scholarly journals Stellate Reticulum

2020 ◽  
Author(s):  
Keyword(s):  
Stellate Reticulum

scholarly journals Ameloblastic Fibro-Odontoma in a Bovine

2019 ◽  
Vol 47 ◽  
Author(s):  
Marina Maurente Berón ◽  
Filipe Krasinski Cestari ◽  
João Pedro Cavasin ◽  
Luísa Favaretto ◽  
Enedi Zancheti ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Mammalian Species ◽  
Central Zone ◽  
Surgical Excision ◽  
Odontogenic Tumor ◽  
Surgical Removal ◽  
Pathology Laboratory ◽  
Young Cattle ◽  
Stellate Reticulum ◽  
Bacteria And Fungi

Background: Ameloblastic fibro-odontoma is a benign tumor derived from odontogenic epithelium and mesenchymal tissue, which forms enamel and dentin. It is a rare neoplasm in all species. One of the most common sites for their occurrence is the anterior mandibules. The prevalence of this odontogenic tumor is higher in young animals and only few cases are described in cattle. The purpose of this article is describe the clinical, surgical and the histopathological characteristic of a fibro-odontoma case in a Jersey Cow. Case: A 3-year-old Jersey cow was presented with a progressively growing mass in the anterior mandible displacing the incisor teeth. The mass measured approximately 12 cm diameter and there was a focal area of myiasis. The owner reported weight loss and eating difficulties. The animal was treated with antibiotics for a few weeks but the conservative treatment failed, and the heifer underwent surgical removal of the lesion. The tumor was sent for histopathological evaluation at UFPR-Palotina Pathology laboratory. Microscopically, the excised mass was poorly delimited, and was composed of tumor cells of mesenchymal and epithelial origin which infiltrated and compressed surrounding tissues. Neoplastic cells were arranged in bundles which multifocally formed dental sacs (dental follicles) of various sizes. These dental sacs were formed by neoplastic ameloblasts, and were surrounded by abundant fibrous connective tissue. The central zone of the tumor consisted of a loose, vacuolated neoplastic stellate reticulum. Mitotic figures were rare, and there was moderate anisokaryosis. In some areas, neoplastic ameloblasts surrounded the stellate reticulum. The presence of a sparse, well-organized basophilic extracellular matrix produced presumably by the tumor cells and interpreted as dentin. These microscopic characteristics led to the diagnosis of an ameloblastic fibro-odontoma. The heifer made a full recovery after surgical removal of the mandibular mass.Discussion: Although rare in all mammalian species, ameloblastic fibro-odontoma is the most common odontogenic tumor in cattle. There are also reports of this neoplasm in humans, cats, horses, sheep, nonhuman primates and rats. Despite being benign these neoplasms may be infiltrative or expansile which make them difficult to be surgically removed. Similar to observed in this case the most majority of these tumors occurs in the anterior mandibules of young cattle of either sex. The ameloblastic fibro-odontoma is a variant of ameloblastic fibroma in which mineralized tissue is absent.  Ameloblastic fibro-odontoma is a tumor formed by odontogenic epithelial and mesenchymal tissues which form enamel or dentin (or both). The presence of enamel helps the pathologist to diagnose an ameloblastic fibro-odontoma by histopathology in the slides. Surgical excision of the neoplasm with wide margins should be performed in order to reduce the risk of local recurrence of this tumor, and when well executed they are curative. In this animal there was no recurrence of the neoplasm after a 16-month follow-up. Ameloblastic fibro-odontoma, other odontogenic neoplasms, inflammatory lesions due to infectious agents such as bacteria and fungi, and congenital lesions should be considered in the differential diagnosis of young cattle presented with localized swelling of the maxillae or oral cavity.

scholarly journals Localization of Putative Stem Cells in Dental Epithelium and Their Association with Notch and Fgf Signaling

1999 ◽  
Vol 147 (1) ◽  
pp. 105-120 ◽  
Author(s):  
Hidemitsu Harada ◽  
Päivi Kettunen ◽  
Han-Sung Jung ◽  
Tuija Mustonen ◽  
Y. Alan Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Epithelial Cells ◽  
Cell Lineage ◽  
Fgf Signaling ◽  
Epithelial Stem Cells ◽  
Lunatic Fringe ◽  
Reticulum Cells ◽  
Stellate Reticulum ◽  
Mouse Incisor ◽  
Basal Epithelial Cells

