Biosynthesis of glycosaminoglycans and aggrecan by tumor cells in salivary pleomorphic adenoma: ultrastructural evidence

The present study attempted to discover the sites of synthesis of various glycosaminoglycans (GAGs) and aggrecan in salivary pleomorphic adenoma (PA) with the use of a highly sensitive and specific post-embedding immunogold-silver staining technique at the ultrastructural level. Silver particles representing various GAGs and aggrecan were found to accumulate frequently in the intercellular spaces of non-luminal cells in the epithelial clusters and were dispersed in the myxoid matrix of the mesenchyme-like areas. Furthermore, the non-luminal epithelial cells were demonstrated to contain immunopositive intracytoplasmic vesicles and vacuoles, some of which were of Golgi complex origin. In contrast, intracellular silver particles for hyaluronic acid were mostly attached to the inner surface of the cell membrane. These observations agree well with the current theories of the biosynthesis of GAGs and proteoglycans and provide direct evidence for the production of various GAGs and aggrecan by tumor epithelial cells of PA. Such findings support the ideas that in PA a loss of epithelium occurs by stromalization following epithelial secretion of extracellular matrix substances and transformation of epithelium to mesenchyme represents the basic principle of the tissue heterogeneity in this tumor.

Lambert-Eaton myasthenic syndrome associated with idiopathic thrombocytopenic purpura and diffuse panbronchiolitis: long-term remission after a course of intravenous immunoglobulin combined with low-dose prednisolone

We report a case of Lambert-Eaton myasthenic syndrome (LEMS) associated with idiopathic thrombocytopenic purpura (ITP) and diffuse panbronchiolitis (DPB). An extensive search for malignancy yielded negative results. Interestingly, ITP and DPB developed simultaneously when the patient suffered from myasthenic symptoms. This is the first report in the Japanese or English literature of an association of LEMS, ITP, and DPB. The use of cholinesterase blocker alone did not improve the myasthenic symptoms, and the symptoms and signs relapsed with the tapering of prednisolone (PSL) dosage. However, after administration of immunoglobulin (IVIG) (0.4 g/kg/day x 5 days), low-dose PSL (20 mg/day) alleviated the LEMS and ITP, and the diseases have remained in remission for 8 months without additional IVIG. We suspect that there is a synergistic relationship between IVIG and PSL.

So-called 'hybrid' lesion of desmoplastic and conventional ameloblastoma: report of a case and review of the literature

So-called 'hybrid' lesion of ameloblastoma, which is composed of desmoplastic ameloblastoma and conventional follicular/plexiform ameloblastoma, is an unusual variant of ameloblastoma and only eight cases of 'hybrid' lesion have been published in the English literature. To enhance knowledge of this interesting tumor, we add a case of 'hybrid' lesion that occurred in the right mandible of a 48-year-old Japanese male. Radiographic examination disclosed a honeycomb appearance at the anterior alveolar region, combined with a unicystic radiolucency in the molar region of the mandibular body. Histologically, the former showed microscopic features of desmoplastic ameloblastoma and the latter those of follicular ameloblastoma with focal granular cell transformation. The lesion was enucleated with curettage of surrounding bone and the lesional cavity was marsupialized. Although tumor tissues reappeared at 3, 5, 7 and 14 months after the surgery, the patient has remained disease free for 11 years after the last vaporization by CO2 laser of the recurred tumor. Many more cases of 'hybrid' lesion are needed to clarify the clinicopathological, histopathological and biological characteristics of this interesting variant of ameloblastoma.

Reduced expression of p27(Kip1) protein in relation to salivary adenoid cystic carcinoma metastasis

BACKGROUND

Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin. It tends to grow slowly but shows frequent recurrence and metastasis, ultimately with a poor outcome. Reduced expression of a cyclin-dependent kinase inhibitor, p27(Kip1), has been reported to correlate with poor survival for patients with various types of carcinoma. However, there has been no previous study reported of p27(Kip1) expression in ACC, to the authors' knowledge.

METHODS

To evaluate p27(Kip1) as a prognostic marker, the authors examined the immunohistochemical expression of p27(Kip1) protein in 29 ACCs and correlated its expression with clinicopathologic findings. Eleven pleomorphic adenomas (PAs) were also examined to compare the p27(Kip1) expression in benign and malignant salivary gland tumors.

