Salivary Gland Ducts Research Articles

MR-Sialographie: Optimierung und Bewertung ultraschneller Sequenzen mit paralleler Bildgebung und oraler Stimulation

To optimise a fast sequence for MR-sialography and to compare a parallel and non-parallel acquisition technique. Additionally, the effect of oral stimulation regarding the image quality was evaluated. All examinations were performed by using a 1.5-T superconducting system. After developing a sufficient sequence for MR-sialography, a single-shot turbo-spin-echo sequence (ss-TSE) with an acquisition time of 2.8 sec was used in transverse and oblique sagittal orientation in 27 healthy volunteers. All images were performed with and without parallel imaging technique. The assessment of the ductal system of the submandibular and parotid gland was performed using a 1 to 5 visual scale for each side separately. Images were evaluated by four independent experienced radiologists. For statistical evaluation, an ANOVA with post-hoc comparisons was used with an overall two-tailed significance level of P =.05. For evaluation of interobserver variability, an intraclass correlation was computed and correlation >.08 was determined to indicate a high correlation. All parts of salivary excretal ducts could be visualised in all volunteers, with an overall rating for all ducts of 2.26 (SD +/- 1.09). Between the four observers a high correlation could be obtained with an intraclass correlation of 0.9475. A significant influence regarding the slice angulations could not be obtained (p = 0.74). In all healthy volunteers the visibility of excretory ducts improved significantly after oral application of a Sialogogum (p < 0.001; eta (2) = 0.049). The use of a parallel imaging technique did not lead to an improvement of visualisation, showing a significant loss of image quality compared to an acquisition technique without parallel imaging (p < 0.001; eta (2) = 0.013). The optimised ss-TSE MR-sialography seems to be a fast and sufficient technique for visualisation of excretory ducts of the main salivary glands, with no elaborate post-processing needed. To improve results of MR-sialography, it is reasonable to use an oral Sialogogum.

Apical Localization of a Functional TRPC3/TRPC6-Ca2+-Signaling Complex in Polarized Epithelial Cells: ROLE IN APICAL Ca2+ INFLUX

Receptor-coupled [Ca2+]i increase is initiated in the apical region of epithelial cells and has been associated with apically localized Ca2+-signaling proteins. However, localization of Ca2+ channels that are regulated by such Ca2+-signaling events has not yet been established. This study examines the localization of TRPC channels in polarized epithelial cells and demonstrates a role for TRPC3 in apical Ca2+ uptake. Endogenously and exogenously expressed TRPC3 was localized apically in polarized Madin-Darby canine kidney cells (MDCK) and salivary gland epithelial cells. In contrast, TRPC1 was localized basolaterally, whereas TRPC6 was detected in both locations. Localization of Galpha(q/11), inositol 1,4,5-trisphosphate receptor-3, and phospholipase Cbeta1 and -beta2 was also predominantly apical. TRPC3 co-immunoprecipitated with endogenous TRPC6, phospholipase Cbetas, Galpha(q/11), inositol 1,4,5-trisphosphate receptor-3, and syntaxin 3 but not with TRPC1. Furthermore, 1-oleoyl-2-acetyl-sn-glycerol (OAG)-stimulated apical 45Ca2+ uptake was higher in TRPC3-MDCK cells compared with control (MDCK) cells. Bradykinin-stimulated apical 45Ca2+ uptake and transepithelial 45Ca2+ flux were also higher in TRPC3-expressing cells. Consistent with this, OAG induced [Ca2+]i increase in the apical, but not basal, region of TRPC3-MDCK cells that was blocked by EGTA addition to the apical medium. Most importantly, (i) TRPC3 was detected in the apical region of rat submandibular gland ducts, whereas TRPC6 was present in apical as well as basolateral regions of ducts and acini; and (ii) OAG stimulated Ca2+ influx into dispersed ductal cells. These data demonstrate functional localization of TRPC3/TRPC6 channels in the apical region of polarized epithelial cells. In salivary gland ducts this could contribute to the regulation of salivary [Ca2+] and secretion.

