Search results for "growth"
showing 10 items of 5134 documents
Secondary cytotoxic allograft responsein vitro. I. Antigenic requirements
1975
The antigenic requirementsfor in vitro induction of secondary murine cytotoxic allograft responses were tested. The proliferative responses were assayed by the [3H]thymidine uptake technique; the generation of cytotoxic T lymphocytes (CTL) was tested in a 51Cr-cytotoxicity assay. Spleen cells from normal or alloantigen preimmunized CBA mice (H-2k) were used as responder cells. Allogeneic x-irradiated splenic lymphocytes (normal stimulator cells) were UV light treated, heat treated or glutaradehyde fixed and subsequently tested for their capacity to induce CTL in a primary or secondary mixed lymphocyte culture (MLC). In addition allogeneic fibroblasts were tested as stimulator cells. The res…
CD44v6 is a marker of constitutive and reprogrammed cancer stem cells driving colon cancer metastasis.
2014
SummaryCancer stem cells drive tumor formation and metastasis, but how they acquire metastatic traits is not well understood. Here, we show that all colorectal cancer stem cells (CR-CSCs) express CD44v6, which is required for their migration and generation of metastatic tumors. CD44v6 expression is low in primary tumors but demarcated clonogenic CR-CSC populations. Cytokines hepatocyte growth factor (HGF), osteopontin (OPN), and stromal-derived factor 1α (SDF-1), secreted from tumor associated cells, increase CD44v6 expression in CR-CSCs by activating the Wnt/β-catenin pathway, which promotes migration and metastasis. CD44v6− progenitor cells do not give rise to metastatic lesions but, when…
Antigen-independent in vitro expansion of T cells does not affect the T cell receptor V beta repertoire.
1997
Analysis of the variable chains (V alpha/V beta) of the specific T cell receptor (TCR) of organ-infiltrating T cells may provide further insights into the pathogenesis of many infectious diseases, malignancies, and autoimmune disorders. To determine the TCR V beta repertoire of these small T cell populations antigen-independent in vitro expansion is necessary but may select for certain T cell subpopulations. In this study various antigen independent T cell activation protocols were used to stimulate peripheral blood mononuclear cells (PBMC) of six healthy blood donors, and TCR V beta molecules were analyzed by flow cytometry and semiquantitative reverse-transcriptase polymerase chain reacti…
Differential effects of IL-10 on proliferation and cytokine production of human gamma/delta and alpha/beta T cells.
1994
Gamma/delta TCR bearing T lymphocytes represent a T-cell subset whose functional relevance remains unclear. Nevertheless these T cells may play a role in the early immune response against bacteria. Until now the regulatory mechanisms on this response have not been investigated. The study described here evaluated the immunoregulatory effects of Interleukin-10 on gamma/delta and alpha/beta TCR-positive T-cell clones and freshly isolated peripheral-blood mononuclear cells (PBMC). IL-10 has been shown previously to inhibit lectin and antigen-induced proliferation and cytokine production by alpha/beta T cells. The results outlined below show that rhIL-10 strongly inhibits lectin-induced producti…
Tumorigenic conversion of endothelial cells.
2003
Tumors of endothelial origin develop rarely. Until now, only two angiosarcoma (AS)-derived endothelial cell lines have been be isolated, ISO-HAS and AS-M. Both AS-derived endothelial cell lines presented the typical endothelial characteristics, such as the expression of CD31 and von Willebrand factor, but differed from normal endothelial cells in a nuclear expression of p53, in a delayed angiogenic reaction, and a reduced expression of caveolin. In addition, differences in the expression of cytokines and cell adhesion molecules responsive to proinflammatory stimuli were observed. While AS-M showed an expression pattern similar to that of human umbilical vein endothelial cells (HUVEC), ISO-H…
Angiogenesis-related prognosis in patients with oral squamous cell carcinoma-role of the VEGF +936 C/T polymorphism.
2014
BACKGROUND: The aim of the study was the immunohistological assessment of VEGF-single nucleotide polymorphism (SNP)-related angiogenic activity in oral squamous cell carcinoma (OSCC) in correlation with prognosis. METHODS: Fifty OSCC samples were immunostained with CD31-antibodies. Mean microvessel density (MVD) and staining intensity were determined and associated with clinicopathological/prognostic features as well as with the VEGF +936C/T SNP. RESULTS: A significant higher MVD could be seen for T3 and T4 compared with T1 and T2, N > 0 vs. N0 as well as G3–G4 vs. G1–G2 OSCCs (all: P < 0.05). A higher MVD was also associated with increased and earlier rates of local relapses, more metastas…
Endothelial VEGFR-3 expression in colorectal carcinomas is associated with hematogenous metastasis
2009
Vascular endothelial growth factor receptor 3 (VEGFR-3) is a major inducer of lymphangiogenic signalling and seems to be involved also in angiogenesis. Since both processes are closely linked with tumor metastasis this study investigated the expression of VEGFR-3 in tumor-associated vessels in colorectal carcinomas and evaluated its relevance for lymphogenous and hematogenous metastasis. In a comparative study between microvascular endothelial cells isolated from the tumor (HCTEC) and the corresponding non-neoplastic tissue (HCMEC) from five patients with colorectal cancer VEGFR-3 expression was measured using a specific ELISA. The expression pattern was individually different, with cases s…
Searching for the right timing of surgical delay: angiogenesis, vascular endothelial growth factor and perfusion changes in a skin-flap model.
2009
Summary Background The angiogenic potential of vascular endothelial growth factor (VEGF) and its oxygen pressure-dependent regulation suggest a strong connection between this growth factor and the ‘delay phenomenon'. In this study we focused on the chronological changes in VEGF concentration and flap perfusion in order to optimise the duration of surgical delay. Methods The VEGF concentration in skin and underlying muscle was measured in oversized, random-pattern flaps on 38 male Sprague-Dawley rats after 3, 5 or 7 days of surgical delay. Additionally, flaps were raised 5 or 7 days past preconditioning. The effect on flap perfusion was measured using indocyanine green fluoroscopy and the si…
Uterine glomeruloid hemangioma in a patient without POEMS syndrome.
2011
Cutaneous glomeruloid hemangioma is a hallmark of POEMS syndrome. These patients have elevated serum levels of vascular endothelial growth factor. The authors report an extracutaneous uterine glomeruloid hemangioma in an 82-year-old woman with a history of breast and endometrial carcinomas. Within the lumen of myometrial vessels, a lobular, glomeruloid proliferation of capillary-like CD31 and vascular endothelial growth factor receptor-1-positive endothelial cells was found. The capillary loops were lined by endothelial cells, most of them containing PAS-positive and immunoglobulin-positive eosinophilic hyaline globules (thanatosomes). This vascular proliferation was consistent with a glom…
Paracrine Effects Influenced by Cell Culture Medium and Consequences on Microvessel-Like Structures in Cocultures of Mesenchymal Stem Cells and Outgr…
2011
Mesenchymal stem cells (MSC) from bone marrow and outgrowth endothelial cells (OEC) from peripheral blood are considered as attractive cell types for applications in regenerative medicine aiming to build up complex vascularized tissue-engineered constructs. MSC provide several advantages such as the potential to differentiate to osteoblasts and to support the neovascularization process by release of proangiogenic factors. On the other hand, the neovascularization process can be actively supported by OEC forming perfused vascular structures after co-implantation with other cell types. In this study the formation of angiogenic structures in vitro was investigated in cocultures of MSC and OEC,…