An unsuspected ameloblastoma in the subpontic region of the mandible with consideration of pathogenesis from the radiographic course

The purpose of this report is to document a case of unsuspected ameloblastoma involving the right man dibular subpontic region in a 38-year-old Cambodian female patient. This lesion was purportedly preceded by multiple radiolucencies which were diagnosed as radi cular cysts and treated a few times in the past years by enucleation followed by endodontic therapy of the affected teeth. Bridgework restoration of the partially edentulous area was performed. This case report de monstrates radiographic changes that occurred in the periods before and after the diagnosis of amelo blas to ma. The case may represent an example of radicular cysts and ameloblastoma occurring as a collision phenomenon, or the ameloblastoma may have arisen as a result of neoplastic transformation of the lining epi thelium in an inflammatory odontogenic epithelial cyst

Differential expression of basement membrane collagen-IV alpha l to alpha 6 chains during oral carcinogenes

This study aimed to resolve if basement membrane (BM) collagen alpha chains undergo remodeling during oral. carcinogenesis. Using immunohistochemistry and transmission electron microscopy, we found that BMs in oral epithelial dysplasias (OED: mild, n=10; moderate, n=10; severe, n=10) and carcinoma in situ (CIS) (n=10) differed from normal mucosa (n=6) and oral epithelial hyperplasia (n=5) in showing: (1) excessive lamina densa-like material ultrastructurally, and (2) stronger immunoexpression for alpha 5(IV) than for alpha 1(IV), alpha 2(IV), and alpha 6(IV) chains-findings that implicate these molecules' role as an adhesive template for the attachment and persistence of basal dysplastic cells. Incipient loss of BM integrity in CIS, where alpha 5(IV)/alpha 6(IV) chains were more frequently absent than alpha 1(IV)/alpha 2(IV) chains, suggests that alpha(IV) network disruption is crucial for progression of dysplastic cells into the extracellular compartment, marking transition into the invasive phase. In carcinomatous BM, the disappearance of alpha(IV) chains was more severe in poorly differentiated oral squamous cell carcinoma (OSCC) (n=10) than in well-differentiated OSCC (n=10). In all samples examined, alpha 3(IV) and alpha 4(IV) chains were absent. These findings taken together suggest that BM collagen-IV alpha chains undergo remodeling where selective increase and loss of these molecules are probably early and late events, respectively, during progression of oral dysplasia to cancer. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

Overview of Cytological Dynamics of Periodontal Ligament Inflammatory Lesions

Cyto-pathological features of the periodontal ligament tissue inflammatory lesions have somehow been carried out but detailed cellular dynamics remain unclear. Therefore, in this review, we overviewed mainly our recent experimental model studies. That is performed using using ordinary ddY mice and BMP bone marrow transplanted mouse model. Regaring the experimental apical inflammatory periodontitis, at four weeks, micro-CT confirmed the presence of a radiolucent image at the apex of the tooth, which was then removed for histological examination. The results showed granulation tissue with fibrosis gradually formed at the periphery of an abscess. Next, if perforation were large, granulation tissue would grow to form periodontal polyp. Results of micro-CT revealed alveolar bone resorption and widening of periodontal ligament. Histopathological examination showed proliferation of fibroblasts with some round cells and blood vessels in the granulation tissue. Double immunofluorescent staining of GFP and Runx2 revealed that both proteins were expressed in spindle-shaped cells. Double immunofluorescent staining of GFP and CD31 revealed that both proteins were expressed in vascular endothelial cells in morphologically distinct vessels. The results suggest that fibroblasts, periodontal ligament fibroblasts and blood vessels in granulation tissue were derived from transplanted-bone marrow cells. Thus, essential growth of granulation tissue in periodontal polyp was caused by the migration of undifferentiated mesenchymal cells derived from bone marrow, which differentiated into fibroblasts and later on differentiated into other cells in response to injury

Notch signaling and ghost cell fate in the calcifying cystig odontogenic tumor

Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs) are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites). Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (GCOT), their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4) and three ligands (Jagged1, Jagged2 and Delta1) was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0), mild (+), moderate (2+) and strong (3+). Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive

