近红外荧光量子点表皮生长因子受体单克隆抗体探针对头颈部鳞状细胞癌活体可视化成像和体内分布的动物实验研究

目的探讨近红外荧光量子点（QDs）表皮生长因子受体（EGFR）单克隆抗体（mAb）探针对头颈部鳞状细胞癌的原位可视化成像和体内分布情况。方法将发射波长为800 nm的近红外荧光QDs与EGFR mAb连接,制备QD800-EGFR mAb探针。在体外将QD800-EGFR mAb与人颊鳞状细胞癌BcaCD885细胞共培养30 min,使用激光扫描共聚焦显微镜（LSCM）观察QD800-EGFR mAb对BcaCD885细胞的结合情况。将QD800-EGFR mAb通过尾静脉注射到裸鼠头颈部鳞状细胞癌模型,在不同时间点通过活体成像观察QD800-EGFR mAb对头颈部鳞状细胞癌的可视化成像情况和QD800-EGFR mAb在体内的分布。结果静脉注射QD800-EGFR mAb探针后能对裸鼠头颈部鳞状细胞癌进行清楚的可视化荧光成像,成像一直持续到24 h,但在30 min～6 h时间段内肿瘤成像最完整和荧光信噪比最高。对体内QD800-EGFR mAb在肿瘤和器官的分布检测证明：QD800在肝中分布最多,在肿瘤中的聚集随着时间的延长逐渐下降,心、脑、肠、肺、胃中均未见有QD800。结论QD800-EGFR mAb探针对头颈部癌能进行清楚的可视化个体成像检测,在非侵入可视化成像研究头颈部癌的发生发展和个体化治疗等方面有巨大的发展前景。     

Comparison between the use of magnetic resonance imaging and conebeam computed tomography for mandibular nerve identification

Objective: Conebeam computed tomography (CBCT) and magnetic resonance imaging (MRI) have been used to identify the mandibular nerve but a comparison of the reliabilities of the two imaging modalities has not been performed. It was hypothesized that the reliabilities were not different between the two. Materials and methods: Twelve dental postgraduates in five disciplines were recruited to assess two sets of reformatted oblique images (CBCT and MRI) of 11 patients who were scanned before wisdom teeth extraction. The variance of the identified locations of mandibular nerve, the mental foramen and the mandibular foramen between two sets of images of each patient was compared. Each set of images was rated by assessors to reveal the satisfaction in determining the structures. Results: It was found that by using MRI images, significantly lesser variances and significantly higher satisfactory scores were given by the assessors than by using CBCT images in the identification of the structures. Conclusions: We concluded that MRI is a promising imaging modality that can be used to identify the mandibular nerve when it cannot be found in CBCT images. To cite this article:
Chau A, Comparison between the use of MRI and CBCT for mandibular nerve identification.
Clin. Oral Impl. Res. 23 , 2012; 253–256.
doi: 10.1111/j.1600‐0501.2011.02188.x     

Lack of association between chronic periodontitis and the Toll-like receptor 4 gene polymorphisms in a Czech population

BACKGROUND AND OBJECTIVE: Periodontitis is a bacterially induced chronic inflammatory disease and a major cause of tooth loss among adults. Toll-like receptors are signal molecules essential for the cellular response to bacterial cell wall components. The aim of this study was to investigate relationships between chronic periodontitis and variations in the TLR4 gene. MATERIAL AND METHODS: A total of 171 patients with chronic periodontitis and 218 unrelated controls were genotyped for the Asp299Gly (896A>G) and Thr399Ile (1196C>T) polymorphisms of the TLR4 gene. RESULTS: Both variants were in nearly complete linkage disequilibrium. No homozygotes for the less common alleles, 299Gly and 399Thr, respectively, were found. The prevalence of the Asp299Gly and the Thr399Ile heterozygotes was 5.3% and 5.0% in controls, and 7.0% and 7.0% in periodontitis patients. CONCLUSION: In conclusion, TLR4 gene polymorphisms were not significantly associated with the susceptibility to, or severity of, chronic periodontitis in our population.     

MR imaging of maxillomandibular lesions

This paper addresses maxillomandibular lesions including cyst, tumor and osteomyelitis in terms of their general features and discusses the use of MR imaging techniques, interpretation of images and their characteristic findings. MR imaging of odontogenic keratocyst improved the visualization of a cystic pattern, regularly thin walls, weak enhancement of cyst walls and inhomogeneous intensity of fluid contents. However, some of them could be misdiagnosed as mixed or solid patterns by non-contrast study alone. Ameloblastoma showed mixed solid and cystic components, irregularly thick walls, papillary projections, and marked enhancement of the walls. In mandibular osteomyelitis, MR imaging could give us more detailed information regarding residual activity of infection and the extent of involvement. MR findings were suggestive to differentiate between tumors and cysts and characterize many cystic entities in the maxillomandibular region.     

