Immunohistochemical observations on carbonic anhydrase I and II in human salivary glands and submandibular obstructive adenitis

Immunohistochemical identification of carbonic anhydrase I and II (CA-I, CA-II) was made in human major salivary glands and obstructive adenitis in submandibular glands. Normal salivary glands stained the strongest for CA-II in serious acinar cells and were negative in mucous cells. Moderate to strong staining for CA-I and CA-II was found in ductal segments. Submandibular glands with obstructive adenitis exhibited reduced CA-I activity in atrophic acinar cells, but not in ductal elements in the early and intermediate stages of the disorder. In the late stage of the obstructive lesion, CA staining in duct-like structures was moderate; however, almost degenerate ductal cells were negative for CA. During the progression of the degeneration in the obstructive lesion, the CA staining decreased dependent on acinar atrophy. Even after longstanding obstruction of the salivary gland, altered ductal epithelia may retain some of their functions.     

Immunohistochemical observations on carbonic anhydrase I and II in human salivary glands and submandibular obstructive adenitis

Abstract Immunohistochemical identification of carbonic anhydrase I and II (CA-I, CA-II) was made in human major salivary glands and obstructive adenitis in submandibular glands. Normal salivary glands stained the strongest for CA-II in serous acinar cells and were negative in mucous cells. Moderate to strong staining for CA-I and CA-II was found in ductal segments. Submandibular glands with obstructive adenitis exhibited reduced CA-1 activity in atrophic acinar cells, but not in ductal elements in the early and intermediate stages of the disorder. In the late stage of the obstructive lesion, CA staining in duct-like structures was moderate; however, almost degenerate ductal cells were negative for CA. During the progression of the degeneration in the obstructive lesion, the CA staining decreased dependent on acinar atrophy. Even after longstanding obstruction of the salivary gland, altered ductal epithelia may retain some of their functions.     

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.     

涎腺结石的形成过程及其机制

涎石病是涎腺常见的疾病,主要累及大涎腺.当腺体发生涎石阻塞时,会出现与进食相关的肿胀、疼痛等症状.随着内窥镜技术的发展,可以对涎石进行直视下的诊断和治疗,创伤也更小.但是关于涎石的病因学及确切的形成机制目前尚不明确,本文就涎腺结石形成的过程及机制进行综述.结石通常是由矿化的内核及外周层状结构所构成.机体在刺激因素作用下...     

Immunochemical analysis of laminin in duct-ligated submandibular glands of rats

Immunochemical methods have been used to study the expression of laminin during experimental atrophy of the submandibular gland of rats caused by ductal ligation. In normal submandibular glands, laminin immunoreactivity appeared as continuous linear staining around acini and ducts. In the ligated glands, it exhibited an irregular pattern and intensity. Staining was usually stronger around small ducts and acini, which were most prominent in glands ligated for 30 days. Immunoblot analysis showed that the laminin of the rat submandibular gland contains bands that correspond to the EHS α1, β1 and γ1 chains, and that the composition of the laminin chains does not change during the atrophy.     

Structural and functional injury in minipig salivary glands following fractionated exposure to 70 Gy of ionizing radiation: an animal model for human radiation-induced salivary gland injury

This study explored the feasibility of developing an animal model for radiation-induced salivary gland injury with a radiation protocol identical to current clinical practice. Three male Hanford minipigs were subjected to fractionated daily irradiation with a total dose of 70 Gy; structural and functional measures were compared with those of a control group of minipigs. We found that irradiated submandibular and parotid glands were one-third to one-half the gross size of control glands. Whereas no pathologic changes were noted in control glands, irradiated glands consistently demonstrated significant parenchymal loss with extensive acinar atrophy and interstitial fibrosis, enlarged nuclei in remaining acinar cells, and ductal dilatation and proliferation. Stimulated salivary flow was reduced by 81% in irradiated animals compared with preirradiation flow (P <.001); salivary flow in the control group increased by 30% during the same period (P <.001). The observed radiation-induced structural and functional salivary gland changes are comparable in every respect to those observed following irradiation of human salivary glands.     

