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.     

Expression of cytoskeletal proteins in developing human minor salivary glands

The presence of an epithelium at different stages of proliferation and differentiation raises interesting questions concerning the histogenesis, cell turnover and differentiation of normal salivary glands. In order to expand knowledge of these aspects, we investigated the expression of cytokeratins (CKs) 7,8,10,13,14,16,18 and 19, vimentin (VIM), and smooth muscle actin (SMA) in developing human minor salivary glands using monoclonal antibodies. Labial, buccal, palatine, and lingual salivary glands and those from the floor of the mouth were obtained from human fetuses (forensic postmortem) ranging in age from gestational weeks 10 to 29. Serial sections, 3 microm thick, were immunostained using a strepto-avidin-biotin technique. Reactivity for all antibodies was negative in the salivary gland epithelium during the developmental stages of bud formation, cord growth, and branching of cord. During canalization and cytodifferentiation, the glandular epithelial cells showed a positive reaction to some CKs and SMA. Cytokeratins 7, 8, 18, and 19 showed strong labeling in luminal duct cells that exhibited some degree of morphological differentiation. Myoepithelial cellc were recognized by antibodies to SMA. Cytoskeletal protein expression changes according to the cell type, degree of differentiation, and stage of morphological development of the glandular structure. These changes occur independently of the localization of the gland.     

增殖细胞核抗原在涎腺腺癌中的表达及其临床意义

目的探讨增殖细胞核抗原(PCNA)在涎腺腺癌中的表达及临床意义。方法选择47例涎腺腺癌石蜡标本,用免疫组化方法(SABC)测定PCNA表达。结果PCNA在涎腺腺癌中的表达阳性率为(76.12±19.24)%,表达呈异质性。PCNA指数与口腔癌的肿瘤大小、分化程度、淋巴结转移相关,与TNM分期无关。结论PCNA可作为判断涎腺腺癌恶性程度及预后的有效指标。     

Histochemical study of lectin binding in the human fetal minor salivary glands

The emerging synthesis of glycoconjugates containing specific oligosaccharides in developing human fetal labial and lingual salivary glands has been investigated by lectin histochemistry. An avidin-biotin technique was used to study the binding of lectins from Ulex europeus I (UEA-I), Dolichos biflorus (DBA), Glycine maximus (SBA), Helix pomatia (HPA), Arachis hypogaea (PNA) and Triticum vulgare (WGA) to specific sugars on sections of tissue from labial glands, glands of Blandin and Nuhn, glands of von Ebner and the dorsoposterior lingual salivary glands. Incipient synthesis of glycoconjugates in early glands and their presence in the cells and ducts of the later glands was shown. The study also showed a time-related increase in both staining intensity and binding sites of serous acinar cells from all glands and for all lectins used. For mucous cells, peak intensity of staining was reached by the middle phase of development. During later gland development this intensity was maintained in dorsoposterior lingual glands but tended to decline in labial glands. The various lectins showed different degrees of binding but UEA-I lectin generally bound the L-fucose sugar group in all salivary glands at all gestational ages. The results showed that lectins appear to bind to the oligosaccharides on epithelial cell surfaces of fetal salivary glands at all stages of development. The degree of change depends upon the stage of differentiation and maturation of the glands.     

Immunohistochemical localization of members of the transforming growth factor (TGF)-β superfamily in normal human salivary glands and pleomorphic adenomas

Although pleomorphic adenoma is the most common type of salivary gland epithelial tumor, it frequently contains "mesenchymal"-like components, including myxoid or chondroid tissues. We reported previously that chondroid tissue formation in pleomorphic adenoma was associated with overexpression of bone morphogenetic proteins (BMPs) by neoplastic myoepithelial cells. BMPs belong to the transforming growth factor (TGF)-beta superfamily, so we hypothesized that pleomorphic adenoma may express TGF-betas and that these molecules may regulate mesenchymal-like tissue formation. To evaluate this hypothesis, we immunohistochemically examined TGF-beta1, -beta2 and -beta3 expression and localization in normal salivary glands and in 43 cases of pleomorphic adenomas. There was no evidence of TGF-beta1 expression in normal salivary glands or pleomorphic adenomas. Signals for TGF-beta2 in the normal salivary glands were observed in the intercalated ducts, while in pleomorphic adenomas they were observed in the inner ductal cells of the tubulo-glandular structures. Signals for TGF-beta3 in the normal salivary glands were observed in mucous cells, whereas in pleomorphic adenomas they were observed in the solid nests of neoplastic myoepithelial cells, in the portion showing squamous metaplasia, and in the inner ductal cells of tubulo-glandular structures. TGF-betas induce ectopic cartilage formation in vivo, but chondroid tissues in pleomorphic adenomas showed only weak TGF-beta3 expression. TGF-beta may be related to differentiation of the inner ductal cells and the neoplastic myoepithelial cells. In conclusion, pleomorphic adenomas expressed TGF-beta2 and -beta3, which may be associated with differentiation of the inner ductal cells and neoplastic myoepithelial cells.     