Constitutive (HO-2) and inducible (HO-1) haem oxygenase in pleomorphic adenomas of the human parotid: an immunocytochemical study

This study examines the expression HO-1 and HO-2 isozymes in human parotid pleomorphic adenomas. They are members of the heat shock protein family, and are thought to play a role in the regulation of tumoral blood flow. Immunocytochemistry using antibodies specific for HO-1 and HO-2 were undertaken in 12 pleomorphic adenoma specimens, all sections of which contained adjacent normal salivary tissue. Normal salivary gland acini and ducts displayed significantly stronger immunoreactivity for HO-2 compared to tumour cells (p < 0.001). Expression for HO-1 was minimal in both normal salivary gland acini and tumour cells with no difference (p = 1.000). However, positive staining for HO-1 was seen in normal salivary ducts and in pleomorphic adenomas showing ductal differentiation. In conclusion, this is the first study to examine the expression of HO-1 and HO-2 within normal salivary glands and pleomorphic adenomas. Our findings suggest that HO may be implicated in the pathogenesis of salivary pleomorphic adenomas.

Examination of the distribution of the transferrin homologue, melanotransferrin (tumour antigen p97), in mouse and human

Melanotransferrin (MTf) is a transferrin homologue initially identified in melanoma cells. Serum transferrin (Tf) contains two iron (Fe)-binding sites and plays a vital role in Fe transport. However, human MTf has only a single, high affinity, Fe-binding site. Furthermore, while isolated MTf can bind Fe, it plays little role in Fe uptake by cells and its function remains elusive. To further understand the biological role of this molecule, we examined the expression profile of mouse MTf (mMTf) and human MTf (hMTf) and the splice variant of the latter. Analysis of mMTf in 18 normal mouse tissues and 4 embryonic stages (7-17 days) using an RNA dot blot demonstrated it was expressed at high levels in the pancreas, salivary gland and epididymis of the adult, while embryonic tissues showed low expression. The expression pattern was very different from that of mouse transferrin receptor 1 (TfR1) mRNA, which was found at high levels in the spleen and embryo. Using the more sensitive RT-PCR technique, mMTf expression was demonstrated across all 24 normal mouse tissues assessed. Analysis of the mMTf genomic sequence predicted only one mMTf transcript, although two putative transcripts were found in the testis using Northern blotting. An alternate hMTf transcript, h delta MTf, has been identified by others, although its tissue distribution was not previously examined. In human heart and skeletal muscle, three putative hMTf transcripts were identified at approximately 2, 3 and 4 kb, the smallest transcript being consistent with h delta MTf. The two larger transcripts were also found in 10 other human tissues. The h delta MTf transcript was detected using RT-PCR and Southern blotting in tumour-derived cell lines, with the highest expression being identified in melanoma cells. Immunohistochemistry showed that hMTf was expressed primarily within epithelia. In fact, the most pronounced expression was within the epidermis of the skin, tubules of the kidney and the ducts of sweat and salivary glands. The distribution of MTf and its splice variants may provide clues to their possible biological roles.

Intraductal Papilloma of Minor Salivary Glands : Case Report

The authors present a case of intraductal papilloma. It is the rarest among ductal papillomas, which is a group of salivary gland neoplasms that comprise three different histological sub-types : intraductal papilloma, inverted duct papilloma, and sialadenoma papilliferum. Intraductal papilloma is localized mainly in the ducts of minor salivary glands but it is rare in the parotid gland, the submandibular gland, and the sublingual gland. Patients' mean age is about 50-60 years. The growth is slow and asymptomatic. The overlying mucosa seems to be normal. Microscopically, the intraductal papilloma shows fibrovascular papillae surrounded by columnar or cuboidal epithelial cells to form a mass protruding into the duct lumen to create a cyst-like cavity ; usually mitoses are absent, but sometimes low grade cellular atypia is seen in a few areas. Preoperatory diagnosis is difficult, and only histopathologic examination is definitive. Fine needle aspiration biopsy is the best method for preoperative diagnosis, even if sometimes its results are deceptive. Excision is the resolutive therapy, and no recurrences after surgical excision have been reported. The purpose of this paper is to emphasize the importance of differential diagnosis of various ductal papillomas with this single case of intraductal papilloma.

