The Experts below are selected from a list of 537 Experts worldwide ranked by ideXlab platform
Richard J Zarbo - One of the best experts on this subject based on the ideXlab platform.
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defining the role of Myoepithelium in salivary gland neoplasia
Advances in Anatomic Pathology, 2004Co-Authors: Adnan T Savera, Richard J ZarboAbstract:Abstract:Neoplastic Myoepithelium is considered to be the key cellular participant in morphogenetic processes responsible for the variable histologic appearances of many salivary gland tumors. Nevertheless, controversy still exists concerning its participation in some types of salivary gland neoplas
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immunolocalization of three novel smooth muscle specific proteins in salivary gland pleomorphic adenoma assessment of the morphogenetic role of Myoepithelium
Modern Pathology, 1997Co-Authors: Adnan T Savera, Allen M Gown, Richard J ZarboAbstract:Myoepithelial cells of salivary glands have a complex cytoskeletal immunophenotype. To elaborate the smooth muscle phenotype of salivary gland Myoepithelium and to assess its contribution to the histogenesis of pleomorphic adenomas, we evaluated the immunohistochemical expression of three novel monoclonal antibodies (MAbs) to alpha smooth muscle actin (alpha-SMA), smooth muscle myosin heavy chains (SMMH), and calponin in formalin-fixed tissues of 65 pleomorphic adenomas (51 contained surrounding normal salivary gland as well). Different cell types within the pleomorphic adenomas were classified as inner tubular epithelial cells, Myoepithelium-like cells (juxtatubular, cuboidal, and spindle), modified Myoepithelium (myxoid, chondroid, hyaline), and transformed Myoepithelium (solid epithelioid, squamous, basaloid-cribriform). Periacinar and periductal myoepithelial cells of all of the 51 normal salivary glands were diffusely stained by all of the 3 MAbs, whereas all of the acinar/ductal epithelial cells were entirely negative. Of 65 pleomorphic adenomas, 61 (94%) reacted to all of the 3 MAbs. None of the smooth muscle markers stained the inner-tubular epithelial cells. Both alpha-SMA and SMMH were essentially limited to the Myoepithelium-like cells, whereas modified and transformed myoepithelia lacked these myofilaments. Calponin was found in 64 (98%) of the tumors, reacting to almost all of the Myoepithelium-like cells, to 60% of the modified Myoepithelium, and to 30% of the transformed Myoepithelium. We found the expression of these smooth muscle-specific proteins in the neoplastic Myoepithelium to be associated with morphologic differentiation. Alpha-SMA and SMMH are only expressed in better differentiated neoplastic Myoepithelium. Calponin is the most sensitive marker of neoplastic Myoepithelium, and its identification in different cell types of pleomorphic adenomas denotes a major histogenetic role of myoepithelial cells.
Adnan T Savera - One of the best experts on this subject based on the ideXlab platform.
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defining the role of Myoepithelium in salivary gland neoplasia
Advances in Anatomic Pathology, 2004Co-Authors: Adnan T Savera, Richard J ZarboAbstract:Abstract:Neoplastic Myoepithelium is considered to be the key cellular participant in morphogenetic processes responsible for the variable histologic appearances of many salivary gland tumors. Nevertheless, controversy still exists concerning its participation in some types of salivary gland neoplas
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immunolocalization of three novel smooth muscle specific proteins in salivary gland pleomorphic adenoma assessment of the morphogenetic role of Myoepithelium
Modern Pathology, 1997Co-Authors: Adnan T Savera, Allen M Gown, Richard J ZarboAbstract:Myoepithelial cells of salivary glands have a complex cytoskeletal immunophenotype. To elaborate the smooth muscle phenotype of salivary gland Myoepithelium and to assess its contribution to the histogenesis of pleomorphic adenomas, we evaluated the immunohistochemical expression of three novel monoclonal antibodies (MAbs) to alpha smooth muscle actin (alpha-SMA), smooth muscle myosin heavy chains (SMMH), and calponin in formalin-fixed tissues of 65 pleomorphic adenomas (51 contained surrounding normal salivary gland as well). Different cell types within the pleomorphic adenomas were classified as inner tubular epithelial cells, Myoepithelium-like cells (juxtatubular, cuboidal, and spindle), modified Myoepithelium (myxoid, chondroid, hyaline), and transformed Myoepithelium (solid epithelioid, squamous, basaloid-cribriform). Periacinar and periductal myoepithelial cells of all of the 51 normal salivary glands were diffusely stained by all of the 3 MAbs, whereas all of the acinar/ductal epithelial cells were entirely negative. Of 65 pleomorphic adenomas, 61 (94%) reacted to all of the 3 MAbs. None of the smooth muscle markers stained the inner-tubular epithelial cells. Both alpha-SMA and SMMH were essentially limited to the Myoepithelium-like cells, whereas modified and transformed myoepithelia lacked these myofilaments. Calponin was found in 64 (98%) of the tumors, reacting to almost all of the Myoepithelium-like cells, to 60% of the modified Myoepithelium, and to 30% of the transformed Myoepithelium. We found the expression of these smooth muscle-specific proteins in the neoplastic Myoepithelium to be associated with morphologic differentiation. Alpha-SMA and SMMH are only expressed in better differentiated neoplastic Myoepithelium. Calponin is the most sensitive marker of neoplastic Myoepithelium, and its identification in different cell types of pleomorphic adenomas denotes a major histogenetic role of myoepithelial cells.