RESULTS

All PAs expressed p27(Kip1) at high levels, whereas 83% of ACCs (24 of 29) showed reduced expression of this protein. Furthermore, the expression levels were significantly lower in ACCs with metastasis than in those without metastasis. The authors also examined the expression of p27(Kip1) in 2 ACC cell lines (ACCh and ACC3) by Northern and Western blot analysis to elucidate the possible mechanism of p27(Kip1) reduction in ACC. Both ACCh and ACC3 expressed p27(Kip1) mRNA, but ACCh did not produce p27(Kip1) protein. In ACCh, the expression of p27(Kip1) protein was induced by treatment with a proteasome inhibitor.

CONCLUSIONS

Overall, these findings suggest that reduced expression of p27(Kip1) may correlate with the development and progression of salivary ACC and can be an indicator of its malignant behavior. They also suggest that increased proteasome-mediated degradation may play an important role in this reduction of p27(Kip1) expression.

Prognostic significance of apoptotic index in completely resected non-small-cell lung cancer

PURPOSE

To evaluate the significance of apoptotic index (AI) as a prognostic factor after surgery for non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A total of 236 patients who underwent surgery for previously untreated pathologic stage I to IIIa NSCLC between 1985 and 1990 were reviewed. AI was defined as the number of apoptotic cells, detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling, per 1,000 tumor cells. Proliferative index (PI) and aberrant p53 expression were also evaluated immunohistochemically.

RESULTS

The 5-year survival rate for the lowest-AI group (AI < 5.0) was 74.7%; those for the lower-AI group (5.0 < or = AI < 11.0) and the higher-AI group (11.0 < or = AI < 25.0) were 51.6% and 57.8%, respectively. These survival rates were significantly lower than that of the lowest-AI group (P =.021 and P =.043, respectively). The highest-AI group (25.0 < or = AI), however, showed the most favorable prognosis, with a 5-year survival rate of 83.2%. Multivariate analysis confirmed that a moderate AI (5.0 < or = AI < 11.0 or 11.0 < or = AI < 25.0) was a significant factor to predict poor prognosis. The PIs for the lowest-, the lower-, the higher-, and the highest-AI groups were 32.3%, 48.0%, 54.3%, and 50.7%, respectively. The lowest-AI group showed a favorable prognosis because of its low PI, whereas the lower- and the higher-AI groups had a poor prognosis caused by increased cancer-cell proliferation. The highest-AI group showed the most favorable prognosis because apoptotic cell death overcame cell proliferation. No significant correlation was observed between AI and aberrant p53 expression.

CONCLUSION

AI proved to be an independent prognostic factor in NSCLC.

The alteration of penicillin-binding proteins (PBPs) in drug-resistant Streptococcus pneumoniae isolated from acute otitis media

Streptococcus pneumoniae is the micro-organism most frequently isolated from acute otitis media (AOM). Recently, drug-resistant or insensitive strains have been prevalent among pneumococcal AOM cases and were reportedly associated with persistent or recurrent otitis media. The purpose of this study was to examine the alterations of penicillin-binding proteins (PBPs) in Streptococcus pneumoniae isolated from AOM. The PBP samples from 21 clinically isolated strains were examined by 14C-penicillin binding assay and also by adding CCL and CDTR as competitors of 14C-penicillin. Reduced signals in PBP1A and PBP2X/2A were typically observed with the penicillin-resistant Streptococcus pneumoniae samples, while widely different PBP profiles were obtained in each strain of penicillin-insensitive Streptococcus pneumoniae. The competitive binding assay with penicillin-insensitive strains revealed the reduced affinity of CCL to PBPs in comparison with that of CDTR. The results of the penicillin-binding assay were consistent with the results from minimal inhibitory concentration analysis, and its potential usefulness for the prediction of drug resistance was demonstrated.

Odontogenic ghost cell carcinoma: report of four new cases and review of the literature

Only 12 odontogenic ghost cell carcinomas (OGCC) have been reported in the English language literature to date. This article reports four additional cases of this rare odontogenic tumour and examines them in relation to those previously described. Judging from the number of published cases, the OGCC is more prevalent in Asians than other racial groups, occurs more often in the maxilla than the mandible, and is slightly more common in males than females. Histologically, elements of a benign calcifying odontogenic cyst (COC) can be identified in all the malignant variants, either separated or admixed with the malignant epithelial component. The latter can consist of either small basaloid cells or large epithelial cells. Despite the differing histological presentations, the biological behavior of the tumour is unpredictable, with some cases characterized by relatively indolent growth and others by a locally aggressive and potentially fatal course. The tumour apparently arises most often from malignant transformation of a preexisting benign COC, although it may also develop from other odontogenic tumours.