Immunohistochemical study of lymphoid tissue in human fetal salivary gland

Immunoreactivity of lysozyme (LY), lactoferrin (LF), α₁ antichymotrypsin (α₁-ACT), α-antitrypsin (α₁-AT), keratin proteins KL1, PKK1, K8.12, S-100 protein, MAM-3, MAM-6, and epithelial membrane antigen (EMA) were evaluated in lymphoid and glandular tissues of developing salivary gland of human fetus (gestational age ranging from 17 to 40 wk to investigate the role of lymphoid tissue in developing salivary glands. In a total of 79 cases, lymphoid cell aggregations were noted in parotid (57 cases), submandibular (21 cases) and sublingual (5 cases) glands. Mononuclcar cells showing intense activity of LY, α₁-ACT and α₁-AT were present in the lymphoid aggregation. The glandular ducts embedded in lymphoid tissue were negative to MAM-3, MAM-6, EMA and S-100 protein, but showed positive PKK1 and KL1 reaction during early stages of development, and showed degeneration and effacement upon increase in number and LY activity of the mononuclear cells. The lymphoid aggregations progressively emerged as lymph nodes.     

Immunoprofile of focal lymphocytic infiltration in minor salivary glands of healthy individuals

Aim: To characterize the immunohistochemical profile of the inflammatory cells included in the focal lymphocytic infiltration in the minor salivary glands of healthy individuals. Materials and Methods: Tissue samples of the labial and palatal salivary glands from 46 postmortem subjects, demonstrating the presence of focal lymphocytic infiltration were quantitatively evaluated for the presence of T‐ and B‐cell lymphocytes, plasma cells and macrophages by immunohistochemical and morphometric methods. Results: B‐cell lymphocytes, the predominant cell population in labial (67.5%) and palatal salivary glands (60.8%), were more frequent than T‐cell lymphocytes in both glands (P < 0.001). Among the T‐cell lymphocytes, CD₄‐positive cells were significantly more prevalent than the CD₈‐positive cells (P < 0.001). Plasma cells were almost absent, comprising only 0.01% of the focal lymphocytic infiltration cells of the labial and palatal salivary glands. Conclusions: Focal lymphocytic infiltration in the samples of the salivary glands obtained from healthy individuals is devoid of plasma cells. This can serve as an additional means to differentiate between focal lymphocytic infiltration in patients with Sjögren's syndrome, in which plasma cells are abundant, and focal lymphocytic infiltration in individuals with other causes of focal sialadenitis.     

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.     

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.     

Localization of lysozyme mRNA in the labial salivary glands by in situ hybridization in Sjögren's syndrome

Abstract – In this study, lysozyme mRNA in labial salivary glands has been localized with in situ hybridization technique using 35S-labeled hen lysozyme cDNA (cDNALZM) as a hybridization probe in normals and in patients with Sjögren's syndrome. 35S-DNALZM:mRNA hybrids were detected only in acinar serous cells, although lysozyme was identified in ductal cells using immunohistochemical techniques. Our results suggest that the serous acinar cells are the only site of lysozyme synthesis in small salivary glands. The presence of lysozyme in ductal cells may be a result of reabsorption from the saliva or concentration from the blood or surrounding tissues.     

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。     

Cell culture and characterization of human minor salivary gland duct cells

In order to facilitate studies on human salivary glands, a method was developed for the culture of minor salivary gland duct cells from tissues obtained from oral surgery protocols. Minor salivary glands were isolated from such tissues, and a serum-free growth medium was developed which supported the growth of the ductal component of these glands. The ductal origin of these cells was confirmed through immunohistochemical localization of replicating nuclei through incorporation of BrdU. The presence of epidermal keratin in replicating cells and the absence of smooth muscle myosin further substantiated the ductal origin of cells. Using normal growth medium calcium concentrations (1.05 mM), these cells produced a keratinized multilayer of cells unable to undergo routine subculture procedures. A reduction in calcium ion concentration to 0.1 mM resulted in a cell monolayer, without evidence of terminal keratinization, which could undergo at least eight serial passages (1:3 ratio) under cell culture conditions. It is advanced that these minor salivary gland duct cell cultures will be of use to those studying diseases and disorders of the salivary glands.     

