Spatial organization of the excretory ducts and sections of microcirculatory blood flow of the labial salivary glands in older adults.

OBJECTIVE: Introduction: Salivary glands have a significant impact on the state of the homeostasis of the human body, oral cavity in particular, sensitively responding to pathological processes. The reactivity of the salivary glands in response to pathological processes that are organically linked to morphology and functions of the organ's structures, and particularly the excretory ducts of the glands and their microcirculatory blood flow, is one of the problems which have not been solved to date. The aim of the paper was to elucidate the features of the stereomicroscopic structure of the excretory ducts and sectors of the microcirculatory blood flow in labial glands of older adults. PATIENTS AND METHODS: Materials and methods: The object of the study was the labial mucosa of the older adults, which was cut into 3х3 mm pieces and fixed in the buffered 4% glutaraldehyde solution with subsequent 2-hour fixation in osmium. Once the pieces were washed and dehydrated they were embedded into the Epon-812. The series of the semi-thin sections, made from the obtained epoxy blocks, were stained in phosphate buffered 0,1% toluidine blue solution. The serial semi-thin sections were subjected to histological and cytological studies and multilayered plastic reconstruction. RESULTS: Results and conclusions: The series of histological epoxy semi-thin sections, as well as graphic and plastic reconstruction of the sectors of microcirculatory blood flow and excretory ducts of the human labial glands have demonstrated a range of morphological facts that can be used to clarify the intertissue stereological relationships. They also determined the syntopic proximity of the capacitive sectors of microcirculatory blood flow to the excretory ducts of the gland. Such pattern is especially notable in the collecting venules and intralobular ducts. It has been shown that the biggest venule is the collecting venous vessel. Anastomoses between the intralobular arterioles and collecting venules have been found in the microcirculatory blood flow of the labial glands.

Characterization of Angiogenesis and Lymphangiogenesis in Human Minor Salivary Glands with Sjögren's Syndrome.

Angiogenesis has been proposed to play a role in the inflammation observed in Sjögren's Syndrome (SS). However, no studies have validated the degree of angiogenesis in salivary glands with SS. Therefore, the goal of this study was to determine the presence and localization of angiogenesis and lymphangiogenesis in salivary glands with SS. We used frozen tissue sections from human minor salivary glands (hMSG) with and without SS in our analyses. To investigate signs of angiogenesis, hMSG tissue lysates were used to detect levels of the pro-angiogenic protein vascular endothelial growth factor (VEGF) by western blot analyses. Additionally, we labeled blood vessels using antibodies specific to platelet endothelial cell adhesion molecule-1 (PECAM-1) and von Willebrand Factor (vWF) to determine blood vessel organization and volume fraction using fluorescence microscopy. Lymphatic vessel organization and volume fraction were determined using antibodies specific to lymphatic vessel endothelial hyaluronan receptor (LYVE-1). Our results suggest that expression levels of VEGF are decreased in hMSG with SS as compared with controls. Interestingly, there were no significant differences in blood or lymphatic vessel organization or volume fraction between hMSG with and without SS, suggesting that angiogenesis and lymphangiogenesis have little impact on the progression of SS.

Angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma of minor salivary glands.

BACKGROUND: Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands. This tumor is characterized by a great variability in clinical behavior, and little is known about the pathological mechanisms involved in its variance. Angiogenesis is an important step in tumor progression and is believed to be an essential event for metastatic dissemination. METHODS: We aimed to investigate angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma measuring the density of neoformed and lymphatic vessels using CD105 and D2-40 antibodies, respectively, and by immunohistochemical evaluation of VEGF-A and VEGF-C proteins. It was also investigated the expression of D2-40 in neoplastic cells. RESULTS: We studied 26 cases of mucoepidermoid carcinoma, which showed great angiogenic activity measured by neoformed vessel density. However, a low density of lymphatics was observed. VEGF-A, VEGF-C, and D2-40 were commonly detected in mucoepidermoid carcinoma, but only VEGF-A expression correlated with neoformed vessel density. Recurrence and nodal metastasis were associated with low VEGF-A expression and low neoformed vessel density, indicating that impaired angiogenesis could lead to an aggressive phenotype. CONCLUSIONS: Angiogenesis seems important in the modulation of mucoepidermoid carcinoma pathogenesis; however, none of the parameters analyzed could predict tumor behavior.

