1,721,088 research outputs found
Various mesonephric tumors of the female genital tract with special reference to the significance of glomerulus-like units in Schiller's mesonephroma.
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Value of immunohistochemistry in the diagnosis of salivary gland tumors.
No full textSalivary gland tumors are rare entities that may hide diagnostic difficulties. Immunohistochemistry is a useful tool in daily diagnostic work to evaluate diagnostic and prognostic features. Mucoepidermoid carcinoma (MEC) is characterized by a zoning pattern, with cytokeratin (CK) 7 present in the central part and CK14 and mitochondria in the peripheral part of the neoplastic nests. High proliferative activity and c-ERB-B2 expression may indicate poor prognosis. Salivary duct carcinoma (SDC) should be differentiated from metastatic breast carcinoma demonstrating an in situ component. Staining the basal membrane with collagen IV and laminin, and the basal cells with CK14 might be useful for this purpose. SDC frequently shows androgen receptor positivity, and a case of tumor regression with antiandrogen therapy has been reported. Acinic cell carcinoma is positive with low-molecular weight CK, and with lysozyme and amylase. Adenoid cystic carcinoma may show areas of dedifferentiation, evidenced by a high proliferative rate with Ki-67 and by the loss of myoepithelial markers. Epithelial–myoepithelial carcinoma shows markers of epithelial and myoepithelial differentiation. Among the latter, smooth muscle actin and calponin are the most frequently expressed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The pre-lymphatic pathway, the rooths of the lymphatic system in breast tissue: a 3D study.
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Merkel cell differentiation in trichoblastoma
No full textFour cases of trichoblastoma rich in Merkel cells (MCs) are reported. They occurred in two men and two women, with ages ranging from 58 to 76 years (mean 67.5 years). MCs were detected immunohistochemically with antibodies to keratin 20, chromogranin A and neuron-specific enolase (NSE). In an attempt at better definition of the nature and role of MCs in trichoblastoma, the distribution of MCs in normal adult and fetal skins obtained at autopsy was studied. In addition, ten cases of sebaceous naevus of Jadassohn (NSJ) were evaluated along similar lines. MCs made up 2-20% of the tumour cells in trichoblastomas; they were present in normal fetal skin and were rare in normal adult skin. All but one of the cases of NSJ showed numerous positive cells in the epidermal component of the lesion with all three antibodies. Six basal cell carcinomas and one syringocystadenoma papilliferum associated with NSJ were negative with keratin 20, chromogranin A and NSE antibodies, whereas a minute trichoblastoma arising against the same background was positive for these markers. Hair follicle cell tumours may recapitulate the skin embryogenesis, as numerous MCs are present in fetal follicles, but only occasional such cells are seen in adult skin
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