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.     

Stereological and immunohistochemical study of development of human fetal labial salivary glands and their S-100 protein reactivity

Stereological and certain histochemical aspects of fetal growth and development of human labial salivary glands are reported. Stereological analysis showed a highly significant progressive increase in proportional gland volume occupied by acini from 27% at 20 weeks to 56% at 38 weeks ( P <0.0001), and a comparable halving of the relative gland volume occupied by connective tissue in the same period ( P <0.0001). Linear regression fitted the data well (r²= 0.59 and 0.47 respectively, n=46 ). The change in relative volume occupied by ducts or by vascular tissue was small and did not reach significance. S-100 protein reactivity was demonstrated in the cytoplasm of cells of the labial gland primordia from their origin. As gland differentiation progressed, the S-100 reactivity became localized in basophil acinar cells and in proximal (intercalated and intralobular), but not in distal, duct cells. A gradual increase in intensity of S-100 protein activity at these sites during salivary gland development was observed. Morphological maturity seems to be complete before 29 weeks but myocpithelial cells could not be identified with certainty.     

兜甲蛋白和细胞色素P4503A5在口腔黏膜下纤维化中的表达及意义

目的探讨兜甲蛋白（LOR）和细胞色素P450 3A5（CYP 3A5）在口腔黏膜下纤维化颊黏膜（OSF）和正常颊黏膜中的表达以及在上皮防御作用中的意义。方法首先采用免疫组化染色检测66例OSF颊黏膜和14例正常颊黏膜中LOR和CYP 3A5这2种蛋白的表达和定位,然后采用Western blot和RT-PCR方法分别在OSF患者颊黏膜和正常人颊黏膜中检测LOR和CYP 3A5的蛋白和mRNA表达。结果42例（63.6%）OSF呈LOR阳性表达,其在早、中期之间差异有统计学意义（P<0.05）,而中、晚期之间差异无统计学意义（P＞0.05）;正常颊黏膜中CYP 3A5均呈阳性表达,5例（7.6%）OSF出现棘细胞弱阳性表达,33例（50%）出现内皮细胞弱阳性表达,与病理分期呈负相关（P<0.05）。RTPCR显示LOR和CYP 3A5 mRNA在OSF与正常黏膜中表达的差异均有统计学意义（P<0.05）;而Western blot检测显示,只有CYP 3A5蛋白表达在两者间差异有统计学意义（P<0.05）。结论LOR和CYP 3A5的异常表达是OSF黏膜上皮防御能力改变的表现,它们在OSF发生发展和癌变过程中可能发挥了重要作用。     

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.     

Immunohistochemical and electronmicroscopic studies of obstructive lesions in submandibular glands

Obstructive sialoadenitis was examined by immunohistochemical techniques for keratin (MoAb KL1, PKK1 and K8.12) and actin. Electronmicroscopy (EMS) was used to identify ultrastructural changes in myoepithelial cells and ductal basal cells. With immunohistochemistry, actin staining was used as a marker of myoepithelium, MoAbs KL1 and PKK1 for ductal luminal cells, and MoAb K8.12 for ductal basal cells. Histologic features of the lesion usually showed degenerative changes of acinar and duct cells with cell infiltration and fibrous replacement. Immunohistochemical findings indicated that actin staining in the changed myoepithelial cells was irregularly positive or negative, and also keratin staining in luminal and ductal basal cells was reduced or disappeared. Ultra-structural features of the changed myoepithelial cells indicated that these cells appeared less altered than adjacent acinar and ductal cells and showed increased amounts of lipid droplets and lipofuscin granules, and also wrinkled processes filled the prominent myofilament material.     

Anorexia/bulimia-related sialadenosis of palatal minor salivary glands

In patients affected by alimentary disorders sialadenosis is frequently observed. This non-inflammatory condition is described to affect major salivary glands, leading to the characteristic parotid and/or submandibular swelling. Thus fine-needle aspiration cytology or parotid open biopsy are generally required to diagnose histologically the disorder. We report the case of a 28-year-old patient affected by bulimia/anorexia nervosa who presented, in addition to parotid enlargement, a bilateral symmetric painless soft swelling of the hard palate. The lesion was biopsied and histopathological examination showed the classical features of sialadenosis. To our knowledge, this is the first case of sialadenosis affecting palatal minor salivary glands. It underlines that when sialadenosis is clinically suspected, clinicians could check also patients' oral cavity for minor salivary glands involvement, in order to potentially avoid invasive extra-oral procedures and to easily confirm diagnosis with an intra-oral biopsy.