Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunocytochemical studies, using the antibodies CAM 5.2 and NA1/34 (CD1a), were performed on normal lymphoid tissue and malignant lymphomas. A population of dendritic cells in the paracortex of lymph nodes and in T cell lymphomas reacted with both antibodies. Colocalisation with antibodies was also found in gastrointestinal epithelium. Immune blotting shows that the likely basis of this reactivity is a 12 kilodalton peptide which is recognised by both antibodies. This is almost certainly the beta t peptide which has been described as the light chain of CD1a.
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PMID:Association between CAM 5.2 and anti-CD1a reactivity in lymph nodes and gastrointestinal tract epithelium. 246 25

Human skin is believed to harbor a reservoir population of precursor melanocytes. It has been difficult to identify these putative cells experimentally, because they lack phenotypic features that define mature melanocytes. We have evaluated expression of the KIT tyrosine kinase receptor, which is critical for melanocyte development, as a possible marker of these cells. Sections of human skin were evaluated with single- and double-immunolabeling techniques. KIT-reactive dendritic cells were identified in the basal layer of the epithelia and were most numerous in the follicular infundibula and the rete ridges. These cells were located on the epithelial side of the basement membrane and lacked expression of cytokeratin and mast cell tryptase. The location of the KIT-reactive cells was distinctly different from that of Langerhans cells (identified with anti-CD1a) or Merkel cells (identified with CAM 5.2). Within the epidermis and upper follicular infundibulum the majority of the KIT-reactive dendritic cells also coexpressed TRP-1, a marker present in differentiated melanocytes. In the deeper follicular regions, the coexpression of TRP-1 in the KIT-reactive cells was absent. Throughout the epidermis and follicle, however, the KIT-reactive cells coexpressed BCL-2, a marker known to be increased in melanocytes. Thus, KIT expression reveals a population of intraepithelial cells that have immunophenotypic characteristics of mature melanocytes within the upper epithelial regions, but lack the differentiated melanocytic phenotype within the deeper follicular regions. We propose that these KIT(+), BCL-2(+), and TRP-1(-) cells constitute a precursor melanocyte reservoir of human skin.
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PMID:KIT expression reveals a population of precursor melanocytes in human skin. 861 59

We describe 18 cases of a distinctive morphologic variant of primary thymic epithelial neoplasm characterized by a micronodular growth pattern associated with florid lymphoid follicular hyperplasia of the stroma. The tumors occurred in seven women and 11 men aged 41 to 76 years (mean, 58 years). All cases were asymptomatic and discovered incidentally on routine chest radiograph or during coronary artery bypass surgery. The tumors measured from 3 to 10 cm in greatest dimension and were well circumscribed and encapsulated. In seven cases, the lesions were grossly described as cystic or partially cystic masses. Histologically, they were characterized by a proliferation of small tumor nodules separated by abundant lymphoid stroma with prominent germinal centers. The nodules were composed of spindle cells containing oval nuclei devoid of atypia or mitotic activity. Immunohistochemical studies showed strong positivity of the spindle tumor cells for CAM 5.2 and broad spectrum keratin antibodies. The surrounding lymphoid cell population was strongly positive for LCA and L26 and showed a polyclonal pattern of staining for kappa and lambda. Stains for UCHL-1, CD1a, CD3, CD5, and CD99 were negative in the stromal lymphoid cell population. The tumor in one of the patients was associated with active pulmonary tuberculosis, and in another with anemia and splenomegaly of unknown etiology. None of the patients had clinical signs or history of myasthenia gravis or other autoimmune disorders. The present cases are interpreted as an unusual morphologic variant of spindle cell thymoma with prominent B-cell lymphoid hyperplasia. The possible significance of this phenomenon is discussed.
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PMID:Micronodular thymoma with lymphoid B-cell hyperplasia: clinicopathologic and immunohistochemical study of eighteen cases of a distinctive morphologic variant of thymic epithelial neoplasm. 1043 66

