1,721,149 research outputs found
Normal and neoplastic cells of brown adipose tissue express the adhesion molecule CD31.
No full textCONTEXT: CD31 (platelet-endothelial cell adhesion molecule-1; PECAM-1), an adhesion molecule involved in the process of angiogenesis, is used as a marker of normal and neoplastic vascularization. During the assessment of angiogenesis and vascular invasion in a thymic carcinoid tumor, we observed unexpected immunostaining for CD31 in perithymic brown fat nests.
OBJECTIVE:
To determine whether CD31 is expressed by normal and neoplastic cells of brown fat, a tissue whose thermogenetic activity depends heavily on high perfusion.
DESIGN:
Formalin-fixed, paraffin-embedded archival tissues were immunostained by the labeled avidin-biotin method using antibodies against CD31 (clones JC70A and 1A10) after retrieval of heat-induced epitopes. Archival tissues included perithymic, periadrenal, axillary, and neck adipose tissue in which were embedded nests of brown fat (n = 15), hibernoma (n = 3), lipoma (n = 6), well-differentiated liposarcoma (n = 4), and myxoid liposarcoma (n = 4).
RESULTS:
Invariably, multivacuolated and univacuolated adipocytes of normal brown fat and hibernomas were intensely positive for the CD31 antigen. The immunostaining "decorated" cell membranes and the membranes of intracytoplasmic vacuoles. No expression of CD31 was found in normal adipocytes of white fat, in neoplastic cells of lipomas, or in multivacuolated lipoblasts of well-differentiated and myxoid liposarcomas.
CONCLUSIONS:
The spectrum of cell types that express CD31 is expanded to include normal and neoplastic brown fat cells. We speculate that the expression of CD31 may play a role in the development and maintenance of the vascular network characterizing this specialized adipose tissue. Moreover, CD31 may inhibit the Bax-mediated apoptosis of brown fat cells. For practical purposes, CD31 may be used as an immunohistochemical marker for distinguishing between white and brown fat and for diagnosing hibernoma in paraffin sections
NOSE2012
No full textNOSE2012 is the Third biannual International Conference on Envinonmental Odour Monitoring & Control.
The book contains selected papers presented at the conference in Palermo -Italy 23-26 September 201
Neuroendocrine carcinoma of the skin with lymphoepithelioma-like features.
No full textWe report a case of primary neuroendocrine carcinoma of the skin (PNECS) mimicking a lymphoepithelioma-like carcinoma of the skin (LELCS) with respect to both cytomorphology and the presence of a dense lymphoplasmacytic stroma. The tumor occurred in the left forearm of a 86-year-old woman, and its history was marked by aggressive behavior, with metastases to lymph nodes and to visceral sites within 1.5 years of diagnosis. The neoplastic epithelial cells had an immunophenotypic profile typical of PNECS, reacting for cytokeratin 20 and other low-molecular weight cytokeratins, neuron-specific enolase, neurofilament protein, synaptophysin, and chromogranin A. In addition, they were immunoreactive for epithelial membrane antigen, carcinoembryonic antigen, and S-100 protein, as observed in LELCS of supposed adnexal differentiation. The tumor-infiltrating lymphocytes were mostly of T-lineage, with a predominance of CD8+ cells. We believe the case is a morphologic variant of PNECS, retaining its aggressive behavior and high metastatic potential, and should not be confused with true LELCS, which has a more favorable outcome. Immunohistochemistry is paramount in establishing the diagnosis. Lymphoid infiltration, even if prominent, does not seem to be of favorable prognostic significance in such a context
Pilot plant tests for glyoxal production: Reactor thermal behavior
No full textTest data for catalytic oxidation of ethylene glycol to glyoxal performed with a laboratory continuous flow tubular reactor and successively with a pilot plant scale apparatus are reported using a Cu, Ag, P catalyst (94.5%, 4.5% and 1%, respectively). Reaction parameters (O2 concentration, temperature, space velocity) deeply affect the reactor thermal behavior. Relevant features of the complex reaction path can be hypothesized together to useful information on designing the reactor
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