39 research outputs found

    CONGENITAL FIBROUS EPULIS: A CASE REPORT

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    An unusual case of fibrous epulis in a newborn is presented. The clinical appearance, histological features and method of treatment are described. A short review of the literature is also included

    Histologic and histomorphometric evaluation of peri-implant bone subjected to immediate loading: An experimental study with Macaca fascicularis

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    Purpose: Immediately loaded splinted implants can become osseointegrated when they are placed in the anterior part of the mandible. The concept of immediate loading has not been well examined in the posterior mandible. The aim of this study was to evaluate the hard tissue reactions around immediately loaded implants placed in the posterior mandible in the monkey model. Materials and Methods: Six adult M. fascicularis monkeys were used in this study. Thirty-six Ankylos implants (Degussa Dental, Hanau-Wolfgang, Germany) were placed after extraction of the second premolar, first, and second molar teeth and complete healing of the sockets. Control (C) group implants were placed and, after osseointegration, were loaded for 1 month using temporary acrylic resin prostheses and later for 2 months using splinted metal crowns. In the contralateral region of the mandible, test (T) group implants were placed and loaded immediately with the same sequence as carried out for the C implants. After sacrifice of the animals, specimens were examined histologically and evaluated histomorphometrically. Results: All implants were osseointegrated. Compact, cortical bone In contact with the implant surface without any gaps or connective tissue formation was demonstrated. Discussion: Histomorphometric findings of the bone-implant-contacts showed no significant differences between the T and C group implants. Peri-implant mineralized bone areas presented statistically significant differences and showed a higher density of bone between the threads of immediately loaded implants (P < .05). Conclusions: Immediately loaded splinted implants in the posterior mandible can become osseointegrated with a hard tissue peri-implant response similar to that of delayed loaded implants. Moreover, immediate loading seems to increase the ossification of the alveolar bone around endosseous implants. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

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

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    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

    NRAS and BRAF mutation frequency in primary oral mucosal melanoma

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    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

    Early subretinal allograft rejection is characterized by innate immune activity

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    Successful subretinal transplantation is limited by considerable early graft loss, despite pharmacological suppression of adaptive immunity. We postulated that early innate immune activity is a dominant factor in determining graft survival and chose a non-immunosuppressed mouse model of retinal pigment epithelial (RPE) cell transplantation to explore this. Expression of almost all measured cytokines by DH01 RPE cells increased significantly following graft preparation and the neutrophil chemoattractant, KC/GRO/CINC, was most significantly increased. Subretinal allografts of DH01 cells (C57BL/10 origin) into healthy, non-immunosuppressed C57BL/6 murine eyes were harvested and fixed at 1, 3, 7 and 28 days post-operatively and subsequently cryosectioned and stained. Graft cells were detected using SV40 large T antigen (SV40T) immunolabeling and apoptosis/necrosis by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Sections were also immunolabeled for macrophage (CD11b & F4/80), neutrophil (Gr1 Ly-6G), and T-lymphocyte (CD3-ε) infiltration. Images captured with an Olympus FV1000 confocal microscope were analyzed using Imaris software. The proportion of the subretinal bolus comprising graft cells (SV40T+) was significantly (p<0.001) reduced between post-operative day (POD) 3 (90% ± 4%) and POD 7 (20% ± 7%). CD11b+, F4/80+ and Gr1 Ly-6G+ cells increased significantly (p<0.05) from POD 1 and predominated over SV40T+ cells by POD 7. Co-labeling confocal microscopic analysis demonstrated graft engulfment by neutrophils and macrophages at POD 7 and reconstruction of z-stacked confocal images confirmed SV40T inside Gr1 Ly-6G+ cells. Expression of CD3-ε was low and did not differ significantly between time-points. By POD 28, no graft cells were detectable and few inflammatory cells remained. These studies reveal for the first time a critical role for innate immune mechanisms early in subretinal graft rejection. The future success of subretinal transplantation will require more emphasis on techniques to limit innate immune-mediated graft loss, rather than focusing exclusively on suppression of the adaptive immune response

    TEETH IN OSTEOGENESIS IMPERFECTA: A LIGHT MICROSCOPIC STUDY

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    The light microscopic features of the dentine in three teeth from two cases of osteogenesis imperfecta (OJ) are presented. Results show that teeth in OJ distinctively have a more uniform and tubular mantle dentine, and a characteristic laminated circumpulpal dentine formed by distorted incremental bands alternating with parallel rows of interglobular dentine and interrupted by comet-shaped vascular canals. The study indicated that in the absence of overt OJ features, t~e changes in dentine alone are sufficiently characteristic to establish such a diagnosis

    So-called Hybrid Odontogenic Tumors: Do they really exist?

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    Sarcoid-like foreign body reaction in body piercing - A report of two cases

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    We report two cases of body piercing as a religious practice that subsequently led to the development of granulomatous nodules at previously punctured sites of the skin and oral mucosa. These lesions were diagnosed as sarcoid-like foreign body reaction after other possible causes including sarcoidosis, tuberculosis, tuberculoid leprosy, fungal infections, viral infections, and Crohn's disease were excluded. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down
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