿过隧道,然后在胫骨前。一年后,他的症状复发,发现他在胫骨前动脉吻合术附近有严重的静脉移植物狭窄。用支架球囊血管成形术和冠状动脉zotarolimus洗脱球囊扩张支架进行治疗,这也很顺利。然而,他的跛行在1年后再次复发。诊断性血管造影显示球囊扩张支架的挤压,变形和再狭窄,需要手术修复旁路移植物。
  • 【使用三次谐波产生显微镜对骨骼多尺度孔隙率和界面进行无标记成像。】 复制标题 收藏 收藏
    DOI:10.1038/s41598-017-03548-5 复制DOI
    作者列表:Genthial R,Beaurepaire E,Schanne-Klein MC,Peyrin F,Farlay D,Olivier C,Bala Y,Boivin G,Vial JC,Débarre D,Gourrier A
    BACKGROUND & AIMS: :Interfaces provide the structural basis of essential bone functions. In the hierarchical structure of bone tissue, heterogeneities such as porosity or boundaries are found at scales ranging from nanometers to millimeters, all of which contributing to macroscopic properties. To date, however, the complexity or limitations of currently used imaging methods restrict our understanding of this functional integration. Here we address this issue using label-free third-harmonic generation (THG) microscopy. We find that the porous lacuno-canalicular network (LCN), revealing the geometry of osteocytes in the bone matrix, can be directly visualized in 3D with submicron precision over millimetric fields of view compatible with histology. THG also reveals interfaces delineating volumes formed at successive remodeling stages. Finally, we show that the structure of the LCN can be analyzed in relation with that of the extracellular matrix and larger-scale structures by simultaneously recording THG and second-harmonic generation (SHG) signals relating to the collagen organization.
    背景与目标: : 接口提供了基本骨骼功能的结构基础。在骨组织的分层结构中,在从纳米到毫米的范围内发现了诸如孔隙率或边界之类的异质性,所有这些都有助于宏观特性。然而,迄今为止,当前使用的成像方法的复杂性或局限性限制了我们对这种功能集成的理解。在这里,我们使用无标签的三次谐波产生 (THG) 显微镜解决了这个问题。我们发现,多孔腔-小管网络 (LCN) 揭示了骨基质中骨细胞的几何形状,可以在与组织学兼容的毫米视野中以亚微米精度在3D中直接可视化。THG还揭示了描绘在连续重塑阶段形成的体积的界面。最后,我们表明,通过同时记录与胶原蛋白组织有关的THG和二次谐波产生 (SHG) 信号,可以分析LCN的结构与细胞外基质和较大规模的结构有关。
  • 【是否可以使用囊肿体积对髂嵴移植重建囊肿缺损后并发症的风险进行分层?】 复制标题 收藏 收藏
    DOI:10.1016/j.jcms.2017.05.010 复制DOI
    作者列表:Safi AF,Grandoch A,Dreiseidler T,Nickenig HJ,Zöller J,Kreppel M
    BACKGROUND & AIMS: INTRODUCTION:The role of the volume of radicular and dentigerous cysts on clinical symptoms is unclear and potentially may predict development of pre- and postoperative complications, especially after cystectomies with large bony defects. Therefore the aim of this study was to assess pre- and postoperative symptoms associated to the volume of jaw cysts. MATERIAL AND METHODS:Retrospective chart review of 111 patients with follicular or dentigerous cysts from 2008-2012. Anterior iliac crest grafts were used to fill defects after cystectomy. χ2-test was performed to analyze associations between two qualitative variables. Binary logistic regression analysis was used as multivariate analysis. P-values p < 0.05 were considered as significant. Volume measurement was performed in a semiautomatic segmentation method with the software "ITK-Snap". RESULTS:Postoperative hypaesthesia correlated significantly with histology (p = 0.025) and localization (p = 0.006). Volume was associated significantly with preoperative hypaesthesia (p = 0.052), postoperative hypaesthesia (p < 0.001), wound healing complications (p < 0.001) and length of wound healing complications (p = 0.001). Multivariate analysis identified volume as independent risk factor for postoperative hypaesthesia (p = 0.015). CONCLUSIONS:Volume analysis appears to be a method that allows risk stratification after surgery of jaw cysts. Therefore we recommend a precise treatment planning with the means of volume analysis to improve therapy outcome of patients with jaw cysts.