Bruce L Webber - One of the best experts on this subject based on the ideXlab platform.
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use of monoclonal antibody 1h1 anticortactin to distinguish normal and neoplastic smooth muscle cells comparison with anti α smooth muscle actin and antimuscle specific actin
Human Pathology, 1995Co-Authors: David M Parham, Albert B Reynolds, Bruce L WebberAbstract:In preliminary experiments, we found that 1H1, a monoclonal antibody directed against the v-src substrate cortactin, reacts with smooth muscle, Myoepithelium, myofibroblasts, and macrophages in formaldehyde-fixed human tissues. To evaluate the use of this antibody as a diagnostic reagent, we tested the immunohistochemical distribution of cortactin in 61 mesenchymal neoplasms, 11 neuroectodermal neoplasms, and eight embryonal epithelial neoplasms. The results were compared with those obtained using antibodies against alpha-smooth muscle actin and muscle-specific actin on a similar set of tissues. With the exception of positive staining in rhabdomyosarcoma, in this series only tumors with smooth muscle differentiation appeared to contain cortactin (16 of 19 leiomyosarcomas, one infantile fibrosarcoma, one malignant fibrous histiocytoma). Immunoelectron microscopy localized cortactin to the actin-associated dense bodies of the microfilament network. We conclude that cortactin may be a useful adjunct to alpha-smooth muscle actin and muscle-specific actin as a marker for the study and diagnosis of smooth muscle neoplasms and related lesions.
H J Kahn - One of the best experts on this subject based on the ideXlab platform.
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s 100 protein antibodies do not label normal salivary gland Myoepithelium histogenetic implications for salivary gland tumors
American Journal of Pathology, 1991Co-Authors: I Dardick, M Stratis, W R Parks, F G Denardi, H J KahnAbstract:Abstract Neoplastically modified myoepithelial cells have a key role in developing the histologic characteristics of some salivary gland tumors. S-100 protein expressed in certain of these tumors is suggested to support this role, as the principal component in the human salivary gland reported to be S-100 protein-positive is Myoepithelium. Confirmation of such an important aspect is required. Immunoperoxidase staining of parotid salivary gland shows considerably different patterns obtained with antibodies to S-100 protein, neuron-specific enolase, and neurofilaments compared with those for muscle-specific actin and cytokeratin 14; many more cells and their processes associated with acini and ducts are evident with the latter two antibodies. Double immunofluorescent staining with antibodies to either S-100 protein or neuron-specific enolase combined with muscle-specific actin does not reveal colocalization of these antigens in myoepithelial cells. The former localize only to nerve fibers adjacent to, but separate from, acini, and the latter only to myoepithelial cells. It is apparent that S-100 protein staining of the rich network of unmyelinated nerves in the interstitial tissues, evident ultrastructurally, has been misinterpreted as Myoepithelium. This result has important implications for histogenetic classifications of salivary gland tumors.
Annikka Weissferdt - One of the best experts on this subject based on the ideXlab platform.
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WT1 expression in salivary gland pleomorphic adenomas: a reliable marker of the neoplastic Myoepithelium
Modern Pathology, 2011Co-Authors: Gerald Langman, Claire L Andrews, Annikka WeissferdtAbstract:Pleomorphic adenoma is a benign salivary gland neoplasm with a diverse morphology. This is considered to be a function of the neoplastic Myoepithelium, which shows histological and immunophenotypical variability. Wilms’ tumor 1 gene ( WT1 ) protein, involved in bidirectional mesenchymal–epithelial transition, has been detected by reverse transcription PCR in salivary gland tumors showing myoepithelial–epithelial differentiation. The aim of this study was to investigate the immunoreactivity of WT1 in pleomorphic adenomas and to compare the pattern of staining with p63 and calponin, two reliable markers of myoepithelial cells. A total of 31 cases of pleomorphic adenoma were selected. The Myoepithelium was classified as myoepithelial-like (juxtatubular and spindled), modified Myoepithelium (myxoid, chondroid and plasmacytoid) and transformed Myoepithelium (solid epithelioid, squamous and basaloid cribriform). Immunohistochemistry for WT1, p63 and calponin was assessed in each myoepithelial component, as well as in nonneoplastic myoepithelial cells and inner tubular epithelial cells. There was no immunostaining of tubular epithelial cells by any of the markers. In contrast to p63 and calponin, WT1 did not react with normal myoepithelial cells. Cytoplasmic WT1 staining was present in all pleomorphic adenomas, and in 29 cases (94%), >50% of neoplastic myoepithelial cells were highlighted. p63 and calponin stained the Myoepithelium in 30 tumors. In comparison, 50% of cells were positive in 21 (68%) and 9 (29%) cases of p63 and calponin, respectively. Staining with WT1 showed less variability across the spectrum of myoepithelial differentiation with the difference most marked in the transformed Myoepithelium. WT1 is a sensitive marker of the neoplastic myoepithelial cell in pleomorphic adenomas. The role of this protein in influencing the mesenchymal–epithelial state of cells suggests that WT1 and the myoepithelial cell have an important role in the histogenesis of pleomorphic adenomas.