年龄对小鼠腹腔巨噬细胞TLR2/4表达水平及功能的影响

目的：观察不同年龄组小鼠腹腔巨噬细胞Toll样受体2/4（TLR2/4）表达水平的差别,以及该细胞在脂多糖（LPS）刺激下,炎症因子TNF-α分泌水平的差别。方法：采用real-time PCR和流式细胞技术,检测低龄组和高龄组小鼠腹腔巨噬细胞TLR2/4 mRNA和蛋白表达水平的差异;同时检测1μg/mL大肠杆菌（E.coli）LPS或1mg/L牙龈卟啉单胞菌（P.gingivalis）LPS刺激后,两组细胞TLR2/4表达水平的变化;采用ELISA技术检测炎症因子TNF-α分泌水平的变化。结果：刺激前,两组细胞TLR2/4 mRNA和蛋白表达水平均无明显差别。E.co-li LPS或P.gingivalis LPS刺激后,低龄组细胞TLR2/4mRNA和蛋白表达水平均明显高于高龄组（P〈0.05）,其分泌的TNF-α水平也显著高于高龄组（P〈0.05）。结论：年龄对小鼠腹腔巨噬细胞TLR2/4表达水平没有显著影响,但增龄性变化可能导致TLR2/4功能的减退。     

Melatonin and cancer: current knowledge and its application to oral cavity tumours

J Oral Pathol Med (2011) 40 : 593–597 Background: Melatonin (MLT) is a molecule secreted by the pineal gland in cyclical periods. In mammals, MLT is involved in physiological processes, such as sleep/wake regulation in the circadian cycle. It has antioxidant and anti‐inflammatory properties, functions as an immunomodulator, and stimulates bone metabolism. MLT is also involved in tumour processes in breast, prostate, liver, and bone cancers, among others, and in oral cavity tumours like epidermoid carcinoma. We are gradually increasing our knowledge of the underlying mechanism of MLT action in the aforementioned tumour processes, in which MT1, MT2, MT3, and RZR receptors appear to play a highly important role. These receptors belong to a large family of G‐protein‐coupled transmembrane receptors, some of which have been linked to melatonin’s anticancer action, to tumour growth, and to prognosis. The objective of this article is to provide a clear review of research into the range of MLT functions, focusing specifically on MT receptors. We aim to contribute interesting, new approaches to research into oral cavity tumours. Methods: An extensive review of the research literature was conducted using PubMed, Science Direct, ISI Web of Knowledge, and the Cochrane base. Results: This study highlights the growing importance of MLT in the prognosis and treatment of certain tumours, including epidermoid carcinoma in the oral cavity. Moreover, it opens up a highly original, encouraging line of research in the field of tumours. Conclusions: MLT contributes to protecting the oral cavity from tissue damage caused by receptor action. Experimental evidence suggests that it may be useful in the treatment and prognosis of tumour processes in the oral cavity.     

Toll-like receptors 2 and 5 in human gingival epithelial cells co-operate with T-cell cytokine interleukin-17

Background/aim:  Periodontitis begins as the result of perturbation of the gingival epithelial cells caused by subgingival bacteria interacting with the epithelial cells via pattern recognition receptors. Toll-like receptors (TLRs) have been shown to play an important role in the recognition of periodontal pathogens so we have studied the interaction of TLR ligands with TLR2 and TLR5 for cytokine production in the cultures of gingival epithelial cells.
Methods:  Immunohistochemistry was used for the localization of TLR2 and TLR5 in tissue specimens. Enzyme-linked immunosorbent assays were performed to detect the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), released from gingival epithelial cell cultures following stimulation with TLR ligand alone or in combination with IL-17.
Results:  Both TLR2 and TLR5 were increased in periodontitis (2128 ± 159 vs. 449 ± 59 and 2456 ± 297 vs. 679 ± 103, respectively, P  < 0.001) including gingival epithelial cells that stained strongly. Cultured gingival epithelial cells stimulated with their respective ligands (HKLM, a TLR2 ligand that is also found in Porphyromonas gingivalis , and flagellin, a TLR5 ligand that is also found in Treponema denticola ) produced both IL-1β and TNF-α. To mimic T-cell help, IL-17 was added. This further greatly enhanced TLR ligand-induced IL-1β ( P  < 0.001) and TNF-α ( P  < 0.01) production.
Conclusions:  These findings show how pathogen-associated molecular patterns, shared by many different periodontopathogenic bacteria, stimulate the resident gingival epithelial cells to inflammatory responses in a TLR-dependent manner. This stimulation may be particularly strong in periodontitis and when T helper type 17 cells provide T-cell help in intercellular cooperation.     

Advances in imaging: impact on studying craniofacial bone structure

Methods for measuring the structure of craniofacial bones are discussed in this paper. In addition to the three-dimensional macro-structure of the craniofacial skeleton, there is considerable interest in imaging the bone at a microscopic resolution in order to depict the micro-architecture of the trabecular bone itself. In addition to the density of the bone, the microarchitecture reflects bone quality. An understanding of bone quality and density changes has implications for a number of craniofacial pathologies, as well as for implant design and understanding the biomechanical function and loading of the jaw. Trabecular bone micro-architecture has been recently imaged using imaging methods such as micro-computed tomography, magnetic resonance imaging, and the images have been used in finite element models to assess bone mechanical properties. In this paper, some of the recent advances in micro-computed tomography and magnetic resonance imaging are reviewed, and their potential for imaging the trabecular bone in mandibular bones is presented. Examples of in vitro and in vivo images are presented.