Contact sensitivity reactions in the oral mucosa

Although the role of T cells in skin contact sensitivity (CS) immune reactions has been intensely studied, much less is known about the regulatory properties of T cells in the oral mucosa. Animal experiments have shown that hapten sensitization of the ectodermal oral mucosa leads to antigen-specific hypersensitivity reactions in the skin. Furthermore, oral mucosa or skin hapten sensitization resulted in CS inflammatory reactions in the oral mucosa on challenge. The oral mucosa CS responses were similar to those found skin with regard to cell phenotypes and cytokines. CS-like reactions were also found in the oral mucosa after exposure to an irritant detergent, sodium lauryl sulfate (SLS). The oral mucosa reacted at smaller SLS doses than did skin. Ions and molecules released fron dental restorative materials (together with saliva and food and/or beverages) expose the gastrointestinal mucosa continuously over long time periods. From animal experiments we have learned that mice given antigen by gastric feeding, subsequently antigen-sensitized on skin, and finally elicited in the oral mucosa and in ear skin, showed tolerance in skin but gave simultaneous CS inflammatory reactions in the oral mucosa. Moreover, exposure of colon mucosa to antigen produced CS reactions in oral mucosa after challenge. Are there CS reactions in the oral mucosa? Clinical and experimental studies indicate that the oral mucosa can function both as induction and expression site of CS. The GI tract may be an important modifier of the CS inflammatory reactions seen in the oral mucosa.     

Hypersensitivity of the oral mucosa: clinics and pathology

Hypersensitivity reactions of the oral mucosa comprise an array of clinical manifestations. Some of the reactions are difficult to differentiate from toxic reactions. Hypersensitivity reactions of type I, type III, and type IV are well known, although, especially for types I and III, they are rarely encountered. Type-I reactions are most frequently seen related to application of polymers in the oral cavity, such as orthodontic bonding and fissure sealant materials. There may also be systemic manifestations such as urticaria. Type-IV reactions may be seen related to most dental materials used, from amalgam and gold to polymers. These reactions appear as chronic reddening and/or ulceration of the oral mucosa. Lichenoid reactions have histopathological characteristics compatible with type-IV hypersensitivity reactions and are the most prevalent material-adverse reactions seen in the oral cavity. A special variety inside the lips with multiple papules and/or diffuse redness has recently been identified. This lesion comprises a serious treatment challenge. Skin patch tests, applying a series of dental materials in non-toxic concentrations on the skin, have been used to identify sensitization. However, the value of those tests can be questioned. Exacerbation of geographic stomatitis may be another form of hypersensitivity to dental materials.     

Betaine reduces the irritating effect of sodium lauryl sulfate on human oral mucosa in vivo

Our aim was to evaluate whether betaine has a protective effect during exposure of the human oral mucosa in vivo to sodium lauryl sulfate (SLS) or cocoamidopropylbetaine (CAPB) as measured with a multifrequency electrical impedance spectrometer (EI). Both detergents were used at the concentration of 2.0% w/v with and without 4.0% w/v betaine in distilled water in 20 volunteers, and 0.5% and 1.0% w/v SLS combined with 4.0% w/v betaine in 5 volunteers. EI measurements were taken before application of the test solutions, after their removal, and every 15 min up to 45 min. Both 0.5% and 1% SLS solutions showed a significant reduction in 3 of the 4 indices, indicating mucosal irritation after the 15-min exposure (P < 0.05), whereas 2% SLS did so in all 4 indices (P < 0.001). Betaine had no effect on the detergent-induced decline with either the 2% or the 0.5% SLS solutions. However, when combined with the 1% SLS solution, betaine significantly (P < 0.05) reduced mucosal irritation by abolishing decreases in indices MIX (magnitude index) and IMIX (imaginary part index) and lowering it for PIX (phase index). The 2% CAPB solution showed a significant (P < 0.05) reduction in all 4 indices after the 15-min exposure, but the effect was significantly weaker than that of 2% SLS (P < 0.05). Betaine did not reduce the irritating effect of 2% CAPB. These findings can be used in the development of less irritating products for oral health care.     

A novel method for sampling the microbiota from the oral mucosa

The purpose of this study was to develop a site-specific sampling method that could give representative and quantitative results for defined areas of the oral mucosa and would be easy to use. Two site-specific sampling methods (swab and filter paper imprint) were compared. The filter paper sampling method was developed for this study. Samples were collected from 14 volunteers. All samples were cultured under aerobic and anaerobic conditions. The number of viable bacteria and yeasts was determined and expressed per unit area. The filter paper recovered a significantly higher number of colony types of bacteria compared to the swab sample. Both collected a large number and variety of different oral microbes. The filter paper sampling method could be the optimal technique for quantitative site-specific oral mucosal samples and is highly suitable for both culture-based and non-culture-based identification of oral microbes.     

