抗肿瘤坏死因子单抗对脂多糖诱导的人牙周膜成纤维细胞TRAIL和TNF-α的影响

目的: 观察脂多糖对人牙周膜成纤维细胞(HPLFs )肿瘤坏死因子(TNF)受体相关凋亡诱导配体(TRAIL) 和TNF-α的诱导作用及抗肿瘤坏死因子单抗(抗TNF单抗)对其的影响,探讨TNF超家族参与牙周病的可能作用机制。方法: HPLFs培养至第6代, 加入不同浓度的脂多糖(0、0.1、1、10、100 μg/mL)培养 24 h,分为命名为Z₀组、Z_0.1组、Z₁组、Z₁₀组、Z₁₀₀组,并取Z₁组浓度的脂多糖,在加药的同时加抗TNF单抗 75 μg/mL( Z₁+75组)。分别采用实时荧光定量PCR法或Western blot法测定TRAIL 和TNF-α mRNA或蛋白的表达。结果: Z₁组、Z₁₀组HPLFs TRAIL mRNA的表达水平显著高于Z₀组或Z_0.1 组(均P<0.05),Z₁组与Z₁₀组之间差异无统计学意义(P>0.05); Z₁₀₀组显著高于Z₀组(P<0.05)且与Z_0.1组、Z₁组和Z₁₀组比较差异无统计学意义(均P>0.05)。Z₁组或Z₁₀组TNF-α mRNA的表达水平显著高于Z₀组或Z₁₀₀组(均P<0.05);Z₁组与Z₁₀组之间,Z₀组、Z_0.1组和Z₁₀₀组之间差异无统计学意义(均P>0.05)。HPLFs TRAIL 蛋白的表达水平在Z₁₀₀组0组0.1组1组(均P<0.05 或<0.01);Z₁₀组显著高于Z₀组或Z₁₀₀组(均P<0.01),但与Z_0.1组或Z₁组之间差异无统计学意义(均P>0.05)。抗TNF单抗治疗后TRAIL mRNA及蛋白和TNF-α mRNA的表达水平显著低于Z₁组(P<0.05 和P<0.01)。TRAIL和TNF-α mRNA的表达水平呈显著直线正相关(r=0.819,n=30, P<0.01)。结论: HPLFs经脂多糖诱导后,其TRAIL和TNF-α的表达呈现先升高后下降,且随脂多糖的浓度变化而相应地变化,这种诱导作用能被抗TNF单抗所抑制。     

ASME法规中筒体壁厚计算不同方法的合理选用

在对ASME法规开孔筒体强度计算中的减弱系数法和开孔补强法进行对比分析的基础上,得出了当筒体开孔节距小于或等于补强有效范围时,采用开孔补强法求得了筒体壁厚较小;当前者大于后者时,采用减弱系数法求得了筒体壁厚较小的结论。指出根据筒体结构的不同特点,合理选用法规中的相应计算方法,可以使设计的产品既保证安全又节省材料。还给出了作为上述结论论据的例题。     

In Vivo Characteristics of Premixed Calcium Phosphate Cements When Implanted in Subcutaneous Tissues and Periodontal Bone Defects