    背景与目标:
  • 【提出了一种用有限元方法模拟无骨水泥中骨向内生长过程的方法。】 复制标题 收藏 收藏
    DOI:10.1016/j.medengphy.2012.10.010 复制DOI
    作者列表:Tarala M,Janssen D,Verdonschot N
    BACKGROUND & AIMS: :In cementless total hip arthroplasty, long-term implant stability is achieved by bone ingrowth. The strength of the new bond gradually increases in time, due to bone maturation and progression of ingrowth. In finite element simulations, osseointegration generally is implemented as an instant change in the mechanical behavior of the implant-bone interface, although this is a simplified interpretation of the bone ingrowth process. The aim of the present study was to build on previous bone ingrowth simulations and propose a new methodology to simulate bone ingrowth as a time-dependent process. We developed an algorithm to calculate the strength of the local implant-bone bond based of the magnitude of interface micromotions and gaps in time. Our algorithm was subsequently tested in multiple hip reconstructions in which the bone quality and implant-bone contact area were varied. The results of the simulations showed that in the ideal situation (good bone quality and no interface gaps), 91% of implant area could achieve ingrowth, while in the worst case only 17% of implant area showed ingrowth. The initial contact area had a significant effect on ingrowth, overruling the effect of variations in bone quality. The progression of ingrowth had a stabilizing effect on adjacent regions, especially in the high contact area cases. Further development and validation of the presented algorithm requires more information on the nature of the relation between the ingrowth rate and the magnitude of micromotions and gap.
    背景与目标: : 在无骨水泥全髋关节置换术中,植入物的长期稳定性是通过骨向内生长来实现的。由于骨骼的成熟和向内生长的进展,新键的强度随时间逐渐增加。在有限元模拟中,骨整合通常是作为植入物-骨界面的机械行为的即时变化来实现的,尽管这是对骨向内生长过程的简化解释。本研究的目的是在以前的骨向内生长模拟的基础上,提出一种新的方法来模拟骨向内生长,这是一个与时间有关的过程。我们开发了一种算法,可以根据界面微动的大小和时间间隙来计算局部植入物-骨键的强度。随后,我们的算法在多次髋关节重建中进行了测试,其中骨质量和植入物-骨接触面积发生了变化。模拟结果表明,在理想情况下 (良好的骨质量和无界面间隙),植入物区域的91% 可以实现向内生长,而在最坏的情况下,只有17% 的植入物区域显示向内生长。初始接触面积对向内生长有显着影响,从而推翻了骨质量变化的影响。向内生长的进程对相邻区域具有稳定作用,尤其是在高接触面积的情况下。提出的算法的进一步开发和验证需要更多有关向内生长速率与微动和间隙大小之间关系的性质的信息。
  • 【T细胞缺失骨髓移植后慢性粒细胞性白血病患者嵌合和白血病复发的细胞遗传学分析。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Offit K,Burns JP,Cunningham I,Jhanwar SC,Black P,Kernan NA,O'Reilly RJ,Chaganti RS
    BACKGROUND & AIMS: :Serial cytogenetic studies were performed on 64 patients with chronic myelogenous leukemia (CML) after T cell-depleted allogeneic bone marrow transplantation (BMT). Forty patients with CML in chronic phase (CP) received cytoreduction followed by BMT with HLA-matched T cell-depleted allogeneic marrow. The remaining 24 patients were transplanted in second chronic, accelerated, or blastic phase, or received T cell-depleted grafts with a dose of T cells added back. The Y chromosome and autosomal heteromorphisms were used to distinguish between donor and host cells. Mixed hematopoietic chimerism (presence of donor and host cells) was identified in 90% of patients in first CP. The Philadelphia (Ph) chromosome reappeared in 16 of the 40 first CP CML patients. As expected, patients who had detectable Ph chromosome positive cells at any time during the posttransplant period had a high likelihood of subsequent clinical relapse. Transient disappearance of the Ph positive clone was rarely observed, and was followed by reappearance of the Ph chromosome or clinical relapse. A subset of engrafted patients with greater than 25% host cells within 3 months post-BMT had a significantly shorter survival time free of cytogenetic or clinical relapse compared with other patients. In patients who had received donor T cells added to the T cell-depleted graft, there was a higher proportion of complete chimerism. Clonal progression of Ph positive as well as negative cells was observed and may be the result of radiation induced breakage. Serial cytogenetic studies of patients post-BMT can provide useful information regarding the biologic and clinical behavior of CML.