Comparison of CD34 expression in fibrous reactive hyperplasia and healthy oral mucosa

ObjectivesFibrous reactive hyperplasia (FRH) is a common fibrous lesion in the oral cavity. The disease characteristics of FRH, including the expression patterns of CD34, which is a well-known fibroblast marker, have not been investigated in detail. Therefore, in this study, we aimed to investigate the characteristics of FRH compared to those of the healthy mucosa, based on CD34 expression profiles.MethodsCD34 expression was analyzed at the protein and mRNA levels using immunohistochemistry, quantitative polymerase chain reaction, and in situ hybridization (ISH).ResultsCD34 was not expressed in the lamina propria of the oral mucosa, but was commonly observed in submucosal fibroblasts. CD34-positive fibroblasts were commonly observed in FRH. A total of 17 out of 19 cases (89.5%) were CD34-positive. Furthermore, we identified a significant difference in the ratio of CD34-positive cells between the healthy and FRH tissues. Quantitative polymerase chain reaction showed that CD34 mRNA was expressed in all cases of FRH, and CD34 mRNA expression in FRH samples was found to be localized to spindle-shaped fibroblasts, as determined by ISH. A positive correlation was also found between the CD34 mRNA levels and the proportion of the CD34-positive cells.ConclusionsThese findings suggest that the increase in collagen synthesis in CD34-positive fibroblasts in the submucosa leads to the development of FRH. To our knowledge, this is the first report confirming the mRNA expression patterns of CD34 in FRH.     

Allopurinol-amplified lichenoid reactions of the oral mucosa

Three cases of oral lichenoid reaction linked with the administration of allopurinol are presented. Withdrawal of the drug resulted in considerable clinical improvement in one case and complete resolution of the ulcerative lesions in the other two cases. The consideration of drug-induced reactions in the differential diagnosis of oral mucosal diseases has been emphasized.     

Pigmentation of the oral mucosa by PCB poisoning in Yusho patients

Objectives

Toxins, such as PCBs, dramatically affect patients even decades after exposure. Although 40 years have passed since the accidental poisoning with polychlorinated biphenyl (PCB) in Western Japan in 1968, high concentrations of PCBs are still detected in the serum of the “Yusho” (oil disease) patients. In this study, an epidemiological examination was carried out to reveal the prevalence of the oral pigmentation and blood concentrations of PCBs and polychlorinated quaterphenyl (PCQ) in Yusho victims.

Design

We performed a group examination of patients (Yusho victims) from 2004 to 2006, including 72 Yusho victims and 15 control subjects. The oral examination was performed by two oral and maxillofacial surgeons. The serum concentrations of PCB and PCQ were determined using gas chromatography; blood samples from Yusho victims were analyzed for PCB and PCQ by saponification in 1 M NaOH ethanol solution, extraction with n-hexane column chromatography on silica gel, and then gas chromatography with electron capture detection.

Results

The mean Yusho victim's serum PCB and PCQ concentrations were 3.3 ppb and 0.9 ppb, respectively. In controls, these were 0.7 ppb and 0 ppb, respectively. Oral pigmentation was observed in 24 out of 72 Yusho patients. In controls, oral pigmentation was observed in one out of 15 persons. Oral pigmentation was most frequently observed in the buccal mucosa, followed by gingival mucosa. The blood concentration of PCB in Yusho patients with oral pigmentations was significantly higher than that in Yusho patients without oral pigmentation.

Conclusion

These results indicated that PCB-related compounds may be responsible for the higher prevalence of oral pigmentation in Yusho victims, even though a long time has passed since the Yusho poisoning accident.     