Immunohistochemical and histochemical characterization of the mucosubstances of odontogenic myxoma: histogenesis and differential diagnosis

To discuss the dental origin of odontogenic myxoma and to provide further information for the differential diagnosis between this tumor and myxoid malignant fibrous histiocytoma (MFH) which occasionally occurs in jaw bones, the contents of glycosaminoglycans (GAGs) and proteoglycans (PGs) in the mucosubstances of 15 odontogenic myxomas, 5 myxoid MFH and 3 human fetal tooth germs in the bell stage of development were characterized using histochemical and immunohistochemical methods. Histochemical staining of hyaluronic acid (HA) was undertaken using biotinylated HA binding protein (B-HABP), and immunohistochemical detection was done using a panel of antibodies against chondroitin 6-sulfate (CS-6), chondroitin 4-sulfate (CS-4), dermatan sulfate (DS), keratan sulfate (KS), heparan sulfate (HS), aggrecan, PG-M/versican, decorin and biglycan. In odontogenic myxoma, CS-6, HA and PG-M/versican were observed in the myxomatous matrix of all cases, while KS and HS were seen in none. As for CS-4, DS, aggrecan, decorin and biglycan, only irregular and mild stainings were shown. Consistent and strong positive straining for CS-6, HA and PG-M/versican were seen in dental papilla and provided evidence supporting the origin of this tumor from dental papilla. Except for the constant staining for HA, the myxoid matrix was rarely stained for most GAGs and PGs in myxoid MFH. Immunodetection of CS-6 and PG-M/version with the use of monoclonal antibodies 3-B-3 and 2-B-1 is therefore recommended as a useful tool in differentiating odontogenic myoma from myxoid MFH.

A new quadruple therapy for Helicobacter pylori: influence of resistant strains on treatment outcome

BACKGROUND

There have been no reports concerning the efficacy and safety of a 1-week quadruple therapy regimen of omeprazole, amoxycillin, roxithromycin and metronidazole for Helicobacter pylori infections and the impact of primary resistance on the eradication rate.

METHODS

One hundred and sixty-nine consecutive patients with peptic ulcer disease as well as gastritis with biopsy-proven H. pylori infection were entered into an open study of omeprazole 20 mg o.m., amoxycillin 500 mg t.d.s., roxithromycin 150 mg b.d., and metronidazole 250 mg t.d.s. Helicobacter pylori status was determined by urease test, histology and culture. Susceptibility to amoxycillin, metronidazole and roxithromycin was determined by the E-test.

RESULTS

H. pylori was eradicated in 155 out of 169 (92%; 95% CI 88-96%) by intention-to-treat analysis, and in 155 out of 163 (95%; 95% CI 92-98%) by per protocol analysis. The prevalence of primary resistance against amoxycillin, roxithromycin and metronidazole was 2 out of 166 (1%), 16 out of 166 (10%) and 27 out of 166 (16%), respectively. H. pylori was eradicated in 25 out of 27 (93%) patients with metronidazole-resistant strains compared with 130 out of 136 (96%) in patients with metronidazole-sensitive strains of H. pylori. It was eradicated in 15 out of 16 (94%) patients with roxithromycin-resistant strains while in 140 out of 147 (95%) patients with roxithromycin-sensitive strains of H. pylori, and in two out of two (100%) patients with amoxycillin-resistant stains compared with 153 out of 161 (95%) in patients with amoxycillin-sensitive strains. H. pylori was eradicated in three out of four (75%) patients with double resistance against metronidazole and roxithromycin compared with 152 out of 159 (96%) patients with sensitive strains to metronidazole and or roxithromycin. None of these differences were statistically significant. Severe side-effects were found in only one out of 169 patients-anaphylaxis due to penicillin.

CONCLUSIONS

The 1-week quadruple therapy with omeprazole, amoxycillin, metronidazole and roxithromycin was found to eradicate H. pylori in over 90% of all patients. This regimen was also found to be beneficial for patients with pre-treatment resistant strains to metronidazole, roxithromycin or amoxycillin, and was observed to be safe and well-tolerated.