Utility of three dimension fast asymmetric spin‐echo (3D‐FASE) sequences in MR sialographic sequences: model and volunteer studies

To evaluate the utility of 3D-FASE for the visualization of salivary gland ducts for use in MR sialographic sequences. We compared MR sialographic images and virtual endoscopic views from 3D-FASE with those from three kinds of sequences described by previous reports in a 3D parotid gland duct model and volunteer. The four sequences were two-dimension fast spin-echo (2D-FSE), three-dimension fast spin-echo (3D-FSE), two-dimension fast asymmetric spin-echo (2D-FASE), and three-dimension fast asymmetric spin-echo (3D-FASE). In the 3D parotid gland duct model, image visibility on visual score was clearest with 3D-FSE, followed by 3D-FASE (P = 0.028). In the volunteers, the visualization of images improved in the following order: 3D-FASE > 3D-FSE > 2D-FSE > 2D-FASE. The technique of 3D-FASE sequencing is more suitable and useful for MR sialography with an appropriate acquisition time.

Molecular cloning and characterisation of DESC4, a new transmembrane serine protease

Type II transmembrane serine proteases (TTSPs) are a growing family of multidomain proteins. Among the TTSPs, a new subfamily of HAT/DESC1-like ( human airway trypsin-like protease/ differentially expressed in squamous cell carcinoma gene 1) proteases is emerging consisting so far of four members: DESC1-3 and HAT. The cDNA of a new member of this subfamily, named DESC4, was isolated from rat tongue tissue and characterised. Analysis of selected tissues by RT-PCR demonstrated expression of DESC4 in brain, colon, heart, liver, lung and tongue. At the cellular level, DESC4 expression is confined to epithelial cells within the cleft of the circumvallate papillae extending into the ducts of minor salivary glands, the respiratory epithelium of the nasal cavity and tear gland ducts of the eyes as analysed by in situ hybridisation of sensory organ tissues. In transfected mammalian cells, DESC4 is localised to the plasma membrane as shown by immunocytochemistry and subcellular fractionation experiments. Our results suggest that we have identified a protease that is an important constituent of sensory systems and other organs.

Küttner’s Tumor of Salivary Glands Resembling Marginal Zone B-cell Lymphoma of the MALT Type: A Histopathologic and Immunohistochemical Study of 7 Cases

Kuttner's tumor is a benign inflammatory process of the submandibular gland that presents as a hard mass mimicking a malignant neoplasm clinically. The histologic feature varies according to stage of evolution and severity of inflammation. We report here 7 cases of Kuttner's tumor that morphologically resemble primary salivary gland marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. Histologically, the lobular architecture was distorted and the septa showed sclerosis. There was a dense lymphoplasmacytoid infiltration with lymphoid follicle formation accompanied by loss of acini and ducts. In 4 cases, a few salivary gland ducts contained the lymphoid cells within the epithelium. However, a true lymphoepithelial lesion was observed in none of the 7 cases. Immunohistochemical study demonstrated a disrupted follicular dendritic cell network, which is a characteristic finding of follicular colonization of MALT-type lymphoma. In 6 cases, there were a few small foci of lymphocytes somewhat resembling centrocyte-like cells of MALT-type lymphoma. However, immunohistological study demonstrated the mixed nature of the cells resembling centrocyte-like cells. Moreover, the polytypic nature of B lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction.