口腔粘膜嗜酸性溃疡的临床病理分析

目的 探讨口腔粘膜嗜酸性溃疡的病因、临床病理表现、诊疗与预后,以期对该病有所了解和认识。方法 对８例口腔粘膜嗜酸性溃疡病人进行临床病理分析。结果 口腔粘膜哮酸性溃疡界限清楚,表面清洁,所有病例均正规闰于舌部且为单发,３例有复发史,镜下以固有层嗜酸性细胞为特点。结论 口腔粘膜嗜酸性是一种少见的自限性良性疾病,好于发老人和儿童,病因不清,可能与创伤有关,诊断根据临床病理表现,治疗采用活检切除产完全切除     

正常人口腔粘膜不同部位表面感觉的测试

目的 建立正常人口腔粘膜不同部位表面感觉的正常参考值，并测试各年龄组感觉值是否存在差异。方法 利用动静两点辨别觉试验，测试90例健康人口腔粘膜不同部位的表面感觉。结果 舌尖感觉功能最好，其次为舌背、舌腹、颊粘膜、口底和硬腭。健康人的口腔粘膜不同部位的表面感觉随着年龄增长有显著性变化。结论 口腔粘膜不同部位感觉辨别力存在差异，健康人口底、舌腹、舌背、颊和硬腭粘膜感觉功能有增龄性变化。     

Reduced expression of nuclear factor kB in oral mucosa undergoing preoperative chemoradiotherapy

Radiotherapy as well as chemotherapy in head and neck cancer induces severe oral mucositis. Even after healing of the mucositis, however, the oral mucosa looking atrophic is known to be susceptible to injury and infection. In order to investigate such vulnerability of mucosa, we immunohistochemically studied the expressions of Ki-67, proliferating cell nuclear antigen (PCNA), cyclin D₁, nuclear factor (NF)-kB, and keratinocyte growth factor (KGF) receptor in the oral mucosal keratinocytes undergoing preoperative concurrent chemoradiotherapy for oral cancer, compared with those of the oral mucosa without such therapy. As a result, the expressions of Ki-67, PCNA, and cyclin D₁ were decreased in the chemoradiotherapy-treated oral keratinocytes. Interestingly, NF-kB expression, which is known to be enhanced in oral mucositis, was reduced after chemoradiotherapy. The chemoradiotherapy had no effect on the expression of KGF receptor in oral keratinocytes. In conclusion, the vulnerability of oral mucosa undergoing chemoradiation may be associated with reduced NF-kB expression and impaired growth activity.     

Quantitative study of taste bud distribution within the oral cavity of the postnatal mouse

The aim of this study was to investigate the age-related developmental changes of taste bud distribution within the subpopulations at different postnatal ages in the mouse oral cavity.

Developmental changes of taste bud distribution on the soft palate, fungiform, foliate and circumvallate papillae in the mouse oral cavity were examined histologically at different postnatal ages. After paraffin embedding, complete serial sections at 10 μm thickness were made and stained by routine hematoxylin–eosin staining methods. Digitised images for each section were examined carefully. The existence of a taste pore was used to identify mature taste buds. A two-way analysis of variance (group versus age) was used to analyse differences in taste bud number and characteristics for each of the developmental changes. An independent measures t-test was used to compare two means. No taste buds with pores were observed at birth within circumvallate and foliate papillae. However, 61% of the circumvallate and 58% of the foliate taste buds contained taste pores at 2 weeks after birth. In contrast, at birth, 55% of the taste buds on the soft palate and only 22% of the taste buds within fungiform papillae contained taste pores. Then, the number of mature taste buds (taste buds with pores) increased rapidly 1 week after birth, resulting in 90% of soft palate taste buds and 32% of fungiform taste buds containing taste pores.

These results suggests that the earlier maturation of soft palate taste buds compared with the other populations in the oral cavity raises evidence of their significant role in the taste mechanism, especially in the early life of the mouse.     

槟榔碱对口腔黏膜肌成纤维细胞分化的影响

目的探讨口腔黏膜下纤维性变组织中肌成纤维细胞的来源。方法通过体外口腔黏膜角质形成细胞和成纤维细胞共培养，用免疫组化、反转录聚合酶链反应等方法观察α-平滑肌肌动蛋白的表达。结果体外培养的口腔黏膜下纤维性变成纤维细胞中α-平滑肌肌动蛋白的阳性率为（85.80±3.56）％，正常口腔黏膜成纤维细胞中阳性率为（3.82±0.76）％。槟榔碱直接干预成纤维细胞后α-平滑肌肌动蛋白的表达与对照组相比差异无统计学意义（P〉0.05）；角质形成细胞与成纤维细胞共同培养组成纤维细胞中α-平滑肌肌动蛋白的表达增强；角质形成细胞经槟榔碱预处理后与成纤维细胞共同培养组α-平滑肌肌动蛋白的表达强于无干预共同培养组。结论口腔黏膜下纤维性变组织中成纤维细胞向肌成纤维细胞分化可能是槟榔成分与角质形成细胞共同作用的结果。     