We describe the case of a 39-year-old man with idiopathic myelofibrosis, who developed histiocytic sarcoma (true histiocytic lymphoma) 6 months after diagnosis. The patient developed generalized lymphadenopathy. A lymph node biopsy showed pronounced distension of the sinuses in the medulla and periphery, caused by the accumulation of large tumor cells. The tumor cells had abundant clear or eosinophilic cytoplasm. The nuclei were of various sizes and shapes, with condensed chromatin and prominent nucleoli. Some tumor cells displayed erythrophagocytosis. Immunohistochemically, the tumor cells were positive for CD68, alpha(1)-antitrypsin, CD45, CD45RO, and S100 protein, and were negative for B- and T-cell markers, CD30, CD1a, lysozyme, myeloperoxidase, factor VIII-related antigen, CAM 5.2, and HMB-45. Despite multiagent chemotherapy, the patient died of disease 25 months after diagnosis. Although histiocytic sarcomas are very rare, their recognition may be important for clinical and prognostic reasons.
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PMID:Histiocytic sarcoma associated with idiopathic myelofibrosis. 1538 2

Histiocytic sarcoma is a rare, malignant neoplasm of the lymphohematopoietic system that usually occurs in the skin, lymph node, and intestinal tract. Here we describe a unique case of primary central nervous system histiocytic sarcoma that initially showed an indolent clinical course following local resection and radiotherapy. However, relapse of disease within the mediastinum was noted 3 1/2 years later. Biopsies of the initial brain lesion and subsequent mediastinal recurrence each revealed an identical, diffuse proliferation of histiocytes with expression of CD45, CD68, and CD163 but not pan-cytokeratin, epithelial membrane antigen, CD3, CD15, CD20, CD30, CD43, CD79a, CD138, myeloperoxidase, ALK-1, PAX-5, CAM 5.2, S100, CD1a, or glial fibrillary acidic protein. In the literature, central nervous system histiocytic sarcoma portends a poor prognosis with median survival of 4.5 months. To our knowledge, this case represents the first case of "low-grade" primary central nervous system histiocytic sarcoma with relatively indolent clinical course. A thorough discussion of the differential diagnosis of histiocytic sarcoma and a review of primary central nervous system histiocytic sarcoma are also presented.
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PMID:Primary central nervous system histiocytic sarcoma with relapse to mediastinum: a case report and review of the literature. 1728 18

Several studies have demonstrated the multipotentiality of human neonatal foreskin stromal cells (hNSSCs) as being able to differentiate into adipocytes and osteoblasts and potentially other cell types. Recently, we demonstrated that hNSSCs play a role during in vitro angiogenesis and appear to possess a capacity to differentiate into endothelial-like cells; however, their angiogenic potential within an ex vivo environment remains unclear. Current study shows hNSSCs to display significant migration potential in the undifferentiated state and high responsiveness in the in vitro wound healing scratch assay. When hNSSCs were seeded onto the top of the CAM, human von Willebrand factor (hVWF), CD31, smooth muscle actin (SMA), and factor XIIIa positive cells were observed in the chick endothelium. CAMs transplanted with endothelial-differentiated hNSSCs displayed a higher number of blood vessels containing hNSSCs compared to CAMs transplanted with undifferentiated hNSSCs. Interestingly, undifferentiated hNSSCs showed a propensity to differentiate towards ectoderm with indication of epidermal formation with cells positive for CD1a, CK5/6, CK19, FXIIIa, and S-100 cells, which warrant further investigation. Our findings imply a potential angiogenic role for hNSSCs ex vivo in the differentiated and undifferentiated state, with potential contribution to blood vessel formation and potential application in tissue regeneration and vascularization.
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PMID:Angiogenic Potential of Human Neonatal Foreskin Stromal Cells in the Chick Embryo Chorioallantoic Membrane Model. 2622 Nov 44