Previous studies showed that water-free, premixed calcium phosphate cements (Pre-CPCs) exhibited longer hardening times and lower strengths than conventional CPCs, but were stable in the package. The materials hardened only after being delivered to a wet environment and formed hydroxyapatite as the only product. Pre-CPCs also demonstrated good washout resistance and excellent biocompatibility when implanted in subcutaneous tissues in rats. The present study evaluated characteristics of Pre-CPCs when implanted in subcutaneous tissues (Study I) and used for repairing surgically created two-wall periodontal defects (Study II). Pre-CPC pastes were prepared by combining CPC powders that consisted of CPC-1: Ca(4)(PO(4))(2)O and CaHPO(4), CPC-2: α-Ca(3)(PO(4))(2) and CaCO(3) or CPC-3: DCPA and Ca(OH)(2) with a glycerol at powder-to-liquid mass ratios of 3.5, 2.5, and 2.5, respectively. In each cement mixture, the Ca to P molar ratio was 1.67. The glycerol contained Na(2)HPO(4) (30 mass %) and hydroxypropyl methylcellulose (0.55 %) to accelerate cement hardening and improve washout resistance, respectively. In Study I, the test materials were implanted subcutaneously in rats. Four weeks after the operation, the animals were sacrificed and histopathological observations were performed. The results showed that all of the implanted materials exhibited very slight or negligible inflammatory reactions in tissues contacted with the implants. In Study II, the mandibular premolar teeth of mature beagle dogs were extracted. One month later, two-wall periodontal bone defects were surgically created adjacent to the teeth of the mandibular bone. The defects were filled with the Pre-CPC pastes and the flaps replaced in the preoperative position. The dogs were sacrificed at 1, 3 and 6 months after surgery and sections of filled defects resected. Results showed that one month after surgery, the implanted Pre-CPC-1 paste was partially replaced by bone and was converted to bone at 6 months. The pockets filled with Pre-CPC-2 were completely covered by newly formed bone in 1 month. The Pre-CPC-2 was partially replaced by trabecular bone in 1 month and was completely replaced by bone in 6 months. Examination of 1 month and 3 month samples indicated that Pre-CPC-2 resorbed and was replaced by bone more rapidly than Pre-CPC 1. Both Pre-CPC pastes were highly osteoconductive. When implanted in periodontal defects, Pre-CPC-2 was replaced by bone more rapidly than Pre-CPC-1.     

Enhanced phagocytosis of Aggregatibacter actinomycetemcomitans cells by macrophages activated by a probiotic Lactobacillus strain

The activation of phagocytosis is one important approach to clearing pathogenic cells in a host. This study evaluated the ability of probiotic lactobacilli to induce phagocytic activity as well as the clearance of a periodontal pathogen, Aggregatibacter actinomycetemcomitans. First, the activation of phagocytosis was found by using lyophilized dead cells. Probiotic Lactobacillus strains significantly enhanced the phagocytic activity of macrophage cells, indicating that the probiotic lactobacilli have a remarkable ability to stimulate the macrophages. Essentially, 3 Lactobacillus strains tested did not have any critical toxic effect on the murine macrophage, and Lactobacillus johnsonii NBRC 13952 showed the least cytotoxic effect on the RAW264.7 macrophages. The expression of classically activated macrophage markers, IL-1β, and cluster of differentiation 80 increased by L. johnsonii NBRC 13952; however, there was no significant difference for IL-18. The highest phagocytic activity by macrophages was found in a condition in which the macrophage activated by L. johnsonii NBRC 13952 functions to kill the cells of A. actinomycetemcomitans. Correlating with the result, a high amount of hypodiploid DNA (SubG1) was detected from the macrophage cells stimulated by L. johnsonii NBRC 13952. Taken together, the results suggest that macrophages activated by the Lactobacillus strain can facilitate the phagocytosis of A. actinomycetemcomitans cells by linking with enhanced apoptotic activities. In conclusion, L. johnsonii NBRC 13952 has a certain role in activating the RAW264.7 macrophages, thereby counteracting the infection of A. actinomycetemcomitans.     

三七总皂苷对体外培养人牙周膜细胞增殖和分化的影响

目的探讨三七总皂苷对体外培养的人牙周膜细胞(Human periodontal ligament cell,hPDLC)增殖、碱性磷酸酶(Alkaline phosphatase,ALP)活性及表达的影响。方法采用组织块法原代培养hPDLC,并经免疫组化鉴定;分别用10、1.0、0.1和0.01 mg/L浓度的三七总皂苷处理体外培养的hPDLC,设只加含10%FBS的DMEM培养基为空白对照,分别于1、3、5、7 d后,MTT法检测其对hPDLC增殖活性的影响,酶标仪上检测细胞中ALP活性,Western blot法检测细胞中ALP蛋白的表达。结果免疫组化结果显示,细胞来源于外胚间充质;MTT结果显示,0.1 mg/L浓度组在第5天和1.0、10 mg/L浓度组在第3、5天hPDLC增殖活性明显高于空白对照组(P<0.01);0.1、1.0、10 mg/L浓度组在第3、5天ALP活性明显高于空白对照组(P<0.01),1.0 mg/L浓度组APL活性明显高于其他各组(P<0.01);0.01、0.1、1.0、10 mg/L浓度组ALP蛋白表达量均明显高于空白对照组(P<0.01),以1.0 mg/L浓度组ALP表达量最高。结论三七总皂苷有促进hPDLC增殖的作用,并能增加ALP活性及其表达水平。     

