唾液腺:新型冠状病毒的“蓄水池”和“受累者”

新型冠状病毒引发的肺炎(简称新冠肺炎,coronavirus disease 2019,COVID-19)已在全球蔓延并快速进展,对人类的健康、经济活动和生活方式造成了巨大影响。口腔诊疗操作依赖牙科涡轮机,产生大量气溶胶,使口腔医护人员暴露于高风险环境中。唾液腺是唾液的来源,其是否感染新型冠状病毒和口腔诊疗风险密切相关。本文搜集国内外已发表的相关文献,总结新冠病毒对唾液腺感染及其在唾液腺内的复制过程和对唾液腺功能影响等方面的最新信息,旨在为口腔医护人员在疫情暴发及常态化防控期间的防护提供帮助。     

Oral management of the patient with cancer in the head and neck region

Cancer therapies--including surgery, radiation, and chemotherapy--may unfavorably affect the oral/dental health of patients. Existing dental problems can also result in serious complications that may be prevented by dental intervention prior to cancer therapy. This paper will be limited to a discussion of the detrimental effects of radiation therapy on the oral cavity and salivary glands and appropriate dental management.     

Trefoil factor family 3 expression in the oral cavity

This study examined the expression, in oral keratinocytes and in the major and minor salivary glands, of Trefoil factor family 3 (TFF3) peptide. Trefoil factor family 3 messenger RNA (mRNA) and peptide were detected in cultures of normal oral keratinocytes by quantitative real‐time polymerase chain reaction (PCR) and western blotting, respectively. Trefoil factor family 3 was found, by immunohistochemical analyses, to be expressed in the basal layers of the oral mucosal epithelium. In salivary glands, immunohistochemical staining showed that TFF3 peptide expression was strongest in the mucous acini of the submandibular and the small salivary glands. Serous cells in the same glands showed weak staining. In the parotid gland, many serous acini showed weak positive staining, while other areas did not. In all glands examined, the intercalated, striated, and collecting ducts were moderately TFF3‐positive. Double immunostaining confirmed that mucous (MUC5B positive) cells were moderately or strongly positive for TFF3 and that some serous (MUC7 positive) cells showed restricted TFF3 expression, mostly in a granular pattern. The prevalence of the TFF3 peptide in the salivary secretions of healthy volunteers was detected by western blotting of saliva from minor salivary glands (four of five) and the parotid gland (one of five) and of mixed submandibular/sublingual saliva (five of five). In conclusion, the submandibular and small salivary glands appear to be the major producers of oral TFF3, but duct cells of all glands and keratinocytes of the oral mucosa may also contribute as sources of TFF3 in the oral cavity.     

The impact of tissue engineering on dentistry

BACKGROUND: Tissue engineering is a novel and highly exciting field of research that aims to repair damaged tissues as well as create replacement (bioartificial) organs. OVERVIEW: The authors provide a general review of the principles underlying key tissue engineering strategies, as well as the typical components used. Several examples of preclinical and clinical progress are presented. These include passive approaches, such as dental implants, and inductive approaches that activate cells with specific molecular signals. PRACTICE IMPLICATIONS: Tissue engineering will have a considerable effect on dental practice during the next 25 years. The greatest effects will likely be related to the repair and replacement of mineralized tissues, the promotion of oral wound healing and the use of gene transfer adjunctively.     

The National Institute of Dental and Craniofacial Research: research for the practicing dentist

BACKGROUND AND OVERVIEW: Established in 1948, the National Institute of Dental and Craniofacial Research (NIDCR) has helped transform dentistry into a profession that is based firmly in prevention and technological innovation. This article introduces the new NIDCR initiative in general dentistry practice-based research. It also highlights research supported by the NIDCR and its implications for dental practice in restorative dentistry, oral and systemic disease, stem cell research, salivary diagnostics, gene transfer therapy and pain. CLINICAL IMPLICATIONS: The NIDCR supports research that will help guide the practitioner in the delivery of patient care and have a direct impact on the practice of dentistry.     

