Showing papers on "Stem cell marker published in 1989"

Homogeneous mammalian hematopoietic stem cell composition

Abstract: Highly concentrated hematopoietic stem cell compositions are provided which are substantially free of differentiated or dedicated hematopoietic cells. The cells are obtained by subtraction of cells having particular markers and selection of cells having particular markers. The resulting composition may be used to provide for individual or groups of hematopoietic lineages, to reconstitute stem cells of the host, and to identify an assay for a wide variety of hematopoietic growth factors.

10T1/2 cells: an in vitro model for molecular genetic analysis of mesodermal determination and differentiation.

Abstract: Progress has been made in understanding the molecular mechanisms that regulate cell type-specific gene expression during the terminal differentiation of cells into specialized tissue types. These studies have concentrated largely on defining the cis elements and trans-acting factors responsible for the transcription of differentiation-specific genes. Valuable as these investigations have been, they have not been able to place differentiation into the larger context of development, specifically into the context of the earlier developmental process of cell determination, when embryonic stem cell lineages are formed and the genetic regulatory programs for cell type-specific gene activation and expression are acquired by stem cells. The clonal mouse embryo cell line, C3H/10T1/2, clone 8 (10T1/2) provides a unique opportunity to examine the molecular genetic regulation of both the developmental determination of vertebrate stem cell lineages and their subsequent differentiation. 10T1/2 is an apparently multipotential cell line that can be converted by 5-azacytidine into three mesodermal stem cell lineages. These determined proliferative stem cells are stable in culture and retain their ability to differentiate in mitogen-depleted medium. The most significant discovery has been that 10T1/2 lineage determination is under simple genetic control and that the regulatory genes that mediate the formation of myogenic cell lineages, and likely the chondrogenic and adipogenic lineages, can be demonstrated and studied by genomic DNA and cDNA transfection approaches. This paper is a description of the remarkable properties and genetic behaviors of the 10T1/2 cells and a discussion of the insights that future studies of this cell may provide.

An immunohistochemical study of fibrous papule of the nose: 25 cases.

Abstract: Twenty-five cases of fibrous papule of the nose were studied by light microscopy and by immunohistochemistry using a panel of 4 cell markers. These included polyclonal antibodies against S100 protein and Factor XII-a (FXIII-a), and 2 monoclonal antibodies, MAC 387 which labels monocyte derived macrophage cells and Ulex Europaeus Agglutinin-1 (UEA-1) a pan endothelial cell marker. An increase in the number of S100 protein positive cells, particularly in the upper dermis, was observed in 3 lesions. Melanin was identified in phagocytes in the superficial dermis in 6 lesions, including those with S100 protein positive cells. In all of the papules there was a marked increase in FXIII-a labelling of dendritic connective tissue cells, including spindle, stellate and multinucleate stellate cells. Immunoreactivity with FXIII-a was especially strong in the increased mononuclear dendritic cell population (<80%) seen in the mid-and upper dermis. However, only 15% of the larger multinucleate stellate cells were immunostained with FXIII-a. The results achieved with markers to the macrophage cell series (MAC 387) or endothelial cells (UEA-1) showed no significant increase in labelling of the dermal cell population compared to normal skin taken from the nose. Our study suggests that fibrous papule of the nose, a lesion of uncertain histogenesis, probably represents a proliferative reactive process consisting mainly of dermal dendritic cells as identified by FXIII-a in most of the lesions. There is some evidence that a small percentage of the dendritic cells may represent involuted that a small percentage of the dendritic cells may represent involuted naevi and be of melanocytic origin.

Immunohistochemical study of cells positive for glial fibrillary acidic protein (GFAP) in the human pituitary gland, with special reference to folliculo-stellate cells.

Abstract: The cytology and the distribution of cells which contain glial fibrillary acidic protein (GFAP) were studied immunohistochemically in thick frozen sections of human pituitary glands. Immunoreactive cells were constantly demonstrated in both neuro- and adenohypophysis. In the neural lobe, an irregular network of long GFAP-positive pituicyte processes was revealed. Within this network, some asymmetric pituicytes became visible. A variable number of cells was stained in cell cords and follicles of the pars distalis and the intermediate zone. The morphology of these cells could be studied in detail, providing strong evidence to support the hypothesis that adenohypophyseal GFAP-immunoreactive cells belong to the folliculo-stellate (FS) cell system. Cells with similar cytological features in the pars distalis or the intermediate zone were found to share common immunoreactivities against GFAP and the presumable FS cell markers vimentin and S-100 protein. Our results corroborate the notion that, in the human pituitary, GFAR can be regarded as a marker protein of pituicytes and FS cells, which is expressed at varying degrees.

Immunocytochemical profile of Kaposi's sarcoma cells: their reactivity to a panel of antibodies directed against different tissue cell markers.

Abstract: Thirty-three cases of European Kaposi's sarcoma (KS) were investigated by immunohistochemical methods using a panel of antibodies specific for the markers of the cell types proposed for its histogenesis in the literature: S-100 protein for Schwann cells; lysozyme for histiocytes; alpha-actin, desmin and vimentin for pericytes and other mesenchyme-derived cells; factor VIIIR:Ag and Ulex europaeus agglutinin-I for endothelial cells. Antifibronectin antibodies were also used in order to investigate some functional activities of the proliferating cells. Immunohistochemical results showed that KS cells were diffusely positive for vimentin and alpha-actin and negative for all other cell markers. Furthermore, KS cells were constantly surrounded by fibronectin-positive material. Since the KS cells are diffusely positive for vimentin, they may be considered a monotypic proliferation of mesenchyme-derived cells which lack the markers of full endothelial cell differentiation; however, the occurrence of fibronectin-positive material around them suggests that these cells are actively proliferating endothelial cells and their diffuse positivity for alpha-actin suggests a possible differentiation to pericytic cells. In conclusion KS cells may be considered as mesenchymal cells which are at an intermediate stage of maturity or immaturity in vascular differentiation.