Ultrastructural localization of salivary mucins MUC5B and MUC7 in human labial glands

Piras M, Hand AR, Tore G, Ledda GP, Piludu M. Ultrastructural localization of salivary mucins MUC5B and MUC7 in human labial glands. Eur J Oral Sci 2010; 118: 14–18. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci
As a result of their presence throughout the mouth in the submucosa or between muscle fibers, minor salivary glands secrete directly and continuously into the oral cavity, providing mucosal surfaces with highly glycosylated proteins that are active in bacterial aggregation and in oral tissue lubrication. In this study, we investigated the ultrastructural localization of the MUC5B and MUC7 mucins in human labial glands by means of a postembedding immunogold technique. Thin sections of normal human labial glands, obtained during surgery, were incubated with polyclonal antibodies to human salivary mucins MUC5B and MUC7, and then with gold-labeled secondary antibodies. Specific MUC5B reactivity was found in the secretory granules of mucous cells of all glands examined, and was associated with the luminal membrane of duct cells. MUC7 labeling was observed in the granules of both mucous and seromucous secretory cells of the glandular parenchyma. Quantitative analyses demonstrated that seromucous granules have higher immunogold labeling densities for MUC7 than mucous granules. Our immunohistochemical data extend the results of previous light microscopic studies of MUC5B and MUC7 localizations, pointing out the significant contribution of human labial glands in the secretion process of these two mucins.     

Amyloid deposits in labial salivary glands identified by electron microscopy

Abnormal proteinaceous deposits identified by light microscopy as amyloid in labial salivary gland biopsies were studied by transmission electron microscopy in order to establish (heir ultrastructural characteristics. Results showed fine fibrils approximately 10 nm in diameter located in close relation to the basal lamina of the secretory end-pieces and ducts as well as in the interstitial connective tissue stroma of labial salivary glands: these are the typical features of amyloid. Thus, the present study confirms the light microscopy diagnosis of amyloid deposits in labial salivary gland biopsies, supporting the use of lip biopsy as a readily accessible method for the diagnosis of secondary amyloidosis.     

Effects of tobacco and diuretics on human palatal salivary glands

The prevalence of macrophotographically documented sialadenitis in the palatal mucosa of 184 probands, aged 23 yr or older, was studied in the Koster Health project. A total of 75 (mean age 58.9) revealed inflammatory changes around the duct orifices of the palatal glands. In 10, biopsies were performed for histomorphologic analyses to confirm the diagnosis of sialadenitis. Statistics with matched pairs showed a significantly higher ratio of tobacco use among individuals with sialadenitis than among those with clinically unchanged palatal gland orifices. A relationship between the use of diuretics and sialadenitis was also statistically significant. It can be concluded that tobacco use and diuretics may induce inflammatory changes in the palatal glands and that macrophotography of the palatal mucosa may serve as a valuable, non-invasive method for scoring sialadenitis.     

Phenotyping of immunocompetent cells in normal labial and palatal salivary glands and in non-autoimmune sialadenitis

Different types of inflammatory cells in healthy major and minor salivary glands (SG), including those in labial and palatal non-autoimmune sialadenitis, were quantified immunohistochemically. Plasma cells, mainly IgA type predominated in all SG types, with the smallest number seen in the palatal glands. The numbers of common leukocyte antigen (CLA) reactive lymphocytes were greater in major SGs than in minor ones and were predominantly UCHL1 positive T cell type. Macrophages and neutrophils were absent in palatal glands, rarely present in labial ones and usually present in major SGs. Increases in the number of IgG and IgM plasma cells and lymphocytes (CLA+) which include both UCHL1+ T and L26+ B cell types, were found in non-autoimmune labial and palatal sialadenitis. There was no significant correlation between the number of the inflammatory cells and the degree of glandular atrophy in both labial and palatal non-autoimmune sialadenitis. Increase in their number represents a protective response of these glands in contrast to the inflammatory cells in major autoimmune sialadenitis playing there a pathogenetic role.     

Epithelial HLA-DR expression in labial salivary glands in Sjögren''s syndrome and nonspecific sialadenitis

The expression of the Class II major histocompatibility antigen HLA-DR was quantified in the epithelial cells of labial salivary glands from patients with Sjögrens Syndrome (SS) and compared with similar expression in glands showing non-specific sialadenitis and normal controls. In all glands more duct cells were positive than acinar cells but only in sialadenitis and SS was strong epithelial staining seen. The proportions of duct and acinar cells expressing HLA-DR were increased between normals and sialadenitis (P < 0.01) and between sialadenitis and SS (P < 0.001). However, for all cases increased expression of HLA-DR correlated to the increased proportion of inflammatory cells in the gland (P < 0.01). The results indicate that although HLA-DR is expressed on the epithelial cells in the glandular lesions of SS, this is not specific as it is also seen in sialadenitis. This supports the view that such expression is secondary to an inflammatory infiltrate and may not be of importance in initiating autoimmune tissue damage.     

