The detection of IgG antibodies to silicone.

Following a recent report of an ELISA test for the detection of antibodies to silicone, we attempted to use the same assay in four patients with known exposure to silicone. These patients all gave similar positive results as did a number of control sera with no known silicone exposure. We conclude that this assay does not measure serum levels of antibodies to silicone.

Production of tumor necrosis factors alpha and beta by human mononuclear leukocytes stimulated with mitogens, bacteria, and malarial parasites.

Tumor necrosis factors alpha and beta (TNF-alpha and TNF-beta) are multifaceted polypeptide cytokines which may mediate some of the significant changes in cellular homeostasis which accompany the invasion of the mammalian host by viruses, bacteria, and parasites. Although it is well established that bacterial lipopolysaccharide is a potent inducer of TNF-alpha, there is still very little known of the types of agents which can trigger the production of TNFs in mononuclear leukocytes. Using an enzyme-linked immunosorbent assay for measuring TNF-alpha and TNF-beta, we examined the capacity of various T-lymphocyte and beta-lymphocyte mitogens as well as microbial components to stimulate production of these cytokines in culture.

Tetrandrine, a plant alkaloid, inhibits the production of tumour necrosis factor-alpha (cachectin) hy human monocytes.

Human mononuclear leucocytes (MNL) or the adherent fraction (monocytes) produced tumour necrosis factor-alpha (TNF-alpha) (by ELISA) in culture when stimulated with killed Staphylococcus aureus. The bisbenzylisoquinoline alkaloid, tetrandrine inhibited the capacity of MNL and monocytes to produce TNF-alpha at a concentration range of 0.1 to 5 micrograms/ml.

Depression of immunity to Naegleria fowleri in mice by selective depletion of neutrophils with a monoclonal antibody.

In an attempt to define the role of neutrophils in immunity to Naegleria fowleri in vivo, we examined the effects of treating immunized (with amoeba culture supernatant antigen) mice with the monoclonal antibody NIMP-R10, which binds to neutrophil complement receptor type 3bi (CR3) and causes selective neutrophil depletion in mice. Mice in the nonimmunized group challenged with amoebae all died by day 12, while 97% in the immunized group survived. By contrast, the immunized group treated with NIMP-R10 showed only 25% survival.

The role of antibody in immunity against experimental naegleria meningoencephalitis ('amoebic meningitis').

Mice immunized with amoeba culture fluid (ACF) from axenically cultured Naegleria fowleri showed marked protection against a lethal amoeba challenge, a result consistent with previous observations from this laboratory. The nature of this acquired resistance is not known. The data presented show that the degree of protection conferred to mice by immunization is related to the levels of antinaegleria antibodies.