Extracellular matrix metalloproteinase inducer expression in salivary gland tumors: a correlation with microvessel density.

The purpose of this study was to investigate the expression pattern of extracellular matrix metalloproteinase inducer (EMMPRIN) as well as the correlation between EMMPRIN and microvessel density (MVD) in salivary gland tumors. Extracellular matrix metalloproteinase inducer expression and MVD were examined immunohistochemically on paraffin-embedded tissue specimens from 95 patients with salivary gland tumors, who underwent surgical resection from 1998 to 2006. Reverse transcription-polymerase chain reaction was used to monitor EMMPRIN mRNA expression in frozen samples. Extracellular matrix metalloproteinase inducer expression in mucoepidermoid carcinomas and adenoid cystic carcinomas was significantly higher than in normal salivary gland tissues and pleomorphic adenomas (P < 0.05). The MVD of mucoepidermoid carcinomas and adenoid cystic carcinomas was significantly higher compared with pleomorphic adenomas (P < 0.05). The MVD of the EMMPRIN-positive expression group was significantly higher than the MVD of the EMMPRIN-negative expression group (P < 0.05). Extracellular matrix metalloproteinase inducer mRNA expression in malignant salivary gland tumors was higher than that in pleomorphic adenomas (P < 0.05). This study suggests that EMMPRIN expression is an important feature of malignant salivary gland tumors and can be used as a biologic marker to characterize salivary gland tumors. Extracellular matrix metalloproteinase inducer is also a positive angiogenic factor in salivary gland tumors.

Bleeding from Wharton's duct after fine-needle aspiration biopsy on submandibular gland.

The case of a fine-needle aspiration biopsy (FNAB) of the patient's salivary gland lesions is considered a rapid, simple, reliable, minimal invasive procedure with markedly rare complications. Herein, we report a case of bleeding from the region of the Wharton's duct after a procedure of a FNAB on the patient's submandibular gland. To our knowledge, this is the first case of bleeding from a salivary duct after a FNAB. For this reason, it is important to recognize that bleeding from the salivary duct after a FNAB can be a rare occurrence.

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.

Submandibular gland duct endoscopy. Diagnostic value for salivary duct disorders in comparison to conventional radiography, sialography, and ultrasonography.

The purpose of this study is to evaluate the usefulness of endoscopy as a procedure for the diagnosis of submandibular gland duct disorders. Endoscopy of the submandibular glands was performed on 12 patients with symptoms of obstructive sialoadenitis to identify the cause of obstruction. The endoscopic findings were then compared to those of diagnostic procedures such as conventional radiography, sialography, and ultrasonography. Six normal subjects also underwent endoscopy to better understand the normal findings of the duct system. Endoscopy demonstrated salivary gland calculus in 5 of 12 patients, which was revealed as filling defects on sialograms and as strongly echogenic structures on ultrasonograms in 4 of the patients. Endoscopy revealed secretion plugs, secretion plaques, and/or stenosis, which could not be seen by any other diagnostic procedures in 5 patients, as the cause of recurrent swelling in all 7 patients not demonstrating sialolith. Abnormal findings of the duct wall such as vasodilatation, fibrosis, edema, or erythema were seen in four patients, three of whom exhibited dilatation of the duct system on sialograms. In four patients, a decreasing internal echo level of the gland was seen on ultrasonograms. Our initial results for submandibular gland duct endoscopy thus appear to be promising.

Human adipose tissue­derived stem cells alleviate radiation­induced xerostomia.

Hyposalivation is an intractable side­effect of radiotherapy for head and neck cancer. It is caused by the irreversible loss of acinar cells and decreased saliva secretion. However, this situation severely compromises the quality of life of affected patients. Currently, there is no effective treatment for this condition. In the present study, we developed a novel approach to regenerate the function of the irradiation­damaged salivary glands using human adipose tissue­derived stem cell (hADSC) intraglandular transplantation. ZsGreen­labeled hADSCs were adoptively transferred into Sprague­Dawley (SD) rat submandibular glands immediately following exposure to 18 Gy irradiation. A higher salivary flow rate (SFR) was observed in the hADSC­treated group. Tissue improvement, including angiogenesis, anti­apoptosis and anti­fibrosis, was detected in the hADSC­treated glands as compared to the untreated glands. Quantitative reverse transcription PCR (RT-qPCR) revealed a significantly higher expression of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), cyclooxygenase­2 (COX­2) and matrix metalloproteinase­2 (MMP­2) in the hADSC­treated rats. Furthermore, immunohistochemical analysis indicated that the hADSCs had differentiated into acinar and ductal cells in the rat submandibular glands. Thus, our results suggest that hADSCs are able to regenerate irradiation­damaged salivary glands through glandular transplantation.

Are myoepithelial cells responsible for the widespread expression of inducible nitric oxide synthase in pleomorphic adenoma? An immunohistochemical study.

Many of the actions of nitric oxide (NO) are still poorly understood. Recently, it has been shown that the inducible isoform of the enzyme nitric oxide synthase, iNOS, is expressed in both salivary ducts and pleomorphic adenoma. The current immunohistochemistry study determined whether or not this distribution correlated with smooth muscle actin (SMA) expression, thereby suggesting the expression by myoepithelial cells in both sites. Twenty cases of histologically confirmed pleomorphic adenoma, the sections of which contained adjacent normal salivary gland tissue, were stained for iNOS and smooth muscle actin (clone 1A4). The salivary ducts of all cases were stained intensely by both antibodies, with smooth muscle actin staining also being noted around acini in the normal gland parenchyma. Moderate or heavy staining for iNOS was found in all specimens of pleomorphic adenoma, with smooth muscle actin being distributed in a similar manner in 19 cases. Smooth muscle actin, but not iNOS, was also noted in blood vessels of both normal glands and tumours. The correlation between iNOS and SMA in pleomorphic adenoma was significant (P<0.001). The presence of iNOS in normal salivary ducts and pleomorphic adenoma is most likely due to expression by myoepithelial cells.