Expression of p53 and p21CIP1/WAF1 proteins in oral epithelial dysplasias and squamous cell carcinomas

The expression of tumor suppressor gene, p53 and cyclin-dependent kinase inhibitor, p21 in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC) was examined immunohistochemically and its relationship with clinicopathological findings was analyzed. Among 24 epithelial dysplasias, 4 cases (17%) expressed p53 protein and 23 cases (96%) expressed p21 protein. On the other hand, expression of p53 was observed in 64% of OSCCs, and expression of p21 was observed in 77% of OSCCs. In the analyses of the correlation between the expression of p53 and p21 in epithelial dysplasia and OSCC, 79% of epithelial dysplasias were p53-negative and p21-positive, compared to 25% of the OSCCs. p21 expression did not correlate with p53 expression. These results were also demonstrated in OSCC cell lines by western blot analysis. Cumulative survival rate of the patients p53-negative and p21-positive was higher than those p53-positive and p21-negative, those p53-negative and p21-negative and those p53-positive and p21-positive. These findings suggest that p53 expression and p21 negative expression may involve in neoplastic transformation of oral epithelium. In the present study, we did not observe correlation between the expression of p53 and p21 proteins in OSCC. p21 expression may be regulated by p53-independent pathways as well as p53-dependent ones. However, combination of the p21 and p53 expression may be useful as a prognostic marker.

Fulminant form of acute disseminated encephalomyelitis: successful treatment with hypothermia

We described herein a case of the fulminant form of acute disseminated encephalomyelitis (ADEM) that developed after mycoplasma pneumonia. A 28-year-old man who presented with fever, headache, and writing difficulty was admitted to our hospital in August 1997. He developed hernia on the 3rd hospital day. Surgical decompression and intravenous prednisolone failed to halt his progressive deterioration. We introduced systemic hypothermia and he has shown marked recovery; despite having Broca's type aphasia, he could comprehend spoken language and communicate with others by gesture. Head MRI demonstrated diffuse high signals over the white matter on fluid attenuated inversion recovery (FLAIR) images, which suggested extensive demyelination. The clinical course, imaging studies and presence of polymorphonuclear dominant leucocytosis in the blood and CSF in the patient are somewhat similar to findings in acute hemorrhagic leukoencephalitis, however, the result of a brain biopsy was inconclusive. The fulminant form of ADEM is usually fatal. Treatments such as corticosteroids, intravenous immunoglobulin, and surgical decompression have been performed to improve the prognosis. Our case results indicate that hypothermia, which suppresses both brain edema and immune response, may be included in the repertoire of treatment for the fulminant form of ADEM.

Periodontitis in the house musk shrew (Suncus murinus): a potential animal model for human periodontal disease

BACKGROUND

Our understanding of periodontal diseases has been facilitated greatly by the use of animal models. However, no animal model has been identified that truly reflects the disease seen in humans. Suncus murinus, a rat-sized laboratory house musk shrew, has received attention as a valuable animal model due to ease of handling. In the studies described here, periodontal conditions in Suncus murinus were evaluated to determine the usefulness of the shrew as an experimental model for understanding various aspects of periodontal diseases.

METHODS

Periodontal tissues of 34 Suncus murinus (18 to 430 days old) were examined macroscopically, morphometrically, histologically, and ultrastructurally.

RESULTS

Dentition pattern is I3/1, C1/1, P2/1, M3/3. Spontaneous gingival swelling with accumulation of plaque was observed in more than two-thirds of animals older than 200 days. Morphometric analysis of alveolar bone demonstrated a pattern of bone loss that correlated closely with animal age. Histologically, periodontal lesions varying from gingivitis to periodontitis, similar to those observed in humans, were noted. Marked infiltration of lymphocytes and plasma cells in the connective tissue was noted, usually not seen in periodontal lesions of rodents. Although osteoclastic alveolar bone resorption was noted, active bone resorption was not a frequent feature in specimens obtained from chronic inflammatory lesions. Ultrastructurally, degradation of collagen fibers in the inflamed area and ingestion of collagen fibrils by fibroblasts in the deeper connective tissue were often seen.