Minor salivary glands morphology in xerostomia patients / Morfología de las Glándulas Salivales Menores en Pacientes Xerostomizados

Las glándulas salivales menores son encontradas distribuidas a través de la mucosa oral, especialmente en los labios y en la mucosa del paladar blando. Varios factores pueden causar xerostomía, donde las características histológicas de las glándulas salivales son también consideradas como factores para definir la etiología. Así, las biopsias de las glándulas salivales menores representan una herramienta fundamental para alcanzar los criterios diagnósticos requeridos en la clasificación de pacientes con síndrome de Sjõgren, ya que no representa riesgo para los pacientes. El objetivo de este estudio es determinar las características histológicas de las glándulas mencionadas, obtenidas de biopsias de pacientes con xerostomía y clasificar los aspectos histológicos de las glándulas en el síndrome de Sjõgren. Estudiamos 40 láminas de pacientes con xerostomía, cuyas glándulas salivales menores fueron sometidas a biopsia en el Servicio de Estomatología de la Santa Casa de São Paulo, Brasil. Se observaron las variaciones de su aspecto histológico, desde la normalidad hasta la presencia de focos inflamatorios, los cambios del tejido conjuntivo entre los acinos y conductos, como también el parénquima. En 15 casos, el infltrado de células inflamatorias invadió el foco, es decir, grupos de al menos 50 células inflamatorias alrededor de acinos o conductos, lo cual es un aspecto característico del síndrome de Sjõgren. Por lo tanto, el hallazgo de al menos un foco inflamatorio de 4 mm2 de tejido glandular, representa un buen criterio, aunque no es uno de los criterios a considerar cuando se trata de clasificar a los pacientes con el Síndrome de Sjõgren.

The minor salivary glands are found scattered throughout the oral mucosa, especially in the lips and soft palate mucosa. Several factors can cause xerostomia, whereas the salivary glands histological characteristics are also considered as factors for defining the etiology. Thus, the minor salivary glands biopsy represents an essential tool for attending the required diagnosis criterion in the classification of Sjögren's Syndrome patients, since it does not present risk for the patient. The objective of this study is to determine the histological description of the minor salivary glands obtained from the biopsies of xerostomia patients and to classify the minor salivary gland histological aspect as the Sjögren's Syndrome. Forty laminas of xerostomia patients that were submitted to minor salivary glands biopsy at the Santa Casa de Sao Paulo Stomatology ambulatory were retrospectively studied. The variation in the glands histological aspect was observed, from the normality up to the presence of inflammatory focus, replacing the conjunctive between acini and ducts, as well as the parenchyma. In 15 cases, the infiltrated inflammatory cells amounted to focus, that is to say, groups of at least 50 inflammatory cells around the acini or ducts, which is a characteristic aspect of the Sjögren's Syndrome. Therefore, the finding of at least one inflammatory focus of 4 mm2 of glandular tissue represents a set criterion, although, not the only one in order to classify this patient as having the Sjögren's Syndrome.

Intravascular tumour in intra-oral pleomorphic adenomas: a diagnostic and therapeutic dilemma.

AIMS: Intravascular tumour has been described very rarely in pleomorphic adenomas. The aim of this study was to establish the frequency of intravascular tumour in pleomorphic adenomas arising in minor salivary glands and to determine the biological significance of this phenomenon. METHODS AND RESULTS: Representative sections of 67 widely excised pleomorphic adenomas were examined for the presence of intravascular tumour. Sixty-two cases were derived from the palate while the remaining five were from the cheeks and lips. In instances where intravascular tumour was identified, multiple serial sections were assessed and immunohistochemical stains were performed. None of these cases showed cytological evidence of malignancy. Solid cords of intravascular tumour were present in six palatal tumours (8.9%) and consisted of plasmacytoid myoepithelial cells permeating muscular walled blood vessels and capillaries both within the tumour and capsule. Immunoperoxidase staining confirmed that the intravascular cells were phenotypically identical to those of the tumour being S100- and smooth muscle actin (SMA) positive. There is some evidence that this phenomenon represents true vascular invasion although artefactual spillage cannot be excluded. CONCLUSIONS: Although the biological significance of intravascular tumour in pleomorphic adenomas of minor salivary glands remains unknown, the occurrence of metastatic disease has not been demonstrated nor have aggressive behaviour or recurrences.

