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Epithelial Characteristics (epithelial + characteristic)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

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]

The Effect of Ovariectomy on Rat Vaginal Tissue Contractility and Histomorphology

THE JOURNAL OF SEXUAL MEDICINE, Issue 2 2006
F. Fatih Önol MD
ABSTRACT Introduction., Ovarian hormones have an important role in age-related genital arousal disorders; however, our knowledge regarding possible vaginal wall morphology and contractility changes in low-hormonal states is limited. Aims., To investigate morphological and functional alterations in the vaginal tissue in a rat ovariectomy model and to show the differences between proximal and distal vagina. Methods., Six weeks following ovariectomy, vaginal tissues were examined under light and electron microscopy. Circularly cut distal and proximal tissues were studied in the organ bath under isometric tension and compared with age-matched controls. Contractile responses to electrical field stimulation (EFS), phenylephrine, carbachol, and the effects of alpha-1 and alpha-2 blockade on EFS-induced contractility were investigated. Relaxation responses to EFS and vardenafil were investigated in precontracted strips. Main Outcome Measures., Differences between control and ovariectomy groups in terms of vaginal tissue contractility and histomorphological properties. Results., Distal vagina showed different epithelial characteristics and a better-developed muscularis compared with proximal vagina. Ovariectomy caused thinning of the epithelium, severe degeneration in epithelial architecture, and smooth muscle atrophy. Contraction and relaxation responses of distal strips were significantly lower in ovariectomized rats. Contractile responses to neuropharmacological stimulation were insignificant in proximal strips of both groups. EFS-induced contractions in distal strips diminished significantly after alpha-1 and alpha-2 adrenergic blockade. EFS caused frequency-dependent relaxation responses in precontracted distal strips, which were significantly decreased after nitric oxide synthase inhibition. Conclusions., Ovariectomy causes significant alteration in rat vaginal tissue morphology and contractility. Contraction and relaxation responses of distal vagina are significantly greater compared with morphologically distinct proximal vagina. Alpha-1 and alpha-2 receptors are the main mediators of contraction in distal rat vaginal tissue whereas nitric oxide pathway may have at least a partial role in relaxation. Main mediators of the rat vaginal tissue relaxation and the effect of ovariectomy on this regulation are yet to be defined. Önol FF, Ercan F, and Tarcan T. The effect of ovariectomy on rat vaginal tissue contractility and histomorphology. J Sex Med 2006;3:233,241. [source]

Patterns of spread in an orthotopic mouse model of bladder cancer

BJU INTERNATIONAL, Issue 2006
J.P. BRENNAN
Purpose:, To develop an orthotopic model of muscle-invasive transitional cell carcinoma (TCC) of the bladder which models primary tumour growth and metastasis. Methodology:, Cell lines were derived from the TCC cell line T24 (Tsu-Pr1) using in vivo selection for metastatic ability (Chaffer et al. Clin Exp Metastasis 2005; 22(2): 115,25). Each of these cell lines (Tsu-Pr1 and sub-lines, B1 and B2) was then injected intramurally into the mouse bladder wall (n = 25 × 3). The cell lines were also injected intravesically and intraperitoneally (n = 15 × 3 in each group). Results:, There were no differences between the three sub-lines in primary tumour formation, presence of macroscopic metastases and survival. This model produced more macroscopic and lymph node metastases in comparison with other orthotopic models reported in the literature. After intraperitoneal injection, the B2 cell line produced a higher number of discrete intra-abdominal masses in comparison with the parental line. This is likely to be related to the phenotype of the cells with parental cells being more mesenchymal, versus the B2 sub-line, which has more epithelial characteristics. Conclusion:, The TSU-Pr1 series is a useful, clinically relevant model of muscle-invasive TCC. In addition, this model may also provide insights into the role of mesenchymal-epithelial transition in the metastatic process. [source]

Human ovarian surface epithelial cells immortalized with hTERT maintain functional pRb and p53 expression

CELL PROLIFERATION, Issue 5 2007
N. F. Li
Normal human ovarian surface epithelial (OSE) cells, which are thought to be the origin of most of human ovarian carcinomas, have a very limited lifespan in culture. Establishment of immortalized OSE cell lines has, in the past, required inactivation of pRb and p53 functions. However, this often leads to increased chromosome instability during prolonged culture. Materials and Methods:,In this study, we have used a retroviral infection method to overexpress human telomerase reverse transcriptase (hTERT) gene, in primary normal OSE cells, under optimized culture conditions. Results:,In vitro and in vivo analysis of hTERT-immortalized cell lines confirmed their normal epithelial characteristics. Gene expression profiles and functional analysis of p16INK4A, p15INK4B, pRb and p53 confirmed the presence of their intact functions. Our study suggests that inactivation of pRb and p53 is not necessary for OSE immortalization. Furthermore, down-regulation of p15INK4B in the immortalized cells may indicate a functional role for this protein in them. Conclusion:,These immortal OSE cell lines are likely to be an important tool for studying human OSE biology and carcinogenesis. [source]