Clinical application of magnetic resonance sialographic 3-dimensional reconstruction imaging and magnetic resonance virtual endoscopy for salivary gland duct analysis

In a previous study, we showed that the new and fast sequence 3-dimensional (3D)-fast asymmetric spin-echo sequencing could be applied in magnetic resonance (MR) sialographic 3D reconstruction imaging of the parotid gland ducts and in producing virtual endoscopic views of the parotid gland with MR data. In the present study, we examined the clinical application of these MR sialographic 3D reconstruction imaging and virtual endoscopy of the salivary gland ducts using MR data sets with 3D-fast asymmetric spin-echo sequencing. The MR sialographic 3D reconstruction images showed a complete view in the branch paths from all angles, and the MR virtual endoscopic views showed conditions in the endoluminal tracts of the large branches in 20 patients with salivary gland duct abnormalities, including Sjögren syndrome, cyst, tumor, sialadenitis, and salivary calculi. The clinical use of MR sialographic 3D reconstruction imaging and MR virtual endoscopy for salivary gland ducts may enhance understanding of the 3D relationship between the ducts and the surrounding tissue, as well as the endoluminal circumstance within ducts. Possible future applications abound, and further investigation in this field is expected.

Micromorphology of sialoliths in submandibular salivary gland: A scanning electron microscope and X-ray diffraction analysis

Sialoliths are common in the submandibular gland and its duct system. The exact cause of formation of a sialolith is still a matter of debate. The aim of this study was to analyze 6 sialoliths ultrastructurally to determine their development mechanism in the submandibular salivary glands. Six sialoliths retrieved from the hilus and duct of the submandibular salivary glands of 6 patients with sialadenitis were analyzed ultrastructurally by scanning electron microscope and x-ray diffractometer. Scanning electron microscope revealed mainly irregular, partly rudely hexagonal, needle-like and plate-shaped crystals. The cross-section from the surface to the inner part of the sialoliths showed no organic material. X-ray diffraction showed that the sialoliths were composed of hydroxyapatite crystals. Energy dispersive x-ray microanalysis showed that all of the samples contained high levels of Ca and P, and small amounts of Mg, Na, Cl, Si, Fe, and K. The main structures of the submandibular sialoliths were found to be hydroxyapatite crystals. No organic cores were observed in the central parts of the sialoliths. In accordance with these preliminary results, sialoliths in the submandibular salivary glands may arise secondary to sialadenitis, but not via a luminal organic nidus.

Regularity of distribution of immunoreactive pulmonary surfactant protein A in rat tissues

Existing data has shown that SP-A-like protein or mRNA is widely distributed in lamellar bodies such as tissues and mucosal surfaces. Using immunohistochemistry method with a polyclonal antibody against human SP-A, in this study we investigated distribution of immunoreactive pulmonary surfactant protein A (IR-SP-A) in a number of rat tissues. The SP-A-like immunoreactivity was found in alveolar, parenchyma, pleura of lung; myelin sheath of brain; epithelia of Bowman's capsule, glomerulus and renal tubules of kidney; epithelia of colon, stomach, duct of salivary gland, pharynx; and blood vessel wall and connective tissue of extracellular matrix. The positive signal was blocked by pre-absorbed SP-A antigen from recombinant or bronchoalveolar lavage (BAL). SP-A has long been considered as an important frontier host defense molecule which participates in immune and inflammatory regulation of lung. With every inhalation, small particles, viruses, bacteria, and antigens from environment are continuously deposited onto the vast pulmonary epithelial surface. While a proper host defense is required to protect the lung, an over-exuberant response can disrupt the appropriate balance between pro- and anti-inflammatory. Traditional Chinese medicine believes that body is an open system relevant to the external environment. The physical, chemical and biological environmental factors constantly affect the open system, and the body properly reacts to maintain homeostasis of body machinery. The Chinese traditional medicine scholars have thus hypothesized that 'Qi' (meaning air) is the communication way between the body and external environment. What is 'Qi'? The results from our study suggest that IR-SP-A is a candidate of 'Qi'. It is compatible with the sites, theoretically containing collagenous and lectin domain molecules, also compatible with the primary injury sites of some autoimmune diseases. SP-A may be as one of 'Qi' molecules mentioned in traditional Chinese medicine that trigger some of autoimmune diseases.