口腔微生物稳态与口腔鳞癌患者顺铂敏感性的相关性分析

目的 探讨口腔鳞癌（oral squamous cell carcinoma,OSCC）患者口腔内微生物与顺铂敏感性之间的相关性。方法 采集29例OSCC患者化疗前唾液样本,根据RECIST 1.1评价标准将患者分为顺铂耐药组（无效）和顺铂敏感组（有效）,采用16S rRNA基因测序,分析OSCC患者口腔微生物物种组成、群落多样性及丰度、样本间差异。采用SPSS 19.0软件包对数据进行统计学处理,LEfSe分析2组样本间物种差异。结果 与顺铂化疗敏感组相比,顺铂耐药组唾液样本中微生物多样性和丰度显著增加。在属水平上,顺铂耐药组患者口腔内奇异菌属、红蝽菌、微单胞菌、尤里优杆菌以及梭杆菌与顺铂敏感组相比存在显著差异。结论 顺铂耐药组与敏感组OSCC患者口腔内微生物结构和组成存在显著差异,提示微生物可能成为OSCC患者顺铂化疗前筛选的生物标志物。     

口腔粘膜缺损两种治疗方法的比较研究

目的评价自体中厚皮片和脱细胞异体真皮基质口腔粘膜补片两种方法治疗口腔粘膜缺损的临床效果。方法选取口腔粘膜缺损的病例共32例，随机分为A、B两组，每组各16例，缺损部位为舌、口底及腭部，A组用自体中厚皮片修复，B组用脱细胞异体真皮基质口腔粘膜补片修复，用反包扎法固定，术后随访6个月～3年。结果两组均无失败病例，A组有2例大部分成活，B组均完全成活。A、B两组3个月后收缩率无明显差异。结论脱细胞异体真皮修复口腔粘膜缺损，效果满意。     

表皮生长因子及受体在牙齿萌出时的表达及意义

目的观察萌出前后,表皮生长因子(EGF)及受体(EGFR)在口腔粘膜中的表达,探讨EGF在牙齿萌出时软组织通道形成中可能发挥的作用。方法免疫组化法检测牙齿萌出过程中,表皮生长因子及其受体在牙萌出部位口腔粘膜的表达变化。结果牙齿萌出时,EGF在萌出牙齿冠方粘膜的上皮层呈弱阳性表达,EGFR在口腔上皮全层呈强阳性表达。而牙齿萌出后,EGF的表达集中于口腔粘膜的固有层,EGFR的表达集中于上皮基底层。结论表皮生长因子及其受体可能促进萌出牙齿冠方实性上皮团的形成,从而参与软组织通道的建立。     

Screening methylation of DNA repair genes in the oral mucosa of chronic smokers

ObjectiveThe aim of this study was to evaluate the epigenetic changes in the process of oral carcinogenesis by screening the methylation of repair genes in chronic smokers.DesignTwo groups were formed: Group 1: 16 smokers with consumption of 20 cigarettes/day for at least 10 years; and Group 2: 10 non-smoking. Exfoliative cytology of the tongue was performed, and the extracted DNA was treated by enzymes. The PCR Array System performed methylation screening to evaluate 22 DNA repair genes, and the results were validated by RT-qPCR for each gene with methylation levels ≥10%.ResultsHighest percentages of methylation were observed for MLH3 and XRCC1 genes (11–20% methylation) and in one case for MRE11A and PMS2 (>50% methylation). Statistical analysis showed significant differences in the expression of the genes MRE11A (p = 0.0002), PMS2(p = 0.0068), XRCC1 (p = 0.0080) and MLH3 (0.0057) between the two groups.ConclusionThe effects of chronic smoking on oral mucosa led to the methylation of genes MRE11A PMS2, XRCC1 and MLH3, but resulted in a reduction of gene expression of MRE11A and PMS2, which showed ≥50% methylation. These results provide evidence that smoking cause methylation and reduced expression of repair genes.     

肝移植术后口腔粘膜病变的诊治

目的：探讨肝移植术后口腔粘膜病变的诊治。方法：通过所经治的１０例临床活体肝部分移植术患儿，报告了口腔粘膜病变的特点。结果：有４例患儿出现了口腔粘膜病变，分别为单纯疱疹１例，口腔真菌感染１例，原因不清的复合性病变２例，全部病例都经治而愈。结论：肝移植术后口腔粘膜病变主要由病毒、真菌、药物或营养失衡所致，其诊治各有特点，需区别对待