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Lining Epithelium (lining + epithelium)

Distribution by Scientific Domains

Medical Sciences	62%

Selected Abstracts

Structure of the Lining Epithelium of the Cauda Epididymis of the Golden Hamster

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009
C. C. L. Beu
Summary The ductus epididymis has roles in the maturation and storage of spermatozoa. The main function of the cauda epididymis is the storage of spermatozoa; however, this region exerts other morphophysiological roles. So, this study was aimed at investigating structural features of the cauda epididymis epithelium, which could indicate roles other than the storage. The relative percentages of the cell types in the epithelium were 74.9, 6.9, 12.5 and 5.6% of principal, clear, basal and halo cells respectively. Large intercellular spaces were seen among the lateral plasmatic membranes of adjacent principal cells or among these cells and others cell types. These spaces were found to be filled with multivesicular bodies, myelin figures, scrolls and debris of membranes or flocculent dense material. Clear cells had the cytoplasms filled with lysosomes (¾ of basal cytoplasm), and vacuoles and vesicles (¼ of apical cytoplasm). The observations allowed us to infer that clear cells could act in the process of endocytosis and also in water transfer from the lumen to the interstitium through the epithelium compartment. Moreover, transcytosis may occur at the cauda epididymis of Golden hamster. [source]

Histopathological and immunohistochemical analysis of calcifying odontogenic cysts

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 10 2001
Mitsuhide Yoshida
Abstract: Method and Results: Calcifying odontogenic cysts (COCs) were examined histopathologically and immunohistochemically to characterize the histological and cytological properties of these lesions. Histopathologically, COCs showed thin or thick lining epithelium with ghost cells. COCs were classified according to proliferative type or nonproliferative type lining epithelium, the presence or absence of ameloblastomatous appearance, and the presence or absence of odontoma in the cyst walls. Immunohistochemically, amelogenin protein was expressed chiefly in ghost cells, whereas cytokeratin 19 (CK19) and bcl-2 proteins were expressed chiefly in lining epithelial cells. The proportion of cases positive for bcl-2 protein was slightly higher in COCs with odontoma than in those without odontoma. Lining epithelial cells sporadically showed positive reactions for Ki-67 antigen. Mean Ki-67 labeling index was slightly greater in COCs with proliferative type lining epithelium, COCs with ameloblastomatous appearance of the cyst walls, and COCs with odontoma of the cyst walls than in COCs without these histological features. Our results suggest that ghost cells or lining epithelial cells show ameloblastic cytodifferentiation or odontogenic epithelial characteristics, that bcl-2 protein is associated with survival of lining epithelial cells in COCs, and that high proliferation potential is associated with ameloblastomatous proliferation or combined odontoma. COCs exhibited various histological features with several transitional forms, and immunohistochemical examinations revealed little or no difference in cytodifferentiation and cellular activity among COCs. Conclusion: We conclude that COCs with various histological features have neoplastic potential and may not be separate entities within the same histological spectrum. [source]

A histopathological and lectin-histochemical study of the lining epithelium in postoperative maxillary cysts

ORAL DISEASES, Issue 5 2002
M Maruyama
OBJECTIVE:,Histopathological and lectin-histochemical characteristics were studied in the lining epithelium of postoperative maxillary cysts (POMC). MATERIALS AND METHODS:,Histological (HE, PAS, AB), immunohistochemical (CD3 and L26) and lectin (wheat germ agglutinin, WGA; Ulex europaeus agglutinin I, UEA-I; concanavalin A, ConA) stainings were performed in the 360 POMC specimens. The number of goblet cells and inflammatory cells was counted and statistically analyzed. RESULTS:,The lining epithelium was classified into three types based on histopathological characteristics; pseudostratified ciliated epithelium (pSCE), transitional epithelium (TE) and stratified squamous epithelium (SSE). Local infiltration of inflammatory cells into the cyst wall was associated with an increased number of goblet cells in the lining epithelium. The observed association between the infiltration of inflammatory cells and an increase in the number of goblet cells was statistically significant in groups with lining pSCE and TE. Glycoconjugate histochemical analysis revealed that the surfaces of the lining epithelium with squamous metaplasia showed an increased degree of staining reactivity with UEA-I, whereas the staining reactivity with ConA was reduced. Goblet cells were able to be stained with WGA and UEA-I, but showed extremely low reactivity with ConA. CONCLUSION:,Changes in the glycoconjugate expression of the metaplastic lining epithelium and goblet cell development play an important role in the local defense mechanisms against inflammatory factors in POMC. [source]