Submandibular gland aplasia and progressive dental caries: a case report

When severe caries occurs in mandibular permanent incisor teeth, the clinician should consider the possibility of associated submandibular gland aplasia or salivary hypofunction. Early diagnosis of submandibular gland disease is essential, as operative problems involving restoration of mandibular incisor teeth are considerable. Furthermore, progressive severe dental caries can present a dilemma for the clinician in affected individuals, despite intensive preventive and restorative therapy. A case report describing severe progressive dental caries and enamel demineralization of the permanent mandibular incisor teeth in a young girl is presented. Further investigation revealed absence of functional bilateral submandibular salivary glands contributing to the rapid breakdown of the teeth despite intensive preventive measures.     

Foci of infection and oral supportive care in cancer patients

Radiation therapy in the head and neck area and treatment with high dose chemotherapy entail damage to healthy tissue in the mouth. In order to reduce to a minimum the chances of these side effects of cancer treatment developing, it is necessary to carry out oral foci tests prior to oncological therapy. In addition supplementary oral and dental care measures seem to be important in order to limit the side effects of oncological therapy on the teeth, salivary glands and jaw as much as possible. This supportive oral care is not only necessary during, but also for years after the oncology treatment. Therefore not only dental professionals affiliated to oncology teams will have to take care of cancer patients, but also family dentists and dental hygienists.     

Gene transfer mediated by different viral vectors following direct cannulation of mouse submandibular salivary glands

The salivary gland has been suggested as an accessible organ for gene transfer to express recombinant proteins locally in the saliva, as well as for secretion to the blood circulation. The aim of this study was to evaluate the efficiency of gene transfer to salivary glands using different viral vectors: adenovirus, vaccinia, herpes simplex type 1 (HSV), and two retroviral vectors (murine leukemia virus (MuLV) and lentivirus). We show, by in situ staining and beta-galactosidase reporter activity assay, that the adenoviral and vaccinia vectors were able to deliver the reporter gene efficiently to acinar and duct cells. The HSV vector was less efficient and infected only the acinar cells. The lentiviral vector infected acinar and duct cells, but at a relatively low efficiency. The MuLV vector did not infect the salivary gland unless cell proliferation was induced. Host immune responses to viral infection, inflammation, apoptosis and lymphocyte infiltration, in the transduced glands, were assessed. The DNA viral vectors induced local lymphocyte infiltration and apoptosis. In contrast, the retroviral vectors did not induce an immune response. Our results describe the outcome of salivary gland infection with each of the five different viral vectors and indicate their advantages and limitations for transferring genes to the salivary glands.     

Gene therapy in periodontics: a review and future implications

New advancements in gene therapy continue to have a significant impact on dentistry since 1995. At the same time, periodontal disease has attracted the attention of scholars and research scientists as a global concern. With a better understanding of disease progression and new advancement in biological science, gene therapy has emerged to enhance existing therapy and has radically recast approaches to the management of periodontal disease. Since the advent of gene therapy in dentistry, significant progress has been made to control periodontal disease and reconstruct the dentoalveolar apparatus. However, to date, gene therapy methods have not been developed to control periodontal disease due to its multifactorial origin, complex genetic predisposition, and risk associated with it. This review article provides a brief insight into the ever-expanding field of gene therapy and its possible future implication in the field of periodontics. Most of the modalities described in this article are more theoretical and still in infancy stage except for genetically fabricated materials used for regenerative purposes.     

Dental management of the irradiated patient.

There is an increasing number of patients receiving radiation therapy for oral malignancies. In many malignant tumors, radiation is often the treatment of choice, while in others it may be used in conjunction with surgery or chemotherapy. There are inherent dental and oral problems associated with radiation therapy. It is the purpose of this paper to deal briefly with the physical principles and the biological basis of radiation therapy. In addition, the specific radiation effects on oral mucous membranes, taste buds, salivary glands, bone, the periodontium and teeth will be discussed. Radiation complications in edentulous patients, and in particular the problems of wearing dentures in such patients will be evaluated. An approach to the problem of dental extractions and other dental treatments in the pre- and post-irradiated patient is suggested.     

