Age-related changes in human sublingual glands: a post mortem study

OBJECTIVES: To analyse age- and gender-related microscopic changes in sublingual glands obtained from human cadavers. STUDY DESIGN: One hundred eighty six human sublingual glands were obtained from 93 autopsies. Approximately five individuals of each gender per decade of life were allocated to three age groups: group I (0-30 years, n=26); group II (31-60 years, n=32) and group III (61-90 years, n=35). The specimens were fixed in 10% formalin and submitted to routine histological processing, and sections were stained with hematoxylin and eosin. RESULTS: Significant differences with increasing age were observed for the following microscopic aspects: acinar atrophy (r=0.26, p=0.0115); replacement of parenchyma by fibrous tissue (r=0.79, p<0.0001) and/or adipose tissue (r=0.63, p<0.0001); oncocytosis (r=0.61, p<0.0001); duct-like structures (chi(2)=14.68, p=0.0006) and congested blood vessels (chi(2)=7.18, p=0.0276). The mononuclear infiltrate changed from focal to diffuse with age (H=8.47, p=0.0144). No significant differences were observed between genders. CONCLUSIONS: The aging process starts with acinar atrophy, followed by the presence of duct-like structures and ends with the replacement of the parenchyma by fibrous and/or adipose tissue. The mononuclear infiltrate changes from focal to diffuse. No difference in the aging of the sublingual glands is observed between men and women.     

Postmortem acinar autolysis in rat sublingual gland: a morphometric study

Objective

To analyze and to quantify morphological acinar postmortem changes in rat sublingual glands (SLG).

Material and Methods

Fifty rats were divided into two groups of 25 animals each. Group I was used for morphological and morphometric evaluations and group II for the determination of gland density and processed gland volume. Acinar autolytic changes were studied at 0 (control group), 3, 6, 12 and 24 h postmortem periods. The morphometric analysis of the volume density (Vv) and total volume (V_T) of intact (ia) and autolyzed (aa) acini was performed under light microscopy using a Zeiss II integration grid with 100 symmetrically distributed points.

Results

Morphologically, temporal progressive nuclear alterations and gradual loss of the structural architecture of acinar cells were found. Regarding quantitative results, both the Vvaa and the Vvia showed statistically significant differences among all postmortem periods (p<0.05). Vvaa increased from 0.42% at 0 h to 75.84% at 24 h postmortem and Vvia decreased from 71.16% to 0% over the same period. For V_Taa and V_Tia, no statistically significant differences occurred between 12-24 h and 0-3 h (p>0.05), respectively. Vtaa increased from 0.18 mm³ at 0 h to 38.17 mm³ at 12 h, while Vtia showed a decrease from 33.47 mm³ to 0 mm³ between 3-24 h postmortem. Data concerning V_Taa were adjusted by twovariable linear regression, obtaining the equation: y=-3.54 + 3.38x (r²=0.90). The V_Taa growth rate calculated by this equation was 3.38 mm³/h between 0-12 h.

Conclusion

Acinar autolysis on rat SLG demonstrated the most significant signs during the first 6 h postmortem and was widely spread through the gland at 12 h.     

Phenotype and cell proliferation activity of duct-like structures in human sublingual glands: a histological and immunohistochemical study

There are several age-related microscopic changes in the salivary glands, including the increase in the number of duct-like structures (DLS). However, the true origin and the phenotype of the DLS are not known.

Objective

To evaluate the phenotype and the cell proliferation index of the DLS of human sublingual glands.

Material and Methods

Sixty sublingual glands obtained from human cadavers were divided into two groups - 0-30 and 61-90 years old. The phenotype was estimated by immunostaining for cytokeratin 19 (CK 19) and the S-100 protein as well as by the presence of mucin and glycogen. The cell proliferation index was determined by the Ki-67 antibody. The histochemical techniques used periodic acid-Schiff (PAS) and Alcian Blue. In each captured microscopic field, the DLS were counted to establish a percentage for the staining profile. The statistical analysis was accomplished using Student’s t-test, the Mann-Whitney test and Pearson’s correlation coefficient (p<0.05).