Comparative study and application of MR sialography using different pulse sequences

目的 评价MR涎管造影的各种序列技术和临床应用.方法依次采用短时反转恢复序列(STIR)、重T2加权快速自旋回波序列(重T2WI FSE)、单次激发快速自旋回波序列(SS FSE),厚层扫描,快速采集,于服用维生素C(Vit C)前后分别扫描.检查了30例,其中13例为志愿者,17例为可疑涎管异常者.结果3种序列均能显示正常腮腺和颌下腺主导管.13例志愿者STIR序列均能清晰显示涎管1级和2级分支,2例能显示管径约为0.8 mm的末梢分支;重T2WI FSE序列可清晰显示13例志愿者1级分支、10例2级分支;SS FSE序列可显示10例涎管1级分支、6例2级分支.STIR序列能清晰显示患者主导管和涎管1、2级分支;重T2WI FSE序列清晰显示患者12例涎管1级、8例2级分支;SS FSE序列清晰显示患者10例1级分支、4例2级分支.17例可疑异常者,腺体炎症7例,急性炎症主导管稍增粗,末梢导管呈点、球状扩张;颌下腺癌1例,导管受压移位,呈截断状改变;良性肿瘤7例,涎管受压移位,无中断;干燥综合征及涎腺病各1例,涎管未见明显异常.16例患者含服Vit C 0.2 g后5 min重复扫描,涎管显示较前增粗.结论MR涎管造影能清晰显示腮腺和颌下腺导管系统,其中STIR序列能清晰显示导管2级分支,是1种显示涎管的非侵袭性方法,含服Vit C后可使唾液分泌增多,从而使涎管显示率增加,具有较高的临床实用价值。

Cytochemical detection of endogenous peroxidase in the intralobular ducts of hamster major salivary glands

Light and electron microscopic cytochemical investigation of endogenous peroxidase activity in the intralobular ducts of hamster major salivary glands was carried out using the diaminobenzidine-hydrogen peroxidase method. The peroxidase reaction product was localized in the nuclear envelope, the cisternae of the endoplasmic reticulum, the Golgi apparatus and secretory granules in both the intercalated duct cells and the striated duct light cells of all glands. These results suggest the ability of the intralobular duct cells to secrete peroxidase the same as that of acinar cells in hamster salivary glands.

Electrolyte concentrations in saliva of children aged 6-10 years with Down syndrome

Study design In this study sodium, potassium, calcium, phosphorus, zinc, and magnesium ion concentration was analyzed in stimulated whole saliva in 22 children with Down syndrome aged 6 to 10 years. These children were compared with 21 healthy children of the same age. Stimulated saliva was collected by chewing a piece of parafilm for 10 minutes. The pH was measured with a portable pH meter after collection. Electrolyte concentrations were determined by inductively coupled argon plasma with atomic emission spectrometry. Results No statistically significant differences were observed in phosphorus, zinc, magnesium, and calcium concentration between the children with Down syndrome and the control children. The sodium concentration showed about 66.8% higher value in the Down syndrome than in the control group. On the other hand the flow rate and potassium concentration were lower in the Down syndrome than in the control group. Conclusion Our results suggest that there is alteration in the metabolism of the duct and/or acinar cells of salivary glands of Down syndrome children.

Nouvelles techniques de traitements des lithiases salivaires : sialoendoscopie et lithotripsie extra-corporelle: À propos de 1 773 cas