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目的    观察糖尿病大鼠腮腺、颌下腺、舌下腺超微结构变化。方法    雄性Wistar大鼠20只,随机分对照组和实验组,各10只。实验组：腹腔注射四氧嘧啶制作糖尿病大鼠模型;对照组：正常饲养。动物模型建成后第8周时称重并测定各组大鼠空腹血糖,然后取材制片,应用透射电镜观察大鼠腮腺、颌下腺、舌下腺超微结构变化。结果    建模后第8周时对照组大鼠体重（282.40±14.00）g,血糖（5.50±0.40）mmol／L;实验组大鼠体重 （148.45±8.45）g,血糖（25.20±4.10）mmol／L,组间比较差异有统计学意义（P < 0.05）。实验组大鼠腮腺细胞细胞核轮廓不规则,线粒体肿胀,粗面内质网扩张;颌下腺细胞细胞核固缩,线粒体出现空泡变性、嵴断裂;舌下腺细胞未见明显改变。结论    糖尿病可导致腮腺和颌下腺分泌功能受损而出现口干症状,但未影响舌下腺功能,舌下腺可能起到一定的代偿作用。     

Focal lymphocytic infiltration in aging human palatal salivary glands: a comparative study with labial salivary glands

Investigation of age-related prevalence of various types of focal lymphocytic infiltration (FLI) and degrees of histomorphologic changes was conducted on 120 biopsies of palatal and labial salivary glands (PSG and LSG, respectively) obtained from autopsy subjects free of salivary gland tumors/diseases. Biopsies were divided into young (<30 years, n=30), adult (30-60 years, n=45) and old (>60 years, n=45) age groups. A modified Chisholm & Mason grading system was used to record grades of FLI and a modified Greenspan et al. system was used to evaluate the severity of histomorphologic changes. The prevalence of FLI in PSG increased significantly from 10% in the young group to 46.6% in the old group (P=0.0012). No significant changes were found with aging in LSG. FLI was significantly more prevalent in the adult and old age groups in PSG as compared with LSG (P=0.015 and P=0.003, respectively). Both glands demonstrated significant histomorphologic changes among age groups (p<0.0001); however, these changes were significantly less common in the old age group in PSG as compared to LSG (P=0.003). In cases showing severe histomorphologic changes, FLI was not present. Therefore, FLI should not be considered as part of the deteriorating histomorphologic changes that are usually encountered in salivary glands with aging. The immunologic profile of these infiltrates should be further clarified to understand their role, both in physiologic and pathologic conditions.     

Ultrastructure of salivary calculi

ABSTRACT – Twenty-one submandibular salivary calculi from 19 patients were examined with the light and electron microscope. Adjacent to the peripheral parts of the calculi metaplastic squamous epithelium or connective tissue was seen in close contact to the mineralized matrix. Disintegrated cellular substances from these tissue components were in some cases found to condense in a peripherally located zone of the salivary calculi. The morphology of the examined salivary calculi varied extensively not only within each calculus but also from one calculus to another. High and low incidence of crystals gave rise to the lamellated pattern. In some cases the crystals were so abundant as to give a dense homogeneous appearance. In the central parts of the calculi spheroid bodies of very low electron density with a size ranging from 1 to 100μm were found in an amorphous matrix. The origin of these structures is discussed. In the peripheral parts of some calculi os-miophilic spherical bodies with an electron microscopical appearance similar to lipid granules as well as bacteria of cocci or coliform type were found. Degenerated bacteria might in some cases contribute in forming part of the peripheral organic matrix.     

Increase of microliths in inactive salivary glands of cat.

Secretory inactivity could be a factor in the formation of microliths, and so their occurrence in feline salivary glands after the secretory inactivity produced by parasympathectomy was investigated. Parasympathectomy was followed by a greatly increased occurrence of microliths in the submandibular salivary gland, but not in the parotid and sublingual, which may relate to residual secretory activity in these glands. This discovery suggests that secretory inactivity may indeed be a factor in the production of microliths in human salivary glands, and consequently of chronic sialadenitis and sialothiasis.     

Inverted ductal papilloma of minor salivary glands

Inverted ductal papillomas are rare tumours of minor salivary glands. A case is reported on the lower lip of a 50–year-old man. The tumour showed a characteristic endophytic growth pattern and was composed of bulbous papillary projections of basaloid cells dilating and filling the superficial portion of the excretory duct. Histologically, inverted ductal papillomas resemble the inverted papilloma of the nose and paranasal sinuses, but are completely benign and are not associated with malignant change.     