关节镜下先进人工韧带加强系统韧带重建前交叉韧带5年随访研究

目的评估先进人工韧带加强系统韧带(1igament advancement reinforcement system,LARS)重建前交叉韧带(anterior cruciate ligament,ACL)术后1~5年膝关节功能。方法选择符合标准的LARS人工韧带关节镜下重建ACL患者36例(36膝),对其进行Lysholm、Tegner评分及IKDC评级等多指标回顾性分析。结果 LARS人工韧带重建ACL术后第1年、第3年及第5年的Lysholm、Tegner评分及IKDC评级明显高于术前(P0.01);而术后第1年、第3年及第5年的Lysholm、Tegner评分及IKDC评级之间差异无统计学意义(P0.05)。最终术后5年随访优良率为97.2%。结论 (1)LARS人工韧带重建ACL能较好地恢复膝关节稳定性及功能,对于膝关节前交叉韧带的重建是一种有效的移植物。(2)术后5年内关节功能稳定,无较大变化,说明LARS人工韧带在5年随访期内无严重的性能减退。(3)长期疗效是否仍然能保持术后中短期随访的优良结果,需继续长期随访。     

Impact of Leptin on Periodontal Ligament Fibroblasts during Mechanical Strain

Orthodontic treatment to correct dental malocclusions leads to the formation of pressure zones in the periodontal ligament resulting in a sterile inflammatory reaction, which is mediated by periodontal ligament fibroblasts (PDLF). Leptin levels are elevated in obesity and chronic inflammatory responses. In view of the increasing number of orthodontic patients with these conditions, insights into effects on orthodontic treatment are of distinct clinical relevance. A possible influence of leptin on the expression profile of PDLF during simulated orthodontic mechanical strain, however, has not yet been investigated. In this study, PDLF were exposed to mechanical strain with or without different leptin concentrations. The gene and protein expression of proinflammatory and bone-remodelling factors were analysed with RT-qPCR, Western-blot and ELISA. The functional analysis of PDLF-induced osteoclastogenesis was analysed by TRAP (tartrate-resistant acid phosphatase) staining in coculture with human macrophages. Pressure-induced increase of proinflammatory factors was additionally elevated with leptin treatment. PDLF significantly increased RANKL (receptor activator of NF-kB ligand) expression after compression, while osteoprotegerin was downregulated. An additional leptin effect was demonstrated for RANKL as well as for subsequent osteoclastogenesis in coculture after TRAP staining. Our results suggest that increased leptin concentrations, as present in obese patients, may influence orthodontic tooth movement. In particular, the increased expression of proinflammatory factors and RANKL as well as increased osteoclastogenesis can be assumed to accelerate bone resorption and thus the velocity of orthodontic tooth movement in the orthodontic treatment of obese patients.     

一种无图像导航下ACL重建的等距规划方法

针对膝关节前交叉韧带(ACL)移植位置不易确定的问题,采用光电跟踪技术,提出了一种基于等长规划的ACL无图像导航重建方法.首先根据韧带等距理论,设计了一种基于计算胫骨绕股骨运动过程中距离变化最小的点对的等距规划方法,然后分析了无图像导航系统的总体结构及关键技术,包括手术空间各对象的坐标转换、关节特征采集原则和表面重建方法,最后利用该方法进行了2例牛腿骨实验.结果表明,该规划方法合理有效,在股骨/胫骨的生长区域内的定位精度达1.45mm,能够满足临床手术要求.     