    背景与目标: : 在T细胞耗尽的同种异体骨髓移植 (BMT) 后,对64例慢性粒细胞性白血病 (CML) 患者进行了系列细胞遗传学研究。40例慢性期 (CP) 的CML患者接受了细胞减灭,然后接受了HLA匹配的T细胞耗尽的同种异体骨髓的BMT。其余24例患者被移植到第二个慢性,加速或母细胞期,或接受T细胞耗尽的移植物,并加回一定剂量的T细胞。Y染色体和常染色体异形被用来区分供体细胞和宿主细胞。在第一个CP的90% 患者中鉴定出混合的造血嵌合体 (供体和宿主细胞的存在)。费城染色体重新出现在40例第一批CP CML患者中的16例中。如预期的那样,在移植后的任何时候都具有可检测到的Ph染色体阳性细胞的患者随后临床复发的可能性很高。很少观察到Ph阳性克隆的瞬时消失,随后出现Ph染色体或临床复发。与其他患者相比,BMT后3个月内移植的宿主细胞大于25% 的患者亚群的无细胞遗传学或临床复发的生存时间明显更短。在接受T细胞耗尽移植物中添加了供体T细胞的患者中,完全嵌合的比例更高。观察到Ph阳性细胞和阴性细胞的克隆进程,这可能是辐射引起的破坏的结果。BMT后患者的一系列细胞遗传学研究可以提供有关CML生物学和临床行为的有用信息。
  • 【微型机组周围牙槽骨密度变化: 一项前瞻性临床研究。】 复制标题 收藏 收藏
    DOI:10.1016/j.ajodo.2012.07.013 复制DOI
    作者列表:Al Maaitah EF,Safi AA,Abdelhafez RS
    BACKGROUND & AIMS: INTRODUCTION:Our objective was to assess the effects of miniscrews on interproximal alveolar bone density and adjacent gingival tissue health. METHODS:Forty-four titanium miniscrews were inserted between maxillary second premolars and first molars on both sides of the dentition in 22 consecutive patients (15 female, 7 male; ages, 14-24 years). A control area (between the maxillary first and second premolars) was also assessed. Both miniscrew (study) and control areas were monitored clinically and radiographically at different time points: before insertion of the miniscrews and at 1 month, 3 months, and 6 months after insertion. Software associated with a digital intraoral radiography machine was used to assess changes in alveolar bone density. Clinical gingival parameters of the study and control areas were also recorded. A repeated-measures analysis of variance and the Bonferroni post-hoc pairwise comparison tests were used to assess the changes at the different time points. RESULTS:Thirty-nine miniscrews were successful for the study duration. Male subjects had significantly (P <0.001) higher alveolar bone density than did the females at baseline. Alveolar bone density around the miniscrews increased significantly (P <0.001) between 3 and 6 months after insertion upon loading. Alveolar bone density of the control area did not change significantly during the experiment (P >0.05). The width of keratinized gingiva increased significantly (P <0.001) in the study and control areas after insertion of miniscrews and remained with no significant change throughout the study. CONCLUSIONS:Miniscrews increased the alveolar bone density significantly after 3 months of insertion and were not associated with detrimental effects on the adjacent gingival tissues.
    背景与目标:

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