Keratin proteins identified in epithelial fragments of salivary mucoceles

Immunohistochemically detected keratin proteins in mucoceles of oral mucosa were used to served as markers to identify epithelial-derived cells of minor salivary glands. Normal ducts of minor salivary glands showed an intense keratin staining. Epithelial lining and or epithelial fragments in cystic walls of mucoceles displayed a strong reaction to keratin proteins too, whereas granulation tissue or connective tissue fibers of the walls were not seen. Foamy macrophages present in cystic cavities signify higher staining with the use of keratin proteins. Mucoceles in oral minor salivary glands are probably caused by ductal obstructions leading to continuous mucous secretion. Keratin proteins were used as an epithelial marker of ductal segments.     

Salivary gland disorders: A comprehensive review

Salivary glands are complex in nature. They could be either tubulo acinar, merocrine or exocrine glands secreting mainly saliva. Salivary gland is one of the main soft tissue structures in the maxillofacial area. Saliva is a clear, slightly acidic muco serous fluid that coats the teeth, mucosa and thereby helps to create and maintain a healthy environment in the oral cavity. Salivary glands may be affected by a number of diseases: local and systemic and the prevalence of salivary gland diseases depend on various etiological factors. The glands may be infected by viral, bacterial, rarely fungal or its ductal obstruction which may cause painful swelling or obstruction, affecting their functions. The salivary gland may also be affected by a various benign and malignant tumours. This review article briefly describes about the various salivary gland disorders, diagnostic techniques and their management including the recent advances and the future perspective.     

Ultrastructural localization of microliths in salivary glands of cat

Although microliths occur in normal human salivary glands and may be an aetiological factor of sialadenitis, little is known of their natural history. In an attempt to remedy this, we investigated a large archival collection of normal and experimental feline parotid, submandibular and sublingual salivary glands. In submandibular and sublingual glands, microliths were detected ultrastructurally in: all types of acinar secretory cells; myoepithelial cells; ductal cells; lumina; intercellular spaces; basement membrane; stroma; macrophages; multinuclear giant cells; and neutrophils. Microliths were not detected ultrastructurally in parotid glands. Microliths appear to form in acinar cells during autophagy and in stagnant secretory material in lumina. Microliths appear to be removed by secretion in the saliva, discharge from cells laterally and basally, and engulfment by macrophages. There appears to be a turnover of microliths, which possibly is upset by secretory inactivity with a resulting accumulation that leads to localized obstruction and sialadenitis.     

A qualitative and quantitative study of the ageing human labial salivary glands

A series of 36 post-mortem labial salivary glands from both male and female subjects with ages ranging from 25 to 80 yr were examined histologically. Features such as acinar atrophy, fibrous replacement and ductal aberrations were noted in the aged glands. By the stereological method of point counting, the volume proportions of various defined gland constituents were calculated for individual glands in the series. An age-related decrease in acinar volume proportion and an increase in ductal and connective tissue volume proportion is recorded. These changes should be considered when diseased glands are studied.     

Advances in imaging of obstructed salivary glands can improve diagnostic outcomes

Introduction

Obstruction of the major salivary glands is a relatively common condition defined as the blockage of the salivary outflow in the glandular ductal system. It can however mimic more aggressive pathology.

Methods

The most common cause of salivary obstruction is sialolithiasis, followed by ductal strictures. Salivary obstruction is clinically characterized by a food-related painful swelling of the affected gland, known as ‘mealtime syndrome’.

Results

When obstruction is clinically suspected, the role of imaging consists of confirming the obstruction, identifying its cause, evaluating the position and extent of the obstruction and evaluating for associated complications. However, if imaging shows up signs of a tumour or other pathology which can mimic an obstructed gland clinically instead, the radiologist can alert the clinician accordingly to change the course and plan of treatment. Several imaging techniques are available for investigating the obstructed salivary glands.