Salivary lithiasis is a relatively common medical problem. Treatment by invasive endoscopy, intracorporeal lithotripsy, and extracorporeal lithotripsy has been developing worldwide as an alternative to open surgical procedures. We hypothesized that treatment of salivary gland duct stones with endoscopic ductal intervention and extracorporeal lithotripsy could eliminate ductal stones while exposing the patient to less morbidity. In the current study, we analyzed a large clinical series to determine the success of the new techniques and develop an algorithm for comprehensive treatment of salivary stones. Retrospective chart study of 1773 treated salivary ductal pathology cases. Treatment of salivary lithiasis using either duct endoscopy with instrumentation and/or intracorporeal laser lithotripsy or electromagnetic extracorporeal shock wave lithotripsy was undertaken for 1773 lithitic glands between 1988 and 2002. A total of 1105 endoscopies were performed on pathologic glands. 668 therapeutic extracorporeal lithotripsies were conducted. Stones were eliminated endoscopically in 96% of patients. Lithotripsy completely destroyed the stones in 63% of the lithotriptor cases; and an additional 35% of these procedures resulted in stone fragmentation with spontaneous expulsion or ancillary endoscopic removal. There were no major complications such as nerve or tooth damage. Early in the endoscopic series, one patient required surgical removal of a lodged wire-basket snare. TIssue effects such as edema, swelling bleeding or infection were temporary and treated as necessary. Four percent of the endoscopic cases and 2% of the lithotriptor cases ultimately required gland excision to remove the stone. The treatment algorithm for salivary stones, which once contained only conventional open surgery, may now include endoscopic instrumentation and extracorporeal lithotripsy. Both techniques are particularly valuable for stones located in the major salivary ducts. This series demonstrates the efficacy of both endoscopic and lithotriptor techniques.

Condyloma acuminatum and condyloma-like lesions of the oral cavity: a study of 11 cases with an intraductal component.

We studied the clinicopathological features of 11 condyloma and condyloma-like lesions of the oral cavity with an unusual mixed pattern of exophytic and intraductal growth. The latter manifest as involvement of minor salivary gland ducts by the proliferative squamous lesions. This pattern of ductal involvement has not been previously described in oral condyloma. The clinical history was available for nine patients ranging in age from 17 to 73 years. Two were female and seven male. The buccal mucosa (five cases) was the most common site of occurrence, followed by the floor of mouth (two cases), lingual frenum (two cases), and hard palate (one case). All lesions exhibited exophytic and intraductal growth. The latter manifested itself as extension of the lesions into the excretory ducts of minor salivary glands. Underlying minor salivary glands, present in many of the excisional biopsy specimens, typically showed changes of obstructive atrophy. The exophytic components of all cases exhibited some degree of parakeratosis, and cryptic invaginations of parakeratin were typically present. Koilocytes were present in seven lesions and were equivocal in four. Mucous cells were present in the intraductal component of all cases and the intraductal component was never keratinized, but often papillary. A mild stromal-based, lymphocytic host response was present in three. A variably prominent neutrophilic infiltrate was present in the exophytic component of eight. Dysplasia was not present in any case. Five of 11 cases were positive with anti-human papillomavirus (HPV) and two of 11 cases were positive for in-situ hybridization probes directed against HPV 6/11. All cases were negative for HPV 16/18 and 13/33/35. Oral condyloma acuminatum may involve the excretory ducts of minor salivary glands. The diagnosis of oral condyloma acuminatum is difficult, as these lesions share considerable histological overlap with squamous papilloma. Finally, the relationship between these two lesions is incompletely understood.

Sjögren’s syndrome: a condition with features of chronic graft-versus-host disease: does duct cell adhesion or permeability play a role in pathogenesis?

Primary and Secondary Sjögren’s syndrome are disease complexes characterized by periductal inflammatory cell infiltration of the salivary and lacrimal glands and manifest as dry mouth and dry eyes. Secondary Sjögren’s syndrome may be associated with a connective tissue disorder. Additional extraglandular features in Sjögren’s syndrome include a generalized inflammatory exocrinopathy that might be associated with abnormalities of both humoral and cellular mediated immunity. Similar inflammatory changes and extraglandular features, including an altered immune response, have been reported in patients developing graft-versus-host disease after bone-marrow transplantation and in patients with primary biliary cirrhosis. The periductal nature of the inflammatory response involving minor salivary and other glands raises the possibility of altered duct cell adhesion or permeability in playing a role in the aetiopathogenesis of Sjögren’s syndrome. The paper pulls together evidence that could be interpreted in this light. Evidence for bacterial or viral factor(s) altering the antigenicity of the histocompartibility (HC) complex on ductal cells in Sjögren’s syndrome patients is also described. A hypothesis is proposed for Sjögren’s syndrome in which the principal feature is an alteration in salivary gland duct cell adhesion or permeability. A re-evaluation of current knowledge of these two conditions from a clinical and experimental context are interpreted in this light.