Results

Comparing both groups, only CK 19 showed a statistically significant difference (p=0.033), with the strongest expression in the elderly group. There was no significant difference between PAS and Alcian Blue (p=0.270). In both groups, the immunostaining for CK 19 was stronger than that for S-100 (p=0.004;p<0.001), but there was no correlation between the two immunomarkers (ρ=-0.163; p=0.315). There was no immunostaining for Ki-67.

Conclusions

DLS demonstrate a ductal phenotypic profile and do not present cell proliferation activity. DLS may represent a regressive process arising from acini or represent the result of metaplasia.     

Morphology and morphometry of the human sublingual glands in mouth floor enlargements of edentulous patients

Asymptomatic mouth floor enlargements may be observed in edentulous patients. These masses, which protrude from the mouth floor, may complicate the fitting of dentures and require surgery. Whether this "entity" may be considered an anatomical variation of the mouth floor or represent specific alterations in the sublingual gland is not known.

Objective

The aim of this work is to investigate the morphological and morphometric aspects of the sublingual glands of edentulous patients with mouth floor enlargements and compare the glands of these patients with the sublingual glands of human cadavers.

Material and Methods

Microscopic evaluation was performed on human sublingual glands from edentulous patients with mouth floor enlargements (n=20) and edentulous cadavers (n=20). The patients and cadavers were of similar ages. The data were compared using Mann-Whitney U, Fisher''s exact and Student''s t tests (p<0.05).

Results

Acinar atrophy, duct-like structures, mononuclear infiltrates, replacement of parenchyma with fibrous/adipose tissue, mucous extravasation and oncocytosis were similar between the groups (p>0.05). Only the variables "autolysis" and "congested blood vessels" presented statistical difference between groups (p=0.014; p=0.043). The morphometric study revealed that the volume densities of acini, ducts, stroma and adipose tissue were similar between the groups (p>0.05).

Conclusion

The microscopic characteristics of the sublingual glands in mouth floor enlargements in edentulous patients correspond to characteristics associated with the normal aging process. The glands are not pathological and represent an age-related alteration that occurs with or without the presence of the mouth floor enlargements.     

Analysis of age-related changes in the functional morphologies of salivary glands in mice

Background and Objectives

Salivary glands in the elderly commonly exhibit salivary dysfunction resulting dry mouth, poor oral hygiene, and dental caries. However, in vivo changes of salivary glands during aging have not been well documented in the literature. This study was undertaken to determine age-related morphometric and functional changes of salivary glands using an aging mouse model.

Methods

Male C57BL/6 mice were divided into three groups, group A (10 weeks old; n = 10), group B (30 weeks old; n = 10), and group C (90 weeks old; n = 10). Body weights, salivary gland weights, salivary flow rates, and salivary lag times were measured and compared. Histomorphometric examinations and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed. In addition, changes in salivary uptake and excretion were observed by single-photon emission computed tomography (SPECT).

Results

Body and gland weights increased with age. Gland weight was significantly higher in group B than in groups A and C. Salivary lag time was significantly greater in group C than in groups A and B, and salivary flow rate was significantly greater in group B than in groups A and C. Histologic evaluations exhibited acinar cell atrophy, cytoplasmic vacuolization, lymphocyte infiltration, small mucin component and more periductal fibrosis in salivary glands of group C. TUNEL assays revealed that apoptotic salivary epithelial cells were significantly more numerous in group C than in groups A and B. ^99mTc-pertechnetate excretion rate was significantly lower in group C than in groups A and B in SPECT.

Conclusion

Various morphometric and histopathological changes were observed in the salivary glands of aging mouse as well as relevant functional alterations, such as, decreased saliva production and excretion. Increased number of apoptotic salivary epithelial cells may contribute to the observed functional deterioration.     

5种哺乳动物和人涎腺组织学及超微结构观察

目的研究5种动物涎腺组织形态学及超微结构特点.方法选用成年小型猪5只,猕猴2只,新西兰白兔7只、Wistar大鼠7只和昆明小鼠7只及人类正常腮腺和颌下腺组织各一例,行腮腺和颌下腺组织学、组织化学及超微结构观察.结果5种动物的腮腺组织学表现差异不明显,均为浆液性腺体.5种动物的颌下腺组织学差异较大,人、小型猪、猕猴颌下腺均为混合性腺体,而大、小鼠和兔颌下腺为浆粘液性腺体.组化染色结果表明形态相似的腺泡细胞,其合成产物不尽相同.5种动物腮腺和颌下腺腺泡细胞在超微结构方面除分泌颗粒表现出明显的差异外,其余结构差异不明显.结论在小型猪、猕猴、兔、大鼠和小鼠5种动物的涎腺组织学及超微结构上,猕猴和小型猪与人类最接近.     