CONCLUSIONS

These results indicate the potential utility of Suncus murinus as a model to study periodontal disease; e.g., chronic nature of the inflammatory periodontal lesions, similar to those in humans, as well as other advantages including size and ease of handling and housing of these animals.

'Alice in Wonderland' syndrome and Lilliputian hallucinations in a patient with a substance-related disorder

The present paper describes a patient who exhibited 'Alice in Wonderland' (AIW) syndrome as well as Lilliputian hallucinations. The patient regularly consumed a cough syrup that contained dihydrocodein phosphate and dl-methylephedrine hydrochloride over 3 years. At the age of 46, he developed AIW syndrome. The patient ingested a large dose of triazolam and exhibited delirium. Even after the disappearance of symptoms associated with AIW syndrome and delirium, the patient continued to experience Lilliputian hallucinations. We believe that these hallucinations were caused by some of the components of the cough syrup.

Immunohistochemical evaluation of the small and large proteoglycans in pleomorphic adenoma of salivary glands

This study investigated the immunolocalization of small and large proteoglycans (PGs), including decorin, biglycan, PG-M/versican and aggrecan, in salivary pleomorphic adenoma (PA) using monoclonal and polyclonal antibodies. In addition, a polyclonal antibody, A0082, recognizing blood vessels was also used to help identify truly mesenchymal tissues in PA. Decorin reactivity was detected only in tumor capsule and interstitial tissue of non-neoplastic salivary gland, but not in the tumor tissue. Biglycan was frequently revealed throughout the matrix of small chondroid regions and in the peripheral portion of larger chondroid regions. PG-M/versican was mainly localized to the truly mesenchymal tissues in PA and the innermost portion of tumor capsule. On the contrary, aggrecan was extensively expressed in the non-luminal epithelial areas as well as in the myxoid and chondroid areas, but not in the truly mesenchymal tissues. These findings suggest that aggrecan is the most widely distributed PG in PA and may be produced mainly by non-luminal tumor cells. The absence of aggrecan from the truly mesenchymal tissues argues against its origin from this source. Both aggrecan and biglycan may play important roles in the chondroid differentiation and morphogenesis of PA.

Reduced expression of cyclin-dependent kinase inhibitor p27Kip1 is an indicator of malignant behavior in oral squamous cell carcinoma

BACKGROUND

Reduced expression of the cyclin-dependent kinase inhibitor p27Kip1 has been reported to correlate with poor survival in cohorts of breast and colorectal carcinoma patients. Posttranslational ubiquitin-mediated proteasomal proteolysis is related to p27Kip1 protein levels. However, to the authors' knowledge, no previous study has examined the expression of p27Kip1 in oral squamous cell carcinoma (OSCC).

METHODS

To examine the expression of p27Kip1 and its clinicopathologic roles in OSCC, the authors studied the expression of p27Kip1 protein by immunohistochemistry in deparaffinized tissue sections of 20 normal oral mucosa specimens, 22 epithelial dysplasia specimens, and 70 OSCCs, and analyzed its correlation with clinicopathologic parameters. They also studied the expression of p27Kip1 mRNA and protein in six OSCC cell lines by Northern blot and Western blot analysis. To examine the mechanism of reduced expression of p27Kip1, OSCC cell lines were treated with the proteasome inhibitor LLnV.

RESULTS

All the normal oral mucosa specimens and 73% (16 of 22) of the oral epithelial dysplasia specimens expressed p27Kip1 at high levels, whereas 87% of the OSCCs (61 of 70) showed reduced expression of p27Kip1. Furthermore, the levels of expression of this protein were significantly lower in carcinomas with metastasis than those without metastasis. Although OSCC cell lines expressed p27Kip1 mRNA at various levels, most of them expressed p27Kip1 protein at lower or undetectable levels. LLnV induced the expression of p27Kip1 protein in HSC2 cells, in which p27Kip1 protein was originally undetectable.

CONCLUSIONS

These findings suggest that 1) reduced expression of p27Kip1 may correlate with the development and progression of OSCC and can be an indicator of malignant behavior of this neoplasm, and 2) increased proteasome-mediated degradation may play an important role in the reduction of p27Kip1 protein expression.