The continuously growing mouse incisor is an excellent model to analyze the mechanisms for stem cell lineage. We designed an organ culture method for the apical end of the incisor and analyzed the epithelial cell lineage by 5-bromo-2′-deoxyuridine and DiI labeling. Our results indicate that stem cells reside in the cervical loop epithelium consisting of a central core of stellate reticulum cells surrounded by a layer of basal epithelial cells, and that they give rise to transit-amplifying progeny differentiating into enamel forming ameloblasts. We identified slowly dividing cells among the Notch1-expressing stellate reticulum cells in specific locations near the basal epithelial cells expressing lunatic fringe, a secretory molecule modulating Notch signaling. It is known from tissue recombination studies that in the mouse incisor the mesenchyme regulates the continuous growth of epithelium. Expression of Fgf-3 and Fgf-10 were restricted to the mesenchyme underlying the basal epithelial cells and the transit-amplifying cells expressing their receptors Fgfr1b and Fgfr2b. When FGF-10 protein was applied with beads on the cultured cervical loop epithelium it stimulated cell proliferation as well as expression of lunatic fringe. We present a model in which FGF signaling from the mesenchyme regulates the Notch pathway in dental epithelial stem cells via stimulation of lunatic fringe expression and, thereby, has a central role in coupling the mitogenesis and fate decision of stem cells.

scholarly journals Ameloblastic Fibrodentinoma Presenting as a False Gingival Enlargement in the Maxillary Anterior Region

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Shiny Joseph ◽  
Lakshmi Priya ◽  
Dinesh Gopal ◽  
Mary Devachen ◽  
Ajay Narayan ◽  
...  
Keyword(s):  
Microscopic Examination ◽  
Anterior Region ◽  
Excision Biopsy ◽  
Common Site ◽  
Dental Papilla ◽  
Odontogenic Epithelium ◽  
Gingival Enlargement ◽  
Hematoxylin And Eosin ◽  
Stellate Reticulum ◽  
Odontogenic Neoplasm

Ameloblastic fibrodentinoma is a rare benign mixed odontogenic neoplasm usually occurring in the first two decades of life. It is more common in males and the most common site of occurrence is in the mandibular premolar molar area. This report presents a case of ameloblastic fibrodentinoma in a 12-year-old boy in the maxillary anterior region, a less common site for the occurrence of ameloblastic fibrodentinoma. A 12-year-old boy presented with a midline diastema in 11 and 21 region and a swelling in the palatal aspect of 11 and 12. Intraoral periapical radiograph showed the presence of rarefaction of bone on the mesial aspect of the cervical and middle third of the root of 11. Excision biopsy was done. The specimen was processed and stained with hematoxylin and eosin. Microscopic examination showed islands, chords and strands of odontogenic epithelium in a primitive ectomesenchyme resembling dental papilla. The odontogenic epithelium exhibited peripheral ameloblast-like and central stellate reticulum-like cells. The presence of dentinoid material was seen adjacent to the odontogenic epithelium in some foci. The lesion was diagnosed as ameloblastic fibrodentinoma.

Ultrastructural and immunocytochemical characterization of cultured cells from rat molar stellate reticulum

1990 ◽  
Vol 35 (8) ◽  
pp. 603-613 ◽  
Author(s):  
G.E. Wise ◽  
V.L. Rudick ◽  
A.M. Brun-Zinkernagel ◽  
W. Fan
Keyword(s):  
Cultured Cells ◽  
Stellate Reticulum ◽  
Rat Molar

scholarly journals Daughters of the Enamel Organ: Development, Fate, and Function of the Stratum Intermedium, Stellate Reticulum, and Outer Enamel Epithelium

2016 ◽  
Vol 25 (20) ◽  
pp. 1580-1590 ◽  
Author(s):  
Hui Liu ◽  
Xiulin Yan ◽  
Mirali Pandya ◽  
Xianghong Luan ◽  
Thomas G.H. Diekwisch
Keyword(s):  
Enamel Organ ◽  
Organ Development ◽  
Enamel Epithelium ◽  
Stellate Reticulum ◽  
And Function
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