Search results for "Pokeweed mitogen"
showing 6 items of 6 documents
Detection of DNA damage in stimulated human lymphocytes after enflurane exposure in vitro
1992
DNA damage was detected by nucleoid sedimentation in human lymphocytes stimulated with pokeweed mitogen after exposure to enflurane. Enflurane induces DNA damage at an exposure concentration of 0.2 vol%. Higher enflurane concentrations increase the rate of DNA damage. The DNA damage seen after exposure to enflurane concentrations of 0.2 and 3.0% vol is comparable to damage after X-radiation of 0.1 and 0.7 Gy. DNA single-strand breaks can be demonstrated by nucleoid sedimentation and can indicate damage before DNA repair begins. Therefore, detected DNA single-strand breaks may be reversible. However, DNA repair is not always successful and an increased number of DNA single-strand breaks coul…
The presence of high amounts of HBV-DNA in serum is associated with suppressed costimulatory effects of interleukin 12 on HBV-induced immune response
1999
Abstract Background/Aims: The aim of this study was to examine the influence of the viral load on costimulatory effects of rhIL-12 on the hepatitis B virus (HBV)-induced immune response. Methods: Peripheral blood mononuclear cells of HBsAg positive patients without cirrhosis were stimulated with HBsAg, HBcAg, preSlAg and tetanus toxoid in the absence or presence of IL-12 (0.01, 0.1 and 1 ng/ml). Stimulation by α-CD3+α-CD28, pokeweed mitogen (PWM) and lipopolysaccharide (LPS) were used as controls. Then, proliferation and cytokine production were determined by 3 H-thymidine uptake and ELISA after 72 h. The patients were divided into group 1 ( n =21): HBV-DNA: not detectable, group 2 ( n =13)…
COMPLEMENT-DEPENDENT B-CELL ACTIVATION BY COBRA VENOM FACTOR AND OTHER MITOGENS?
1974
It has been proposed that two distinct signals are required for the triggering of the precursors of antibody-forming bone marrow-derived cells (B cells): (a) the binding of antigen or of a mitogen to the corresponding receptor sites on B-cell membranes and (b) the interaction of activated C3 with the C3 receptor of B lymphocytes. There is growing evidence that B-cell mitogens and T (thymus-derived cell)-independent antigens are capable of activating the alternate pathway of the complement system (bypass). Therefore, the effect of another potent bypass inducer was investigated with regard to B-cell activation and the role of C3. Purified, pyrogen-free cobra venom factor was mitogenic for bot…
In vitro secretion of specific antimitochondrial antibodies in primary biliary cirrhosis
1992
Antimitochondrial antibodies are present in the serum of virtually all patients with primary biliary cirrhosis. They have a well-defined antigen reactivity that is diagnostic for the disease. The role of these autoantibodies in the disease process remains to be defined. In this study we show that antimitochondrial antibodies can be produced in vitro by peripheral blood lymphocytes, that the cells producing antimitochondrial antibodies are present in the peripheral blood in a high frequency and seem to be maximally activated. Stimulation with pokeweed mitogen did not augment the in vitro production of antimitochondrial antibodies in patients nor did it induce the production of these antibodi…
Analysis of impaired in vitro immunoglobulin synthesis in rheumatoid arthritis.
1990
Decreased immunoglobulin production in pokeweed mitogen driven lymphocyte cultures has been reported in rheumatoid arthritis (RA). Here various activators and experimental designs have been used to determine the contribution of B cells, T cells, or monocytes to this low response. Sixty patients with RA and paired controls were studied at the onset of disease and again six months later. Concentrations of IgA, IgG, and IgM in cultures of RA peripheral blood mononuclear cells stimulated with thymus dependent activators were already decreased at the onset of the disease. Six months later RA mononuclear cells produced even lower concentrations of immunoglobulin. In contrast, stimulation with a T…
Interleukin 12 enhances deficient HCV-antigen-induced Th1-type immune response of peripheral blood mononuclear cells
1998
The aim of this study was to examine the possible immunomodulating effects of rhIL-12 on the immune response induced by different hepatitis C virus (HCV) antigens. Freshly isolated peripheral blood mononuclear cells (PBMC) of 33 patients with chronic HCV infection were stimulated with optimal concentrations of antigens from the NS3, NS4, NS5, and core region of HCV in the absence or presence of interleukin12 (IL-12). Stimulation by α-CD3 + α-CD28, lipopolysaccharide (LPS), and pokeweed mitogen (PWM) were used as controls. Proliferation and cytokine production were determined by 3H-thymidine uptake and enzyme-linked immunosorbent assay (ELISA) after 72 hr. After stimulation with antigen or a…