NRAS and BRAF mutation frequency in primary oral mucosal melanoma

Oral mucosal melanoma (OMM) is a fatal sarcoma of unknown etiology. Histological morphology and genetic events are distinct from those of its cutaneous counterpart. Mutation and up-regulation of c-kit has been identified in OMM which may activate downstream molecules such as RAS and RAF. These molecules are involved in the mitogen-activated protein kinase (MAPK) pathway leading to tremendous cell proliferation and survival. NRAS and BRAF mutation and protein expression have been studied in other melanoma subtypes. The purpose of this study was to determine RAS protein expression and NRAS and BRAF mutation in 18 primary OMM cases using immunohistochemistry and mutation analysis. Results showed that RAS is intensely expressed in both in situ and invasive OMMs. However, NRAS mutation was only observed in 2/15 polymerase chain reaction (PCR) amplified cases both of which were silent mutations. On the other hand, BRAF missense mutations were observed only in 1/15 cases with PCR amplification. NRAS and BRAF mutations were independent from previously reported c-kit mutations. The classical V600E BRAF mutation was not found; instead a novel V600L was observed suggesting that the oncogenic event in OMM is different from that in skin melanoma. The low frequency of NRAS and BRAF mutations indicate that these genes are not common, but probable events in OMM pathogenesis, most likely independent of c-kit mutation. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

In Vivo Tissue Response of Endodontic Bio-ceramic Materials

In order to evaluate the biocompatibility and mineral repair capacity, mineral trioxide aggregate (MTA ProRoot-Dentsply, Tulsa, Tulsa, Oklahoma-USA), Portland cement (PCn) normal setting (CP; Loma Negra-Argentina) and fast setting (PCf) (CP; Klaukol- Argentina) and Calcium hydroxide-based paste (Calen SS White Dental Articles Ltda.- Brazil) filled silicone tube were implanted into the dorsal subcutaneous connective tissues of 25 Wistar rats. Animals were euthanized at 24, 72 hours, 7, 15 and 30 days. Implants with surrounding tissues were fixed with 10% buffer formaldehyde and processed for histological routine techniques. Slides (5 µ serial cuts) were stained with H&E and Von Kossa stains for morphological, qualitative and quantitative analysis by light microscopy. HOCa2 (Calen) showed severe and moderate inflammatory response and granulomatous reaction with psammoma body-like formation. PCn and MTA have similar behavior, with mild inflammatory reaction from 8 % and 4%, respectively. Even though, PCn and MTA demonstrated analogous biological reaction, MTA developing thick artificial mineral precipitation (p=0,007). All sealers demonstrated a similar inflammatory response at all time periods studied (p=0.678).Fil: Romano, Teresita. Universidad Nacional de Tucumán. Facultad de Odontología; ArgentinaFil: Jammal, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Nakano, K.. Okayama Univ, Med.dent.and Pharm Sci. School, Oral Path; JapónFil: Garcia Rusco, Ana. Universidad Nacional de Tucumán. Facultad de Odontología; ArgentinaFil: Olmos Fassi, Jorge. Universidad Nacional de Tucumán. Facultad de Odontología; ArgentinaFil: Kozuszko, Silvia. Universidad Nacional de Tucuman. Facultad de Odontologia. Cat.de Anatomia Patologica/laboratorio de Patologia Molecular; ArgentinaFil: Takabatake, K.. Okayama Univ, Med.dent.and Pharm Sci. School, Oral Path; JapónFil: Nagatsuka, H.. Okayama Univ, Med.dent.and Pharm Sci. School, Oral Path; JapónFil: Missana, Liliana Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin

A Pulse Compression Ultrasonic Test Instrument and Its Applications

In recent years, so called “digital ultrasonic test instruments” have been commercially available. These conventional instruments employ electrical impulse excitation of ultrasonic probes. In this configuration, waveforms of ultrasonic pulses into a test object are determined only by the characteristics of probes. This means that variation of probe characteristics causes variation of evaluated results and reproducibility of evaluation is poor. Furthermore, some of the conventional instruments do not provide enough information required for quantitative nondestructive evaluation (QNDE) about a test object, since ultrasonic echo signals are A/D converted after an envelope detector in a receiver and only information of echo height and position is obtained

SQUAMOUS ODONTOGENIC TUMOR OF THE MANDIBLE: A CASE REPORT DEMONSTRATING IMMUNOEXPRESSION OF NOTCH1, 3, 4, JAGGED1 AND DELTA1