[An immunohistochemical study of the proliferating activity of ameloblastic fibroma and ameloblastic fibrosarcoma]

Six cases of ameloblastic fibroma (AF) and three cases of ameloblastic fibrosarcoma (AFS) were immunohistochemically investigated with a proliferating cell nuclear antigen (PCNA) monoclone antibody. Data on the PCNA labeling index (LI) of both epithelial and mesenchymal components were analyzed. The results showed that the PCNA LI of mesenchymal component of AFS (40.8%) was significantly higher than that of AF (3.2%) (P < 0.01) and that of the epithelial component of AFS (5.3%) was significantly lower than that of the mesenchymal one of AFS (P < 0.01). The results suggested that PCNA LI be a useful marker for the differentiation diagnosis of AF and AFS.

Odontogenic tumors. A demographic study of 759 cases in a Chinese population

Seven hundred fifty-nine cases of odontogenic tumors retrieved from the files of College of Stomatology, West China University of Medical Sciences were classified according to the World Health Organization's Histological Classification of Odontogenic Tumors and compared with similar reports from other countries. Among these cases, 93.9% of the tumors were benign and 6.1% were malignant. Ameloblastomas predominated (58.6%) with a predilection for the mandible, while odontomas, generally regarded as the most frequent odontogenic tumor in North America, only accounted for 6.7%, the fourth most common tumor in this series. The mandible and the maxilla were divided into eight anatomic regions, and the distribution of each odontogenic tumor type amongst these regions was recorded. The relative incidence of each tumor type, patient age and gender were also compared with data from other selected large series. Geographic differences were noted in the relative incidence of ameloblastoma, odontoma and malignant odontogenic tumors among the Chinese/African, North American and Turkish/German groups. Ameloblastoma and malignant odontogenic tumors are not considered rare in a Chinese population.

Proliferative activity of calcifying odontogenic cysts as evaluated by proliferating cell nuclear antigen labeling index

The calcifying odontogenic cyst (COC) presents with diverse histological features; thus, several subclassifications have been proposed. To evaluate the significance of the various histological features and subtypes of COC from the perspective of proliferative activity, the proliferating cell nuclear antigen (PCNA) labeling index (LI; the percentage of positive nuclei) was assessed immunohistochemically in 25 cases of COC (21 benign and four malignant). All of the benign cases were of the cystic variety and further subclassified into non-proliferative subtype (NPS; four cases); proliferative subtype (PS; eight cases); and COC associated with odontoma (COCaO, nine cases). The PCNA LI of the malignant COC (65.2+/-5.6) was significantly higher than that of the benign COC (11.6+/-9.0; P = 0.002). Non-proliferative subtype (6.8+/-2.8) showed the lowest PCNA LI and PS (17.2+/-11.2) the highest of among the three subtypes of benign cystic COC (P = 0.028). In nine cases of COCaO, six showed epithelial lining of the non-proliferative type as NPS and the other three had lining with proliferative features as PS. The PCNA LI of the latter COCaO group (14.3+/-6.6) was significantly higher than that of the former (6.1+/-4.3; P = 0.05), as seen between PS and NPS. These results demonstrate that PCNA LI is a possible parameter for differentiating malignant COC from benign COC and, whatever the subtypes, the proliferative features in the lining are the main factor influencing the proliferating activity of COC.

Protein extracts of dentin affect proliferation and differentiation of osteoprogenitor cells in vitro

Proteins associated with the mineral phase of dentin are considered to have the potential to alter cell function within the local environment, during development and regeneration of tooth/periodontal tissues. Cells that may be altered include osteoblasts, ameloblasts, periodontal ligament cells, odontoblasts, and cementoblasts. However, specific factors within dentin controlling cell activity have not been elucidated. To investigate further the role of dentin proteins in regulating cell behavior, MC3T3-E1 cells, a mouse osteoprogenitor cell line, were exposed to guanidine/EDTA extracts of dentin (G/E-D) prepared from bovine teeth. Cells, with or without G/E-D (2 to 50 microg/ml), were evaluated for proliferative activity and for mRNA expression of bone-associated genes. Results indicated that G/E-D suppressed cell proliferation and caused striking morphological changes, including the conversion of cuboidal cells into fibroblastic, spindle-shaped cells. Markers of osteoblast differentiation, osteocalcin and bone sialoprotein mRNA were decreased, while osteopontin mRNA was enhanced in cells exposed to G/E-D. Since transforming growth factor beta (TGFbeta1) has been reported to influence cells in a similar fashion, G/E-D were examined for the presence of and concentration of TGFbeta using slot blot analysis and enzyme immunoassay (ELISA), respectively. These analyses demonstrated that G/E-D contained 6.6 ng/mg of TGFbeta1. Next, cells were exposed to G/E-D in conjunction with anti-TGFbeta1,2,3 antibody. When cells were exposed to antibody, G/E-D-mediated changes in morphology and gene expression were blocked. These results suggest that TGFbeta1 and perhaps other factors in dentin can regulate cell behavior and, therefore, can influence development, remodeling, and regeneration of mineralized tissues.