Conclusions

This review looks at the causes of obstruction and the use, diagnostic performance and practicality of the various imaging modalities. Importantly, an imaging approach algorithm for the evaluation of the obstructed salivary gland is also proposed.     

Cell population changes during atrophy and regeneration of rat parotid gland

Limited data exist regarding the changes in number and location of myoepithelial cells during salivary gland atrophy and regeneration. Through the use of double immunohistochemical labeling for muscle-specific actin and amylase coupled with morphometric analysis, this study investigated the changes in distribution and proportion of cell types during salivary gland atrophy/regeneration phases in a model previously used to study proliferation in rat parotid gland. The double immunohistochemical labeling clearly showed the changes in proportion of cell types in the atrophying and regenerating glands. The morphometric analysis showed that the relative myoepithelial area increased (as did the intercalated duct and striated duct areas) as the gland atrophied. Myoepithelial cells occupied 19.0% of the total epithelial area by day 7 of atrophy, up from 2.7% in the resting gland. Regeneration of acinar cells was obvious 1 day after duct release. The myoepithelial cell area decreased to 4.3% of the total epithelial area by day 14 of regeneration; this value was higher than the percentage of area in the resting gland (p = 0.02). The relative areas of acinar, striated duct, and intercalated duct cells returned to resting levels after 14 days of regeneration. The morphometric and histologic results of this study show that the parotid gland is capable of regenerating to essentially normal anatomic condition after 7 days of gland atrophy and then 14 days of regeneration. Each type of cell, however, responded to the atrophy and regeneration differently. Atrophy of salivary glands from radiation therapy, Sjögren's syndrome, or sialadenitis is an important clinical problem. Study of the salivary gland response to atrophy and regeneration may provide a framework for designing strategies for the radioprotection of salivary glands or methods by which to treat or reverse the effects of gland atrophy.     

A quantitative study of histological changes in the human parotid gland occurring with adult age

Parotid samples from 63 'sudden death' necropsies of both sexes, aged 17-90 years, were collected after exclusions for chronic illness or medications. Advancing age was accompanied by acinar atrophy and ductal irregularities. The adipose content varied widely at all ages but, together with fibrovascular tissue, tended to increase with age. Stereological analysis demonstrated a linear reduction of acinar proportional volume amounting to 30% over the age range. Females tended to have more adipose tissue and less fibrous tissue than males. These structural age changes resemble those of other salivary glands, but unlike the latter are not accompanied by age-dependent functional impairments. This suggests a greater acinar secretory efficiency or larger secretory reserve volume in the parotid than in other glands. The frequent high levels of parotid adiposity encountered suggest this feature is not pathological nor necessarily a reliable indicator of nutritional or hormonal diseases, excluded from the present study.     

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.     

Production of microliths and sialadenitis in rats by a short combined course of isoprenaline and calcium gluconate.

The relationship between microliths and sialadenitis in man is unclear, so an attempt was made to investigate it experimentally in rats with the use of isoprenaline and calcium gluconate either alone or combined. The acini of the submandibular and parotid glands of rats that were given isoprenaline were enlarged, and degenerate acinar cells were seen, with extravasated secretions in the submandibular gland. Similar changes were seen in the submandibular and parotid glands of rats that were given isoprenaline combined with calcium gluconate; in addition, ductal microliths with regions of atrophic sialadenitis were observed. The results suggest that there is temporary obstruction to the salivary flow after isoprenaline is injected, and in the rats that were also given calcium gluconate some of the stagnant saliva calcified to form microliths, which produced a lasting obstruction and obstructive sialadenitis. This supports the possibility that microliths, which are present in normal salivary glands of man, are a primary etiologic factor in sialadenitis.     

