Laser microdissection is a method for the procurement of targeted cells from a tissue section, and its use enables one to analyze both nucleic acid and protein from procured cells. However, contamination by cells other than the target cells and damage to mRNA are problems that have been encountered. We have developed a laser pressure cell transfer method that is similar to the laser pressure catapulting method, but it has some advantages with regard to ease of the handling of an original thin film, the procedure for the preparation before laser microdissection, and the use of toluidine blue stain. We demonstrated that the quality of total RNA extracted from procured cells using the laser pressure cell transfer method was excellent for subsequent analysis, and this method could obtain clear morphological images of targeted cells before and after laser microdissection. Furthermore, as trial research for this method, we examined the expression profile of various transcriptional products related to invasive and metastatic potential using surgical materials of oral squamous cell carcinoma (OSCC). Lymph node metastasis tended to be often seen in cases that express VEGF, VEGFC and CD44s (2 of 3 cases) and in cases that express vimentin, keratin 19 and osteopontin (2 of 3 cases). These findings indicate that there may be a close relationship between those molecules in OSCC. This technique seems to be significantly better than the laser microdissection method currently available for obtaining clear morphological images, preserving the form of procured targeted cells, procuring mRNAs efficiently, and preserving them.

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The present study aimed at investigating whether part of the enamel opacities found in 20 permanent premolars could be ascribed to uptake of excess fluoride and whether there are appreciable differences in prevalence and progression of dental caries between tooth groups with and without developmental enamel defects. Fluoride content of enamel was assessed by electron probe microanalysis. Based on visual inspection, F/Ca determination, and histopathologic examination, the pooled premolars were divided into three groups: enamel without developmental defects (n=6), enamel with fluoride-relative defects (n=6), and enamel with fluorotic-irrelative developmental defects (n=8). This data shows a high incidence of developmental enamel malformations. The present histopathologic findings indicate that there were no significant differences in caries experience between the tooth groups regarding the entire coronal enamel, but that mild fluorotic enamel is associated with a lower risk of caries susceptibility in these smooth surfaces, while caries development still remains predominant in pits and fissures.

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Using immunohistochemistry, we studied the expression of S100A4 and E-cadherin in 43 oral squamous cell carcinomas (SCC) to evaluate the metastatic potential and patient survival. Expression levels of S100A4 correlated with lymph node metastasis (P=0.024) and poor prognosis (P=0.0136). Reduced E-cadherin expression was also associated with lymph node metastasis (P=0.023) and poor prognosis (P=0.0146) and was inversely correlated with S100A4 expression (P=0.011). We also found that S100A4(2+,3+)/E-cadherin(-,+) expression was significantly associated with lymph node metastasis (P=0.04) and poor prognosis (P=0.0021). Furthermore, we systematized the evaluation of oral SCC metastasis and prognosis by analyzing the expression of S100A4, E-cadherin, and other histopathological factors. Cases with total points greater than 8 were associated with lymph node metastasis (P=0.000) and poor prognosis (P=0.0022). These results indicate that S100A4, as both a single factor and in combination with E-cadherin, may be one of the most useful markers predicting the metastatic potential and prognosis of oral SCC patients.

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The purpose of this study was to determine the immunolocalization of glycosaminoglycans (GAGs) in the mandibular condylar cartilage of senescence-accelerated mice (SAM) with early osteoarthritis (OA). The cartilages in the mandibular condyles and in the proximal tibial epiphyses from two 10-month-old SAM strains, SAMP8 and SAMR1 (a control), were examined for the immunolocalization of chondroitin-4-sulphate (C4S) and keratan sulphate (KS). Morphologically, the mandibular condylar cartilage was disrupted with clefts in SAMP8 but not in SAMR1. C4S was distributed throughout the two cartilages. In contrast, KS was located in extracellular regions in the fibrous and proliferative cell layers of mandibular cartilage and in the lower maturative cell layer of epiphyseal cartilage. The two GAGs, particularly KS, were intensely immunostained around the clefts. These results suggest that C4S and KS could play differential roles in the structural function of articular cartilage and their functions might be involved in early mandibular OA lesions.

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A case of malignant midline oral ulceration in a 51-yr-old woman is reported. Midline granuloma is rare, well documented and has a variety of names. Lethal midline granuloma is a malignant lymphoma, most commonly NK or T cell lineage. The patient developed recurrent oral ulceration over a period of a year requiring several biopsies before the correct diagnosis was made. A high grade NK/T cell lymphoma with an angiocentric growth pattern was confirmed, the lymphoma cells expressing T-cell markers (CD3, CD43) and co-expressing CD30. Natural killer T-cell markers (CD56 and CD57) were not expressed but there are strong expression cytotoxin granule associated proteins granzyme B and perforin markers of activated NK cells. No association with Epstein-Barr virus was found with immunohistochemistry and in-situ hybridisation. The patient failed to respond to chemotherapy and died several months later. This case illustrates the difficulty in making the diagnosis of T-cell lymphoma as the oral ulcers often show secondary inflammatory changes, which mask the lymphoma cells, and multiple biopsies may be required to make the correct diagnosis.

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We report a rare case of a completely isolated hemangioma with the histological findings of an arteriovenous hemangioma which occurred in the tongue of a 42-year-old female. This lesion was completely encapsulated by fibrous connective tissue and had focally proliferated with extensive vascular development. The tumor showed a lobular arrangement of vessels of generally uniform wall thickness. Vessel walls were stained by EVG and were immunohistochemically stained with SMA. Mast cells reactive for toluidine blue staining were frequently identified in the stroma and in the surrounding vascular area.

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