The underlying mechanisms and strategies of DNA damage and repair in radiation sialadenitis

Radiation therapy is a critical strategy for the treatment of malignant tumors. X-ray external radiation has been successfully used to treat head and neck cancer. On the other hand, ¹³¹I internal radiation has been effective in managing differentiated thyroid cancer. However, these therapies cause radiation damage to salivary glands. Radiation sialadenitis is the most common complication associated with radiotherapy applied to the head and neck and it severely affects patients’ quality of life. Since DNA is the main intracellular target of radiation, and the integrity of the DNA structure is critical to genomic stability and the cellular survival of salivary glands, regulating radiation-induced DNA damage offers great promise in preventing and managing radiation sialadenitis. In this review, we summarize recent progress in DNA damage and repair in irradiated salivary glands.     

Oral and periodontal status in Sj?gren's syndrome.

Sj?gren's syndrome is a multi-system chronic inflammatory disease of the exocrine glands. Inflammation of the salivary glands leads to reduction in salivary output, which imposes a significant impact on oral health. Dentists and dental hygienists are the primary healthcare providers to identify early signs and symptoms of Sj?gren's syndrome. Early diagnosis of Sj?gren's syndrome is fundamental for effective management of the disease.     

Salivary gland gene therapy

Salivary glands have proven to be unusual but valuable target sites for multiple clinical gene transfer applications. Access to salivary glands for gene transfer is easy. Multiple studies in animal models have yielded proofs of concept for novel treatments for damaged salivary glands following therapeutic irraditation, in Sj?gren's syndrome, and for gene therapeutics systemically by way of the blood-stream and locally in the oral cavity and upper gastrointestinal tract.     

基因转导及组织工程重建涎腺功能

涎腺功能低下或丧失在临床上很常见,目前尚无较理想有效的治疗方法。近年来随着涎腺基因转导及组织工程等新技术方法的应用,涎腺功能重建取得了可喜的进展。通过传导腺病毒介导的水通道基因治疗涎腺放射损伤,已在美国获批进入临床实验,长期稳定的载体介导的水通道基因在大型动物的临床前研究正在进行中。     

Salivary glands as a model for craniofacial applications of gene transfer

The potential applications of gene transfer technology to all branches of medicine are increasing. It is quite likely that within the next 10-20 years surgical practice routinely will utilize gene transfer, at least adjunctively. The purpose of this review is to familiarize the oral and maxillofacial surgeon with this technology. Studies performed with salivary glands in animal models are presented as examples of proof of concept.     

Occlusion: reflections on science and clinical reality

The last 50 years have seen progress in emphasizing scientific evidence as a basis for dental practice, including occlusal therapy. Although a proper understanding of the contributory role of occlusion to temporomandibular disorders should not be minimized, the importance of occlusion in other areas of dental education and practice should not be overlooked. The primary objective of this article is to discuss the nature of this problem as it relates to the duality of science and clinical reality in the evidence-based paradigm, information transfer, quality of evidence, clinical trials, and clinical aspects of occlusion. Some suggested solutions for the problem and thoughts on past and future perspectives of occlusion are expressed in context of inquiry.     

唾液的诊断应用研究

唾液由口腔腺体分泌产生,具有清洁和保护口腔、抗菌、消化等多种功能。随着唾液组学的发展,研究发现唾液是一个潜在的巨大生物标志物储存库。唾液采集无侵袭性、可避免病毒传播,有望成为血液的替代品。本文就关于唾液生化指标、DNA、RNA、蛋白质和微生物等生物标志物在口腔疾病、癌症、糖尿病等全身系统性疾病早期诊断中的应用,结合近期研究成果与学者观点,阐述唾液在疾病早期诊断和精准医疗中的应用前景。     

Scanning of the major salivary glands by using scintigraphy after radiotherapy

Five patients suffering from cancerous lesions in oral and pharyngeal areas, were studied in this research and in comparing with two normal cases. The major salivary glands were indirectly exposed to irradiation where the patients receiving a radiation therapy which is Cobalt(60). Scintigraphy was performed for both patients and normal cases to visualize the functional capacity and activity of the salivary glands following the high radiation doses. It was found from the results that the dynamic and static scintigrams of the salivary glands which were in the field of irradiation appeared faint in visualization and delayed in perfusion. Also an increase in concentration of the radiotracer 99m Tc-pertechnetate in the gland after physiologic stimulation. This attributed to fibrosis and dysfunction in the glands as a results of the previous irradiation.