Ontogeny of guanylin-immunoreactive cells in rat salivary glands.

Guanylin-like peptides regulate electrolyte/water transport through the epithelia. Moreover, these peptides possess antiproliferative activity and regulate the turnover of epithelial cells. In an earlier study we localized guanylin immunoreactivity in secretory ducts of adult rodent salivary glands. In this study we investigated the appearance and distribution pattern of this peptide during the development of rat salivary glands. Guanylin immunoreactivity appeared at the beginning of cell differentiation from solid bud, on embryonic day 17 in the submandibular and sublingual glands and after day 18 in the parotid gland. Guanylin immunoreactivity appeared first in ductal and acinar anlage: its cell distribution pattern and fate differed in these two compartments. In the duct cells guanylin immunoreactivity spread after the duct system developed, whereas in acinar cells it disappeared after cell differentiation. The guanylin immunoreactivity we detected in adult salivary duct cells accords with guanylin's role in regulating electrolyte and water transport through the various epithelia. It does so by activating guanylate cyclase-C receptor, increasing intracellular cGMP concentration, and phosphorylating the cystic fibrosis transmembrane conductance regulator (CFTR) protein by the cGMP-dependent protein kinase II. This signaling cascade couples to the ductal electrolyte/water secretion and modulates finally the electrolyte composition of the saliva. On the other hand, CFTR is also involved in mechanisms of cell growth, by regulating apoptosis, and promoting cell differentiation. The early diffuse guanylin immunoreactivity we observed in ducts and acinar anlage, before the secretory set is operative, suggests guanylin has a role in cell differentiation.

Sialadenoma papilliferum: immunohistochemical study

Sialadenoma papilliferum (SP) is a rare benign tumour of salivary gland origin, which has been included among the ductal papillomas in the latest classification of tumours by the World Health Organisation. Two SP from the minor salivary gland of the palate of middle age patients were presented and studied by immunohistochemical. Our results showed presence of cytokeratins (CKs) 13, 14, 7, 8, 19 and absence of vimentin and smooth muscle actin. This immunoprofile is similar to the excretory duct of salivary gland.

Flow cytometric isolation of endodermal progenitors from mouse salivary gland differentiate into hepatic and pancreatic lineages.

Experimental injury is useful to induce tissue stem cells, which may exist in small numbers under normal conditions. The salivary glands originate from the endoderm and consist of acinar and ductal epithelial cells, which have exocrine function. After salivary gland duct ligation, acinar cells disappear as a result of apoptosis, and duct epithelium subsequently proliferates. In this study, we analyzed the tissue stem cells induced by salivary gland duct ligation in mice using immunohistochemistry and flow cytometry. We sorted the Sca-1(+)/c-Kit(+) fraction from adult mice salivary glands by way of fluorescence-activated cell sorting. The sorted cells were apparently homogeneous and were designated mouse salivary gland-derived progenitors (mSGPs). mSGP cells differentiated into a hepatic lineage when cultured in matrigel. In spherical culture in the presence of glucagon-like peptide-1 (GLP-1), these cells differentiated into a pancreatic endocrine lineage. When spheroidal bodies of mSGP, 20 to 30 microm in diameter, were transplanted into liver via the portal vein, the cells integrated into hepatic cords and expressed albumin and alpha1-antitrypsin, suggesting that they had differentiated into hepatic-type cells. Moreover, ductlike structures formed by mSGP cells also appeared, epithelial cells of which were positive for cytokeratin 19. In conclusion, fluorescence-activated cell sorting (FACS) based on histologic evidence is efficient in isolating adult tissue stem cells of the salivary gland. Tissue stem cells of endodermal origin (e.g., hepatic oval cells, pancreatic epithelial progenitor cells, and salivary gland progenitor cells) have similarities in their molecular markers and tissue location. Our findings suggest the existence of common tissue stem cells in endoderm-derived organs.