Variation in the response to ductal obstruction of feline submandibular and sublingual salivary glands and the importance of the innervation

A variable response following ductal ligation of feline salivary glands corresponds to the human condition but contrasts with a predictable atrophy in obstructed salivary glands of rodents popularly used as a model for human salivary problems. The present investigation is concerned with a possible reason for the variable response, namely the preservation of the innervation. Ducts of feline submandibular and sublingual salivary glands were ligated with or without the inclusion of the chorda tympani. Inclusion led to a delayed initial response followed by progressive atrophy until the parenchyma was extremely atrophic, whereas avoidance of the chorda led to the variable response in which variable numbers of acini of a similar form to normal persisted. The results establish the atrophic effect of inclusion of the chorda tympani in ductal ligation and indicate the caution that should be exercised in the extrapolation of the rodent model to the human condition.     

Kuttner tumour: an unusual cause of enlargement of a minor salivary gland in the lip

Kuttner tumour is benign, chronic, sclerosing sialadenitis that usually occurs in the submandibular gland and is regarded as a salivary gland neoplasm because of its clinical features. We describe a tumour arising from a minor salivary gland of the upper lip. To our knowledge, there are only two previously reported cases.     

涎腺淋巴上皮病变25例报告

作者对２５例涎腺淋巴上皮病变的临床资料和观察随访结果进行了分析。并对本病的名称和性质，Ｍｉｋｕｌｉｃｚ病与Ｓｊｏｅｇｒｅｒ综合征的关系作了讨论，认为涎腺淋巴上皮病变一般为良性过程，但具有肿瘤的特性。临床易误诊，治疗需按涎腺肿瘤的治疗原则。     

A clinicopathologic study of 196 intraoral minor salivary gland tumours

We present a retrospective study of 196 patients with intraoral minor salivary gland tumours, 128 malignant and 68 benign, diagnosed from 1954 to 1993 in the A.C. Camargo Hospital, São Paulo, Brazil. Sixty-five percent of the cases occurred in the palate, followed by tongue (9.7%) and retromolar area (6.1%). Pleomorphic adenoma was the most common benign tumour, and mucoepidermoid carcinoma was predominant among the malignant tumours. Surgery was the main treatment method and postoperative radiotherapy and radiotherapy alone were used in 40 and 15 patients, respectively. Local recurrence was observed in two patients with pleomorphic adenoma and in eight patients with malignant tumours. Regional lymph node metastases occurred in four cases and distant metastases in five. Forty-six of 47 patients with benigh tumours who were followed up from 1 to 7 years were alive without disease. Twenty-four of 79 patients with malignant tumours who were followed up for at least 5 years died due to the tumour and 47 were alive without disease.     

涎腺恶性肌上皮瘤

目的 分析涎腺恶性肌上皮瘤临床病理特点及生物学行为。方法 对15例患者进行回顾性分析，包括发病情况，临床表现，组织病理学，治疗方法等。随访时间3个月－24年。结果 15例中男性7例，女性8例，年龄24－72岁（平均50岁）。6例肿物由良性肿瘤恶变而来，主要发生于腮腺及腭部小涎腺。临床上主要表现为：快速生长或生长突然加速的包块，溃疡，骨质破坏和神经侵犯。所有肿瘤均在肿物外无瘤区扩大切除，部分病例实施了舌骨上清扫术或全颈淋巴清扫术。15例中8例系复发病例，3例经病理证实有颌下或颈淋巴结转移，1例肺转移。组织学检查发现，绝大多数肿物侵入周围涎腺组织或邻近脂肪，肌肉，骨组织，侵入程度不一。肿瘤细胞形态呈多样化，有透明型，梭形，上皮样型，浆细胞样型或混合型。本组以透明细胞为主，占9例。结论 恶性肌上皮瘤区域淋巴结和远处转移率低但局部复发率很高。是一种低度恶性肿瘤，主要引起局部软组织及骨组织的破坏。     

Primary non-Hodgin's lymphoma of the salivary glands. An analysis of 22 cases

Twenty-two patients with primary non-Hodgkin's lymphoma (P-NHL) of the salivary glands have been studied with reference to age, sex, clinical symptoms, location of primary tumour, histological subtype, grade of malignancy according to the Working Formulation, stage of disease, treatment and follow up.
The clinical features corresponded with previously reported data on salivary gland lymphomas. The most frequent histological diagnosis was MALT lymphoma. Most patients had a localised low-grade lymphoma. Overall survival was influenced by grade of malignancy according to the Working Formulation.