Immunocytochemical localisation of neuropeptide-containing nerve fibres in human labial glands.

Different neuropeptide-containing nerve fibers (vasoactive intestinal polypeptide, substance P, neuropeptide Y) and nitric oxide synthase (NOS) positive nerve fibers were investigated to clarify their role in the function of human labial glands using immunohisto- and immunocytochemical techniques. The distribution pattern of all immunoreactive nerve fibers was similar both in the control and in the Sjögren's syndrome specimens. A large number of thin varicose vasoactive intestinal polypeptide and NOS positive nerve fibers were seen around or in close contact with the acini. Some of the immunoreactive nerve fibers were associated with the salivary ducts and blood vessels. Substance P and neuropeptide Y immunoreactive nerve fibers were located mainly around the blood vessels. Immunocytochemistry demonstrated that some of the positive nerve fibers were in direct contact with the acini, blood vessels and with the lymphocytes. The gap between the membranes of immunoreactive nerve terminals and the target cells was 40 to 200 nm. The number of the nerve terminals in Sjögren's syndrome specimens was decreased and some degenerated axons were also found. These results suggest that these neuropeptides and nitric oxide might act as a neurotransmitter in the regulation of secretion and blood flow in the labial glands. These fibers might also alter the neuroimmunological processes, because the investigated neuropeptides are known to be immunoregulators.

Expression of aquaporin 1 (AQP1) water channels in human labial salivary glands.

Aquaporin (AQP) water channels are widely expressed in the membranes of fluid-transporting epithelia. Despite the fact that salivary glands are the site of considerable water movement, relatively little is known about the role of aquaporins in human salivary glands. We have examined the expression of AQP1 in human parotid, sublingual and labial salivary glands. Total RNA was extracted from glandular tissue obtained from surgery or biopsy. The presence of AQP1 mRNA was demonstrated in each of the three glands by RT-PCR using primers specifically designed for human AQP1. The PCR product from the labial gland RNA was further amplified with nested primers and the sequence confirmed by automated fluorescent DNA sequencing. The cleaned first PCR product from these glands was then used as a 32P-labelled hybridization probe in a Northern analysis which confirmed the presence of significant amounts of AQP1 transcript in all three glands. AQP1 expression was also demonstrated in cryosections of human labial glands by immunohistochemistry using peroxidase-linked antibodies. Antibody labelling was most prominent in the capillaries but was also evident in the basal regions of the labial gland acini, and may therefore be associated with the serous demilunes which are believed to be a significant site of fluid movement.

True malignant mixed tumor (carcinosarcoma) of tonsillar minor salivary gland origin: diagnostic imaging and endovascular therapeutic embolization.

We report a case of carcinosarcoma of the minor salivary glands of the left palatine tonsil, an especially rare location. Imaging characteristics assessed at CT, MR imaging, and angiography are presented. In addition, we describe our experience with preoperative therapeutic endovascular embolization of this hypervascular tumor.

Epidermal growth factor, transforming growth factor-alpha, and epidermal growth factor receptor in labial salivary glands in Sjögren's syndrome.

OBJECTIVE: Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) affect cells through binding to a shared EGF receptor (EGF-R), which is a transmembrane protein with tyrosine kinase activity. They exert trophic effects on vascular endothelial, salivary acinar, and ductal and mucosal epithelial cells. In Sjögren's syndrome (SS) focal sialadenitis leads to salivary gland tissue damage, diminished salivary flow, and changes in the oral epithelium, a complex referred to as xerostomia. We compared the localization of EGF, TGF-alpha, and EGF-R in labial salivary glands in SS and in healthy controls. METHODS: Labial salivary gland tissues of 12 patients with SS and 7 healthy controls were stained with the immunohistochemical peroxidase-antiperoxidase method for EGF, TGF-alpha, and EGF-R. RESULTS: Immunoreactivity for both EGF and TGF-alpha was found in endothelial cells of blood vessels and in some ductal epithelial cells. TGF-alpha, but not EGF, was also found in some acinar cells. EGF-R was found in endothelial, acinar, and salivary duct epithelial cells. There was no difference in the expression of EGF-R between diseased and healthy specimens, but both EGF and TGF-alpha were diminished in SS. CONCLUSION: The interrelated localization of EGF-R and its ligands, EGF and TGF-alpha, suggests an autocrine, juxtacrine, and paracrine mitogenic/trophic role for them and thus a role in the maintenance of the secretory and excretory cells of the normal salivary glands. The trophic effects on acinar cells seem not to be mediated by EGF, but more likely by TGF-alpha. The diminished expression of EGF and TGF-alpha indicates a failure of this trophic system in SS, which may contribute to the acinar atrophy and secondary changes thereof, including atrophy of the oral mucosa.