Oral mucoceles - review of the literature

Oral mucoceles are mucin filled cavities and lined by ductal epithelium or covered by granulation tissue in retention or extravasation type respectively. The extra-vasation type is very common in the minor salivary glands (particularly in the labial glands), but very infrequent in the major salivary glands, whilst most of the retention cyst affect the major salivary glands. Partial obstruction of duct and spillage of mucin following trauma are the chief etiological factors. Though the two lesions are clinically indistinguishable, the patients are typically older than in the case of extra-vasation type. The case history along with heedful clinical examination of the lesion is crucial for diagnosing mucoceles correctly, but to avoid recurrences histopathological examination is mandatory. The surgical approach to mucoceles is the most common mode of treatment amongst various other techniques including cryosurgery, laser and so on.     

A quantitative study of histological changes in the human parotid gland occurring with adult age

Parotid samples from 63 'sudden death' necropsies of both sexes, aged 17–90 years, were collected after exclusions for chronic illness or medications. Advancing age was accompanied by acinar atrophy and ductal irregularities. The adipose content varied widely at all ages but, together with fibrovascular tissue, tended to increase with age. Stereological analysis demonstrated a linear reduction of acinar proportional volume amounting to 30% over the age range. Females tended to have more adipose tissue and less fibrous tissue than males. These structural age changes resemble those of other salivary glands, but unlike the latter are not accompanied by age-dependent functional impairments. This suggests a greater acinar secretory efficiency or larger secretory reserve volume in the parotid than in other glands. The frequent high levels of parotid adiposity encountered suggest this feature is not pathological nor necessarily a reliable indicator of nutritional or hormonal diseases, excluded from the present study.     

Changes of salivary functions in experimental periodontitis model rats

ObjectiveThis study was designed to investigate the mechanism of salivary dysfunction in an experimental periodontitis rat model and to examine the improvements in salivary secretion following treatment of the experimental periodontitis.MethodsIn the experimental periodontitis rat model, which included a unilateral ligature for 4 weeks around the second upper molar, several salivary functions were investigated. Changes in the salivary function were evaluated 4 weeks after removal of the ligature in some rats.ResultsThe periodontitis model showed significant reductions in the weight of the bilateral major salivary glands and pilocarpine-induced salivary secretion. The model also showed an increase in the number of apoptotic cells in bilateral salivary glands. According to Ca²⁺ imaging and Western blotting, there were no differences in the muscarine-induced intracellular Ca²⁺ mobilization in acinar cells or in the M3 receptor and AQP5 expression levels in the salivary glands between the sham and the periodontitis model. Following removal of the ligature, differences in the weights of salivary glands and pilocarpine-induced salivary secretion between the sham and the periodontitis model animals were not found.ConclusionThese results suggest that experimental periodontitis leads to hyposalivation and that relief from it improves salivary function. It is likely that lower levels of salivary secretion are caused by the decrease of functional acinar cells in salivary glands in the experimental periodontitis model, and the bilateral gland effects in the unilateral periodontitis model are caused by systemic rather than by local effects.     

Adenoid cystic carcinoma of minor salivary gland. Histochemical and electron microscopic studies of cystlike space.

Five cases of adenoid cystic carcinoma of minor salivary glands were studied. The mucoid material in the characteristic cystlike space of this neoplasm was distaseresistant periodic acid-Schiff (PAS)--positive, alcain blue-positive, toluidine blue-positive, and mucicarmine-positive. Verhoeff-Van Gieson's method and Weighert's method did not reveal elastic tissue in the cystlike spaces. Mallory's method revealed that a central core in cystlike spaces was similar in stainability to collagen. Wilder's method did not reveal reticular fibers in these spaces. Electron microscopy revealed three readily recognizable zones: a juxtacellular zone of a network of replicated basal lamina, and intermediate zone of stellate granules of mucoid material, and a central core of densely packed aperiodic filaments or collagen fibrils. The histogenesis of cystlike spaces and their realtionship with biologic behaviors of the neoplasm were discussed.