Quantitative age-related differences in human sublingual gland

OBJECTIVE: To quantify morphological age- and gender-related differences in human sublingual glands (SLG). DESIGN: Ninety right human SLG from necropsies were distributed by gender and age groups. Individuals with ages ranging from 7 months to 92 years were divided into Groups I (0-30 years), II (31-60 years) and III (61-92 years). The glandular volume of each SLG was calculated. The morphometric quantifications of the volume density and total volume of acini, ducts, stroma, adipose tissue and septa were realized under light microscopy using a Zeiss II integration grid with 100 points symmetrically distributed. RESULTS: The glandular volume decreased, on average, 33.78% across the groups. The volume density (V(V)) of acini reduced 60.54% and of septa 34.82%, being replaced partly by an increase of 58.82%, 551.22% and 2,783.33% in the volume density of ducts, stroma and adipose tissue, respectively. In absolute terms, with aging, the total volume (V(T)) of the acini decreased by 54.04% and by 34.84% in the septa. In contrast, the total volume of ducts, stroma and adipose tissue showed increases of 62.53%, 363.25% and 2,308.64%, respectively. Both the V(V) and the V(T) of acini, ducts, stroma and adipose tissue and the V(V) of septa were statistically different with age. No significant difference was observed between genders. CONCLUSION: The decrease of parenchyma accompanied by an increase of stroma observed here in SLG is a common feature of aging in human salivary glands.     

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.     

Focal lymphocytic infiltration in the human labial salivary glands: a postmortem study

Focal lymphocytic infiltration in the human labial salivary glands was examined in a series of 190 postmortem subjects after suitable exclusion had been made. Focal lymphocytic infiltration, with or without a slight degree of parenchymal atrophic change, was found in 22.4% of the males and in 35.7% of the females. Of these, 9.0% (12 subjects) of the males and 10.7% (6 subjects) of the females with focal lymphocytic infiltration did not show any atrophic changes of the parenchyma. In the series reported here, the prevalence of focal lymphocytic infiltration apparently differs from the results of earlier investigators who had reported that none of the postmortem subjects without autoimmune diseases or connective tissue diseases showed focal lymphocytic infiltration in minor salivary glands. Although the pathological significance of focal lymphocytic infiltration in the minor salivary glands remains obscure, its diagnostic value for Sjögren's syndrome is discussed.     

Focal lymphocytic infiltration in the human labial salivary glands: a postmortem study

Focal lymphocytic infiltration in the human labial salivary glands was examined in a series of 190 postmortem subjects after suitable exclusion had been made. Focal lymphocytic infiltration, with or without a slight degree of parenchymal atrophic change, was found in 22.4% of the males and in 35.7% of the females. Of these, 9.0% (12 subjects) of the males and 10.7% (6 subjects) of the females with focal lymphocytic infiltration did not show any atrophic changes of the parenchyma. In the series reported here, the prevalence of focal lymphocytic infiltration apparently differs from the results of earlier investigators who had reported that none of the postmortem subjects without autoimmune diseases or connective tissue diseases showed focal lymphocytic infiltration in minor salivary glands. Although the pathological significance of focal lymphocytic infiltration in the minor salivary glands remains obscure, its diagnostic value for Sj?gren's syndrome is discussed.     

Iron deposits in the human labial minor salivary glands: a postmortem study

Iron deposits in the human labial minor salivary glands were examined in a series of 195 postmortem subjects. Iron deposits (hemosiderin granules) were found in 7 subjects (3.6%), and the major types of illness in these cases were liver cirrhosis with or without hepatoma, aplastic anemia and acute myelogenous leukemia. Three out of 7 subjects had a history of blood transfusion. Considerable quantities of hemosiderin granules were deposited within the cytoplasm of the acinar and ductal epithelial cells, and hemosiderin-laden cells were scattered in the interstitial connective tissue.     