Morphological Studies on the Development of the Bronchial Epithelium of the Fetal Camel Lung

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005
G. Kamel
Light microscopic observations revealed that in camel foetuses of 25 mm crown-to-rump length (CRL) the primordial tubular system of the prospective lung was formed of several tubules lined by undifferentiated columnar epithelium. Intra-epithelial neuroendocrine cells were the first elements to be differentiated in the lining epithelium of the primordial tubular system of the prospective lung as early as 25 mm CRL. On reaching 50,67 mm CRL, the primordial tubular system started to differentiate into two systems of primordial tubules, the prospective bronchial or light tubules and the future respiratory or dark tubules. The lining epithelium of the prospective bronchial tubules revealed a clear evidence of ciliogenesis as early as 80 mm CRL. From 800 mm CRL onwards, the bronchial epithelium demonstrated ciliated and non-ciliated secretory cells. The non-ciliated secretory cells of the bronchial epithelium of fetal camel lung showed moderate reaction to AB/PAS technique, for the first time, in fetuses reaching 600 mm CRL. [source]

Ultrastructural Features in the Epididymis of the Dog (Canis familiaris, L.)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2001
Bruno Cesar Chimming
The ultrastructure of the epididymal duct of the dog is described in this paper. The epididymis was divided into three morphofunctional segments: initial, middle and terminal. The cellular population of the lining epithelium is formed from principal, apical, basal and clear cells. The peritubular stroma and the tubular interstitium surrounding the epithelium are also described. The outcome is compared to the description made in other species of mammals. [source]

Hepatic intraductal oncocytic papillary carcinoma

CANCER, Issue 10 2002
Robert C. G. Martin M.D.
Abstract BACKGROUND There has been an increasing incidence and mortality from peripheral cholangiocarcinoma (PC) in the United States over the past 24 years. PC has been classified into two principal types, a mass-forming type and a periductal-infiltrating type, with a significant difference in the clinical behavior between the two. A third type, demonstrating a noninvasive intraductal growth of PC, was described as papillary PC. Rarely, papillary hepatic tumors composed of oncocytic cells have been described. Intraductal oncocytic papillary carcinomas (IOPCs) of the liver present as large, mucin-filled, cystic lesions lined by noninvasive or focally microinvasive oncocytic tumors. METHODS From June 1999 to August 2001, three patients with hepatic IOPCs were identified in the files of the Hepatobiliary Service, Department of Surgery, and the Department of Pathology at Memorial Sloan-Kettering Cancer Center. They form the basis of this study. We report the clinicopathologic presentation, as well as the outcome, with a review of the literature. RESULTS All three cases presented with well defined intrahepatic cystic masses ranging in size from 7.2 to 21.1 cm. The most prominent cells of the lining epithelium were columnar with oncocytic features showing abundant eosinophilic granular cytoplasm and centrally located nucleoli. All three patients underwent resection with one demonstrating local bile duct recurrence that was managed with stenting. Review of the literature has identified 39 patients with papillary PC and 2 patients with IOPC. The biology of these reported cases has been variable with overall survival better than that of nonpapillary PC patients, with recurrence in 15% of the reported cases. CONCLUSION Papillary PC is a rare type of cholangiocarcinoma that includes an interesting variant: IOPC. These tumors are predominantly found in men, who present with large (> 5 cm) mucinous cystic lesions of the bile duct. A noninvasive histology is seen, and long-term survival may be achieved with complete resection. Invasive variants of IOPC have been reported in the literature and have a worse overall prognosis. Cancer 2002;95:2180,7. © 2002 American Cancer Society. DOI 10.1002/cncr.10934 [source]