Detection and Evaluation of Serological Biomarkers to Predict Osteoarthritis in Anterior Cruciate Ligament Transection Combined Medial Meniscectomy Rat Model

Biomarkers are essential tools in osteoarthritis (OA) research, clinical trials, and drug development. Detecting and evaluating biomarkers in OA research can open new avenues for researching and developing new therapeutics. In the present report, we have explored the serological detection of various osteoarthritis-related biomarkers in the preclinical model of OA. In this surgical OA model, we disrupted the medial tibial cartilage’s integrity via anterior cruciate ligament transection combined with medial meniscectomy (ACLT+MMx) of a single joint of Wistar rats. The progression of OA was verified, as shown by the microscopic deterioration of cartilage and the increasing cartilage degeneration scoring from 4 to 12 weeks postsurgery. The concentration of serological biomarkers was measured at two timepoints, along with the complete blood count and bone electrolytes, with biochemical analysis further conducted. The panel evaluated inflammatory biomarkers, bone/cartilage biomarkers, and lipid metabolic pathway biomarkers. In chronic OA rats, we found a significant reduction of total vitamin D3 and C-telopeptide fragments of type II (CTX-II) levels in the serum as compared to sham-operated rats. In contrast, the serological levels of adiponectin, leptin, and matrix metallopeptidase (MMP3) were significantly enhanced in chronic OA rats. The inflammatory markers, blood cell composition, and biochemical profile remained unchanged after surgery. In conclusion, we found that a preclinical model of single-joint OA with significant deterioration of the cartilage can lead to serological changes to the cartilage and metabolic-related biomarkers without alteration of the systemic blood and biochemical profile. Thus, this biomarker profile provides a new tool for diagnostic/therapeutic assessment in OA scientific research.     

Three-Dimensional Culture of Cartilage Tissue on Nanogel-Cross-Linked Porous Freeze-Dried Gel Scaffold for Regenerative Cartilage Therapy: A Vibrational Spectroscopy Evaluation

This study presents a set of vibrational characterizations on a nanogel-cross-linked porous freeze-dried gel (NanoCliP-FD gel) scaffold for tissue engineering and regenerative therapy. This scaffold is designed for the in vitro culture of high-quality cartilage tissue to be then transplanted in vivo to enable recovery from congenital malformations in the maxillofacial area or crippling jaw disease. The three-dimensional scaffold for in-plate culture is designed with interface chemistry capable of stimulating cartilage formation and maintaining its structure through counteracting the dedifferentiation of mesenchymal stem cells (MSCs) during the formation of cartilage tissue. The developed interface chemistry enabled high efficiency in both growth rate and tissue quality, thus satisfying the requirements of large volumes, high matrix quality, and superior mechanical properties needed in cartilage transplants. We characterized the cartilage tissue in vitro grown on a NanoCliP-FD gel scaffold by human periodontal ligament-derived stem cells (a type of MSC) with cartilage grown by the same cells and under the same conditions on a conventional (porous) atelocollagen scaffold. The cartilage tissues produced by the MSCs on different scaffolds were comparatively evaluated by immunohistochemical and spectroscopic analyses. Cartilage differentiation occurred at a higher rate when MSCs were cultured on the NanoCliP-FD gel scaffold compared to the atelocollagen scaffold, and produced a tissue richer in cartilage matrix. In situ spectroscopic analyses revealed the cell/scaffold interactive mechanisms by which the NanoCliP-FD gel scaffold stimulated such increased efficiency in cartilage matrix formation. In addition to demonstrating the high potential of human periodontal ligament-derived stem cell cultures on NanoCliP-FD gel scaffolds in regenerative cartilage therapy, the present study also highlights the novelty of Raman spectroscopy as a non-destructive method for the concurrent evaluation of matrix quality and cell metabolic response. In situ Raman analyses on living cells unveiled for the first time the underlying physiological mechanisms behind such improved chondrocyte performance.