Glycogen content and activities of enzymes involved in the carbohydrate metabolism of the salivary glands of rats during postnatal development

Carbohydrate metabolism was examined in the developing rat salivary glands by analysing enzymatic activity and glycogen content in the postnatal parotid and submandibular glands. The following enzymes of the carbohydrate metabolism, hexokinase (HK), phosphofructokinase-1 (PFK-1), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD), and lactate dehydrogenase (LDH) as well as the content of glycogen were determined in the salivary glands of rats aged 2, 7, 14, 21, 30 and 60 days. The specific activity of HK increased from days 2 to 21 and then it decreased up to 60 days old. The values found for the submandibular glands were from 2.5 to 4.9 times higher than those found for the parotid gland, except for rats aged 60 days. PFK-1 showed a different pattern of variation between the glands. In the submandibular gland there was a statistically significant increase in PFK-1 specific activity from 2 to 30 days of age and then, in the 60 days old group a return to level of the rats aged 2 days. In parotid gland, the specific activity of PFK-1 decreased between 2 and 7 days of age, from 7 to 14 days the specific activity increased markedly and from 14 to 60 days old it gradually decreased. The specific activity of PK followed the same pattern of variation in the submandibular and parotid glands, showing no great variation. The specific activity of LDH decreased from 2 to 60 days old in the submandibular glands. In the parotid glands the mean values for this enzyme were higher for the 2 days old group, and then decreased to remained more or less constant. The potential capacity of the pentose phosphate pathway was greater than that of glycolysis at early ages. The glycogen content showed similar variation in both glands. It was initially high and then decreased. In conclusion, our results on the activities of enzymes involved in carbohydrate metabolism in submandibular and parotid glands may be relevant to the initiation of saliva secretion in these animals.     

Sialoendoscopy with and without holmium:YAG laser-assisted lithotripsy in the management of obstructive sialadenitis of major salivary glands

Obstructive sialadenitis is a major cause of dysfunction of the salivary glands, and increasingly sialoendoscopy is used in both diagnosis and treatment. At present the limit of the endoscopic approach is the size of the stone as only stones of less than 4 mm can be removed. Endoscopic laser lithotripsy has the potential to treat many stones larger than this with minimal complications and preservation of a functional salivary gland. The holmium:YAG laser has been widely and safely used in urology, and its use has been recently proposed in salivary lithotripsy for the removal of bigger stones. We describe our experience with sialoendoscopy for stones in the parotid and submandibular glands and assess the feasibility and the efficacy of holmium:YAG laser lithotripsy. We have used the procedure 50 times for 43 patients with obstructive sialadenitis; 31 patients had sialolithiasis, 15 of whom (48%) had stones with diameters between 4 and 15 mm (mean 7). Total extraction after fragmentation was possible in 14 of the 15 patients without complications. Intraductal holmium:YAG laser lithotripsy is effective and safe, and allows the treatment of large stones in Stensen's and Wharton's ducts.     

Recovery of INS-R and ER-alpha expression in the salivary glands of diabetic mice submitted to hormone replacement therapy

The interaction between proteins and cell receptors is related to tissue homeostasis such as in salivary glands. In this respect, alterations in hormone levels caused by hyperglycaemic conditions may interfere with this interaction, intensifying the damage caused by diabetes mellitus. Hormone replacement therapy is an option to reverse this damage, but doubts still exist regarding the efficacy of this procedure. The objective of this study was to evaluate the effect of oestrogen replacement therapy combined with insulin treatment on the expression of oestrogen (ER-alpha) and insulin receptors (INS-R) in the salivary glands of spontaneously diabetic mice. Twenty-five mice were divided into five group of 5 animals each: group I (NOD diabetic), group II (NOD diabetic treated with insulin), group III (NOD diabetic treated with oestrogen), group IV (NOD diabetic treated with insulin and oestrogen), and group V (control BALB/c mice). Group II received insulin, group III received oestrogen, and group IV received insulin plus oestrogen administered daily for 20 days. Groups I and V received saline for the same period of time to simulate treatment. Glucose and oestrogen levels were monitored during the experimental period and salivary gland samples were collected at the end of the experiment for fluorescence microscopy analysis of ER-alpha and INS-R. Animals receiving oestrogen replacement therapy plus insulin showed regulation of the expression of oestrogen and insulin receptors. Oestrogen treatment alone contributed to the recovery of these cell receptors. These results indicate that oestrogen replacement therapy alone, and especially when combined with insulin, is important for the recovery of the interaction between functional proteins and their receptors, thus contributing to the reestablishment of tissues damaged by the hyperglycaemic condition.     