Three-dimensional appearance of Langerhans cells in human gingival epithelium as revealed by confocal laser scanning microscopy

Detailed three-dimensional morphological information of the cell without distortion due to thin sectioning can be obtained from thick sections using a confocal laser scanning microscope. Here that microscope was used to evaluate human gingival Langerhans cells stained with anti-CD1a antibody. Optical sectioning and reconstruction by laser scanning microscopy revealed not only three-dimensional aspects of Langerhans cells but also spatial information on the distribution of their dendritic processes towards the gingival surface. The orientated configuration of those processes may reflect the reaction of the gingival Langerhans cell to the surrounding moist environment containing antigenic stimuli originating in saliva.

Distribution of macrophage lineage cells in rat gingival tissue after topical application of lipopolysaccharide: an immunohistochemical study using monoclonal antibodies: OX6, ED1 and ED2

To discuss the role of macrophage lineage cells on the periodontal tissue destruction, we immunohistochemically examined the phenotype and the dynamics of macrophage lineage cells 1 or 3 h or 1, 2, 3 or 7 d after topical application of LPS (5 mg/ml in physiological saline) from the rat gingival sulcus using 3 monoclonal antibodies: OX6 (antigen-presenting cells), ED1 (monocytes, macrophages and dendritic cells) and ED2 (resident macrophages). We could detect at least 3 different types of macrophage lineage cells, namely OX6+/ED1+/ED2- dendritic cells and exudate macrophages and ED2+ resident macrophages. After LPS application the majority of macrophage lineage cells accumulated in the subjunctional epithelial area were newly extravasated OX6+/ED1+/ED2- dendritic cells or macrophages. The number of these cells increased progressively with time and reached a maximum level at d 2. On the other hand, number and tissue distribution of ED2+ resident macrophages did not change. These results indicate that several types of macrophage lineage cells exist in rat gingival tissue and suggest that dendritic cells and exudate macrophages transiently accumulated after LPS application are responsible for various host immune response and tissue destruction caused by LPS.

Immunohistochemical demonstration of bone morphogenetic protein-2 and type II collagen in pleomorphic adenoma of salivary glands

Immunohistochemical investigation of bone morphogenetic protein-2 (BMP-2) and type II collagen, two cartilage-associated proteins, was undertaken using monoclonal antibodies in 20 cases of salivary pleomorphic adenoma (PA) in order to explore their possible roles in chondroid differentiation of this tumor. Other salivary gland tumors, including adenoid cystic carcinoma (17 cases), polymorphous low-grade adenocarcinoma (10 cases), basal cell adenoma (3 cases), basal cell adenocarcinoma (1 case), and epithelial-myoepithelial carcinoma (2 cases), were also examined for comparison. In PA, BMP-2 immunoreactivity was detected in the luminal and non-luminal cells of the tubulo-ductal structures, plasmacytoid cells, and other scattered tumor cells in solid areas. In addition, tumor cells in chondroid areas in most cases (14/15), and stellate cells in myxoid areas in many cases (7/19), were also intensely labeled for BMP-2. Furthermore, BMP-2 was also detected in the non-neoplastic ductal cells in salivary glands, whereas no other salivary gland tumors were positively stained for this protein. Type II collagen was localized in the intercellular matrix of chondroid areas and in a few chondroid differentiating cells in myxoid areas, confirming its cartilage-specificity. A proportional relationship was observed between BMP-2 expression and chondroid formation, although BMP-2 was also stained in occasional PAs without chondroid formation. It is speculated that BMP-2 might be secreted by tumor cells and play a role in chondroid formation in PA by inducing some tumor cells to produce type II collagen and other chondroid matrical substances, like glycosaminoglycans. The expression of BMP-2 is specific to PA and may possibly be used as a useful marker in differentiating PA from other salivary gland tumors.