Immunohistochemical findings of arterial fibrinoid necrosis in major and lingual minor salivary glands of primary Sjögren's syndrome.

Arterial fibrinoid lesions in major salivary glands and lingual minor salivary glands from four autopsied patients with primary Sjögren's syndrome were studied histologically and immunohistochemically. On a morphological basis, the preceding arterial fibrinoid necrosis was regarded as medial damage, particularly of smooth muscle cells. The medial smooth muscle cells underwent vacuolated degeneration and disappeared, and resulted in full-blown fibrinoid arteritis. By means of the immunoperoxidase method the distribution of the immunoglobulins, fibrin, complement (C3), transferrin, ferritin, vimentin and lysozyme was studied. The normal arterial wall reacted with the lambda light chain of immunoglobulin, transferrin and vimentin Vacuolated degeneration of medial smooth muscle cells, regarded as the initial change in cases of vascular fibrinoid lesion, was positive for IgG, C3 and vimentin. We suggest that IgG antibody is a useful marker to detect the initial phase of arterial fibrinoid necrosis. In the foci of fibrinoid necrosis, fibrin, C3 and vimentin were detected. Among these three antibodies, only fibrin was negative in the normal arterial wall and vacuolated degenerates of medial smooth muscle cells. Mononuclear cells surrounding areas of fibrinoid necrosis stained strongly with antisera to immunoglobulins, transferrin, ferritin and vimentin, and negatively with fibrin, C3 and lysozyme antibodies.

Necrotizing sialometaplasia: literature review and case reports.

The authors describe necrotizing sialometaplasia, a benign inflammatory lesion primarily involving the minor salivary glands of the hard palate. The lesion presents itself as a deep-seated palatal ulcer with clinical and histologic features mimicking those of a malignant neoplasm. The lesion is believed to be the result of vascular ischemia initiated by trauma. An incisional biopsy is required to confirm the diagnosis, and the lesion heals by secondary intention within four to 10 weeks.

[Necrotizing sialometaplasia: apropos of a case and review of the literature]. / La sialométaplasie nécrosante: à propos d'une observation et revue de la littérature.

Necrotizing Sialometaplasia is an inflammatory, self-healing, reactive process of probable vascular origin, that most commonly involves the minor salivary glands of the palate but can bee seen in all salivary glands. As its clinical and pathological features may suggest malignancy, knowledge of histologic criteria indicating the benign nature of the lesion and the integration of clinical and pathologic elements are required to obviate this mistake. We review the literature reporting to one case.

Vascular changes in major and lingual minor salivary glands in primary Sjögren's syndrome.

A histological investigation of the vascular changes of three major and lingual minor salivary glands in primary Sjögren's syndrome was carried out on eight autopsied Japanese patients. This study compares vascular lesions in salivary glands between one group of four short-term corticosteroid-treated patients (Cases 1, 3, 4 and 7) and the other group of four long-term corticosteroid-treated patients (Cases 2, 5, 6 and 8). We proposed the following five stages for morphogenesis of arteritis; (1) endothelial swelling, (2) thrombosis, (3) fibrinoid degeneration, (4) necrotizing panarteritis and (5) endarteritis obliterans. Endothelial swelling was seen in small-to-large arteries of major salivary glands and the tongue, and this finding was considered as the initial change of vascular lesion. Thrombosis was observed in the small arteries of both organs. Fibrinoid degeneration and necrotizing panarteritis were predominantly localized in small and middle-sized arteries. Endarteritis obliterans was observed in small and large arteries of major and lingual minor salivary glands in primary Sjögren's syndrome. Vascular lesion of this type was common in the four patients who received corticosteroid for more than 12 months. Corticosteroid therapy appears to accelerate the fibrotic change of the vascular wall. Therefore, we suggest that essential vascular lesions of major and lingual minor salivary glands in primary Sjögren's syndrome may include four types (endothelial swelling, thrombosis, fibrinoid degeneration and necrotizing panarteritis), excluding endarteritis obliterans.