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.     

12例唾液腺嗜酸细胞癌临床病理分析

目的:观察唾液腺嗜酸细胞癌的临床和病理组织学特征,探讨其治疗与预后.方法:回顾分析2001年3月—2010年9月诊治的12例唾液腺嗜酸细胞癌患者的临床和病理资料,并进行随访分析.应用SPSS 16.0软件包,采用Kaplan Meier法进行生存分析,并绘制生存曲线.结果:唾液腺嗜酸细胞癌临床多表现为唾液腺无痛性、不规则肿块或颈淋巴结肿大.病理学上表现为嗜酸性肿瘤细胞,异形性明显,核仁显著和浸润性生长特征.手术是首选治疗,术后可结合放疗.本组患者随访6～120个月,7例无复发及转移,1例出现局部复发及远处转移后带瘤生存,2例死于局部复发,1例出现颈淋巴结转移后死于远处转移,1例放弃治疗死于肿瘤进展.随访中2年内复发3例,复发率25％:2年内死亡3例,死亡率25％.结论:唾液腺嗜酸细胞癌是一种罕见的头颈部恶性肿瘤,其病程短、进展快.治疗上首选根治性手术,肿瘤无法彻底切除、局部病变晚期或颈淋巴结转移者需行术后放疗.原发肿瘤分期和颈淋巴结转移是影响预后的主要因素.     

微血管密度和血管内皮生长因子在涎腺腺样囊性癌中的表达

目的研究微血管密度(microvesseldensity,MVD)和血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)在涎腺腺样囊性癌中的表达,探讨其与该肿瘤的临床病理关系。方法采用SP免疫组织化学染色方法检测55例涎腺腺样囊性癌中MVD和VEGF的表达,采用SPSS软件行统计分析。结果VEGF在小涎腺腺样囊性癌中的高表达阳性（强度）率明显高于大涎腺(P=0.0398);随着肿瘤分期的增加,VEGF的高表达率明显增加(P=0.0175);而MVD与肿瘤部位、分期差异无显著性。MVD和VEGF的表达与该肿瘤的局部复发、远处转移、区域淋巴结转移、组织类型及生存率无显著的相关性。VEGF高表达组的平均MVD值明显高于低表达组的平均MVD值(P=0.0202)。结论在涎腺腺样囊性癌中,MVD和VEGF作为预后因素需要进一步的研究分析,二者的表达呈明显的正相关。     

Expression of beta-1 integrin in human developing salivary glands and its parallel relation with maturation markers: in situ hybridisation and immunofluorescence study

BACKGROUND AND OBJECTIVE: Salivary gland development entails co-ordinated processes involving complex molecular interactions in which integrins have a fundamental role. The integrins are a family of heterodimeric transmembrane receptors comprising alpha and beta subunits that mediate intercellular and extracellular signals involved in the organisation of cells in tissues and organs during development. The beta-1 integrin in particular have been implicated in proliferation and differentiation of cells involved in the development of epithelial tissues. To understand the role of beta-1 integrin in salivary gland development we have studied its expression in human foetal tissues. DESIGN: In situ hybridisation was used to compare the expression and localisation of integrin beta-1 with differentiation markers in developing human salivary glands obtained from foetuses of 8-24 weeks gestation. RESULTS: Integrin beta-1 first appeared during bud stage in a few cells and its distribution increased as salivary gland morphogenesis progressed. This increased pattern of beta-1 integrin expression was coincident with the appearance of the differentiation markers CK14, CK low MW and smooth-muscle actin. CONCLUSIONS: The developmentally regulated expression of integrin beta-1 in association with the establishment of a mature phenotype indicated by salivary gland tissue differentiation markers is suggestive of its role in salivary gland morphogenesis.