Background:Squamous odontogenic tumor (SOT) is a rare benign odontogenic epithelial neoplasm. A slow-growing painless expansive swelling is the common presenting symptom. Histopathologically, SOT can be easily misdiagnosed as an acanthomatous ameloblastoma. Although Notch receptors and ligands have been shown to play a role in cell fate decisions in ameloblastomas, the role of these cell signaling molecules in SOT is unknown. Case report:This paper describes a case of SOT affecting the anterior mandible of a 10-year-old Indian female. The patient was treated by local surgical excision and there has been no follow-up clinical record of recurrence 5 years after primary treatment. Histopathological examination revealed a solid, locally-infiltrative neoplasm composed of bland-looking squamatoid islands scattered in a mature fibrous connective tissue stroma and the diagnosis was SOT. Immunohistochemical evaluation showed positive reactivity of varying intensity in the neoplastic epithelial cells for Notch1, Notch3, Notch4, and their ligands Jagged1 and Delta1. Expression patterns showed considerable overlap. No immunoreactivity was detected for Notch2 and Jagged2. Conclusions:Present findings suggest that Notch receptors and their ligands play differential roles in the cytodifferentiation of SOT

Angiogenic squamous dysplasia-like phenomenon in oral epithelial precursor lesions

Statement of the problem: Dysplasia, the morphological yardstick of epithelial precursor lesions, is the collective term for a variety of architectural and cytological changes within the altered oral epithelium. Angiogenic squamous dysplasia (ASD), a distinct morphological characteristic in pre-invasive bronchial lesions, describes the presence of capillary tufts that are closely juxtaposed to and projecting into the dysplastic bronchial epithelium. Objective: To determine whether ASD-like phenomenon occurs in oral epithelial precursor lesions, and to speculate on its relevance. Methods: Twenty cases each of mild, moderate and severe oral dysplasia (inclusive of carcinoma-in-situ), and 10 normal oral mucosa (normal controls) were serial sectioned for H and E staining, and for microvessel density (MVD) scoring with CD31, CD34 and CD105. Microcapillary pattern images were digitally captured for 3-D reconstruction. Results: Oral ASD foci consisting of CD31- and CD34-positive capillary loops abutting onto the overlying dysplastic oral epithelium (and causing it to assume an irregular or papillary surface configuration) were identified in moderate (3/20; 15) and severe dysplasia (13/20; 65), but not in normal oral mucosa and mild dysplasia. MVD score demonstrated increasing vascularity as epithelium progressed from normal to severe dysplasia (p<0.05). CD105 demonstrated increase neo-vascularization in all dysplasia grades (p<0.05). Conclusions: These preliminary Findings taken together suggest that: 1. ASD-like phenomenon may be an important intermediary biomarker in oral precursor lesions; and 2. architectural alterations of the entire disturbed mucosa may be a more useful pre-malignancy index

Differential expression of canonical and non-canonical Wnt ligands in ameloblastoma

BACKGROUND: Canonical and non-canonical Wnt signaling pathways modulate diverse cellular processes during embryogenesis and post-natally. Their deregulations have been implicated in cancer development and progression. Wnt signaling is essential for odontogenesis. The ameloblastoma is an odontogenic epithelial neoplasm of enamel organ origin. Altered expressions of Wnts-1, -2, -5a, and -10a are detected in this tumor. The activity of other Wnt members remains unclarified. MATERIALS AND METHODS: Canonical (Wnts-1, -2, -3, -8a, -8b, -10a, and -10b), non-canonical (Wnts-4, -5a, -5b, -6, 7a, -7b, and -11), and indeterminate groups (Wnts-2b and -9b) were examined immunohistochemically in 72 cases of ameloblastoma (19 unicystic UA, 35 solid/multicystic SMA, eight desmoplastic DA, and 10 recurrent RA). RESULTS: Canonical Wnt proteins (except Wnt-10b) were heterogeneously expressed in ameloblastoma. Their distribution patterns were distinctive with some overlap. Protein localization was mainly membranous and/or cytoplasmic. Overexpression of Wnt-1 in most subsets (UA = 19/19; SMA = 35/35; DA = 5/8; RA = 7/10) (P < 0.05), Wnt-3 in granular cell variant (n = 3/ 3), and Wnt-8b in DA (n = 8/ 8) was key observations. Wnts-8a and -10a demonstrated enhanced expression in tumoral buddings and acanthomatous areas. Noncanonical and indeterminate Wnts were absent except for limited Wnt-7b immunoreactivity in UA (n = 1/ 19) and SMA (n = 1/ 35). Stromal components expressed variable Wnt positivity. CONCLUSION: Differential expression of Wnt ligands in different ameloblastoma subtypes suggests that the canonical and non-canonical Wnt pathways are selectively activated or repressed depending on the tumor cell differentiation status. Canonical Wnt pathway is most likely the main transduction pathway while Wnt-1 might be the key signaling molecule involved in ameloblastoma tumorigenesis. J Oral Pathol Med (2012) 41: 332-33