Labial salivary gland biopsy assessment in rheumatoid vasculitis.

OBJECTIVES: To assess the vascular involvement in labial salivary gland (LSG) from patients with rheumatoid vasculitis (RV). METHODS: Forty seven patients with rheumatoid arthritis (RA) took part in a prospective study. Among them, 12 had proven RV. LSG biopsy was performed after local anaesthesia. RESULTS: Histological appearance of inflammatory vascular damage was observed in all but one patient with proven RV (92%). Inflammatory vascular involvement was also identified in LSG biopsy of seven patients with RA (20%) and only one patient in the control group (8%). A second specimen of LSG was studied after a mean treatment period of six months and failed to show any feature of inflammatory vascular involvement in three of the five cases that were analysed. CONCLUSIONS: The study emphasises the high incidence of immunopathological features of microvascular damage in patients with RV. LSG biopsy is minimally invasive and may be a potential useful tool for the diagnosis of RV especially when skin lesions are absent or impossible to biopsy. The assessment of the predictive value of positive LSG biopsy in RA requires a long term prospective study.

Vascular endothelium and lymphocyte adhesion molecules in minor salivary glands of patients with Sjogren's syndrome.

The aim of this study was to examine the distribution and types of adhesion molecules expressed over endothelial cells and the ligands present on lymphocytes which infiltrate exocrine glands in patients with Sjogren's syndrome. Minor salivary gland biopsies were examined from twelve patients with Sjogren's syndrome and eight normal subjects for the presence of adhesion molecules using monoclonal antibodies and an Indirect Immunoperoxidase technique. There was an increased expression of intercellular adhesion molecule-1 (ICAM-1, CD54) on endothelial cells, lymphocytes, fibroblasts and salivary gland epithelial cells. In addition we documented the expression of endothelial leukocyte adhesion molecule-1 (ELAM-1) on endothelial cells in salivary glands from patients but not the controls. Many of the endothelial cells expressing these adhesion molecules in patients with Sjogren's syndrome had the morphological appearance of high endothelial venules. V-CAM-1 was shown to be present in some of the salivary biopsies from patients with Sjogren's syndrome. Lymphocytes infiltrating salivary glands strongly express LFA-1 (CD11a/CD18) molecules. Some infiltrating lymphocytes, and most monocytes, expressed C3bi-R (CD11b/CD18) and the p150.95 (CD11c/CD18) antigens on their cell surface. The results of this study reveal the enhanced expression of vascular endothelial and lymphocyte adhesion molecules on the minor salivary glands of patients with Sjogren's syndrome. The presence of such receptors and their putative ligands indicate an important role for these molecules in the pathogenesis of Sjogren's syndrome.

Platelets in blood and salivary glands of patients with primary Sjögren's syndrome.

Circulating platelets from 15 patients with primary Sjögren's syndrome (primary SS) and from 15 normal controls were enumerated and their aggregability determined. Blood platelet concentrations were within the normal range, except for two patients in whom they were slightly decreased. Platelet aggregation was enhanced in patients, when measured upon stimulation with epinephrine (p less than 0.05), ADP (p less than 0.01) and collagen (p less than 0.01). Plasma and saliva from 17 patients with primary SS and from 11 normal controls were examined for the platelet-specific release product beta-thromboglobulin (beta-TG). P-beta-TG was increased in the patients, although not significantly (p greater than 0.05). In saliva beta-TG was detected in 5 patients (11-150 ng/ml), but not in any of the controls. There was no correlation between levels of beta-TG in plasma and saliva. Lower lip minor salivary glands from 17 patients under evaluation for SS were examined for platelet accumulation. Indirect immuno-peroxidase staining with the monoclonal mouse anti-human platelet glycoprotein Ib antibody, showed platelet accumulation intravascularly in the inflamed areas. The combined results are in accordance with the hypothesis that platelet activation occurs in the salivary glands of patients with primary SS.